Enhanced Photocatalytic CO2 Reduction via MXene synergism: Constructing a Strong Intra-layer Electric Field Ternary Heterojunction of g-C3N4/Nb2C MXene/CsPbBr3

Enhanced Photocatalytic CO2 Reduction via MXene synergism: Constructing a Strong Intra-layer Electric Field Ternary Heterojunction of g-C3N4/Nb2C MXene/CsPbBr3 | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Enhanced Photocatalytic CO2 Reduction via MXene synergism: Constructing a Strong Intra-layer Electric Field Ternary Heterojunction of g-C3N4/Nb2C MXene/CsPbBr3 Shiding Zhang, Yuhua Wang, Gaber A. M. Mersal, A. Alhadhrami, and 4 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-5012551/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 06 Nov, 2024 Read the published version in Advanced Composites and Hybrid Materials → Version 1 posted 13 You are reading this latest preprint version Abstract Slow charge kinetics and high activation energy seriously hinder the efficiency of photocatalytic CO 2 .Synergies are a commonly used strategy, Nevertheless common synergies have been limited to improving catalytic results.Here, we synthesize a novel nanocomposite ternary heterojunction material, which forms a low interlayer electrostatic potential within the heterojunction through the MXene synergistic.A strong internal electric field from the outside to the inside is formed within the series layer heterojunction, which provides the inner driving force for the effective spatial separation of photoinduced electron-hole pairs. Under visible-light irradiation, the ternary heterojunction exhibited a maximum CO production rate of 53.07 μmol g -1 h -1 , surpassing the rates of pure g-C 3 N 4 , CsPbBr 3 QDs, and the binary composite of g-C 3 N 4 /CsPbBr 3 by approximately 8.4, 10, and 2 times, respectively. Experimental results and theoretical analysis reveal the significance of 2D Nb2C MXene as an electron transporter, benefiting from lower electrostatic potential. This characteristic synergistically facilitated the rapid extraction of photoinduced electrons, enhancing the reduction ability of CO 2 to CO. This research not only provides a novel insight into MXene utilization for designing ternary heterojunction nanocomposite photocatalysts but also presents the potential of utilizing synergism ternary composites to improve solar energy conversion efficiency. Photocatalytic CO2 reduction Ternary heterojunction MXene synergism g-C3N4/Nb2C MXene/CsPbBr3 Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 1. Introduction Solar photocatalytic conversion has emerged as a promising solution to address the energy crisis and environmental challenges by directly directly converting CO 2 into CO or hydrocarbon in the new age[1].For this purpose, extensive research efforts has been done on efficient CO 2 reduction photocatalysts, including organic[2], inorganic[3], transition metal compounds[4-6], and terminal ligands[7, 8]. Among them, MXene, a novel two-dimensional layered metal carbide and metal nitride material, has gained significant attention as a co-catalyst due to its high conductivity, abundant active sites, and large surface area[9-11], making it a potential candidate for promoting photocatalytic CO 2 reduction[12]. However, the efficiency of CO 2 conversion is still unsatisfactory owing to the stable nature of CO 2 as a linear covalent molecule(high dissociation energy)[13] and its sluggish multielectron reduction kinetics[14]. How to overcome these disadvantages? One effective strategy is to construct lattice-matched morphological[15] heterojunctions using nanotubes, ultrathin nanosheets, and quantum dots. This hierarchical heterojunction design[16] offers several advantages, including charge separations at the lattice-matched interface of the two morphological components, prevention of carrier recombination, and improved photon-to-current conversion efficiency, resulting in enhanced photocurrent conversion. Taking advantage of MXene, combining it with narrow-band gap semiconductors (Eg<3eV), such as metal oxides, sulfides, III-V group compounds, and II-VI group compounds, has proven to be an excellent method. These combinations facilitate the establishment of redox abilities and the formation of Z-scheme or type-II [17, 18] heterojunction photocatalytic system. Lattice matching and heterojunction regulation are also important means for the improvement of advanced photocatalytic materials[19]. Considering the aforementioned two issues, the catalytic performance of photocatalytic materials can be significantly enhanced through the reasonable design heterogeneous interface structure. We first thought of Halogen perovskites CsPbX 3 QDs (X=Cl, Br, I) star materials[20, 21] , which have been widely used in photovoltaic and optoelectronics in recent years, due to their super optical properties, including a large extinction coefficient, a wide and tunable light absorption range, a long charge diffusion length, and an extended carrier lifetime. However, the single-component halogen perovskite materials are unsatisfactory due to low CO 2 adsorption capacity, and severe charge recombination, which greatly limits their potential for nonlinear optical properties[22] and catalytic application[23]. Moreover, their susceptibility to water instability poses a big challenge in both synthesis and practical applications. Surface passivation using organic ligands may also not effectively overcome this issue, as ligands can be easily lost during washing process. Adding protective materials is a common strategy, and the two-dimensional material g-C 3 N 4 [24-26] is just right for it. It has attracted considerable attention in the water splitting and photocatalytic CO 2 reduction reactions due to its ideal bandgap with the conduction band (CB) and valence band(VB) edges at -0.59 eV and 2.36 eV vs. normal hydrogen electrode (NHE), respectively. Additionally g-C 3 N 4 offers several advantages, including easy fabrication, good photoelectric chemical properties, strong adsorption capacity, thermal stability, and resistance to acid and alkali chemistry. It exhibits a favorable response to visible light, allows for band structure tuning, possesses rich surface functionality, and demonstrates good chemical stability[27, 28]. However, the rapid recombination of photogenerated holes and electrons in g-C 3 N 4 limits the efficiency of light utilization, resulting in low photocatalytic performance. To overcome the limitations of single component, researchers have explored various theoretical and experimental approaches to enhance the photocatalytic ability of CO 2 , including covalent and noncovalent modifications[29], doping[30], band gap and crystalline regulation[24], and the construction of heterojunction. Compared to conventional heterojunctions, the use of n-type or p-type semiconductors with appropriate band structure can enhance visible light absorption and maintain stable reduction ability of photogenerated electrons on the interface, thereby improving the overall photocatalytic efficiency of CO 2 reduction. Therefore, delicate regulation and matching of heterogeneous are crucial to achieve optimal effect. As demonstrated in nanocomposites[31, 32], the incorporation of low-dimensional materials, such as 0D quantum dots or 1D nanowires with g-C 3 N 4 nanosheets effectively enhances optoelectronic properties. Man Ou et al[33]. anchored CsPbBr 3 QDs on NH x -rich porous g-C 3 N 4 nanosheets to construct composite photocatalysts for photocatalytic CO 2 reduction, demonstrating good stability and an outstanding yield. It is important to note that their system employed acetonitrile/water and ethyl acetate/water as the reaction media, rather than common water-saturated carbon dioxide conditions. Hierarchical band structure matching and good contact between interfaces have been solved, and multiple heterojunctions have also been explored, which mainly focused on metal oxides[34-37], sulfides[38], and semiconductor materials[39]. MXene, as a typical member of two-dimensional layered material can be used as superior photothermal supports for metal nanoparticles, also tandem effects to form a porous layered multiple structure for efficient low-grade thermal energy harvest[40, 41] and energy storage[42, 43]. Ternary nanocomposite of MXene (Ti 3 C 2 )-Cu 2 O-Fe 3 O 4 [44] and g-C 3 N 4 /ZnO/Ti 3 C 2 [45] be used for photoelectrocatalytic CO 2 reduction. According to density functional theory (DFT), calculations of g-C 3 N 4 -based[46] heterostructured photocatalysts with good lattice matching have more stable structures and have greater potential application in the field of heterojunction catalysis, in which the lower electrostatic potential makes the ternary heterojunction of MXene[47] more attractive and promising. In our study, Nb 2 C MXene is employed to tandem heterojunction nanocomposites (g-C 3 N 4 /Nb 2 C MXene/CsPbBr 3 ) as photocatalysts to enhance CO 2 reduction activity. The regulation of heterogeneous interface facilitated lattice matching and coordination among the materials. Furthermore, the combination of the three parent materials naturally created a built-in electric field, promoting efficient carrier separation and significantly improving the catalytic performance. We designed a rational ternary heterojunction structure of g‑C 3 N 4 /Nb 2 C MXene/CsPbBr 3 , Which exhibited remarkable photocatalytic activity due to the synergistic effect among the components. In addition, density functional theory (DFT) calculations provided valuable insights intothe rapid charge separation and transport process within ternary heterojunctions.To demonstrate the practical application of the ternary nanocomposite materials, the photocatalytic CO 2 reduction experiment was tested. The ternary g-C 3 N 4 /Nb 2 C MXene/CsPbBr 3 catalyst outperformed pure g‑C 3 N 4 , CsPbBr 3 QDs and g-C 3 N 4 /CsPbBr 3 catalysts in terms of CO production.The ternary heterojunction exhibited a maximum CO production rate of 53.07 μmol g -1 h -1 , surpassing the rates of pure g-C 3 N 4 , CsPbBr 3 QDs, and the binary composite of g-C 3 N 4 /CsPbBr 3 by approximately 8.4, 10, and 2 times, respectively. Notably, with an increase in the Nb 2 C MXene content, the production of CH 4 was effectively suppressed. This work provides a new insight for design of excellent ternary nanocomposite photocatalysts. 2. Experimental Section 2.1 Chemicals and reagents Cesium carbonate (CsCO 3 , Alfa-Aesar), oleic acid (OA, Alfa-Aesar), oleylamine (OA, Alfa-Aesar)， Lead bromide(PbBr 2 , 99.99%, Sigma-Aldrich), octadecylene (OA, Alfa-Aesar) DMSO (Alfa-Aesar), n-hexane (Alfa-Aesar), urea (Sigma-Aldrich), HF(40%), Nb 2 AlC(qiyue CO.Ltd. xi’an) and acetone (Merck) were used. The pure water used throughout the experiment is deionized water. All reagents and solvents are of analytical grade and directly used without further purification. 2.2 Preparation of CsPbBr 3 QDs The CsPbBr 3 QDs were synthesized based on the literature[48] with some subtle modification. We prepare the QDs precursors[49]. Firstly, 0.843g(0.25mmol) CsCO 3 and 30 mL octadecylene was added into a 50 mL three-necked round bottom flask, the whole process is protected by high purity nitrogen gas. The mixture was heated at 120℃ for 1 hour under Ar flow and 800r/min magnetic stirring, to remove water and impurities from the solution. At the desired temperature, we quickly heat up to 150℃, to completely dissolve cesium carbonate, and then control the temperature to 120℃, turn off the heat button and the mixture comes to room temperature, resulting in the cesium oleate precursor. Secondly, 0.367g of PbBr 2 and 20 mL octadecylene were added into a 100 mL three-necked round bottom flask. The mixture was heated at 120 ℃ for 1 hour under Ar flow and 800r/min magnetic stirring also removeing water and impurities from the solution. Subsequently, 2.5 mL of oleic acid and 2.5 mL of oleylamine were injected into the flask, vacuum it three times to prevent the effects of oxygen and fill the system with argon. A faint yellow homogeneous solution was formed when the above mixture was heated to 180 ℃. Following this, 2.5 mL of the cesium oleate precursor solution was injected into the flask, the yellow-green solution appears immediately, after 10 seconds, 10ml of n-hexane was injected into the flask, stop heating and stirring, cooled the mixture to room temperature with an ice-water bath. The yellow precipitate was centrifuged and washed with n-hexane and ethyl acetate to remove the organic residue. The mixture of yellow octadecylene suspension was centrifuged at 1000 rpm for 5 min to remove the large aggregated particles. The supernatant was again precipitated with ethyl acetate or acetone, then centrifuged at 6000 rpm for 5 min repeatedly to remove the surfactant organic molecules. The obtained CsPbBr 3 QDs were re-dispersed in n-hexane (1~2 mg/mL) for further use. The SEM elemental analysis(EDS) of the dried CsPbBr 3 QDs sample indicated that very low N contents (0.75 wt%) were remaining in the final sample, implying that surfactant organic molecules on the surface of CsPbBr 3 QDs were largely removed. 2.3 Preparation of g-C 3 N 4 nanosheets Graphitic carbon nitride(g-C 3 N 4 ) nanosheets were prepared by direct thermal treatment of urea at 550 ᵒ C in a muffle furnace for 4 hours at 5 ᵒ C/min heating rate. The reaction procedure was carried out in an alumina crucible equipped with an air-tight lid to prevent any evaporation of the precursor along with associated gas loss. A pale yellow colored powdery sample was obtained which was termed g-C 3 N 4 . And then, the obtained g-C 3 N 4 was annealed from 550 ᵒ C to room temperature. However, the samples we obtained are an amorphous graphite-phase nitrogen carbide so no lattice fringes are observed in TEM experiments in our composites. 2.4 Synthesis of 2D MXene Nb 2 C nanosheets Based on the literature[50], 2D Nb 2 C MXene nanosheets were synthesized by etching 2.0 g Nb 2 AlC, which was placed in an oil bath constant thermal magnetic stirrer with a mixture of 40 mL of 40% HF at 60 ° C, 300 rpm for 48h in a sealed plastic cup. After the reaction, the product was washed 3 to 5 times by centrifugation using anhydrous ethanol until the pH reached about 6. Then, the black Nb 2 C MXene was dispersed with DMSO by ultrasonic treatment in deionized water in the glass bottle for 10 hours under nitrogen protection, the supernatant was collected, centrifuged at 3500 rpm, and the precipitate was returned to the glass bottle, then, the main component of the centrifuged supernatant was 2D Nb 2 C MXene nanosheets, the content is 4mg per 100 ml. The nanosheets are dried and stored for further use in the synthesis of the complex. 2.5 Synthesis of the binary g-C 3 N 4 /CsPbBr 3 and the ternary g-C 3 N 4 / Nb 2 C MXene /CsPbBr 3 composites In this synthesis process[33], we developed an one-pot novel method. Firstly, 10mg g-C 3 N 4 white powders were added into 20 mL octadecylene, the mixture was stirred 800r/min for 1 h and maintained at 180 ° C under the protection of argon, vacuum a few times to remove moisture from the solution. Then, 7, 30, 43, and 55 mg of the yellow perovskite quantum dots CsPbBr 3 was added to the solution, and it was stirred for another 8 h and also maintained at 180 °C under the protection of argon. The product was washed multiple times with n-hexane and dried at 80 °C in the vacuum oven. In the composites, the g-C 3 N 4 and perovskite quantum dots CsPbBr 3 can form a g-C 3 N 4 /CsPbBr 3 binary heterojunction, the obtained samples will be further named as CC7, CC30, CC43 CC55, respectively. We have also tried in-situ synthesis of this two-dimensional composite material and found that the results were the same. The same synthesis method described above is used. Firstly, 10mg g-C 3 N 4 white powders and 43 mg(the photocatalytic carbon dioxide reduction performance of these two compounds is better) the yellow perovskite quantum dots CsPbBr 3 were added into 20 mL octadecylene, the mixture was stirred 800r/min for 1 h and maintained at 180 °C under the protection of argon, vacuum three times guarantee to remove moisture from the solution. Then, 10, 20, 30and 40 mg of the Nb 2 C MXene black nanosheets were added to the solution, and it was stirred for another 8 h and also maintained at 180 ° C under the protection of argon. The product powder was washed multiple times with n-hexane and anhydrous ethanol, dried at 80 °C in the vacuum oven. In the composites, the perovskite quantum dots, g-C 3 N 4 and Nb 2 C MXene can form a g-C 3 N 4 / Nb 2 C MXene /CsPbBr 3 composites ternary heterojunction, and the obtained samples will be further named as CCM10, CCM20, CCM30, CCM40, respectively. 2.6 Characterization The morphological structure and chemical properties of the as-prepared samples were characterized and tested as follows. X-ray diffraction (XRD, Cu Kα, Empyrean, Panaco, Netherlands) was used to measure the as-prepared samples structure and phase composition of samples with diffraction angles (2θ) varying from 5° to 90°. The optical absorption behavior of the samples was studied using Fourier transform infrared spectroscopy (FT-IR, IRTracer-100 Shimadzu, Japan) and Ultraviolet–visible (UV-vis) diffuse reflectance spectra (UV-3600Plus DRS, Shimadzu, Japan). Microstructure and morphology were analyzed by Scanning Electron Micrograph (NovaTM NanoSEM 450, FEI, Czech) and Field emission transmission electron microscopy (FETEM) (Talos F200S, FEI, USA) with an energy-dispersive X-ray spectrometer (EDX). Time-resolved transient PL spectra (Edinburgh FLS980, excitation wavelength of 360 nm) obtained the decay curves. X-ray Photoelectron Spectroscopy XPS(Thermo Scientific, USA) was tested by an ultrahigh vacuum VG ESCALAB 250 electron spectrometer and pass Energy 30.0 eVwith Al Kα 1 X-rays, the valence band was also measured. Photoluminescence(PL) spectra (LabRAM HR Evolution HORIBA Jobin Yvon, France) were recorded by applying a 325nm laser excitation. vacuum oven(ZDF6022 yiheng, shanghai) were used to dry the samples. 