Light-induced borazine/triazine-containing conjugated polymers spatial twist boosting high-performance photo-assisted Li-CO2 batteries

Light-induced borazine/triazine-containing conjugated polymers spatial twist boosting high-performance photo-assisted Li-CO2 batteries | 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 Article Light-induced borazine/triazine-containing conjugated polymers spatial twist boosting high-performance photo-assisted Li-CO2 batteries Zong-Huai Liu, Ling Li, Dihua Tian, Fuquan Ma, Xiyue Peng, Xuexia He, and 9 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7907271/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted You are reading this latest preprint version Abstract Photoelectrode materials are essential in facilitating the kinetics of CO 2 redox reaction in photo-assisted Li-CO 2 batteries. However, conventional rigid photoelectrodes suffer from limited in-plane charge carrier separation and transport, leading to poor photoelectric conversion and storage efficiency. Herein, we report a borazine/triazine-containing conjugated polymer (BTCP) with flexible conformational isomerism. Under light exposure, cooperative rotation of the bonds involving B-N, C-B, and C-N induce molecular twisting that redistributes electron cloud and enhances polarized electric field, thereby promoting efficient charge separation and migration, while also enhancing CO 2 adsorption and lowering the Li 2 CO 3 compositional energy barrier. Consequently, the BTCP photoelectrode delivers an ultra-low voltage gap of 0.1 V at 100 µA cm − 2 , a round-trip efficiency of 96% and outstanding cycling stability for 27 days. This work highlights a novel strategy of exploiting light-induced molecular torsion to boost photocatalytic activity, offering new insights into the design of high-performance photoelectrodes for light-driven energy storage systems. Physical sciences/Energy science and technology/Energy storage/Batteries Physical sciences/Materials science/Materials for energy and catalysis/Photocatalysis Photo-assisted batteries spatial twist borazine/triazine-containing conjugated polymer Li-CO2 battery photocatalytic kinetics of CO2RR and CO2ER Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Introduction Lithium-carbon dioxide battery (Li-CO 2 ) has been considered as a unique solution for realizing sustainable energy storage and recycling CO 2 utilization 1 – 3 . This system enables CO 2 conversion in energy storage through the reversible reaction 4Li + 3CO 2 ⇌ 2Li 2 CO 3 + C, providing a superior theoretical energy density of 1876 Wh kg − 1 and an output potential of 2.8 V ( vs. Li + /Li) 4, 5 . However, the sluggish reaction kinetics of CO 2 reduction reactions (CO 2 RR) and CO 2 evolution reactions (CO 2 ER), along with incomplete dissociation of discharge products (Li 2 CO 3 ), resulted in high overpotentials with low round-trip efficiency, limited rate capability and poor reversibility 6 – 11 . To tackle these challenges, photo-assisted Li-CO 2 battery strategies have been proposed to incorporate semiconductor materials with appropriate band structures into the cathode for accelerating the kinetics of CO 2 RR and CO 2 ER by utilizing photoexcited high-energy electrons and holes 12 – 14 . Therefore, semiconductor material serving as photoelectrode is crucial to the performance of the Li-CO 2 battery. Extensive research has demonstrated that photoelectrode efficiency can be enhanced through various strategies, such as designing porous structures, optimizing defect energy levels, constructing heterojunctions, and applying external fields. For instance, Lan’s group recently prepared porous structures with rich porosity phthalocyanine based metal-organic frameworks (CoPc-Mn-O) 15 and metal-covalent organic frameworks (Cu 3 -BTDE-COF) 16 , achieving outstanding round-trip efficiencies of 99% at 0.01 mA cm − 2 and 95% at 200 mA g − 1 , respectively. A In 2 S 3 @CNT/SS 17 photoelectrode materials with hierarchical porous structure has been proposed in Xu’s group, achieving an impressive round-trip efficiency of 98% at 0.01 mA cm − 2 . Our group also prepared a boric acid coated boron (B@BA 2 ) 18 photoelectrode that achieved an overpotential as low as 0.07 V and a round-trip efficiency of 98% at 0.01 mA cm − 2 , with a low charging potential of 2.80 V by utilizing unique dissociation-exposure strategy to introduce defect-rich electron-deficient boron for efficient Li-CO 2 batteries. In addition, Peng’s group developed a heterostructure (CNT@C 3 N 4 ) 19 photoelectrode by leveraging the defect properties of C 3 N 4 