2.7 Photoelectrochemical measurements We carried out the photoelectrochemical test using a three-electrode system (CHI 660E, Shanghai Chenhua) including a Pt foil counter electrode, a saturated Ag/AgCl reference electrode and a working electrode. Using the dip-coating method, with the same amount of photocatalyst, we got the working electrode. Following the detailed process is carried out. First, weighting 5mg of the samples, it was dispersed by ultrasound in 5 mL of n-hexane and 5 μL Nafion adhesive solution to form a uniform slurry. Second, using a Da Long pipette, measuring 10 μL of the slurry, dip-coating on the ITO conductive glass with an exposure area of 1*1 cm 2 . And last, the completed ITO samples were dried in a vacuum oven at 80°C for 1 hour. Following, selecting the electrolyte 100 ml can be used acetonitrile solution with 0.08 mol/L of tetrabutylammonium hexafluorophosphate to avoid any moisture. Before the experiment, to remove the effects of air, the electrolyte was purged with high-purity N 2 gas. The photoinduced current density versus time (I-t) was tested at a 0.01 V bias potential under a solar simulator xenon light source (350 W) switching on and off mode. Using a frequency ranging from 105 Hz to 0.01 Hz, selecting open circuit potential, the electrochemical impedance spectroscopy (EIS) Z’-Z’’ curves can be tested. The photocatalytic CO 2 reduction experiments were performed in a photocatalytic activity evaluation system( CEL-PAEM-D8, Beijing Zhongjiao jinyuan Technology Co. LTD), which included a closed CO 2 circulation reactor system with a top window cell(volume: 150 mL). The inside reaction temperature was controlled at 6℃ by the external circulation of the cooling water system. A 300 W Xe-lamp collocated a 420 nm UV-cut-off filter was placed on the top of the two-neck bottle as the light source passing and positioned 2 cm away from the photocatalytic reactor. The photocatalyst (10mg) was uniformly dispersed into Vessels 50 mm in diameter with n-hexane solvent 3 ml, which was sonicated, vacuum dried to remove the organic solvent and evenly dispersed in 0.0196 m 2 glass petri dishes. Before the photoreaction, we first test the closure of the whole photocatalytic activity evaluation system, the inner circulation reactor was evacuated vacuum throughout the system and washed three times with high-purity CO 2 gas to get rid of the air and water vapor inside. Then we start to regulate the catalytic environment, the high-purity CO 2 gas was filled into the circulation reactor to reach a pressure of 0.08 atmospheric pressure. Finally, it sits for a period of time (about, 1 hour) to form an environment saturated steam with carbon dioxide. The CO and CH 4 gaseous products at different reaction times were automatically detected by an online gas chromatograph (GC 7920-TF2A Beijing Zhongjiao jinyuan Technology Co. LTD). Then the stability of pure g-C 3 N 4 , CsPbBr 3 , CC composite, and CCM series of samples were tested for consecutive photoreaction runs of 8 h in each run. The reactor was evacuated and refilled with 0.08 atmospheric pressure CO 2 -saturated steam every time. 3. Results and discussion The synthesis mechanism of g-C 3 N 4 /Nb 2 C MXene/CsPbBr 3 ternary heterojunction is presented in Fig. 1. The complete synthesis control details are given in the experimental section. The XRD patterns of g-C 3 N 4 , CsPbBr 3 , Nb 2 C MXene, CC43 sample， and CCM30 sample are shown in Fig 2a. The characteristic peak patterns indicate the synthesis of pure phase g-C 3 N 4 , CsPbBr 3 , and Nb 2 C MXene, which are consistent with the corresponding standard references (Fig S1). The crystal structure of the ternary heterojunction CCM series (Fig. S1d) composites still maintain the original perovskite structure. Detailed characterization results in Fig. S1a further support the structural integrity of three parent materials. The XRD peaks of the CC(Fig. S1c) and CCM composites(Fig. S1d, Fig. S2) show similar diffraction peaks to those of g-C 3 N 4 , CsPbBr 3 and Nb 2 C MXene, indicating that the phase structure of g-C 3 N 4 , CsPbBr 3 and Nb 2 C MXene remain unchanged during the composite formation process. It should be noted that the peaks corresponding to g-C 3 N 4 and Nb 2 C MXene are relatively weak in the CCM series composites due to the amorphous nature of the g-C 3 N 4 and the few layers structure of the Nb 2 C MXene. The morphologies of the prepared samples were characterized using SEM, TEM, and High-resolution TEM (HRTEM) techniques, as shown in Fig. 2c and Fig. S3-5. The SEM image (Fig. 2b, S5a) reveals a sheet structure decorated with numerous particles. TEM and HRTEM were performed to confirm the three-phase composition of the CCM30 compound (Fig. 2d). Amorphous g-C 3 N 4 is dispersed in the surface layer of the sample (Fig. 2c). In Fig. 2e and 2g, lattice fringes with a d-spacing of 0.291 nm correspond to (220) panes of CsPbBr 3 QDs, while the lattice fringes with d-spacing of 0.296 nm and 0.431 nm correspond to (220) and (200) planes of Nb 2 C MXene, respectively. HRTEM image with corresponding live Fast Fourier transformation (FFT) patterns (Fig. 2e and 2g) clearly displaylattice signals of CsPbBr 3 and Nb 2 C MXene. The angle between them measures 28 ° and 30 ° , indicating a near-parallel relationship between CsPbBr 3 and Nb 2 C MXene. EDS results (Fig. S5b) demonstrate that the mass fraction of each element in CCM30 composites aligns with the proportion of the synthetic materials used. Additionally, energy-dispersive X-ray spectrometer mapping data (Fig. 2i-l, S2) reveals a uniform distribution of elements (C, N, Br, Pb, Cs, Nb, and F) throughout the nanocomposite structure. Based on the above characterizations, it is evident that the g-C 3 N 4 /Nb 2 C MXene/CsPbBr 3 heterostructure has been successfully formed (Fig. 2c). We carried out a series of optical properties to deeply understand the interaction among ternary compounds and their influence. The FTIR spectra of g-C 3 N 4 , CsPbBr 3 QDs, and Nb 2 C MXene photocatalysts are shown in Fig. 3a and Fig. S6a-d. In the case of g-C 3 N 4 [51, 52], the peak at 1639 cm −1 , 1241 cm −1 correspond to C‒N and C=N stretching vibration modes, respectively. The absorption peaks at 1325 and 1245 cm −1 are associated with the out-of-plane bending vibration of triazine ring. The peak at 808 cm −1 is attributed to the molecule breathing modes of tris-triazine units. The peaks at 2924 cm −1 , 2853 cm −1 , and 1458 cm −1 can be assigned to the asymmetric and symmetric Pb–Br stretching vibrations[53] as well as the bending vibrations of Cs-Pb of CsPbBr 3 QDs. Nb 2 C MXene shows typical peaks at 621 cm -1 and 1086 cm -1 , attributing to the interlayer vibrations of C-Nb [54]. In the FTIR spectrum of the ternary compounds, in addition to the typical peaks of g-C 3 N 4 , CsPbBr 3 QDs, and Nb 2 C MXene, a clear red shift in peak position of in C–N stretching mode and the vibrational modes of tris-s-triazine units in g-C 3 N 4 is observed. The red shift indicates a strong interaction among the g-C 3 N 4 , CsPbBr 3 QDs, and Nb 2 C MXene interface. Moreover, the typical stretching mode of aromatic C–N and C=N heterocycles in g-C 3 N 4 at 1241 cm -1 are shifted to higher values with an increasing content of Nb 2 C MXene (Fig. 3d). This shift can be ascribed to a chemical interaction between the g-C 3 N 4 and Nb 2 C MXene surfaces, leading to an increase in the electron density of ternary heterocycles in g-C 3 N 4 . It is noteworthy that even with a single molar ratio of 1:1:1, all CsPbBr 3 QDs can be effectively incorporated onto the surface of two two-dimensional materials, forming a ternary heterojunction structure. To investigate the light-harvesting property, UV-vis spectra were recorded, as shown in Fig. 3c. The absorption edge of g-C 3 N 4 , CsPbBr 3 QDs, CC30, and CCM30 groups are observed around 450 nm, 570 nm, 560 nm, and 550nm, respectively, corresponding to the band gap energy of approximately 2.95 eV, 2.31 eV, 2.29 eV, and 2.23 eV [33, 55] (Fig. S7). It is evident that all the binary (Fig. S6g) and ternary (Fig. S6h) samples can be excited under visible-light irradiation. Upon the addition of Nb 2 C MXene, both the absorption intensity in the visible region and at the absorption edges increase, which might be correlate with the black color of Nb 2 C MXene. To further investigate the interactions among g-C 3 N 4 /Nb 2 C MXene/CsPbBr 3 binary catalysts, photoluminescence (PL) emission spectra were recorded. The PL intensity is typically indicative of the recombination rate of photoinduced electron-hole pairs, where a lower PL emission intensity suggests a strongly suppressed recombination. As shown in Fig. 3d, it can be observed that pure g-C 3 N 4 and CsPbBr 3 exhibit strong and broad PL emission at approximately 498 nm and 524 nm, respectively, which is consistent with the literature. However, the PL peak intensity of the ternary heterojunction is significantly quenched compared to the other composite samples. In particular, PL emissions of CC43 and CCM30 exhibit the lowest intensity within their respective group (Fig. S6e and S6f). It is important to note that Nb 2 C MXene does no exhibit any emission peak due to its metallic characteristics. These PL results indicate that the addition of Nb 2 C MXene can effectively inhibit the recombination of charge carriers within the system, leading to improved photocatalytic performance. The charge transfer and separation behavior of the photocatalyst was investigated using time-resolved fluorescence decay technique. As shown in Fig. 3e, all samples exhibit a rapid decay within the nanosecond timescale. The average emission lifetime (Fig. 3f) of g-C 3 N 4 CsPbBr 3 QDs, CC43, and CCM30 are 11.20 ns, 9.80 ns, 9.24ns, and 8.70ns, respectively. These results indicate that both binary (Fig. S6i) and ternary heterostructures (Fig. S6j) provide efficient pathways for rapid charge transfer of the photogenerated carriers. The shortened emission lifetimes suggest enhanced charge separation and reduced recombination, which are favorable for efficient photocatalytic performance The bonding information of g-C 3 N 4 , Nb 2 C MXene, CsPbBr 3 , and their composites was investigated using X-ray photoelectron spectroscopy (XPS) (Fig. 4a,c-f and Fig. S8-9). In Fig. 4, CCM30 shows distinct binding energies ascribed to C, N, Br, Pb, Cs, and Nb, indicating the successful synthesis of the ternary composites of g-C 3 N 4 / Nb 2 C MXene / CsPbBr 3 . After fitting the spectra, small binding energy shifts are observed in the ternary structures compared to their individual components such as C1s, N1s, Br3d, and Nd3d. These shifts suggest the presence of intimate interactions within the structure, resulting in charge redistribution. This binding energy shift indicates chemical reactions between the other parent components and g-C 3 N 4 . Consequently, Nb 2 C MXene becomes electron-rich, while the other two components become electron-deficient. This is supported by the negative shift in the binding energy of Nb 3d in CCM30. The binding energy of Br 3d (Fig. 4f) in the CsPbBr 3 QDs is 68.4 eV and 69.5 eV, corresponding to Br 3d 5/2 and Br 3d 3/2 respectively. The shift is -0.2 eV (68.2eV) and -0.3 eV (69.5eV). The binding energy of Nb 3d (Fig. 4e) in the Nb 2 C MXene shows six peaks at 203.1 eV, 205.8 eV, 206.8 eV, and 209.6eV. The shift is 0.4 eV (203.5eV), 0.5 eV (206.3eV), 0.2 eV (207.0eV), and 0.2 eV (209.8eV), indicating a strong electron deficient in Nb 2 C MXene. Fig 4b shows the differential charge density of the three parent materials. According to whether there is a broken band gap at 0eV, it is obvious that g- C 3 N 4 and CsPbBr 3 have obvious semiconductor properties, while Nb 2 C MXene has obvious gold properties. The valence band (VB) potential can be determined by analyzing the VB XPS spectra. As shown in Fig. S10, the energy level of the valence band maximum (VBM) for g-C 3 N 4 and CsPbBr 3 QDs is 2.25 eV and 1.12 eV, respectively. Based on these results, the band structures of g-C 3 N 4 and CsPbBr 3 QDs can be derived, with VBM energies of 2.36 eV and 1.23 eV, respectively. Consequently, the corresponding conduction band energies are -0.59 eV and -1.08 eV respectively. Evidently, the conduction band minimum of g-C 3 N 4 is 0.49 eV lower than that of CsPbBr 3 QDs. These dataprovide insights into the band structure of g-C 3 N 4 and CsPbBr 3 . To further demonstrate the improved efficiency of photocarrier transfer and separation efficiency, we conducted transient photocurrent measurements for g-C 3 N 4 , CsPbBr 3 , CC43, and CCM30 samples (Fig.5a). Among all the samples, CCM30 exhibited the highest photocurrent indicating enhanced photocarrier separation and transfer. The presence of Nb 2 C Mxene is believed to facilitates the efficient separation of photoexcited electrons and holes[15, 56]. Furthermore, electrochemical impedance spectroscopy (EIS) was performed to investigate the catalytic activity of the prepared samples (g-C 3 N 4 , CsPbBr 3 CC43, and CCM30 samples) (Fig.5b). The arc radius of g-C 3 N 4 and CsPbBr 3 samples was larger than that of CC43 and CCM30 composite samples. In contrast, CCM30 exhibited a smaller arc radius, suggesting reduced resistance and enhanced charge transfer. The presence of Nb 2 C Mxene is attributed to the improved conductivity and facilitated charge transfer within the composite structure. The photocatalytic CO 2 reduction activity (Fig. S11) of the samples was evaluated in a photocatalytic system filled with carbon dioxide-saturated water vapor under simulated sunlight[57, 58]. A controlled trial without light irradiation, CO 2 or any photocatalyst did not show any detectable production of CO, CH 4 , H 2 , or other hydrocarbons (Fig. S12), confirming the necessity of the photocatalyst for the CO 2 reduction process. As expected, the bare Nb 2 C MXene showed no photocatalytic activity (Fig. 5c, d) because it is not a photocatalyst[59]. In our system, CO was the main product, accompanied by a small amount of CH 4 . The yields of CO and CH 4 were 6.27 μmol g -1 h -1 and 0.15 μmol g -1 h -1 for pure g-C 3 N 4 , and 5.31 μmol g -1 h -1 and 0.02 μmol g -1 h -1 for CsPbBr 3 QDs, respectively (Fig. S13). The production of CO, significantly improved in the g-C 3 N 4 /CsPbBr 3 binary composite photocatalysts compared to the individual components (Fig. 5d). Furthermore, the introduction of 2D Nb 2 C MXene in ternary heterojunction nanocomposites resulted in even higher performance. Among the samples, CCM30 exhibited the highest CO production rate of 53.07 μmol g -1 h -1 which was about 8.4, 10, and 2 times higher than that of pure g-C 3 N 4 , CsPbBr 3 QDs, and the binary composite g‑C 3 N 4 /CsPbBr 3 , respectively. This significant enhancement in CO production highlights the synergistic effect of the ternary heterojunction nanocomposites. The comparison of g-C 3 N 4 and CsPbBr 3 QDs revealed that the CO yield rate in binary photocatalysts increased by more than 2 times, suggesting the formation of heterojunction structure between g-C 3 N 4 and CsPbBr 3 , which facilitates the transfer of photo-excited charges. This finding is consistent with the results obtained from EIS and photocurrent measurements, as well as with previous reports[32, 33]. By adjusting the ratio of components, slightly changes in the photocatalytic performance were observed. Among the binary photocatalysts, CC43 demonstrateed the best performance. Upon the addition of Nb 2 C MXene, the CO yield rate of ternary photocatalysts initially reached a comparable level to that of the binary ones when the percentage of Nb 2 C MXene was low (CCM10 and CCM20). Subsequently, the maximum performance was achieved in CCM30. However, with further increase in Nb 2 C MXene (CCM40), a slight decrease in the photocatalytic ability was observed, although it still outperformed all the binary photocatalysts. This suggests that the good conductivity of Nb 2 C MXene facilitates charge transfer between g-C 3 N 4 and CsPbBr 3 , as supported by PL and PL delay lifetime characterizations. As a result, the maximum photocatalytic performance in terms of CO production was achieved with a yield rate of 53.07 μmol g -1 h -1 , surpassing the majority of previously the reported studies[60]. The relevant literature on previous reports is listed in Table 1. Obviously, The CO evolution rate on CCM30 has obvious advantages. Table 1 Comparison CO evolution rates of the prepared photocatalyst with other literature. Table 1 Comparison CO evolution rates of the prepared photocatalyst with other literature. Photocatalyst Light source Solvents CO evolution (μmol/g/h) Ref. PCN CsPbBr 3 CsPbX 3 /g-C 3 N 4 . 300 W Xe-lamp (>420 nm) CO 2 and water vapor 5.5 5.0 28.5 [32] PCN CsPbBr 3 CPB-PCN 300 W Xe-lamp acetonitrile/water Ethyl acetate/water 52 9.8 149 [33] CsPbBr 3 CsPbBr 3 /MXene 300 W Xe-lamp (>420 nm) Ethyl acetate 4.13 26.3 [61] CsPbBr 3 NCs CsPbBr 3 NCs/GO 100 W Xe lamp Ethyl acetate 4.12 4.89 [62] CPB-CN 300 W Xe-lamp (>420 nm) CO 2 and water vapor 11.5 [63] g‑C 3 N 4 CsPbBr 3 g‑C 3 N 4 /Nb 2 C MXene/CsPbBr 3 300 W Xe-lamp (>420 nm) CO 2 and water vapor 6.27 5.30 53.07 this work From a thermodynamic perspective, the reduction potential for converting CO 2 to CO and CH 4 (-0.53V and -0.24V) [64]. We have provided a diagram illustrating all possible pathways for CO 2 reduction to C1 products (Fig S12) The formation of CO is believed to proceed through a single elementary step, in which our ternary heterojunction provides the necessary photocatalytic energy for CO generation. On the other hand, the formation of CH 4 is thought to occur through a series of elementary steps involving the transfer of one or two electrons, with CO serving as an intermediate. It is important to note that when the reduction potential of the electrons system is low, the kinetic reaction rate of elementary elements decreases. Consequently, the subsequent catalytic reaction steps after CO formation may not proceed rapidly enough before CO desorbs from the surface of the photocatalyst. This leass to CO being the main product, with CH 4 being the secondary product. After stability testing for eight hours, the loss in activity is only 7.1% (Fig 5d), indicating the good stability of our ternary heterojunction photocatalyst. The XRD patterns and FTIR spectra of CsPbBr 3 and CCM30 before and after the stability test were shown in Fig S17. It is evident that CsPbBr 3 undergoes noticeable crystal changes[65], transitioning from the all-orthorhombic structure to an elongated polyhedron[66, 67]. However, even after nearly 24 hours of catalytic activity, the CO production yield relatively stable. Similar structural changes can also be observed in CCM30 after the stability test, indicating that the transformation is primarily due to the change of CsPbBr 3 . These results suggest that the photocatalyst exhibits goodstability under the reaction conditions. To investigate the electronic and transport properties of the ternary heterojunction, we performed DFT calculations[68, 69]. The (110) surface orientation of three parent materials was chosen as the model to simulate the density of states (DOS) and charge density difference[70]. Since catalysis primarily occurs on the surface rather than in the inner layers, two different slabs of Nb 2 C MXene were used to construct the ternary heterojunction photocatalyst (Fig 6a). In the ternary heterojunction, the conduction band is mainly occupied by Nb and Cs, consisting empty d orbitals (Fig. S14), On the other hand, the valence band is composed of orbitals from N and Br elements. This confirms that Nb 2 C MXene can modify the energy band structure of ternary heterojunction. To maximizethe influence of the ternary composites on the electronic structure, Nb 2 C MXene is positioned in the middle layer. The total and partial DOS of the ternary heterostructures for (110) crystal faces is shown in Fig. S13a-f. Upon formation of the heterostructure, a shift in the band gap is observed near the Fermi level, indicating improved conductivity compared to the three individual parent components. This suggests that the ternary heterojunction exhibits enhanced electronic and transport properties, which can contribute to its improved photocatalytic performance. To gain further insights into the electronic properties at the interface between the CsPbBr 3 /Nb 2 C MXene and Nb 2 C MXene/g‑C 3 N 4 , we performed calculations of the 3D charge density difference and the plane-averaged electrostatic potential drop across the interfaces of the three parent materials. As shown in Fig. 6b and c, the calculated results indicate a charge transfer from CsPbBr 3 to Nb 2 C MXene and subsequently from Nb 2 C MXene to g‑C 3 N 4 , confirming an unbalanced charge distribution at the interfaces. For the ternary heterojunction interface, CsPbBr 3 /Nb 2 C MXene and Nb 2 C MXene/g‑C 3 N 4 , higher electrostatic potential and potential difference of approximately 15.83 eV and 11.93 eV, and 16.21 eV and 11.88 eV, respectively, were observed. This potential drop corresponds to the internal electric field pointing from g‑C 3 N 4 and CsPbBr 3 towards Nb 2 C MXene. Consequently, the internal electric field generated by the potential difference aligns with the direction of the ternary heterostructures. Due to this internal electric field, photogenerated electrons tend to drift from the surfaces of g-C 3 N 4 , or CsPbBr 3 QDs towards the surface of Nb 2 C MXene, while photogenerated holes tend to drift in the opposite direction. This phenomenon facilitates the separation and transfer of photogenerated carrier, thereby promoting enhanced photocatalytic performance. We also compared the charge transfer and distribution ofthe binary interface g-C 3 N 4 /CsPbBr 3 , g-C 3 N 4 / Nb 2 C MXene, and CsPbBr 3 / Nb 2 C MXene shown in Fig. S14. The charge transfer from CsPbBr 3 to g‑C 3 N 4 , g‑C 3 N 4 to Nb 2 C MXene, and CsPbBr 3 to Nb 2 C MXene reveals some unbalanced charge distribution, although less pronounced compared to the ternary heterojunction. The 3D charge density difference and plane-averaged electrostatic potential exhibit lower values, namely 7.18 eV and 2.92 eV, 12.64 eV, and 14.69 eV, respectively. These values indicate a less significant change compared to the ternary heterojunction. The total DOS of the g-C 3 N 4 /CsPbBr 3 binary heterojunction (Fig. S16) shows a relatively large band gap, reflecting the energy difference between the valence band and conduction band. This further supports the improved electronic properties and potential for efficient charge transfer and separation in the ternary heterojunction structure. 4. Conclusions In summary, we have successfully synthesized a g-C 3 N 4 /Nb 2 C MXene/CsPbBr 3 ternary heterojunction through a wet-chemical method. By regulating the heterogeneous interface, we have achieved a significant improvement in the photocatalytic performance, with a CO yield rate of 53.07 μmol g -1 h -1 . This represents a substantial enhancement compared to single g-C 3 N 4 , CsPbBr 3 , and binary structure. The simulation and theoretical calculations support the presence of an internal electrostatic field driven by Nb 2 C MXene, which promotes the transfer of electrons. The lattice matching and enhanced interaction among the three parent materials contribute to the synergistic effect observed in the ternary heterojunction, resulting in excellent photocatalytic activity for CO 2 reduction to CO. These findings provide valuable guidance for the development of efficient ternary heterogeneous structures in various photocatalytic applications. Declarations CRediT authorship contribution statement Shiding Zhang: Writing main manuscript text, Data curation, Investigation. Yuhua Wang: Idea, Conceptualization, Writing - review & editing, Supervision, Project administration. Yitong Wang: Experiment, Project administration. Gaber A. M. Mersal: Methodology : VASP calculation. A. Alhadhrami, Dalal A. Alshammari , and Hassan Algadi : Experiment support. Haixiang Song ： Writing - review & editing. Declaration of Competing Interest The authors report no declarations of interest. Funding This work was supported by the National Natural Science Foundation of China (Grant Nos. 11375136, 11804005, 12204014) , the Science and Technology Planning Project of Henan Province (No.232102241016), Anyang Institute of Technology University-level Scientific Research Cultivation Fund (YPY2021016). Numerical calculation is supported by High-Performance Computing Center of Wuhan University of Science and Technology. Anyang Institute of Technology energy power a new round university-level key discipline funding. The authors extend their appreciation to Taif University, Saudi Arabia for supporting this work through project number (TU-DSPP-2024-21). References J. Gong, C. Li, M.R. Wasielewski, Advances in solar energy conversion, Chem Soc Rev, 48 (2019) 1862-1864. Y. Guo, Q. Zhou, J. Nan, W. Shi, F. Cui, Y. Zhu, Perylenetetracarboxylic acid nanosheets with internal electric fields and anisotropic charge migration for photocatalytic hydrogen evolution, Nat Commun, 13 (2022) 2067. X. Zhang, J. Xiao, M. Hou, Y. Xiang, H. Chen, Robust visible/near-infrared light driven hydrogen generation over Z-scheme conjugated polymer/CdS hybrid, Applied Catalysis B: Environmental, 224 (2018) 871-876. N. Elgrishi, M.B. Chambers, X. Wang, M. Fontecave, Molecular polypyridine-based metal complexes as catalysts for the reduction of CO 2 , Chem Soc Rev, 46 (2017) 761-796. S. Adabala, D.P. Dutta, A review on recent advances in metal chalcogenide-based photocatalysts for CO 2 reduction, Journal of Environmental Chemical Engineering, 10 (2022). N.W. Kinzel, C. Werle, W. Leitner, Transition Metal Complexes as Catalysts for the Electroconversion of CO 2 : An Organometallic Perspective, Angew Chem Int Ed Engl, 60 (2021) 11628-11686. H. Shang, S.K. Wallentine, D.M. Hofmann, Q. Zhu, C.J. Murphy, L.R. Baker, Effect of surface ligands on gold nanocatalysts for CO 2 reduction, Chem Sci, 11 (2020) 12298-12306. Q. Zhu, C.J. Murphy, L.R. Baker, Opportunities for Electrocatalytic CO 2 Reduction Enabled by Surface Ligands, J Am Chem Soc, 144 (2022) 2829-2840. M. Naguib, V.N. Mochalin, M.W. Barsoum, Y. Gogotsi, 25th anniversary article: MXenes: a new family of two-dimensional materials, Adv Mater, 26 (2014) 992-1005. B. Fu, J. Sun, C. Wang, C. Shang, L. Xu, J. Li, H. Zhang, MXenes: MXenes: Synthesis, Optical Properties, and Applications in Ultrafast Photonics (Small 11/2021), Small, 17 (2021) 2170048. B. Shao, Z. Liu, G. Zeng, H. Wang, Q. Liang, Q. He, M. Cheng, C. Zhou, L. Jiang, B. Song, Two-dimensional transition metal carbide and nitride (MXene) derived quantum dots (QDs): synthesis, properties, applications and prospects, Journal of Materials Chemistry A, 8 (2020) 7508-7535. Z. Wu, C. Li, Z. Li, K. Feng, M. Cai, D. Zhang, S. Wang, M. Chu, C. Zhang, J. Shen, Z. Huang, Y. Xiao, G.A. Ozin, X. Zhang, L. He, Niobium and Titanium Carbides (MXenes) as Superior Photothermal Supports for CO 2 Photocatalysis, ACS Nano, 15 (2021) 5696-5705. M.D. Burkart, N. Hazari, C.L. Tway, E.L. Zeitler, Opportunities and Challenges for Catalysis in Carbon Dioxide Utilization, ACS Catalysis, 9 (2019) 7937-7956. J. Gu, S. Liu, W. Ni, W. Ren, S. Haussener, X. Hu, Modulating electric field distribution by alkali cations for CO 2 electroreduction in strongly acidic medium, Nature Catalysis, 5 (2022) 268-276. G.Q. Liu, Y. Yang, Y. Li, T. Zhuang, X.F. Li, J. Wicks, J. Tian, M.R. Gao, J.L. Peng, H.X. Ju, L. Wu, Y.X. Pan, L.A. Shi, H. Zhu, J. Zhu, S.H. Yu, E.H. Sargent, Boosting photoelectrochemical efficiency by near-infrared-active lattice-matched morphological heterojunctions, Nat Commun, 12 (2021) 4296. Z. Ai, K. Zhang, B. Chang, Y. Shao, L. Zhang, Y. Wu, X. Hao, Construction of CdS@Ti 3 C 2 @CoO hierarchical tandem p-n heterojunction for boosting photocatalytic hydrogen production in pure water, Chemical Engineering Journal, 383 (2020). Z.-F. Huang, J. Song, X. Wang, L. Pan, K. Li, X. Zhang, L. Wang, J.-J. Zou, Switching charge transfer of C 3 N 4 /W 18 O 49 from type-II to Z-scheme by interfacial band bending for highly efficient photocatalytic hydrogen evolution, Nano Energy, 40 (2017) 308-316. K.T. Wong, S.C. Kim, K. Yun, C.E. Choong, I.W. Nah, B.-H. Jeon, Y. Yoon, M. Jang, Understanding the potential band position and e – /h + separation lifetime for Z-scheme and type-II heterojunction mechanisms for effective micropollutant mineralization: Comparative experimental and DFT studies, Applied Catalysis B: Environmental, 273 (2020). D. Xiong, Y. Shi, H.Y. Yang, Rational design of MXene-based films for energy storage: Progress, prospects, Materials Today, 46 (2021) 183-211. A. Swarnkar, R. Chulliyil, V.K. Ravi, M. Irfanullah, A. Chowdhury, A. Nag, Colloidal CsPbBr 3 Perovskite Nanocrystals: Luminescence beyond Traditional Quantum Dots, Angew Chem Int Ed Engl, 54 (2015) 15424-15428. X. Yu, Z. Liu, X. Yang, Y. Wang, J. Zhang, J. Duan, L. Liu, Q. Tang, Crystal-Plane Controlled Spontaneous Polarization of Inorganic Perovskite toward Boosting Triboelectric Surface Charge Density, ACS Applied Materials & Interfaces, 13 (2021) 26196-26203. Y.-x. Zhang, Y.-h. Wang, Nonlinear optical properties of metal nanoparticles: a review, RSC Advances, 7 (2017) 45129-45144. J.T. Mulder, I. du Fosse, M. Alimoradi Jazi, L. Manna, A.J. Houtepen, Electrochemical p-Doping of CsPbBr 3 Perovskite Nanocrystals, ACS Energy Lett, 6 (2021) 2519-2525. J. Li, Y. Wang, X. Li, Q. Gao, S. Zhang, A facile synthesis of high-crystalline g-C 3 N 4 nanosheets with closed self-assembly strategy for enhanced photocatalytic H 2 evolution, Journal of Alloys and Compounds, 881 (2021). R. Cheng, L. Zhang, X. Fan, M. Wang, M. Li, J. Shi, One-step construction of FeOx modified g-C 3 N 4 for largely enhanced visible-light photocatalytic hydrogen evolution, Carbon, 101 (2016) 62-70. J. Liu, T. Zhang, Z. Wang, G. Dawson, W. Chen, Simple pyrolysis of urea into graphitic carbon nitride with recyclable adsorption and photocatalytic activity, Journal of Materials Chemistry, 21 (2011). W. Ma, N. Wang, Y. Guo, L. Yang, M. Lv, X. Tang, S. Li, Enhanced photoreduction CO 2 activity on g-C 3 N 4 : By synergistic effect of nitrogen defective-enriched and porous structure, and mechanism insights, Chemical Engineering Journal, 388 (2020). G. Zhang, D. Huang, M. Cheng, L. Lei, S. Chen, R. Wang, W. Xue, Y. Liu, Y. Chen, Z. Li, Megamerger of MOFs and g-C 3 N 4 for energy and environment applications: upgrading the framework stability and performance, Journal of Materials Chemistry A, 8 (2020) 17883-17906. M. Majdoub, Z. Anfar, A. Amedlous, Emerging Chemical Functionalization of g-C 3 N 4 : Covalent/Noncovalent Modifications and Applications, ACS Nano, 14 (2020) 12390-12469. L.K. Putri, B.-J. Ng, C.-C. Er, W.-J. Ong, W.S. Chang, A.R. Mohamed, S.-P. Chai, Insights on the impact of doping levels in oxygen-doped gC 3 N 4 and its effects on photocatalytic activity, Applied Surface Science, 504 (2020). L. Zhou, Y. Tian, J. Lei, L. Wang, Y. Liu, J. Zhang, Self-modification of g-C 3 N 4 with its quantum dots for enhanced photocatalytic activity, Catalysis Science & Technology, 8 (2018) 2617-2623. R. Cheng, H. Jin, M.B.J. Roeffaers, J. Hofkens, E. Debroye, Incorporation of Cesium Lead Halide Perovskites into g-C 3 N 4 for Photocatalytic CO 2 Reduction, ACS Omega, 5 (2020) 24495-24503. M. Ou, W. Tu, S. Yin, W. Xing, S. Wu, H. Wang, S. Wan, Q. Zhong, R. Xu, Amino-Assisted Anchoring of CsPbBr 3 Perovskite Quantum Dots on Porous g-C 3 N 4 for Enhanced Photocatalytic CO 2 Reduction, Angew Chem Int Ed Engl, 57 (2018) 13570-13574. Y. Jiao, H. Jiang, F. Chen, RuO 2 /TiO 2 /Pt Ternary Photocatalysts with Epitaxial Heterojunction and Their Application in CO Oxidation, ACS Catalysis, 4 (2014) 2249-2257. Z. Tang, W. He, Y. Wang, Y. Wei, X. Yu, J. Xiong, X. Wang, X. Zhang, Z. Zhao, J. Liu, Ternary heterojunction in rGO-coated Ag/Cu 2 O catalysts for boosting selective photocatalytic CO 2 reduction into CH 4 , Applied Catalysis B: Environmental, 311 (2022). P. Chang, Y. Wang, Y. Wang, Y. Zhu, Current trends on In 2 O 3 based heterojunction photocatalytic systems in photocatalytic application, Chemical Engineering Journal, 450 (2022). J. Li, Y. Wang, H. Song, Y. Guo, S. Hu, H. Zheng, S. Zhang, X. Li, Q. Gao, C. Li, Z. Zhu, Y. Wang, Photocatalytic hydrogen under visible light by nitrogen-doped rutile titania graphitic carbon nitride composites: an experimental and theoretical study, Advanced Composites and Hybrid Materials, 6 (2023). W. Wang, Z. Wang, R. Yang, J. Duan, Y. Liu, A. Nie, H. Li, B.Y. Xia, T. Zhai, In Situ Phase Separation into Coupled Interfaces for Promoting CO 2 Electroreduction to Formate over a Wide Potential Window, Angew Chem Int Ed Engl, 60 (2021) 22940-22947. M.L.A. Kumari, L.G. Devi, G. Maia, T.W. Chen, N. Al-Zaqri, M.A. Ali, Mechanochemical synthesis of ternary heterojunctions TiO 2 (A)/TiO 2 (R)/ZnO and TiO 2 (A)/TiO 2 (R)/SnO 2 for effective charge separation in semiconductor photocatalysis: A comparative study, Environ Res, 203 (2022) 111841. S. Wei, J. Ma, D. Wu, B. Chen, C. Du, L. Liang, Y. Huang, Z. Li, F. Rao, G. Chen, Z. Liu, Constructing Flexible Film Electrode with Porous Layered Structure by MXene/SWCNTs/PANI Ternary Composite for Efficient Low‐Grade Thermal Energy Harvest, Advanced Functional Materials, 33 (2023). T. Xu, Y. Wang, Y. Xue, J. Li, Y. Wang, MXenes@metal-organic framework hybrids for energy storage and electrocatalytic application: Insights into recent advances, Chemical Engineering Journal, 470 (2023). T. Xu, Y. Wang, Z. Xiong, Y. Wang, Y. Zhou, X. Li, A Rising 2D Star: Novel MBenes with Excellent Performance in Energy Conversion and Storage, Nanomicro Lett, 15 (2022) 6. Y. Wang, Y. Wang, MXene ink printing of high‐performance micro‐supercapacitors, Carbon Neutralization, (2024). Z. Otgonbayar, C.-M. Yoon, W.-C. Oh, Photoelectrocatalytic CO 2 reduction with ternary nanocomposite of MXene (Ti 3 C 2 )-Cu 2 O-Fe 3 O 4 : Comprehensive utilization of electrolyte and light-wavelength, Chemical Engineering Journal, 464 (2023). J. Li, Y. Wang, Y. Wang, Y. Guo, S. Zhang, H. Song, X. Li, Q. Gao, W. Shang, S. Hu, H. Zheng, X. Li, MXene Ti 3 C 2 decorated g-C 3 N 4 /ZnO photocatalysts with improved photocatalytic performance for CO 2 reduction, Nano Materials Science, 5 (2023) 237-245. J. Fu, J. Yu, C. Jiang, B. Cheng, g-C 3 N 4 -Based Heterostructured Photocatalysts, Advanced Energy Materials, 8 (2018). Y. Wang, Y. Wang, Recent progress in MXene layers materials for supercapacitors: High‐performance electrodes, SmartMat, 4 (2022). Y. Wei, K. Li, Z. Cheng, M. Liu, H. Xiao, P. Dang, S. Liang, Z. Wu, H. Lian, J. Lin, Epitaxial Growth of CsPbX 3 (X = Cl, Br, I) Perovskite Quantum Dots via Surface Chemical Conversion of Cs 2 GeF 6 Double Perovskites: A Novel Strategy for the Formation of Leadless Hybrid Perovskite Phosphors with Enhanced Stability, Adv Mater, 31 (2019) e1807592. S. Zhang, F. Ma, J. Jiang, Z. Wang, R.T.K. Kwok, Z. Qiu, Z. Zhao, J.W.Y. Lam, B.Z. Tang, Aggregative Luminescence from CsPbBr 3 Perovskite Precursors, Angew Chem Int Ed Engl, 63 (2024) e202408586. M. Naguib, J. Halim, J. Lu, K.M. Cook, L. Hultman, Y. Gogotsi, M.W. Barsoum, New two-dimensional niobium and vanadium carbides as promising materials for Li-ion batteries, J Am Chem Soc, 135 (2013) 15966-15969. C. Yin, L. Cui, T. Pu, X. Fang, H. Shi, S. Kang, X. Zhang, Facile fabrication of nano-sized hollow-CdS@g-C 3 N 4 Core-shell spheres for efficient visible-light-driven hydrogen evolution, Applied Surface Science, 456 (2018) 464-472. X. She, J. Wu, H. Xu, J. Zhong, Y. Wang, Y. Song, K. Nie, Y. Liu, Y. Yang, M.-T.F. Rodrigues, R. Vajtai, J. Lou, D. Du, H. Li, P.M. Ajayan, High Efficiency Photocatalytic Water Splitting Using 2D α-Fe 2 O 3 /g-C 3 N 4 Z-Scheme Catalysts, Advanced Energy Materials, 7 (2017). T. Xuan, X. Yang, S. Lou, J. Huang, Y. Liu, J. Yu, H. Li, K.L. Wong, C. Wang, J. Wang, Highly stable CsPbBr 3 quantum dots coated with alkyl phosphate for white light-emitting diodes, Nanoscale, 9 (2017) 15286-15290. C. Cui, R. Guo, E. Ren, H. Xiao, M. Zhou, X. Lai, Q. Qin, S. Jiang, W. Qin, MXene-based rGO/Nb 2 CTx/Fe 3 O 4 composite for high absorption of electromagnetic wave, Chemical Engineering Journal, 405 (2021). Y.-J. Dong, Y. Jiang, J.-F. Liao, H.-Y. Chen, D.-B. Kuang, C.-Y. Su, Construction of a ternary WO 3 /CsPbBr 3 /ZIF-67 heterostructure for enhanced photocatalytic carbon dioxide reduction, Science China Materials, 65 (2022) 1550-1559. R. Bhosale, S. Jain, C.P. Vinod, S. Kumar, S. Ogale, Direct Z-Scheme g-C 3 N 4 /FeWO 4 Nanocomposite for Enhanced and Selective Photocatalytic CO 2 Reduction under Visible Light, ACS Appl Mater Interfaces, 11 (2019) 6174-6183. S. Hussain, Y. Wang, L. Guo, T. He, Theoretical insights into the mechanism of photocatalytic reduction of CO 2 over semiconductor catalysts, Journal of Photochemistry and Photobiology C: Photochemistry Reviews, 52 (2022). L. Collado, A. Reynal, F. Fresno, M. Barawi, C. Escudero, V. Perez-Dieste, J.M. Coronado, D.P. Serrano, J.R. Durrant, V.A. de la Pena O'Shea, Unravelling the effect of charge dynamics at the plasmonic metal/semiconductor interface for CO 2 photoreduction, Nat Commun, 9 (2018) 4986. P. Li, T. He, Common-cation based Z-scheme ZnS@ZnO core-shell nanostructure for efficient solar-fuel production, Applied Catalysis B: Environmental, 238 (2018) 518-524. H. Li, Z. Li, S. Liu, M. Li, X. Wen, J. Lee, S. Lin, M.-Y. Li, H. Lu, High performance hybrid MXene nanosheet/CsPbBr 3 quantum dot photodetectors with an excellent stability, Journal of Alloys and Compounds, 895 (2022). A. Pan, X. Ma, S. Huang, Y. Wu, M. Jia, Y. Shi, Y. Liu, P. Wangyang, L. He, Y. Liu, CsPbBr 3 Perovskite Nanocrystal Grown on MXene Nanosheets for Enhanced Photoelectric Detection and Photocatalytic CO 2 Reduction, J Phys Chem Lett, 10 (2019) 6590-6597. Y.F. Xu, M.Z. Yang, B.X. Chen, X.D. Wang, H.Y. Chen, D.B. Kuang, C.Y. Su, A CsPbBr(3) Perovskite Quantum Dot/Graphene Oxide Composite for Photocatalytic CO(2) Reduction, J Am Chem Soc, 139 (2017) 5660-5663. Q. Chen, X. Lan, Y. Ma, P. Lu, Z. Yuan, J. Shi, Boosting CsPbBr 3 ‐Driven Superior and Long‐Term Photocatalytic CO 2 Reduction under Pure Water Medium: Synergy Effects of Multifunctional Melamine Foam and Graphitic Carbon Nitride (g‐C 3 N 4 ), Solar RRL, 5 (2021). S.N. Habisreutinger, L. Schmidt-Mende, J.K. Stolarczyk, Photocatalytic reduction of CO 2 on TiO 2 and other semiconductors, Angew Chem Int Ed Engl, 52 (2013) 7372-7408. Z.-C. Kong, J.-F. Liao, Y.-J. Dong, Y.-F. Xu, H.-Y. Chen, D.-B. Kuang, C.-Y. Su, Core@Shell CsPbBr 3 @Zeolitic Imidazolate Framework Nanocomposite for Efficient Photocatalytic CO 2 Reduction, ACS Energy Letters, 3 (2018) 2656-2662. I. Dursun, M. De Bastiani, B. Turedi, B. Alamer, A. Shkurenko, J. Yin, A.M. El-Zohry, I. Gereige, A. AlSaggaf, O.F. Mohammed, M. Eddaoudi, O.M. Bakr, CsPb 2 Br 5 Single Crystals: Synthesis and Characterization, ChemSusChem, 10 (2017) 3746-3749. G. Li, H. Wang, Z. Zhu, Y. Chang, T. Zhang, Z. Song, Y. Jiang, Shape and phase evolution from CsPbBr 3 perovskite nanocubes to tetragonal CsPb 2 Br 5 nanosheets with an indirect bandgap, Chem Commun (Camb), 52 (2016) 11296-11299. S. Wang, Q. Luo, W.H. Fang, R. Long, Interfacial Engineering Determines Band Alignment and Steers Charge Separation and Recombination at an Inorganic Perovskite Quantum Dot/WS 2 Junction: A Time Domain Ab Initio Study, J Phys Chem Lett, 10 (2019) 1234-1241. D.N. Nguyen, T.K.C. Phu, J. Kim, W.T. Hong, J.S. Kim, S.H. Roh, H.S. Park, C.H. Chung, W.S. Choe, H. Shin, J.Y. Lee, J.K. Kim, Interfacial Strain-Modulated Nanospherical Ni 2 P by Heteronuclei-Mediated Growth on Ti 3 C 2 T x MXene for Efficient Hydrogen Evolution, Small, 18 (2022) e2204797. Y.W. Z. Zhou, L. Li, L. Yang, Y. Niu, Y. Yu, Y. Guo and S. wu, Constructing a full-space internal electric field in hematite photoanode to facilitate photogenerated-carrier separation and transfer, Journal of Materials Chemistry A, (2022). Additional Declarations No competing interests reported. Supplementary Files SupportingInformation.doc GraphicalAbstract.png Cite Share Download PDF Status: Published Journal Publication published 06 Nov, 2024 Read the published version in Advanced Composites and Hybrid Materials → Version 1 posted Editorial decision: Revision requested 16 Sep, 2024 Reviews received at journal 14 Sep, 2024 Reviewers agreed at journal 13 Sep, 2024 Reviews received at journal 11 Sep, 2024 Reviewers agreed at journal 09 Sep, 2024 Reviewers agreed at journal 08 Sep, 2024 Reviewers agreed at journal 08 Sep, 2024 Reviewers agreed at journal 08 Sep, 2024 Reviewers agreed at journal 08 Sep, 2024 Reviewers invited by journal 08 Sep, 2024 Editor assigned by journal 08 Sep, 2024 Submission checks completed at journal 05 Sep, 2024 First submitted to journal 01 Sep, 2024 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-5012551","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":354881961,"identity":"91540291-6df2-41e8-8c3d-061e40f83f93","order_by":0,"name":"Shiding Zhang","email":"","orcid":"","institution":"Wuhan University of Science and Technology","correspondingAuthor":false,"prefix":"","firstName":"Shiding","middleName":"","lastName":"Zhang","suffix":""},{"id":354881962,"identity":"93f5e0f2-6f5c-4aca-9a10-8589d0b53b8f","order_by":1,"name":"Yuhua Wang","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA50lEQVRIiWNgGAWjYPCCAwwM7A0INpFaeEBKE0jSIpFApBaD42cPv+Ztu5PYP/ONmeTPHwxyfDcSGD8X4NNyJi/NmrftWeKM2zlm0jwJDMaSNxKYpWfg0WJ2IMfMmLftcGLD7dxt0kCHJW64kcDGzINPy/k3EC3zb57dJvkjgaGesJYbOcaPQVo23ODdJgF0WIIBIS32N96YMc45d9h445n8z9Y8aRKGM888bJbGp0WyP8f4w5uyw7Lzjh9LvPnDxkae73jywc/4tAABmxSSAgkgZmzAr4GBgfnjD0JKRsEoGAWjYGQDAD87U18N/E6kAAAAAElFTkSuQmCC","orcid":"","institution":"Wuhan University of Science and Technology","correspondingAuthor":true,"prefix":"","firstName":"Yuhua","middleName":"","lastName":"Wang","suffix":""},{"id":354881963,"identity":"b61bac55-03be-48d8-881a-7ad413345c9e","order_by":2,"name":"Gaber A. M. Mersal","email":"","orcid":"","institution":"Taif University","correspondingAuthor":false,"prefix":"","firstName":"Gaber","middleName":"A. M.","lastName":"Mersal","suffix":""},{"id":354881964,"identity":"4803c81a-5f81-4bd4-90ef-4d110e294774","order_by":3,"name":"A. Alhadhrami","email":"","orcid":"","institution":"Taif University","correspondingAuthor":false,"prefix":"","firstName":"A.","middleName":"","lastName":"Alhadhrami","suffix":""},{"id":354881965,"identity":"582a22e1-f819-4aa7-82c9-0176049edbb5","order_by":4,"name":"Dalal A. Alshammari","email":"","orcid":"","institution":"University of Hafr Al-Batin","correspondingAuthor":false,"prefix":"","firstName":"Dalal","middleName":"A.","lastName":"Alshammari","suffix":""},{"id":354881966,"identity":"ad63f538-136e-4e29-a8ed-cdca90a13827","order_by":5,"name":"Yitong Wang","email":"","orcid":"","institution":"Wuhan University of Science and Technology","correspondingAuthor":false,"prefix":"","firstName":"Yitong","middleName":"","lastName":"Wang","suffix":""},{"id":354881967,"identity":"bbc52732-ba26-4f2f-a707-b68f4ce4bdbe","order_by":6,"name":"Hassan Algadi","email":"","orcid":"","institution":"Najran University","correspondingAuthor":false,"prefix":"","firstName":"Hassan","middleName":"","lastName":"Algadi","suffix":""},{"id":354881968,"identity":"05b09520-6c78-421c-8e2a-82849cf97307","order_by":7,"name":"Haixiang Song","email":"","orcid":"","institution":"Anyang Institute of Technology","correspondingAuthor":false,"prefix":"","firstName":"Haixiang","middleName":"","lastName":"Song","suffix":""}],"badges":[],"createdAt":"2024-09-01 10:58:17","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-5012551/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-5012551/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1007/s42114-024-01026-x","type":"published","date":"2024-11-06T15:58:14+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":66167025,"identity":"72c8023d-10a9-42e1-9537-babbbe204ec4","added_by":"auto","created_at":"2024-10-08 10:04:20","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":875776,"visible":true,"origin":"","legend":"\u003cp\u003eSchematic illustration of the fabrication process of the g-C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e/Nb\u003csub\u003e2\u003c/sub\u003eC MXene/CsPbBr\u003csub\u003e3\u003c/sub\u003e ternary heterojunction. QDs and g-C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e.\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-5012551/v1/79fbe10dc346b3d33049f6c0.png"},{"id":66167027,"identity":"d0de61c5-af13-4c28-8807-608a2186e5dd","added_by":"auto","created_at":"2024-10-08 10:04:20","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":1846059,"visible":true,"origin":"","legend":"\u003cp\u003e(a) XRD patterns of CCM30, CC43, Nb\u003csub\u003e2\u003c/sub\u003eC Mxene, CsPbBr\u003csub\u003e3\u003c/sub\u003e QDs, and g-C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e. (b) SEM of the CCM30 (c) EDS result of the region in(b), (d) TEM image of\u0026nbsp; CCM30 , (e, g) Selected area electron diffraction(SAED) , corresponds to the rigion of (d) , (f, h) two-dimension FFT patterns the inverse fast Fourier transforma-tions (IFFTs), (i-l) STEM elemental distribution image of the CCM30 composite and the corresponding EDX mapping images.\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-5012551/v1/e0d9629eef5fa1255b82489b.png"},{"id":66167031,"identity":"0f71f3fb-66b0-49ab-af17-ace78b374fd0","added_by":"auto","created_at":"2024-10-08 10:04:20","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":1750638,"visible":true,"origin":"","legend":"\u003cp\u003eThe FTIR (a) and the magnified FTIR (d) Spectra of CCM30, CC43, pure Nb\u003csub\u003e2\u003c/sub\u003eC MXene, CsPbBr\u003csub\u003e3\u003c/sub\u003e QDs and g-C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e, (b) PL spectra (c) UV-vis\u0026nbsp; DRS, (d), (e) Time-resolved transient PL decay curves, and (f) lifetime of CCM30, CC43, pure CsPbBr\u003csub\u003e3\u003c/sub\u003e QDs and g-C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e.\u003c/p\u003e","description":"","filename":"3.png","url":"https://assets-eu.researchsquare.com/files/rs-5012551/v1/9af1e53d27f1fbe601a6ffa7.png"},{"id":66168306,"identity":"31ad5ee3-ef2b-4e36-b121-f012d2d7a0d6","added_by":"auto","created_at":"2024-10-08 10:12:20","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":2352568,"visible":true,"origin":"","legend":"\u003cp\u003e(a) The XPS survey spectra of the five samples, display the presence of C, N, Br, Nb, and Pb in CC and CCM series samples. XPS spectra of g-C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e, CsPbBr\u003csub\u003e3\u003c/sub\u003e, Nb\u003csub\u003e2\u003c/sub\u003eC MXene, CC43 and CCM30 composite of samples, (b) charge density difference for g-C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e, CsPbBr\u003csub\u003e3\u003c/sub\u003e, Nb\u003csub\u003e2\u003c/sub\u003eC MXene (c) C 1s (d) N 1s, (e) Nb 3d, and (f) Br 3d spectra of different samples.\u003c/p\u003e","description":"","filename":"4.png","url":"https://assets-eu.researchsquare.com/files/rs-5012551/v1/2264d79f631dd94b7c67d0a7.png"},{"id":66168308,"identity":"0558ff63-b200-4f0c-aa3b-2a9123fc6121","added_by":"auto","created_at":"2024-10-08 10:12:20","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":1995669,"visible":true,"origin":"","legend":"\u003cp\u003e(a) Transient photocurrent responses density versus time (i-t curve) and (b) EIS spectra of as-synthesized g-C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e, CsPbBr\u003csub\u003e3\u003c/sub\u003e QDs and CC43 and CCM30 composite. Photocatalytic yield–time courses of the samples: (c) Comparison of the total product and electron yields of the different samples every hour light irradiation. (d) CO and (e) CH\u003csub\u003e4\u003c/sub\u003e.\u003c/p\u003e","description":"","filename":"5.png","url":"https://assets-eu.researchsquare.com/files/rs-5012551/v1/ea428e3753328388269b7562.png"},{"id":66168307,"identity":"6d36f0d0-0701-4b46-a0ec-151bda6972d6","added_by":"auto","created_at":"2024-10-08 10:12:20","extension":"png","order_by":6,"title":"Figure 6","display":"","copyAsset":false,"role":"figure","size":751664,"visible":true,"origin":"","legend":"\u003cp\u003e(a) Optimized structure of the g-C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e, CsPbBr\u003csub\u003e3\u003c/sub\u003e, Nb\u003csub\u003e2\u003c/sub\u003eC MXene, (b,c) 3D charge density difference and the plane-averaged electrostatic potential drop across the interface of the CsPbBr\u003csub\u003e3\u003c/sub\u003e, E\u003csub\u003eF\u003c/sub\u003e, and Evac represent Fermi level and vacuum level, respectively.\u003c/p\u003e","description":"","filename":"6.png","url":"https://assets-eu.researchsquare.com/files/rs-5012551/v1/eb2f0ad6567cd37e0a9495e6.png"},{"id":68750045,"identity":"1fcb1702-ac25-4d83-9e2b-7306fd6eb46b","added_by":"auto","created_at":"2024-11-11 16:08:54","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":9823797,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-5012551/v1/8540ba44-4575-4c54-8dbe-3d88e9fea2c7.pdf"},{"id":66167033,"identity":"54067907-6d70-41c1-baf8-692162229b34","added_by":"auto","created_at":"2024-10-08 10:04:20","extension":"doc","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":15028736,"visible":true,"origin":"","legend":"","description":"","filename":"SupportingInformation.doc","url":"https://assets-eu.researchsquare.com/files/rs-5012551/v1/e3188a3c4f4eb2e17b1fc163.doc"},{"id":66167029,"identity":"454e2e73-8cb6-4498-b818-c1ca49a13a84","added_by":"auto","created_at":"2024-10-08 10:04:20","extension":"png","order_by":2,"title":"","display":"","copyAsset":false,"role":"supplement","size":444502,"visible":true,"origin":"","legend":"","description":"","filename":"GraphicalAbstract.png","url":"https://assets-eu.researchsquare.com/files/rs-5012551/v1/ecf0c8dd59c3ef842fd9538a.png"}],"financialInterests":"No competing interests reported.","formattedTitle":"Enhanced Photocatalytic CO2 Reduction via MXene synergism: Constructing a Strong Intra-layer Electric Field Ternary Heterojunction of g-C3N4/Nb2C MXene/CsPbBr3","fulltext":[{"header":"1. Introduction","content":"\u003cp\u003eSolar photocatalytic conversion has emerged as a promising solution to address the energy crisis and environmental challenges by directly directly converting CO\u003csub\u003e2\u003c/sub\u003e into CO or hydrocarbon in the new age[1].For this purpose, extensive research efforts has been done on efficient CO\u003csub\u003e2\u003c/sub\u003e reduction photocatalysts, including organic[2], inorganic[3], transition metal compounds[4-6], and terminal ligands[7, 8]. Among them, MXene, a novel two-dimensional layered metal carbide and metal nitride material, has gained significant attention as a co-catalyst due to its high conductivity, abundant active sites, and large surface area[9-11], making it a potential candidate for promoting photocatalytic CO\u003csub\u003e2\u003c/sub\u003e reduction[12]. However, the efficiency of CO\u003csub\u003e2\u003c/sub\u003e conversion is still unsatisfactory owing to the stable nature of CO\u003csub\u003e2\u003c/sub\u003e as a linear covalent molecule(high dissociation energy)[13] and its sluggish multielectron reduction kinetics[14]. How to overcome these disadvantages? One effective strategy is to construct lattice-matched morphological[15] heterojunctions using nanotubes, ultrathin nanosheets, and quantum dots. This hierarchical heterojunction design[16] offers several advantages, including charge separations at the lattice-matched interface of the two morphological components, prevention of carrier recombination, and improved photon-to-current conversion efficiency, resulting in enhanced photocurrent conversion. Taking advantage of MXene, combining it with narrow-band gap semiconductors (Eg\u0026lt;3eV), such as metal oxides, sulfides, III-V group compounds, and II-VI group compounds, has proven to be an excellent method. These combinations facilitate the establishment of redox abilities and the formation of Z-scheme or type-II [17, 18] heterojunction photocatalytic system. Lattice matching and heterojunction regulation are also important means for the improvement of advanced photocatalytic materials[19].\u003c/p\u003e\n\u003cp\u003eConsidering the aforementioned two issues, the catalytic performance of photocatalytic materials can be significantly enhanced through the reasonable design heterogeneous interface structure. We first thought of Halogen perovskites CsPbX\u003csub\u003e3\u003c/sub\u003e QDs (X=Cl, Br, I) star materials[20, 21] , which have been widely used in photovoltaic and optoelectronics in recent years, due to their super optical properties, including a large extinction coefficient, a wide and tunable light absorption range, a long charge diffusion length, and an extended carrier lifetime. However, the single-component halogen perovskite materials are unsatisfactory due to low CO\u003csub\u003e2\u003c/sub\u003e adsorption capacity, and severe charge recombination, which greatly limits their potential for nonlinear optical properties[22] and catalytic application[23]. Moreover, their susceptibility to water instability poses a big challenge in both synthesis and practical applications. Surface passivation using organic ligands may also not effectively overcome this issue, as ligands can be easily lost during washing process. Adding protective materials is a common strategy, and the two-dimensional material g-C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e [24-26] is just right for it. It has attracted considerable attention in the water splitting and photocatalytic CO\u003csub\u003e2\u003c/sub\u003e reduction reactions due to its ideal bandgap with the conduction band (CB) and valence band(VB) edges at -0.59 eV and 2.36 eV vs. normal hydrogen electrode (NHE), respectively. Additionally g-C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e offers several advantages, including easy fabrication, good photoelectric chemical properties, strong adsorption capacity, thermal stability, and resistance to acid and alkali chemistry. It exhibits a favorable response to visible light, allows for band structure tuning, possesses rich surface functionality, and demonstrates good chemical stability[27, 28]. However, the rapid recombination of photogenerated holes and electrons in g-C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e limits the efficiency of light utilization, resulting in low photocatalytic performance.\u003c/p\u003e\n\u003cp\u003eTo overcome the limitations of single component, researchers have explored various theoretical and experimental approaches to enhance the photocatalytic ability of CO\u003csub\u003e2\u003c/sub\u003e, including covalent and noncovalent modifications[29], doping[30], band gap and crystalline regulation[24], and the construction of heterojunction. Compared to conventional heterojunctions, the use of n-type or p-type semiconductors with appropriate band structure can enhance visible light absorption and maintain stable reduction ability of photogenerated electrons on the interface, thereby improving the overall photocatalytic efficiency of CO\u003csub\u003e2\u003c/sub\u003e reduction. Therefore, delicate regulation and matching of heterogeneous are crucial to achieve optimal effect. As demonstrated in nanocomposites[31, 32], the incorporation of low-dimensional materials, such as 0D quantum dots or 1D nanowires with g-C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e nanosheets effectively enhances optoelectronic properties. Man Ou et al[33]. anchored CsPbBr\u003csub\u003e3\u003c/sub\u003e QDs on NH\u003csub\u003ex\u003c/sub\u003e-rich porous g-C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e nanosheets to construct composite photocatalysts for photocatalytic CO\u003csub\u003e2\u003c/sub\u003e reduction, demonstrating good stability and an outstanding yield. It is important to note that their system employed acetonitrile/water and ethyl acetate/water as the reaction media, rather than common water-saturated carbon dioxide conditions. Hierarchical band structure matching and good contact between interfaces have been solved, and multiple heterojunctions have also been explored, which mainly focused on metal oxides[34-37], sulfides[38], and semiconductor materials[39]. MXene, as a typical member of two-dimensional layered material can be used as superior photothermal supports for metal nanoparticles, also tandem effects to form a porous layered multiple structure for efficient low-grade thermal energy harvest[40, 41] and energy storage[42, 43]. Ternary nanocomposite of MXene (Ti\u003csub\u003e3\u003c/sub\u003eC\u003csub\u003e2\u003c/sub\u003e)-Cu\u003csub\u003e2\u003c/sub\u003eO-Fe\u003csub\u003e3\u003c/sub\u003eO\u003csub\u003e4\u003c/sub\u003e[44] and g-C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e/ZnO/Ti\u003csub\u003e3\u003c/sub\u003eC\u003csub\u003e2\u003c/sub\u003e [45] be used for photoelectrocatalytic CO\u003csub\u003e2\u003c/sub\u003e reduction. According to density functional theory (DFT), calculations of g-C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e-based[46] heterostructured photocatalysts with good lattice matching have more stable structures and have greater potential application in the field of heterojunction catalysis, in which the lower electrostatic potential makes the ternary heterojunction of MXene[47] more attractive and promising.\u003c/p\u003e\n\u003cp\u003eIn our study, Nb\u003csub\u003e2\u003c/sub\u003eC MXene is employed to tandem heterojunction nanocomposites (g-C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e/Nb\u003csub\u003e2\u003c/sub\u003eC MXene/CsPbBr\u003csub\u003e3\u003c/sub\u003e) as photocatalysts to enhance CO\u003csub\u003e2\u003c/sub\u003e reduction activity. The regulation of heterogeneous interface facilitated lattice matching and coordination among the materials. Furthermore, the combination of the three parent materials naturally created a built-in electric field, promoting efficient carrier separation and significantly improving the catalytic performance. We designed a rational ternary heterojunction structure of g‑C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e/Nb\u003csub\u003e2\u003c/sub\u003eC MXene/CsPbBr\u003csub\u003e3\u003c/sub\u003e, Which exhibited remarkable photocatalytic activity due to the synergistic effect among the components. In addition, density functional theory (DFT) calculations provided valuable insights intothe rapid charge separation and transport process within ternary heterojunctions.To demonstrate the practical application of the ternary nanocomposite materials, the photocatalytic CO\u003csub\u003e2\u003c/sub\u003e reduction experiment was tested. The ternary g-C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e/Nb\u003csub\u003e2\u003c/sub\u003eC MXene/CsPbBr\u003csub\u003e3\u003c/sub\u003e catalyst outperformed pure g‑C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e, CsPbBr\u003csub\u003e3\u003c/sub\u003e QDs and g-C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e/CsPbBr\u003csub\u003e3\u003c/sub\u003e catalysts in terms of CO production.The ternary heterojunction exhibited a maximum CO production rate of 53.07 μmol g\u003csup\u003e-1\u003c/sup\u003e h\u003csup\u003e-1\u003c/sup\u003e, surpassing the rates of pure g-C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e, CsPbBr\u003csub\u003e3\u003c/sub\u003e QDs, and the binary composite of g-C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e/CsPbBr\u003csub\u003e3\u003c/sub\u003e by approximately 8.4, 10, and 2 times, respectively. Notably, with an increase in the Nb\u003csub\u003e2\u003c/sub\u003eC MXene content, the production of CH\u003csub\u003e4 \u003c/sub\u003ewas effectively suppressed. This work provides a new insight for design of excellent ternary nanocomposite photocatalysts.\u003c/p\u003e"},{"header":"2. Experimental Section","content":"\u003cp\u003e\u003cstrong\u003e2.1 Chemicals and reagents\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eCesium carbonate (CsCO\u003csub\u003e3\u003c/sub\u003e, Alfa-Aesar), oleic acid (OA, Alfa-Aesar), oleylamine (OA, Alfa-Aesar)， Lead bromide(PbBr\u003csub\u003e2\u003c/sub\u003e, 99.99%, Sigma-Aldrich), octadecylene (OA, Alfa-Aesar) DMSO (Alfa-Aesar), n-hexane (Alfa-Aesar), urea (Sigma-Aldrich), HF(40%), Nb\u003csub\u003e2\u003c/sub\u003eAlC(qiyue CO.Ltd. xi’an) and acetone (Merck) were used. The pure water used throughout the experiment is deionized water. All reagents and solvents are of analytical grade and directly used without further purification.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e2.2 Preparation of CsPbBr\u003csub\u003e3\u003c/sub\u003e QDs\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe CsPbBr\u003csub\u003e3\u003c/sub\u003e QDs were synthesized based on the literature[48] with some subtle modification. We prepare the QDs precursors[49]. Firstly, 0.843g(0.25mmol) CsCO\u003csub\u003e3\u003c/sub\u003e and 30 mL octadecylene was added into a 50 mL three-necked round bottom flask, the whole process is protected by high purity nitrogen gas. The mixture was heated at 120℃ for 1 hour under Ar flow and 800r/min magnetic stirring, to remove water and impurities from the solution. At the desired temperature, we quickly heat up to 150℃, to completely dissolve cesium carbonate, and then control the temperature to 120℃, turn off the heat button and the mixture comes to room temperature, resulting in the cesium oleate precursor. Secondly, 0.367g of PbBr\u003csub\u003e2\u003c/sub\u003e and 20 mL octadecylene were added into a 100 mL three-necked round bottom flask. The mixture was heated at 120 ℃ for 1 hour under Ar flow and 800r/min magnetic stirring also removeing water and impurities from the solution. Subsequently, 2.5 mL of oleic acid and 2.5 mL of oleylamine were injected into the flask, vacuum it three times to prevent the effects of oxygen and fill the system with argon. A faint yellow homogeneous solution was formed when the above mixture was heated to 180 ℃. Following this, 2.5 mL of the cesium oleate precursor solution was injected into the flask, the yellow-green solution appears immediately, after 10 seconds, 10ml of n-hexane was injected into the flask, stop heating and stirring, cooled the mixture to room temperature with an ice-water bath. The yellow precipitate was centrifuged and washed with n-hexane and ethyl acetate to remove the organic residue. The mixture of yellow octadecylene suspension was centrifuged at 1000 rpm for 5 min to remove the large aggregated particles. The supernatant was again precipitated with ethyl acetate or acetone, then centrifuged at 6000 rpm for 5 min repeatedly to remove the surfactant organic molecules. The obtained CsPbBr\u003csub\u003e3\u003c/sub\u003e QDs were re-dispersed in n-hexane (1~2 mg/mL) for further use. The SEM elemental analysis(EDS) of the dried CsPbBr\u003csub\u003e3\u003c/sub\u003e QDs sample indicated that very low N contents (0.75 wt%) were remaining in the final sample, implying that surfactant organic molecules on the surface of CsPbBr\u003csub\u003e3\u003c/sub\u003e QDs were largely removed.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e2.3 Preparation of g-C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e nanosheets\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eGraphitic carbon nitride(g-C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e) nanosheets were prepared by direct thermal treatment of urea at 550\u003csup\u003eᵒ\u003c/sup\u003eC in a muffle furnace for 4 hours at 5\u003csup\u003eᵒ\u003c/sup\u003eC/min heating rate. The reaction procedure was carried out in an alumina crucible equipped with an air-tight lid to prevent any evaporation of the precursor along with associated gas loss. A pale yellow colored powdery sample was obtained which was termed g-C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e. And then, the obtained g-C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e was annealed from 550\u003csup\u003eᵒ\u003c/sup\u003eC to room temperature. However, the samples we obtained are an amorphous graphite-phase nitrogen carbide so no lattice fringes are observed in TEM experiments in our composites.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e2.4 Synthesis of 2D MXene Nb\u003csub\u003e2\u003c/sub\u003eC nanosheets\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eBased on the literature[50], 2D Nb\u003csub\u003e2\u003c/sub\u003eC MXene nanosheets were synthesized by etching 2.0 g Nb\u003csub\u003e2\u003c/sub\u003eAlC, which was placed in an oil bath constant thermal magnetic stirrer with a mixture of 40 mL of 40% HF at 60\u003csup\u003e°\u003c/sup\u003eC, 300 rpm for 48h in a sealed plastic cup. After the reaction, the product was washed 3 to 5 times by centrifugation using anhydrous ethanol until the pH reached about 6. Then, the black Nb\u003csub\u003e2\u003c/sub\u003eC MXene was dispersed with DMSO by ultrasonic treatment in deionized water in the glass bottle for 10 hours under nitrogen protection, the supernatant was collected, centrifuged at 3500 rpm, and the precipitate was returned to the glass bottle, then, the main component of the centrifuged supernatant was 2D Nb\u003csub\u003e2\u003c/sub\u003eC MXene nanosheets, the content is 4mg per 100 ml. The nanosheets are dried and stored for further use in the synthesis of the complex.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e2.5 Synthesis of the binary g-C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e /CsPbBr\u003csub\u003e3\u003c/sub\u003e and the ternary g-C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e/ Nb\u003csub\u003e2\u003c/sub\u003eC MXene /CsPbBr\u003csub\u003e3\u003c/sub\u003e composites\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eIn this synthesis process[33], we developed an one-pot novel method. Firstly, 10mg g-C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e white powders were added into 20 mL octadecylene, the mixture was stirred 800r/min for 1 h and maintained at 180 \u003csup\u003e°\u003c/sup\u003eC under the protection of argon, vacuum a few times to remove moisture from the solution. Then, 7, 30, 43, and 55 mg of the yellow perovskite quantum dots CsPbBr\u003csub\u003e3\u003c/sub\u003e was added to the solution, and it was stirred for another 8 h and also maintained at 180 °C under the protection of argon. The product was washed multiple times with n-hexane and dried at 80 °C in the vacuum oven. In the composites, the g-C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e and perovskite quantum dots CsPbBr\u003csub\u003e3\u003c/sub\u003e can form a g-C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e/CsPbBr\u003csub\u003e3\u003c/sub\u003e binary heterojunction, the obtained samples will be further named as CC7, CC30, CC43 CC55, respectively. We have also tried in-situ synthesis of this two-dimensional composite material and found that the results were the same.\u003c/p\u003e\n\u003cp\u003eThe same synthesis method described above is used. Firstly, 10mg g-C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e white powders and 43 mg(the photocatalytic carbon dioxide reduction performance of these two compounds is better) the yellow perovskite quantum dots CsPbBr\u003csub\u003e3\u003c/sub\u003e were added into 20 mL octadecylene, the mixture was stirred 800r/min for 1 h and maintained at 180 °C under the protection of argon, vacuum three times guarantee to remove moisture from the solution. Then, 10, 20, 30and 40 mg of the Nb\u003csub\u003e2\u003c/sub\u003eC MXene black nanosheets were added to the solution, and it was stirred for another 8 h and also maintained at 180 \u003csup\u003e°\u003c/sup\u003eC under the protection of argon. The product powder was washed multiple times with n-hexane and anhydrous ethanol, dried at 80 °C in the vacuum oven. In the composites, the perovskite quantum dots, g-C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e and Nb\u003csub\u003e2\u003c/sub\u003eC MXene can form a g-C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e/ Nb\u003csub\u003e2\u003c/sub\u003eC MXene /CsPbBr\u003csub\u003e3\u003c/sub\u003e composites ternary heterojunction, and the obtained samples will be further named as CCM10, CCM20, CCM30, CCM40, respectively.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e2.6 Characterization\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe morphological structure and chemical properties of the as-prepared samples were characterized and tested as follows. X-ray diffraction (XRD, Cu Kα, Empyrean, Panaco, Netherlands) was used to measure the as-prepared samples structure and phase composition of samples with diffraction angles (2θ) varying from 5° to 90°. The optical absorption behavior of the samples was studied using Fourier transform infrared spectroscopy (FT-IR, IRTracer-100 Shimadzu, Japan) and Ultraviolet–visible (UV-vis) diffuse reflectance spectra (UV-3600Plus DRS, Shimadzu, Japan). Microstructure and morphology were analyzed by Scanning Electron Micrograph (NovaTM NanoSEM 450, FEI, Czech) and Field emission transmission electron microscopy (FETEM) (Talos F200S, FEI, USA) with an energy-dispersive X-ray spectrometer (EDX). Time-resolved transient PL spectra (Edinburgh FLS980, excitation wavelength of 360 nm) obtained the decay curves. X-ray Photoelectron Spectroscopy XPS(Thermo Scientific, USA) was tested by an ultrahigh vacuum VG ESCALAB 250 electron spectrometer and pass Energy 30.0 eVwith Al Kα\u003csub\u003e1\u003c/sub\u003e X-rays, the valence band was also measured. Photoluminescence(PL) spectra (LabRAM HR Evolution HORIBA Jobin Yvon, France) were recorded by applying a 325nm laser excitation. vacuum oven(ZDF6022 yiheng, shanghai) were used to dry the samples.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e2.7 Photoelectrochemical measurements\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWe carried out the photoelectrochemical test using a three-electrode system (CHI 660E, Shanghai Chenhua) including a Pt foil counter electrode, a saturated Ag/AgCl reference electrode and a working electrode. Using the dip-coating method, with the same amount of photocatalyst, we got the working electrode. Following the detailed process is carried out. First, weighting 5mg of the samples, it was dispersed by ultrasound in 5 mL of n-hexane and 5 μL Nafion adhesive solution to form a uniform slurry. Second, using a Da Long pipette, measuring 10 μL of the slurry, dip-coating on the ITO conductive glass with an exposure area of 1*1 cm\u003csup\u003e2\u003c/sup\u003e. And last, the completed ITO samples were dried in a vacuum oven at 80°C for 1 hour. Following, selecting the electrolyte 100 ml can be used acetonitrile solution with 0.08 mol/L of tetrabutylammonium hexafluorophosphate to avoid any moisture. Before the experiment, to remove the effects of air, the electrolyte was purged with high-purity N\u003csub\u003e2\u003c/sub\u003e gas. The photoinduced current density versus time (I-t) was tested at a 0.01 V bias potential under a solar simulator xenon light source (350 W) switching on and off mode. Using a frequency ranging from 105 Hz to 0.01 Hz, selecting open circuit potential, the electrochemical impedance spectroscopy (EIS) Z’-Z’’ curves can be tested.\u003c/p\u003e\n\u003cp\u003eThe photocatalytic CO\u003csub\u003e2\u003c/sub\u003e reduction experiments were performed in a photocatalytic activity evaluation system( CEL-PAEM-D8, Beijing Zhongjiao jinyuan Technology Co. LTD), which included a closed CO\u003csub\u003e2\u003c/sub\u003e circulation reactor system with a top window cell(volume: 150 mL). The inside reaction temperature was controlled at 6℃ by the external circulation of the cooling water system. A 300 W Xe-lamp collocated a 420 nm UV-cut-off filter was placed on the top of the two-neck bottle as the light source passing and positioned 2 cm away from the photocatalytic reactor. The photocatalyst (10mg) was uniformly dispersed into Vessels 50 mm in diameter with n-hexane solvent 3 ml, which was sonicated, vacuum dried to remove the organic solvent and evenly dispersed in 0.0196 m\u003csup\u003e2\u003c/sup\u003e glass petri dishes. Before the photoreaction, we first test the closure of the whole photocatalytic activity evaluation system, the inner circulation reactor was evacuated vacuum throughout the system and washed three times with high-purity CO\u003csub\u003e2\u003c/sub\u003e gas to get rid of the air and water vapor inside. Then we start to regulate the catalytic environment, the high-purity CO\u003csub\u003e2\u003c/sub\u003e gas was filled into the circulation reactor to reach a pressure of 0.08 atmospheric pressure. Finally, it sits for a period of time (about, 1 hour) to form an environment saturated steam with carbon dioxide. The CO and CH\u003csub\u003e4\u003c/sub\u003e gaseous products at different reaction times were automatically detected by an online gas chromatograph (GC 7920-TF2A Beijing Zhongjiao jinyuan Technology Co. LTD). Then the stability of pure g-C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e, CsPbBr\u003csub\u003e3\u003c/sub\u003e, CC composite, and CCM series of samples were tested for consecutive photoreaction runs of 8 h in each run. The reactor was evacuated and refilled with 0.08 atmospheric pressure CO\u003csub\u003e2\u003c/sub\u003e-saturated steam every time.\u003c/p\u003e"},{"header":"3. Results and discussion","content":"\u003cp\u003eThe synthesis mechanism of g-C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e/Nb\u003csub\u003e2\u003c/sub\u003eC MXene/CsPbBr\u003csub\u003e3\u003c/sub\u003e ternary heterojunction is presented in Fig. 1. The complete synthesis control details are given in the experimental section.\u003c/p\u003e\n\u003cp\u003eThe XRD patterns of g-C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e, CsPbBr\u003csub\u003e3\u003c/sub\u003e, Nb\u003csub\u003e2\u003c/sub\u003eC MXene, CC43 sample， and CCM30 sample are shown in Fig 2a. The characteristic peak patterns indicate the synthesis of pure phase g-C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e, CsPbBr\u003csub\u003e3\u003c/sub\u003e, and Nb\u003csub\u003e2\u003c/sub\u003eC MXene, which are consistent with the corresponding standard references (Fig S1). The crystal structure of the ternary heterojunction CCM series (Fig. S1d) composites still maintain the original perovskite structure. Detailed characterization results in Fig. S1a further support the structural integrity of three parent materials. The XRD peaks of the CC(Fig. S1c) and CCM composites(Fig. S1d, Fig. S2) show similar diffraction peaks to those of g-C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e, CsPbBr\u003csub\u003e3\u003c/sub\u003e and Nb\u003csub\u003e2\u003c/sub\u003eC MXene, indicating that the phase structure of g-C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e, CsPbBr\u003csub\u003e3\u003c/sub\u003e and Nb\u003csub\u003e2\u003c/sub\u003eC MXene remain unchanged during the composite formation process. It should be noted that the peaks corresponding to g-C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e and Nb\u003csub\u003e2\u003c/sub\u003eC MXene are relatively weak in the CCM series composites due to the amorphous nature of the g-C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e and the few layers structure of the Nb\u003csub\u003e2\u003c/sub\u003eC MXene.\u003c/p\u003e\n\u003cp\u003eThe morphologies of the prepared samples were characterized using SEM, TEM, and High-resolution TEM (HRTEM) techniques, as shown in Fig. 2c and Fig. S3-5. The SEM image (Fig. 2b, S5a) reveals a sheet structure decorated with numerous particles. TEM and HRTEM were performed to confirm the three-phase composition of the CCM30 compound (Fig. 2d). Amorphous g-C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e is dispersed in the surface layer of the sample (Fig. 2c). In Fig. 2e and 2g, lattice fringes with a d-spacing of 0.291 nm correspond to (220) panes of CsPbBr\u003csub\u003e3\u003c/sub\u003e QDs, while the lattice fringes with d-spacing of 0.296 nm and 0.431 nm correspond to (220) and (200) planes of Nb\u003csub\u003e2\u003c/sub\u003eC MXene, respectively. HRTEM image with corresponding live Fast Fourier transformation (FFT) patterns (Fig. 2e and 2g) clearly displaylattice signals of CsPbBr\u003csub\u003e3\u003c/sub\u003e and Nb\u003csub\u003e2\u003c/sub\u003eC MXene. The angle between them measures 28\u003csup\u003e\u0026deg;\u0026nbsp;\u003c/sup\u003eand 30\u003csup\u003e\u0026deg;\u003c/sup\u003e, indicating a near-parallel relationship between CsPbBr\u003csub\u003e3\u003c/sub\u003e and Nb\u003csub\u003e2\u003c/sub\u003eC MXene. EDS results (Fig. S5b) demonstrate that the mass fraction of each element in CCM30 composites aligns with the proportion of the synthetic materials used. Additionally, energy-dispersive X-ray spectrometer mapping data (Fig. 2i-l, S2) reveals a uniform distribution of elements (C, N, Br, Pb, Cs, Nb, and F) throughout the nanocomposite structure. Based on the above characterizations, it is evident that the g-C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e/Nb\u003csub\u003e2\u003c/sub\u003eC MXene/CsPbBr\u003csub\u003e3\u0026nbsp;\u003c/sub\u003eheterostructure has been successfully formed (Fig. 2c).\u003c/p\u003e\n\u003cp\u003eWe carried out a series of optical properties to deeply understand the interaction among ternary compounds and their influence. The FTIR spectra of g-C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e, CsPbBr\u003csub\u003e3\u003c/sub\u003e QDs, and Nb\u003csub\u003e2\u003c/sub\u003eC MXene photocatalysts are shown in Fig. 3a and Fig. S6a-d. In the case of g-C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e[51, 52], the peak at 1639 cm\u003csup\u003e\u0026minus;1\u003c/sup\u003e, 1241 cm\u003csup\u003e\u0026minus;1\u003c/sup\u003ecorrespond to C‒N and C=N stretching vibration modes, respectively. The absorption peaks at 1325 and 1245 cm\u003csup\u003e\u0026minus;1\u003c/sup\u003e are associated with the out-of-plane bending vibration of triazine ring. The peak at 808 cm\u003csup\u003e\u0026minus;1\u003c/sup\u003e is attributed to the molecule breathing modes of tris-triazine units. The peaks at 2924 cm\u003csup\u003e\u0026minus;1\u003c/sup\u003e, 2853 cm\u003csup\u003e\u0026minus;1\u003c/sup\u003e, and 1458 cm\u003csup\u003e\u0026minus;1\u003c/sup\u003e can be assigned to the asymmetric and symmetric Pb\u0026ndash;Br stretching vibrations[53] as well as the bending vibrations of Cs-Pb of CsPbBr\u003csub\u003e3\u003c/sub\u003e QDs. Nb\u003csub\u003e2\u003c/sub\u003eC MXene shows typical peaks at 621 cm\u003csup\u003e-1\u003c/sup\u003eand 1086 cm\u003csup\u003e-1\u003c/sup\u003e, attributing to the interlayer vibrations of C-Nb [54]. In the FTIR spectrum of the ternary compounds, in addition to the typical peaks of g-C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e, CsPbBr\u003csub\u003e3\u003c/sub\u003e QDs, and Nb\u003csub\u003e2\u003c/sub\u003eC MXene, a clear red shift in peak position of in C\u0026ndash;N stretching mode and the vibrational modes of tris-s-triazine units in g-C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e is observed. The red shift indicates a strong interaction among the g-C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e, CsPbBr\u003csub\u003e3\u003c/sub\u003e QDs, and Nb\u003csub\u003e2\u003c/sub\u003eC MXene interface. Moreover, the typical stretching mode of aromatic C\u0026ndash;N and C=N heterocycles in g-C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e at 1241 cm\u003csup\u003e-1\u003c/sup\u003e are shifted to higher values with an increasing content of Nb\u003csub\u003e2\u003c/sub\u003eC MXene (Fig. 3d). This shift can be ascribed to a chemical interaction between the g-C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e and Nb\u003csub\u003e2\u003c/sub\u003eC MXene surfaces, leading to an increase in the electron density of ternary heterocycles in g-C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e. It is noteworthy that even with a single molar ratio of 1:1:1, all CsPbBr\u003csub\u003e3\u003c/sub\u003e QDs can be effectively incorporated onto the surface of two two-dimensional materials, forming a ternary heterojunction structure.\u003c/p\u003e\n\u003cp\u003eTo investigate the light-harvesting property, UV-vis spectra were recorded, as shown in Fig. 3c. The absorption edge of g-C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e, CsPbBr\u003csub\u003e3\u003c/sub\u003e QDs, CC30, and CCM30 groups are observed around 450 nm, 570 nm, 560 nm, and 550nm, respectively, corresponding to the band gap energy of approximately 2.95 eV, 2.31 eV, 2.29 eV, and 2.23 eV [33, 55] (Fig. S7). It is evident that all the binary (Fig. S6g) and ternary (Fig. S6h) samples can be excited under visible-light irradiation. Upon the addition of Nb\u003csub\u003e2\u003c/sub\u003eC MXene, both the absorption intensity in the visible region and at the absorption edges increase, which might be correlate with the black color of Nb\u003csub\u003e2\u003c/sub\u003eC MXene.\u003c/p\u003e\n\u003cp\u003eTo further investigate the interactions among g-C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e/Nb\u003csub\u003e2\u003c/sub\u003eC MXene/CsPbBr\u003csub\u003e3\u003c/sub\u003e binary catalysts, photoluminescence (PL) emission spectra were recorded. The PL intensity is typically indicative of the recombination rate of photoinduced electron-hole pairs, where a lower PL emission intensity suggests a strongly suppressed recombination. As shown in Fig. 3d, it can be observed that pure g-C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e and CsPbBr\u003csub\u003e3\u003c/sub\u003e exhibit strong and broad PL emission at approximately 498 nm and 524 nm, respectively, which is consistent with the literature. However, the PL peak intensity of the ternary heterojunction is significantly quenched compared to the other composite samples. In particular, PL emissions of CC43 and CCM30 exhibit the lowest intensity within their respective group (Fig. S6e and S6f). It is important to note that Nb\u003csub\u003e2\u003c/sub\u003eC MXene does no exhibit any emission peak due to its metallic characteristics. These PL results indicate that the addition of Nb\u003csub\u003e2\u003c/sub\u003eC MXene can effectively inhibit the recombination of charge carriers within the system, leading to improved photocatalytic performance.\u003c/p\u003e\n\u003cp\u003eThe charge transfer and separation behavior of the photocatalyst was investigated using time-resolved fluorescence decay technique. As shown in Fig. 3e, all samples exhibit a rapid decay within the nanosecond timescale. The average emission lifetime (Fig. 3f) of g-C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e CsPbBr\u003csub\u003e3\u003c/sub\u003e QDs, CC43, and CCM30 are 11.20 ns, 9.80 ns, 9.24ns, and 8.70ns, respectively. These results indicate that both binary (Fig. S6i) and ternary heterostructures (Fig. S6j) provide efficient pathways for rapid charge transfer of the photogenerated carriers. The shortened emission lifetimes suggest enhanced charge separation and reduced recombination, which are favorable for efficient photocatalytic performance\u003c/p\u003e\n\u003cp\u003eThe bonding information of g-C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e, Nb\u003csub\u003e2\u003c/sub\u003eC MXene, CsPbBr\u003csub\u003e3\u003c/sub\u003e, and their composites was investigated using X-ray photoelectron spectroscopy (XPS) (Fig. 4a,c-f and Fig. S8-9). In Fig. 4, CCM30 shows distinct binding energies ascribed to C, N, Br, Pb, Cs, and Nb, indicating the successful synthesis of the ternary composites of g-C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e / Nb\u003csub\u003e2\u003c/sub\u003eC MXene / CsPbBr\u003csub\u003e3\u003c/sub\u003e. After fitting the spectra, small binding energy shifts are observed in the ternary structures compared to their individual components such as C1s, N1s, Br3d, and Nd3d. These shifts suggest the presence of intimate interactions within the structure, resulting in charge redistribution. This binding energy shift indicates chemical reactions between the other parent components and g-C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e. Consequently, Nb\u003csub\u003e2\u003c/sub\u003eC MXene becomes electron-rich, while the other two components become electron-deficient. This is supported by the negative shift in the binding energy of Nb 3d in CCM30. The binding energy of Br 3d (Fig. 4f) in the CsPbBr\u003csub\u003e3\u003c/sub\u003e QDs is 68.4 eV and 69.5 eV, corresponding to Br 3d\u003csub\u003e5/2\u003c/sub\u003e and Br 3d\u003csub\u003e3/2\u003c/sub\u003e respectively. The shift is -0.2 eV (68.2eV) and -0.3 eV (69.5eV). The binding energy of Nb 3d (Fig. 4e) in the Nb\u003csub\u003e2\u003c/sub\u003eC MXene shows six peaks at 203.1 eV, 205.8 eV, 206.8 eV, and 209.6eV. The shift is 0.4 eV (203.5eV), 0.5 eV (206.3eV), 0.2 eV (207.0eV), and 0.2 eV (209.8eV), indicating a strong electron deficient in Nb\u003csub\u003e2\u003c/sub\u003eC MXene. Fig 4b shows the differential charge density of the three parent materials. According to whether there is a broken band gap at 0eV, it is obvious that g- C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e and CsPbBr\u003csub\u003e3\u003c/sub\u003e have obvious semiconductor properties, while Nb\u003csub\u003e2\u003c/sub\u003eC MXene has obvious gold properties.\u003c/p\u003e\n\u003cp\u003eThe valence band (VB) potential can be determined by analyzing the VB XPS spectra. As shown in Fig. S10, the energy level of the valence band maximum (VBM) for g-C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e and CsPbBr\u003csub\u003e3\u0026nbsp;\u003c/sub\u003eQDs is 2.25 eV and 1.12 eV, respectively. Based on these results, the band structures of g-C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e and CsPbBr\u003csub\u003e3\u003c/sub\u003e QDs can be derived, with VBM energies of 2.36 eV and 1.23 eV, respectively. Consequently, the corresponding conduction band energies are -0.59 eV and -1.08 eV respectively. Evidently, the conduction band minimum of g-C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e is 0.49 eV lower than that of CsPbBr\u003csub\u003e3\u003c/sub\u003e QDs. These dataprovide insights into the band structure of g-C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e and CsPbBr\u003csub\u003e3\u003c/sub\u003e.\u003c/p\u003e\n\u003cp\u003eTo further demonstrate the improved efficiency of photocarrier transfer and separation efficiency, we conducted transient photocurrent measurements for g-C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e, CsPbBr\u003csub\u003e3\u003c/sub\u003e, CC43, and CCM30 samples (Fig.5a). Among all the samples, CCM30 exhibited the highest photocurrent indicating enhanced photocarrier separation and transfer. The presence of Nb\u003csub\u003e2\u003c/sub\u003eC Mxene is believed to facilitates the efficient separation of photoexcited electrons and holes[15, 56]. Furthermore, electrochemical impedance spectroscopy (EIS) was performed to investigate the catalytic activity of the prepared samples (g-C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e, CsPbBr\u003csub\u003e3\u003c/sub\u003e CC43, and CCM30 samples) (Fig.5b). The arc radius of g-C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e and CsPbBr\u003csub\u003e3\u003c/sub\u003e samples was larger than that of CC43 and CCM30 composite samples. In contrast, CCM30 exhibited a smaller arc radius, suggesting reduced resistance and enhanced charge transfer. The presence of Nb\u003csub\u003e2\u003c/sub\u003eC Mxene is attributed to the improved conductivity and facilitated charge transfer within the composite structure.\u003c/p\u003e\n\u003cp\u003eThe photocatalytic CO\u003csub\u003e2\u003c/sub\u003e reduction activity (Fig. S11) of the samples was evaluated in a photocatalytic system filled with carbon dioxide-saturated water vapor under simulated sunlight[57, 58]. A controlled trial without light irradiation, CO\u003csub\u003e2\u003c/sub\u003e or any photocatalyst did not show any detectable production of CO, CH\u003csub\u003e4\u003c/sub\u003e, H\u003csub\u003e2\u003c/sub\u003e, or other hydrocarbons (Fig. S12), confirming the necessity of the photocatalyst for the CO\u003csub\u003e2\u003c/sub\u003e reduction process. As expected, the bare Nb\u003csub\u003e2\u003c/sub\u003eC MXene showed no photocatalytic activity (Fig. 5c, d) because it is not a photocatalyst[59]. In our system, CO was the main product, accompanied by a small amount of CH\u003csub\u003e4\u003c/sub\u003e. The yields of CO and CH\u003csub\u003e4\u003c/sub\u003e were 6.27 \u0026mu;mol g\u003csup\u003e-1\u003c/sup\u003e h\u003csup\u003e-1\u003c/sup\u003e and 0.15 \u0026mu;mol g\u003csup\u003e-1\u003c/sup\u003e h\u003csup\u003e-1\u003c/sup\u003e for pure g-C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e,\u003csub\u003e\u0026nbsp;\u003c/sub\u003eand 5.31 \u0026mu;mol g\u003csup\u003e-1\u003c/sup\u003e h\u003csup\u003e-1\u003c/sup\u003e and 0.02 \u0026mu;mol g\u003csup\u003e-1\u003c/sup\u003e h\u003csup\u003e-1\u003c/sup\u003e for CsPbBr\u003csub\u003e3\u003c/sub\u003e QDs, respectively (Fig. S13). The production of CO, significantly improved in the g-C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e/CsPbBr\u003csub\u003e3\u003c/sub\u003e binary composite photocatalysts compared to the individual components (Fig. 5d). Furthermore, the introduction of 2D Nb\u003csub\u003e2\u003c/sub\u003eC MXene in ternary heterojunction nanocomposites resulted in even higher performance. Among the samples, CCM30 exhibited the highest CO production rate of 53.07 \u0026mu;mol g\u003csup\u003e-1\u003c/sup\u003e h\u003csup\u003e-1\u003c/sup\u003e which was about 8.4, 10, and 2 times higher than that of pure g-C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e, CsPbBr\u003csub\u003e3\u003c/sub\u003e QDs, and the binary composite g‑C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e/CsPbBr\u003csub\u003e3\u003c/sub\u003e, respectively. This significant enhancement in CO production highlights the synergistic effect of the ternary heterojunction nanocomposites.\u003c/p\u003e\n\u003cp\u003eThe comparison of g-C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e and CsPbBr\u003csub\u003e3\u003c/sub\u003e QDs revealed that the CO yield rate in binary photocatalysts increased by more than 2 times, suggesting the formation of heterojunction structure between g-C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e and CsPbBr\u003csub\u003e3\u003c/sub\u003e, which\u003csub\u003e\u0026nbsp;\u003c/sub\u003efacilitates the transfer of photo-excited charges. This finding is consistent with the results obtained from EIS and photocurrent measurements, as well as with previous reports[32, 33]. By adjusting the ratio of components, slightly changes in the photocatalytic performance were observed. Among the binary photocatalysts, CC43 demonstrateed the best performance. Upon the addition of Nb\u003csub\u003e2\u003c/sub\u003eC MXene, the CO yield rate of ternary photocatalysts initially reached a comparable level to that of the binary ones when the percentage of Nb\u003csub\u003e2\u003c/sub\u003eC MXene was low (CCM10 and CCM20). Subsequently, the maximum performance was achieved in CCM30. However, with further increase in Nb\u003csub\u003e2\u003c/sub\u003eC MXene (CCM40), a slight decrease in the photocatalytic ability was observed, although it still outperformed all the binary photocatalysts. This suggests that the good conductivity of Nb\u003csub\u003e2\u003c/sub\u003eC MXene facilitates charge transfer between g-C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e and CsPbBr\u003csub\u003e3\u003c/sub\u003e, as supported by PL and PL delay lifetime characterizations. As a result, the maximum photocatalytic performance in terms of CO production was achieved with a yield rate of 53.07 \u0026mu;mol g\u003csup\u003e-1\u003c/sup\u003e h\u003csup\u003e-1\u003c/sup\u003e, surpassing the majority of previously the reported studies[60]. The relevant literature on previous reports is listed in Table 1. Obviously,\u003c/p\u003e\n\u003cp\u003eThe CO evolution rate on CCM30 has obvious advantages.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 1\u0026nbsp;\u003c/strong\u003eComparison CO evolution rates of the prepared photocatalyst with other literature.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 1\u0026nbsp;\u003c/strong\u003eComparison CO evolution rates of the prepared photocatalyst with other literature.\u003c/p\u003e\n\u003ctable border=\"0\" cellspacing=\"0\" cellpadding=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 21.2654%;\"\u003e\n \u003cp\u003ePhotocatalyst\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 18.8049%;\"\u003e\n \u003cp\u003eLight source\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 20.0351%;\"\u003e\n \u003cp\u003eSolvents\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 26.0105%;\"\u003e\n \u003cp\u003eCO evolution (\u0026mu;mol/g/h)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 13.884%;\"\u003e\n \u003cp\u003eRef.\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 21.2654%;\"\u003e\n \u003cp\u003ePCN\u003c/p\u003e\n \u003cp\u003eCsPbBr\u003csub\u003e3\u003c/sub\u003e\u003c/p\u003e\n \u003cp\u003eCsPbX\u003csub\u003e3\u003c/sub\u003e/g-C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e.\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 18.8049%;\"\u003e\n \u003cp\u003e300 W Xe-lamp\u003c/p\u003e\n \u003cp\u003e(\u0026gt;420 nm)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 20.0351%;\"\u003e\n \u003cp\u003eCO\u003csub\u003e2\u003c/sub\u003e and water vapor\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 26.0105%;\"\u003e\n \u003cp\u003e5.5\u003c/p\u003e\n \u003cp\u003e5.0\u003c/p\u003e\n \u003cp\u003e28.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 13.884%;\"\u003e\n \u003cp\u003e[32]\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 21.2654%;\"\u003e\n \u003cp\u003ePCN\u003c/p\u003e\n \u003cp\u003eCsPbBr\u003csub\u003e3\u003c/sub\u003e\u003c/p\u003e\n \u003cp\u003eCPB-PCN\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 18.8049%;\"\u003e\n \u003cp\u003e300 W Xe-lamp\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 20.0351%;\"\u003e\n \u003cp\u003eacetonitrile/water\u0026nbsp;\u003c/p\u003e\n \u003cp\u003eEthyl acetate/water\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 26.0105%;\"\u003e\n \u003cp\u003e52\u003c/p\u003e\n \u003cp\u003e9.8\u003c/p\u003e\n \u003cp\u003e149\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 13.884%;\"\u003e\n \u003cp\u003e[33]\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 21.2654%;\"\u003e\n \u003cp\u003eCsPbBr\u003csub\u003e3\u003c/sub\u003e\u003c/p\u003e\n \u003cp\u003eCsPbBr\u003csub\u003e3\u003c/sub\u003e/MXene\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 18.8049%;\"\u003e\n \u003cp\u003e300 W Xe-lamp\u003c/p\u003e\n \u003cp\u003e(\u0026gt;420 nm)\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 20.0351%;\"\u003e\n \u003cp\u003eEthyl acetate\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 26.0105%;\"\u003e\n \u003cp\u003e4.13\u003c/p\u003e\n \u003cp\u003e26.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 13.884%;\"\u003e\n \u003cp\u003e[61]\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 21.2654%;\"\u003e\n \u003cp\u003eCsPbBr\u003csub\u003e3\u003c/sub\u003e NCs\u0026nbsp;\u003c/p\u003e\n \u003cp\u003eCsPbBr\u003csub\u003e3\u003c/sub\u003e NCs/GO\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 18.8049%;\"\u003e\n \u003cp\u003e100 W Xe lamp\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 20.0351%;\"\u003e\n \u003cp\u003eEthyl acetate\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 26.0105%;\"\u003e\n \u003cp\u003e4.12\u003c/p\u003e\n \u003cp\u003e4.89\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 13.884%;\"\u003e\n \u003cp\u003e[62]\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 21.2654%;\"\u003e\n \u003cp\u003eCPB-CN\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 18.8049%;\"\u003e\n \u003cp\u003e300 W Xe-lamp\u003c/p\u003e\n \u003cp\u003e(\u0026gt;420 nm)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 20.0351%;\"\u003e\n \u003cp\u003eCO\u003csub\u003e2\u003c/sub\u003e and water vapor\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 26.0105%;\"\u003e\n \u003cp\u003e11.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 13.884%;\"\u003e\n \u003cp\u003e[63]\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 21.2654%;\"\u003e\n \u003cp\u003eg‑C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e\u003c/p\u003e\n \u003cp\u003eCsPbBr\u003csub\u003e3\u003c/sub\u003e\u003c/p\u003e\n \u003cp\u003eg‑C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e/Nb\u003csub\u003e2\u003c/sub\u003eC MXene/CsPbBr\u003csub\u003e3\u003c/sub\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 18.8049%;\"\u003e\n \u003cp\u003e300 W Xe-lamp\u003c/p\u003e\n \u003cp\u003e(\u0026gt;420 nm)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 20.0351%;\"\u003e\n \u003cp\u003eCO\u003csub\u003e2\u003c/sub\u003e and water vapor\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 26.0105%;\"\u003e\n \u003cp\u003e6.27\u003c/p\u003e\n \u003cp\u003e5.30\u003c/p\u003e\n \u003cp\u003e53.07\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 13.884%;\"\u003e\n \u003cp\u003ethis work\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003eFrom a thermodynamic perspective, the reduction potential for converting CO\u003csub\u003e2\u003c/sub\u003e to CO and CH\u003csub\u003e4\u003c/sub\u003e (-0.53V and -0.24V) [64]. We have provided a diagram illustrating all possible pathways for CO\u003csub\u003e2\u003c/sub\u003e reduction to C1 products (Fig S12) The formation of CO is believed to proceed through a single elementary step, in which our ternary heterojunction provides the necessary photocatalytic energy for CO generation. On the other hand, the formation of CH\u003csub\u003e4\u003c/sub\u003e is thought to occur through a series of elementary steps involving the transfer of one or two electrons, with CO serving as an intermediate. It is important to note that when the reduction potential of the electrons system is low, the kinetic reaction rate of elementary elements decreases. Consequently, the subsequent catalytic reaction steps after CO formation may not proceed rapidly enough before CO desorbs from the surface of the photocatalyst. This leass to CO being the main product, with CH\u003csub\u003e4\u003c/sub\u003e being the secondary product.\u003c/p\u003e\n\u003cp\u003eAfter stability testing for eight hours, the loss in activity is only 7.1% (Fig 5d), indicating the good stability of our ternary heterojunction photocatalyst. The XRD patterns and FTIR spectra of CsPbBr\u003csub\u003e3\u003c/sub\u003e and CCM30 before and after the stability test were shown in Fig S17. It is evident that CsPbBr\u003csub\u003e3\u003c/sub\u003e undergoes noticeable crystal changes[65], transitioning from the all-orthorhombic structure to an elongated polyhedron[66, 67]. However, even after nearly 24 hours of catalytic activity, the CO production yield relatively stable. Similar structural changes can also be observed in CCM30 after the stability test, indicating that the transformation is primarily due to the change of CsPbBr\u003csub\u003e3\u003c/sub\u003e. These results suggest that the photocatalyst exhibits goodstability under the reaction conditions.\u003c/p\u003e\n\u003cp\u003eTo investigate the electronic and transport properties of the ternary heterojunction, we performed DFT calculations[68, 69]. The (110) surface orientation of three parent materials was chosen as the model to simulate the density of states (DOS) and charge density difference[70]. Since catalysis primarily occurs on the surface rather than in the inner layers, two different slabs of Nb\u003csub\u003e2\u003c/sub\u003eC MXene were used to construct the ternary heterojunction photocatalyst (Fig 6a). In the ternary heterojunction, the conduction band is mainly occupied by Nb and Cs, consisting empty d orbitals (Fig. S14), On the other hand, the valence band is composed of orbitals from N and Br elements. This confirms that Nb\u003csub\u003e2\u003c/sub\u003eC MXene can modify the energy band structure of ternary heterojunction. To maximizethe influence of the ternary composites on the electronic structure, Nb\u003csub\u003e2\u003c/sub\u003eC MXene is positioned in the middle layer. The total and partial DOS of the ternary heterostructures for (110) crystal faces is shown in Fig. S13a-f. Upon formation of the heterostructure, a shift in the band gap is observed near the Fermi level, indicating improved conductivity compared to the three individual parent components. This suggests that the ternary heterojunction exhibits enhanced electronic and transport properties, which can contribute to its improved photocatalytic performance.\u003c/p\u003e\n\u003cp\u003eTo gain further insights into the electronic properties at the interface between the CsPbBr\u003csub\u003e3\u003c/sub\u003e/Nb\u003csub\u003e2\u003c/sub\u003eC MXene and Nb\u003csub\u003e2\u003c/sub\u003eC MXene/g‑C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e, we performed calculations of the 3D charge density difference and the plane-averaged electrostatic potential drop across the interfaces of the three parent materials. As shown in Fig. 6b and c, the calculated results indicate a charge transfer from CsPbBr\u003csub\u003e3\u003c/sub\u003e to Nb\u003csub\u003e2\u003c/sub\u003eC MXene and subsequently from Nb\u003csub\u003e2\u003c/sub\u003eC MXene to g‑C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e, confirming an unbalanced charge distribution at the interfaces. For the ternary heterojunction interface, CsPbBr\u003csub\u003e3\u003c/sub\u003e/Nb\u003csub\u003e2\u003c/sub\u003eC MXene and Nb\u003csub\u003e2\u003c/sub\u003eC MXene/g‑C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e, higher electrostatic potential and potential difference of approximately 15.83 eV and 11.93 eV, and 16.21 eV and 11.88 eV, respectively, were observed. This potential drop corresponds to the internal electric field pointing from g‑C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e and CsPbBr\u003csub\u003e3\u003c/sub\u003e towards Nb\u003csub\u003e2\u003c/sub\u003eC MXene. Consequently, the internal electric field generated by the potential difference aligns with the direction of the ternary heterostructures. Due to this internal electric field, photogenerated electrons tend to drift from the surfaces of g-C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e, or CsPbBr\u003csub\u003e3\u003c/sub\u003e QDs towards the surface of Nb\u003csub\u003e2\u003c/sub\u003eC MXene, while photogenerated holes tend to drift in the opposite direction. This phenomenon facilitates the separation and transfer of photogenerated carrier, thereby promoting enhanced photocatalytic performance. We also compared the charge transfer and distribution ofthe binary interface g-C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e/CsPbBr\u003csub\u003e3\u003c/sub\u003e, g-C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e/ Nb\u003csub\u003e2\u003c/sub\u003eC MXene, and CsPbBr\u003csub\u003e3\u003c/sub\u003e/ Nb\u003csub\u003e2\u003c/sub\u003eC MXene shown in Fig. S14. The charge transfer from CsPbBr\u003csub\u003e3\u003c/sub\u003e to g‑C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e, g‑C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e to Nb\u003csub\u003e2\u003c/sub\u003eC MXene, and CsPbBr\u003csub\u003e3\u003c/sub\u003e to Nb\u003csub\u003e2\u003c/sub\u003eC MXene reveals some unbalanced charge distribution, although less pronounced compared to the ternary heterojunction. The 3D charge density difference and plane-averaged electrostatic potential exhibit lower values, namely 7.18 eV and 2.92 eV, 12.64 eV, and 14.69 eV, respectively. These values indicate a less significant change compared to the ternary heterojunction. The total DOS of the g-C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e/CsPbBr\u003csub\u003e3\u003c/sub\u003e binary heterojunction (Fig. S16) shows a relatively large band gap, reflecting the energy difference between the valence band and conduction band. This further supports the improved electronic properties and potential for efficient charge transfer and separation in the ternary heterojunction structure.\u003c/p\u003e"},{"header":"4. Conclusions","content":"\u003cp\u003eIn summary, we have successfully synthesized a g-C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e/Nb\u003csub\u003e2\u003c/sub\u003eC MXene/CsPbBr\u003csub\u003e3\u003c/sub\u003e ternary heterojunction through a wet-chemical method. By regulating the heterogeneous interface, we have achieved a significant improvement in the photocatalytic performance, with a CO yield rate of 53.07 μmol g\u003csup\u003e-1\u003c/sup\u003e h\u003csup\u003e-1\u003c/sup\u003e. This represents a substantial enhancement compared to single g-C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e, CsPbBr\u003csub\u003e3\u003c/sub\u003e, and binary structure. The simulation and theoretical calculations support the presence of an internal electrostatic field driven by Nb\u003csub\u003e2\u003c/sub\u003eC MXene, which promotes the transfer of \u0026nbsp;electrons. The lattice matching and enhanced \u0026nbsp;interaction among the three parent materials contribute to \u0026nbsp;the synergistic effect observed in \u0026nbsp;the ternary heterojunction, resulting in excellent photocatalytic activity for CO\u003csub\u003e2\u003c/sub\u003e reduction to CO. These findings \u0026nbsp;provide valuable guidance for the development of efficient ternary heterogeneous structures in various photocatalytic applications.\u0026nbsp;\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eCRediT authorship contribution statement\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eShiding Zhang:\u0026nbsp;\u003c/strong\u003eWriting main manuscript text, Data curation, Investigation. \u003cstrong\u003eYuhua Wang:\u003c/strong\u003e Idea, Conceptualization, Writing - review \u0026amp; editing, Supervision, Project administration. \u003cstrong\u003eYitong Wang:\u0026nbsp;\u003c/strong\u003eExperiment, Project administration.\u0026nbsp;\u003cstrong\u003eGaber A. M. Mersal:\u003c/strong\u003e Methodology\u003cstrong\u003e:\u003c/strong\u003e VASP calculation. \u003cstrong\u003eA. Alhadhrami,\u003c/strong\u003e \u003cstrong\u003eDalal A.\u003c/strong\u003e\u003cstrong\u003e\u0026nbsp;Alshammari\u003c/strong\u003e, and\u0026nbsp;Hassan Algadi\u003cstrong\u003e:\u003c/strong\u003e Experiment support.\u0026nbsp;\u003cstrong\u003eHaixiang Song\u003c/strong\u003e\u003cstrong\u003e：\u003c/strong\u003eWriting - review \u0026amp; editing.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eDeclaration of Competing Interest\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors report no declarations of interest.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis work was supported by the National Natural Science Foundation of China (Grant Nos. 11375136, 11804005, 12204014) , the Science and Technology Planning Project of Henan Province (No.232102241016), Anyang Institute of Technology University-level Scientific Research Cultivation Fund (YPY2021016). Numerical calculation is supported by High-Performance Computing Center of Wuhan University of Science and Technology. Anyang Institute of Technology energy power a new round university-level key discipline funding. The authors extend their appreciation to Taif University, Saudi Arabia for supporting this work through project number (TU-DSPP-2024-21).\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eJ. Gong, C. Li, M.R. Wasielewski, Advances in solar energy conversion, Chem Soc Rev, 48 (2019) 1862-1864.\u003c/li\u003e\n\u003cli\u003eY. Guo, Q. Zhou, J. Nan, W. Shi, F. Cui, Y. Zhu, Perylenetetracarboxylic acid nanosheets with internal electric fields and anisotropic charge migration for photocatalytic hydrogen evolution, Nat Commun, 13 (2022) 2067.\u003c/li\u003e\n\u003cli\u003eX. Zhang, J. Xiao, M. Hou, Y. Xiang, H. Chen, Robust visible/near-infrared light driven hydrogen generation over Z-scheme conjugated polymer/CdS hybrid, Applied Catalysis B: Environmental, 224 (2018) 871-876.\u003c/li\u003e\n\u003cli\u003eN. Elgrishi, M.B. Chambers, X. Wang, M. Fontecave, Molecular polypyridine-based metal complexes as catalysts for the reduction of CO\u003csub\u003e2\u003c/sub\u003e, Chem Soc Rev, 46 (2017) 761-796.\u003c/li\u003e\n\u003cli\u003eS. Adabala, D.P. Dutta, A review on recent advances in metal chalcogenide-based photocatalysts for CO\u003csub\u003e2\u003c/sub\u003e reduction, Journal of Environmental Chemical Engineering, 10 (2022).\u003c/li\u003e\n\u003cli\u003eN.W. Kinzel, C. Werle, W. Leitner, Transition Metal Complexes as Catalysts for the Electroconversion of CO\u003csub\u003e2\u003c/sub\u003e : An Organometallic Perspective, Angew Chem Int Ed Engl, 60 (2021) 11628-11686.\u003c/li\u003e\n\u003cli\u003eH. Shang, S.K. Wallentine, D.M. Hofmann, Q. Zhu, C.J. Murphy, L.R. Baker, Effect of surface ligands on gold nanocatalysts for CO\u003csub\u003e2\u003c/sub\u003e reduction, Chem Sci, 11 (2020) 12298-12306.\u003c/li\u003e\n\u003cli\u003eQ. Zhu, C.J. Murphy, L.R. Baker, Opportunities for Electrocatalytic CO\u003csub\u003e2\u003c/sub\u003e Reduction Enabled by Surface Ligands, J Am Chem Soc, 144 (2022) 2829-2840.\u003c/li\u003e\n\u003cli\u003eM. Naguib, V.N. Mochalin, M.W. Barsoum, Y. Gogotsi, 25th anniversary article: MXenes: a new family of two-dimensional materials, Adv Mater, 26 (2014) 992-1005.\u003c/li\u003e\n\u003cli\u003eB. Fu, J. Sun, C. Wang, C. Shang, L. Xu, J. Li, H. Zhang, MXenes: MXenes: Synthesis, Optical Properties, and Applications in Ultrafast Photonics (Small 11/2021), Small, 17 (2021) 2170048.\u003c/li\u003e\n\u003cli\u003eB. Shao, Z. Liu, G. Zeng, H. Wang, Q. Liang, Q. He, M. Cheng, C. Zhou, L. Jiang, B. Song, Two-dimensional transition metal carbide and nitride (MXene) derived quantum dots (QDs): synthesis, properties, applications and prospects, Journal of Materials Chemistry A, 8 (2020) 7508-7535.\u003c/li\u003e\n\u003cli\u003eZ. Wu, C. Li, Z. Li, K. Feng, M. Cai, D. Zhang, S. Wang, M. Chu, C. Zhang, J. Shen, Z. Huang, Y. Xiao, G.A. Ozin, X. Zhang, L. He, Niobium and Titanium Carbides (MXenes) as Superior Photothermal Supports for CO\u003csub\u003e2\u003c/sub\u003e Photocatalysis, ACS Nano, 15 (2021) 5696-5705.\u003c/li\u003e\n\u003cli\u003eM.D. Burkart, N. Hazari, C.L. Tway, E.L. Zeitler, Opportunities and Challenges for Catalysis in Carbon Dioxide Utilization, ACS Catalysis, 9 (2019) 7937-7956.\u003c/li\u003e\n\u003cli\u003eJ. Gu, S. Liu, W. Ni, W. Ren, S. Haussener, X. Hu, Modulating electric field distribution by alkali cations for CO\u003csub\u003e2\u003c/sub\u003e electroreduction in strongly acidic medium, Nature Catalysis, 5 (2022) 268-276.\u003c/li\u003e\n\u003cli\u003eG.Q. Liu, Y. Yang, Y. Li, T. Zhuang, X.F. Li, J. Wicks, J. Tian, M.R. Gao, J.L. Peng, H.X. Ju, L. Wu, Y.X. Pan, L.A. Shi, H. Zhu, J. Zhu, S.H. Yu, E.H. Sargent, Boosting photoelectrochemical efficiency by near-infrared-active lattice-matched morphological heterojunctions, Nat Commun, 12 (2021) 4296.\u003c/li\u003e\n\u003cli\u003eZ. Ai, K. Zhang, B. Chang, Y. Shao, L. Zhang, Y. Wu, X. Hao, Construction of CdS@Ti\u003csub\u003e3\u003c/sub\u003eC\u003csub\u003e2\u003c/sub\u003e@CoO hierarchical tandem p-n heterojunction for boosting photocatalytic hydrogen production in pure water, Chemical Engineering Journal, 383 (2020).\u003c/li\u003e\n\u003cli\u003eZ.-F. Huang, J. Song, X. Wang, L. Pan, K. Li, X. Zhang, L. Wang, J.-J. Zou, Switching charge transfer of C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e/W\u003csub\u003e18\u003c/sub\u003eO\u003csub\u003e49\u003c/sub\u003e from type-II to Z-scheme by interfacial band bending for highly efficient photocatalytic hydrogen evolution, Nano Energy, 40 (2017) 308-316.\u003c/li\u003e\n\u003cli\u003eK.T. Wong, S.C. Kim, K. Yun, C.E. Choong, I.W. Nah, B.-H. Jeon, Y. Yoon, M. Jang, Understanding the potential band position and e\u003csup\u003e\u0026ndash;\u003c/sup\u003e/h\u003csup\u003e+ \u003c/sup\u003eseparation lifetime for Z-scheme and type-II heterojunction mechanisms for effective micropollutant mineralization: Comparative experimental and DFT studies, Applied Catalysis B: Environmental, 273 (2020).\u003c/li\u003e\n\u003cli\u003eD. Xiong, Y. Shi, H.Y. Yang, Rational design of MXene-based films for energy storage: Progress, prospects, Materials Today, 46 (2021) 183-211.\u003c/li\u003e\n\u003cli\u003eA. Swarnkar, R. Chulliyil, V.K. Ravi, M. Irfanullah, A. Chowdhury, A. Nag, Colloidal CsPbBr\u003csub\u003e3 \u003c/sub\u003ePerovskite Nanocrystals: Luminescence beyond Traditional Quantum Dots, Angew Chem Int Ed Engl, 54 (2015) 15424-15428.\u003c/li\u003e\n\u003cli\u003eX. Yu, Z. Liu, X. Yang, Y. Wang, J. Zhang, J. Duan, L. Liu, Q. Tang, Crystal-Plane Controlled Spontaneous Polarization of Inorganic Perovskite toward Boosting Triboelectric Surface Charge Density, ACS Applied Materials \u0026amp; Interfaces, 13 (2021) 26196-26203.\u003c/li\u003e\n\u003cli\u003eY.-x. Zhang, Y.-h. Wang, Nonlinear optical properties of metal nanoparticles: a review, RSC Advances, 7 (2017) 45129-45144.\u003c/li\u003e\n\u003cli\u003eJ.T. Mulder, I. du Fosse, M. Alimoradi Jazi, L. Manna, A.J. Houtepen, Electrochemical p-Doping of CsPbBr\u003csub\u003e3\u003c/sub\u003e Perovskite Nanocrystals, ACS Energy Lett, 6 (2021) 2519-2525.\u003c/li\u003e\n\u003cli\u003eJ. Li, Y. Wang, X. Li, Q. Gao, S. Zhang, A facile synthesis of high-crystalline g-C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e nanosheets with closed self-assembly strategy for enhanced photocatalytic H\u003csub\u003e2 \u003c/sub\u003eevolution, Journal of Alloys and Compounds, 881 (2021).\u003c/li\u003e\n\u003cli\u003eR. Cheng, L. Zhang, X. Fan, M. Wang, M. Li, J. Shi, One-step construction of FeOx modified g-C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e for largely enhanced visible-light photocatalytic hydrogen evolution, Carbon, 101 (2016) 62-70.\u003c/li\u003e\n\u003cli\u003eJ. Liu, T. Zhang, Z. Wang, G. Dawson, W. Chen, Simple pyrolysis of urea into graphitic carbon nitride with recyclable adsorption and photocatalytic activity, Journal of Materials Chemistry, 21 (2011).\u003c/li\u003e\n\u003cli\u003eW. Ma, N. Wang, Y. Guo, L. Yang, M. Lv, X. Tang, S. Li, Enhanced photoreduction CO\u003csub\u003e2\u003c/sub\u003e activity on g-C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e: By synergistic effect of nitrogen defective-enriched and porous structure, and mechanism insights, Chemical Engineering Journal, 388 (2020).\u003c/li\u003e\n\u003cli\u003eG. Zhang, D. Huang, M. Cheng, L. Lei, S. Chen, R. Wang, W. Xue, Y. Liu, Y. Chen, Z. Li, Megamerger of MOFs and g-C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e for energy and environment applications: upgrading the framework stability and performance, Journal of Materials Chemistry A, 8 (2020) 17883-17906.\u003c/li\u003e\n\u003cli\u003eM. Majdoub, Z. Anfar, A. Amedlous, Emerging Chemical Functionalization of g-C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e: Covalent/Noncovalent Modifications and Applications, ACS Nano, 14 (2020) 12390-12469.\u003c/li\u003e\n\u003cli\u003eL.K. Putri, B.-J. Ng, C.-C. Er, W.-J. Ong, W.S. Chang, A.R. Mohamed, S.-P. Chai, Insights on the impact of doping levels in oxygen-doped gC\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e and its effects on photocatalytic activity, Applied Surface Science, 504 (2020).\u003c/li\u003e\n\u003cli\u003eL. Zhou, Y. Tian, J. Lei, L. Wang, Y. Liu, J. Zhang, Self-modification of g-C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e with its quantum dots for enhanced photocatalytic activity, Catalysis Science \u0026amp; Technology, 8 (2018) 2617-2623.\u003c/li\u003e\n\u003cli\u003eR. Cheng, H. Jin, M.B.J. Roeffaers, J. Hofkens, E. Debroye, Incorporation of Cesium Lead Halide Perovskites into g-C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e for Photocatalytic CO\u003csub\u003e2\u003c/sub\u003e Reduction, ACS Omega, 5 (2020) 24495-24503.\u003c/li\u003e\n\u003cli\u003eM. Ou, W. Tu, S. Yin, W. Xing, S. Wu, H. Wang, S. Wan, Q. Zhong, R. Xu, Amino-Assisted Anchoring of CsPbBr\u003csub\u003e3\u003c/sub\u003e Perovskite Quantum Dots on Porous g-C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e for Enhanced Photocatalytic CO\u003csub\u003e2\u003c/sub\u003e Reduction, Angew Chem Int Ed Engl, 57 (2018) 13570-13574.\u003c/li\u003e\n\u003cli\u003eY. Jiao, H. Jiang, F. Chen, RuO\u003csub\u003e2\u003c/sub\u003e/TiO\u003csub\u003e2\u003c/sub\u003e/Pt Ternary Photocatalysts with Epitaxial Heterojunction and Their Application in CO Oxidation, ACS Catalysis, 4 (2014) 2249-2257.\u003c/li\u003e\n\u003cli\u003eZ. Tang, W. He, Y. Wang, Y. Wei, X. Yu, J. Xiong, X. Wang, X. Zhang, Z. Zhao, J. Liu, Ternary heterojunction in rGO-coated Ag/Cu\u003csub\u003e2\u003c/sub\u003eO catalysts for boosting selective photocatalytic CO\u003csub\u003e2\u003c/sub\u003e reduction into CH\u003csub\u003e4\u003c/sub\u003e, Applied Catalysis B: Environmental, 311 (2022).\u003c/li\u003e\n\u003cli\u003eP. Chang, Y. Wang, Y. Wang, Y. Zhu, Current trends on In\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e3 \u003c/sub\u003ebased heterojunction photocatalytic systems in photocatalytic application, Chemical Engineering Journal, 450 (2022).\u003c/li\u003e\n\u003cli\u003eJ. Li, Y. Wang, H. Song, Y. Guo, S. Hu, H. Zheng, S. Zhang, X. Li, Q. Gao, C. Li, Z. Zhu, Y. Wang, Photocatalytic hydrogen under visible light by nitrogen-doped rutile titania graphitic carbon nitride composites: an experimental and theoretical study, Advanced Composites and Hybrid Materials, 6 (2023).\u003c/li\u003e\n\u003cli\u003eW. Wang, Z. Wang, R. Yang, J. Duan, Y. Liu, A. Nie, H. Li, B.Y. Xia, T. Zhai, In Situ Phase Separation into Coupled Interfaces for Promoting CO\u003csub\u003e2\u003c/sub\u003e Electroreduction to Formate over a Wide Potential Window, Angew Chem Int Ed Engl, 60 (2021) 22940-22947.\u003c/li\u003e\n\u003cli\u003eM.L.A. Kumari, L.G. Devi, G. Maia, T.W. Chen, N. Al-Zaqri, M.A. Ali, Mechanochemical synthesis of ternary heterojunctions TiO\u003csub\u003e2\u003c/sub\u003e(A)/TiO\u003csub\u003e2\u003c/sub\u003e(R)/ZnO and TiO\u003csub\u003e2\u003c/sub\u003e(A)/TiO\u003csub\u003e2\u003c/sub\u003e(R)/SnO\u003csub\u003e2\u003c/sub\u003e for effective charge separation in semiconductor photocatalysis: A comparative study, Environ Res, 203 (2022) 111841.\u003c/li\u003e\n\u003cli\u003eS. Wei, J. Ma, D. Wu, B. Chen, C. Du, L. Liang, Y. Huang, Z. Li, F. Rao, G. Chen, Z. Liu, Constructing Flexible Film Electrode with Porous Layered Structure by MXene/SWCNTs/PANI Ternary Composite for Efficient Low‐Grade Thermal Energy Harvest, Advanced Functional Materials, 33 (2023).\u003c/li\u003e\n\u003cli\u003eT. Xu, Y. Wang, Y. Xue, J. Li, Y. Wang, MXenes@metal-organic framework hybrids for energy storage and electrocatalytic application: Insights into recent advances, Chemical Engineering Journal, 470 (2023).\u003c/li\u003e\n\u003cli\u003eT. Xu, Y. Wang, Z. Xiong, Y. Wang, Y. Zhou, X. Li, A Rising 2D Star: Novel MBenes with Excellent Performance in Energy Conversion and Storage, Nanomicro Lett, 15 (2022) 6.\u003c/li\u003e\n\u003cli\u003eY. Wang, Y. Wang, MXene ink printing of high‐performance micro‐supercapacitors, Carbon Neutralization, (2024).\u003c/li\u003e\n\u003cli\u003eZ. Otgonbayar, C.-M. Yoon, W.-C. Oh, Photoelectrocatalytic CO\u003csub\u003e2\u003c/sub\u003e reduction with ternary nanocomposite of MXene (Ti\u003csub\u003e3\u003c/sub\u003eC\u003csub\u003e2\u003c/sub\u003e)-Cu\u003csub\u003e2\u003c/sub\u003eO-Fe\u003csub\u003e3\u003c/sub\u003eO\u003csub\u003e4\u003c/sub\u003e: Comprehensive utilization of electrolyte and light-wavelength, Chemical Engineering Journal, 464 (2023).\u003c/li\u003e\n\u003cli\u003eJ. Li, Y. Wang, Y. Wang, Y. Guo, S. Zhang, H. Song, X. Li, Q. Gao, W. Shang, S. Hu, H. Zheng, X. Li, MXene Ti\u003csub\u003e3\u003c/sub\u003eC\u003csub\u003e2\u003c/sub\u003e decorated g-C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e/ZnO photocatalysts with improved photocatalytic performance for CO\u003csub\u003e2\u003c/sub\u003e reduction, Nano Materials Science, 5 (2023) 237-245.\u003c/li\u003e\n\u003cli\u003eJ. Fu, J. Yu, C. Jiang, B. Cheng, g-C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e-Based Heterostructured Photocatalysts, Advanced Energy Materials, 8 (2018).\u003c/li\u003e\n\u003cli\u003eY. Wang, Y. Wang, Recent progress in MXene layers materials for supercapacitors: High‐performance electrodes, SmartMat, 4 (2022).\u003c/li\u003e\n\u003cli\u003eY. Wei, K. Li, Z. Cheng, M. Liu, H. Xiao, P. Dang, S. Liang, Z. Wu, H. Lian, J. Lin, Epitaxial Growth of CsPbX\u003csub\u003e3 \u003c/sub\u003e(X = Cl, Br, I) Perovskite Quantum Dots via Surface Chemical Conversion of Cs\u003csub\u003e2\u003c/sub\u003eGeF\u003csub\u003e6\u003c/sub\u003e Double Perovskites: A Novel Strategy for the Formation of Leadless Hybrid Perovskite Phosphors with Enhanced Stability, Adv Mater, 31 (2019) e1807592.\u003c/li\u003e\n\u003cli\u003eS. Zhang, F. Ma, J. Jiang, Z. Wang, R.T.K. Kwok, Z. Qiu, Z. Zhao, J.W.Y. Lam, B.Z. Tang, Aggregative Luminescence from CsPbBr\u003csub\u003e3\u003c/sub\u003e Perovskite Precursors, Angew Chem Int Ed Engl, 63 (2024) e202408586.\u003c/li\u003e\n\u003cli\u003eM. Naguib, J. Halim, J. Lu, K.M. Cook, L. Hultman, Y. Gogotsi, M.W. Barsoum, New two-dimensional niobium and vanadium carbides as promising materials for Li-ion batteries, J Am Chem Soc, 135 (2013) 15966-15969.\u003c/li\u003e\n\u003cli\u003eC. Yin, L. Cui, T. Pu, X. Fang, H. Shi, S. Kang, X. Zhang, Facile fabrication of nano-sized hollow-CdS@g-C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e Core-shell spheres for efficient visible-light-driven hydrogen evolution, Applied Surface Science, 456 (2018) 464-472.\u003c/li\u003e\n\u003cli\u003eX. She, J. Wu, H. Xu, J. Zhong, Y. Wang, Y. Song, K. Nie, Y. Liu, Y. Yang, M.-T.F. Rodrigues, R. Vajtai, J. Lou, D. Du, H. Li, P.M. Ajayan, High Efficiency Photocatalytic Water Splitting Using 2D \u0026alpha;-Fe\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e3\u003c/sub\u003e/g-C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e Z-Scheme Catalysts, Advanced Energy Materials, 7 (2017).\u003c/li\u003e\n\u003cli\u003eT. Xuan, X. Yang, S. Lou, J. Huang, Y. Liu, J. Yu, H. Li, K.L. Wong, C. Wang, J. Wang, Highly stable CsPbBr\u003csub\u003e3\u003c/sub\u003e quantum dots coated with alkyl phosphate for white light-emitting diodes, Nanoscale, 9 (2017) 15286-15290.\u003c/li\u003e\n\u003cli\u003eC. Cui, R. Guo, E. Ren, H. Xiao, M. Zhou, X. Lai, Q. Qin, S. Jiang, W. Qin, MXene-based rGO/Nb\u003csub\u003e2\u003c/sub\u003eCTx/Fe\u003csub\u003e3\u003c/sub\u003eO\u003csub\u003e4\u003c/sub\u003e composite for high absorption of electromagnetic wave, Chemical Engineering Journal, 405 (2021).\u003c/li\u003e\n\u003cli\u003eY.-J. Dong, Y. Jiang, J.-F. Liao, H.-Y. Chen, D.-B. Kuang, C.-Y. Su, Construction of a ternary WO\u003csub\u003e3\u003c/sub\u003e/CsPbBr\u003csub\u003e3\u003c/sub\u003e/ZIF-67 heterostructure for enhanced photocatalytic carbon dioxide reduction, Science China Materials, 65 (2022) 1550-1559.\u003c/li\u003e\n\u003cli\u003eR. Bhosale, S. Jain, C.P. Vinod, S. Kumar, S. Ogale, Direct Z-Scheme g-C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e/FeWO\u003csub\u003e4\u003c/sub\u003e Nanocomposite for Enhanced and Selective Photocatalytic CO\u003csub\u003e2\u003c/sub\u003e Reduction under Visible Light, ACS Appl Mater Interfaces, 11 (2019) 6174-6183.\u003c/li\u003e\n\u003cli\u003eS. Hussain, Y. Wang, L. Guo, T. He, Theoretical insights into the mechanism of photocatalytic reduction of CO\u003csub\u003e2\u003c/sub\u003e over semiconductor catalysts, Journal of Photochemistry and Photobiology C: Photochemistry Reviews, 52 (2022).\u003c/li\u003e\n\u003cli\u003eL. Collado, A. Reynal, F. Fresno, M. Barawi, C. Escudero, V. Perez-Dieste, J.M. Coronado, D.P. Serrano, J.R. Durrant, V.A. de la Pena O\u0026apos;Shea, Unravelling the effect of charge dynamics at the plasmonic metal/semiconductor interface for CO\u003csub\u003e2\u003c/sub\u003e photoreduction, Nat Commun, 9 (2018) 4986.\u003c/li\u003e\n\u003cli\u003eP. Li, T. He, Common-cation based Z-scheme ZnS@ZnO core-shell nanostructure for efficient solar-fuel production, Applied Catalysis B: Environmental, 238 (2018) 518-524.\u003c/li\u003e\n\u003cli\u003eH. Li, Z. Li, S. Liu, M. Li, X. Wen, J. Lee, S. Lin, M.-Y. Li, H. Lu, High performance hybrid MXene nanosheet/CsPbBr\u003csub\u003e3\u003c/sub\u003e quantum dot photodetectors with an excellent stability, Journal of Alloys and Compounds, 895 (2022).\u003c/li\u003e\n\u003cli\u003eA. Pan, X. Ma, S. Huang, Y. Wu, M. Jia, Y. Shi, Y. Liu, P. Wangyang, L. He, Y. Liu, CsPbBr\u003csub\u003e3\u003c/sub\u003e Perovskite Nanocrystal Grown on MXene Nanosheets for Enhanced Photoelectric Detection and Photocatalytic CO\u003csub\u003e2\u003c/sub\u003e Reduction, J Phys Chem Lett, 10 (2019) 6590-6597.\u003c/li\u003e\n\u003cli\u003eY.F. Xu, M.Z. Yang, B.X. Chen, X.D. Wang, H.Y. Chen, D.B. Kuang, C.Y. Su, A CsPbBr(3) Perovskite Quantum Dot/Graphene Oxide Composite for Photocatalytic CO(2) Reduction, J Am Chem Soc, 139 (2017) 5660-5663.\u003c/li\u003e\n\u003cli\u003eQ. Chen, X. Lan, Y. Ma, P. Lu, Z. Yuan, J. Shi, Boosting CsPbBr\u003csub\u003e3\u003c/sub\u003e‐Driven Superior and Long‐Term Photocatalytic CO\u003csub\u003e2\u003c/sub\u003e Reduction under Pure Water Medium: Synergy Effects of Multifunctional Melamine Foam and Graphitic Carbon Nitride (g‐C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e), Solar RRL, 5 (2021).\u003c/li\u003e\n\u003cli\u003eS.N. Habisreutinger, L. Schmidt-Mende, J.K. Stolarczyk, Photocatalytic reduction of CO\u003csub\u003e2 \u003c/sub\u003eon TiO\u003csub\u003e2\u003c/sub\u003e and other semiconductors, Angew Chem Int Ed Engl, 52 (2013) 7372-7408.\u003c/li\u003e\n\u003cli\u003eZ.-C. Kong, J.-F. Liao, Y.-J. Dong, Y.-F. Xu, H.-Y. Chen, D.-B. Kuang, C.-Y. Su, Core@Shell CsPbBr\u003csub\u003e3\u003c/sub\u003e@Zeolitic Imidazolate Framework Nanocomposite for Efficient Photocatalytic CO\u003csub\u003e2 \u003c/sub\u003eReduction, ACS Energy Letters, 3 (2018) 2656-2662.\u003c/li\u003e\n\u003cli\u003eI. Dursun, M. De Bastiani, B. Turedi, B. Alamer, A. Shkurenko, J. Yin, A.M. El-Zohry, I. Gereige, A. AlSaggaf, O.F. Mohammed, M. Eddaoudi, O.M. Bakr, CsPb\u003csub\u003e2\u003c/sub\u003eBr\u003csub\u003e5\u003c/sub\u003e Single Crystals: Synthesis and Characterization, ChemSusChem, 10 (2017) 3746-3749.\u003c/li\u003e\n\u003cli\u003eG. Li, H. Wang, Z. Zhu, Y. Chang, T. Zhang, Z. Song, Y. Jiang, Shape and phase evolution from CsPbBr\u003csub\u003e3\u003c/sub\u003e perovskite nanocubes to tetragonal CsPb\u003csub\u003e2\u003c/sub\u003eBr\u003csub\u003e5\u003c/sub\u003e nanosheets with an indirect bandgap, Chem Commun (Camb), 52 (2016) 11296-11299.\u003c/li\u003e\n\u003cli\u003eS. Wang, Q. Luo, W.H. Fang, R. Long, Interfacial Engineering Determines Band Alignment and Steers Charge Separation and Recombination at an Inorganic Perovskite Quantum Dot/WS\u003csub\u003e2\u003c/sub\u003e Junction: A Time Domain Ab Initio Study, J Phys Chem Lett, 10 (2019) 1234-1241.\u003c/li\u003e\n\u003cli\u003eD.N. Nguyen, T.K.C. Phu, J. Kim, W.T. Hong, J.S. Kim, S.H. Roh, H.S. Park, C.H. Chung, W.S. Choe, H. Shin, J.Y. Lee, J.K. Kim, Interfacial Strain-Modulated Nanospherical Ni\u003csub\u003e2\u003c/sub\u003eP by Heteronuclei-Mediated Growth on Ti\u003csub\u003e3 \u003c/sub\u003eC\u003csub\u003e2\u003c/sub\u003e T\u003csub\u003ex\u003c/sub\u003e MXene for Efficient Hydrogen Evolution, Small, 18 (2022) e2204797.\u003c/li\u003e\n\u003cli\u003eY.W. Z. Zhou, L. Li, L. Yang, Y. Niu, Y. Yu, Y. Guo and S. wu, Constructing a full-space internal electric field in hematite photoanode to facilitate photogenerated-carrier separation and transfer, Journal of Materials Chemistry A, (2022).\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":true,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"advanced-composites-and-hybrid-materials","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"achm","sideBox":"Learn more about [Advanced Composites and Hybrid Materials](https://link.springer.com/journal/42114)","snPcode":"42114","submissionUrl":"https://submission.nature.com/new-submission/42114/3","title":"Advanced Composites and Hybrid Materials","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"Photocatalytic, CO2 reduction, Ternary heterojunction, MXene synergism, g-C3N4/Nb2C MXene/CsPbBr3","lastPublishedDoi":"10.21203/rs.3.rs-5012551/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-5012551/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eSlow charge kinetics and high activation energy seriously hinder the efficiency of photocatalytic CO\u003csub\u003e2\u003c/sub\u003e.Synergies are a commonly used strategy, \u0026nbsp;Nevertheless common synergies have been limited to improving catalytic results.Here, we synthesize a novel nanocomposite ternary heterojunction material, which forms a low interlayer electrostatic potential within the heterojunction through the MXene synergistic.A strong internal electric field from the outside to the inside is formed within the series layer heterojunction, which provides the inner driving force for the effective spatial separation of photoinduced electron-hole pairs. Under visible-light irradiation, the ternary heterojunction exhibited a maximum CO production rate of 53.07 μmol g\u003csup\u003e-1\u003c/sup\u003e h\u003csup\u003e-1\u003c/sup\u003e, surpassing the rates of pure g-C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e, CsPbBr\u003csub\u003e3\u003c/sub\u003e QDs, and the binary composite of g-C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e/CsPbBr\u003csub\u003e3\u003c/sub\u003e by approximately 8.4, 10, and 2 times, respectively. Experimental results and theoretical analysis reveal the significance of 2D Nb2C MXene as an electron transporter, benefiting from lower electrostatic potential. This characteristic synergistically facilitated the rapid extraction of photoinduced electrons, enhancing the reduction ability of CO\u003csub\u003e2\u003c/sub\u003e to CO. This research not only provides a novel insight into MXene utilization for designing ternary heterojunction nanocomposite photocatalysts but also presents the potential of utilizing synergism ternary composites to improve solar energy conversion efficiency.\u003c/p\u003e","manuscriptTitle":"Enhanced Photocatalytic CO2 Reduction via MXene synergism: Constructing a Strong Intra-layer Electric Field Ternary Heterojunction of g-C3N4/Nb2C MXene/CsPbBr3","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-10-08 10:04:15","doi":"10.21203/rs.3.rs-5012551/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2024-09-16T20:26:40+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2024-09-14T17:06:18+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"316410062168950537150261292066698742293","date":"2024-09-13T18:00:24+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2024-09-11T15:13:28+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"170608563252523579264675597488724910112","date":"2024-09-09T14:29:21+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"142498761807181123103472667764246778578","date":"2024-09-09T01:15:46+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"301650072313902310590244534506897096096","date":"2024-09-09T01:04:50+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"197348854043333500607892551916376037198","date":"2024-09-09T00:31:12+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"261102228498075526376568910341942685245","date":"2024-09-08T17:08:04+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2024-09-08T14:29:18+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2024-09-08T14:01:53+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2024-09-05T13:55:11+00:00","index":"","fulltext":""},{"type":"submitted","content":"Advanced Composites and Hybrid Materials","date":"2024-09-01T10:56:59+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"advanced-composites-and-hybrid-materials","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"achm","sideBox":"Learn more about [Advanced Composites and Hybrid Materials](https://link.springer.com/journal/42114)","snPcode":"42114","submissionUrl":"https://submission.nature.com/new-submission/42114/3","title":"Advanced Composites and Hybrid Materials","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"bdb0bd71-0c09-47fc-9921-04346177d5e1","owner":[],"postedDate":"October 8th, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2024-11-11T16:03:40+00:00","versionOfRecord":{"articleIdentity":"rs-5012551","link":"https://doi.org/10.1007/s42114-024-01026-x","journal":{"identity":"advanced-composites-and-hybrid-materials","isVorOnly":false,"title":"Advanced Composites and Hybrid Materials"},"publishedOn":"2024-11-06 15:58:14","publishedOnDateReadable":"November 6th, 2024"},"versionCreatedAt":"2024-10-08 10:04:15","video":"","vorDoi":"10.1007/s42114-024-01026-x","vorDoiUrl":"https://doi.org/10.1007/s42114-024-01026-x","workflowStages":[]},"version":"v1","identity":"rs-5012551","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-5012551","identity":"rs-5012551","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}