and favorable interfacial charge transfer mechanisms, demonstrating a round-trip efficiency of 89% and excellent cycling stability with 86% after 100 cycles. They also designed a nano-Ag modified TiO 2 nanotubes (TNAs@AgNPs) 20 photoelectrode applied into the dual-field assisted Li-CO 2 battery, which reduced the overpotential to 0.37 V and achieved a round-trip efficiency of 87% at 0.1 mA cm − 2 . Nevertheless, conventional photoelectrode materials still suffer from the limited in-plane molecular carrier separation and transport capabilities based on the static molecular conformation, resulting in the confined polarization electric fields that hinder the improvement of photoelectric conversion and storage performance. Photoinduced molecular twisting harnesses light to drive molecular isomerization, thereby enabling precise modulation of optoelectronic and chemical properties. Upon photoexcitation, the separation of electrons and holes alters the molecular dipole moment, causing the molecular framework to undergo a reversible conformational twist to stabilize the excited state, primarily achieved through the rotation of intramolecular bonds 21 , 22 . Most commonly facilitated by single-bond rotations, as observed in the twisting of C = C, C = N, or N = N bonds in alkenes or aromatic organic molecules 23 – 25 . More recently, coupled photoisomerization involving multi-bond rotations has been demonstrated to be feasible as well. Studies by Jack Saltiel et al. 26 and Aaron Gerwien et al. 27 reported the discovery of simultaneous three-bond twist in conjugated hexane system and hula twist in hemithioindigo, respectively, confirming that C = C and adjacent C-C bonds can rotate simultaneously under light irradiation. Henry Dube et al. 28 introduced two asymmetric aryl substituents in hemithioindigo and presented both hula-twist and dual single-bond rotation photoactivated reactions, enabling the interconversion of eight different isomers under light conditions. Akira Katsuyama’s group 29 constructed a chalcogen-substituted benzamide system that achieves light-induced C-N/C-C concerted bond rotation by introducing a chalcogen substituent into a sterically hindered benzamide system. In addition, the Hai-long Jiang team 30 discovered an asymmetric metal-organic framework (MOF) with electronically insulated Zn 2+ nodes, where two chemically equivalent yet crystallographically independent linkers contain entirely different orbitals. Upon photoexcitation, it experiences a dynamic excited-state structural twist, resulting in orbital rearrangements that inhibits radiative relaxation and foster a long-lived charge-separated state. However, to date, most studies on photoisomerization behaviors have primarily focused on biomolecules or small organic molecules. There is no definitive conclusion as to whether this photoisomerization mechanism can be successfully extended to non-metallic polymer semiconductors. Especially, the relationship between light-induced molecular twisting of semiconductor photocatalyst and variations in optical properties remains limited and requires further in-depth exploration. In this work, we report a borazine/triazine-containing conjugated polymer semiconductor (BTCP) that exhibits light-induced conformational isomerism and demonstrates highly efficient bifunctional photocatalytic activity in photo-assisted Li-CO 2 batteries. Unlike conventional rigid conjugated systems, the coexistence of borazine and triazine rings imparts greater molecular flexibility and torsional freedom due to variations in bond lengths and π-electron delocalization 21 , 32 . Motivated by this, BTCPs were synthesized to investigate their structural evolutions and photoelectronic behavior under light irradiation (synthetic procedure and mechanism are shown in Fig. 1 a, and Supplementary Fig. 1 and Fig. 2 ). As illustrated in Fig. 1 b and 1 c, cooperative bond rotation occurs upon illumination, leading to structural distortion that is fully reversible once the light source is removed. Combined experimental and density functional theory (DFT) calculations reveal that light-induced deformation promotes electron cloud redistribution within BTCP, generating electronic asymmetry that enhances the built-in electric field and optimizes HOMO-LUMO (the highest occupied molecular orbital-the lowest unoccupied molecular orbital) energy level alignment 33 , 34 . These effects significantly improve photogenerated charge separation and migration efficiency. Notably, the electron cloud density around the B atom decreases, further strengthening electron-deficient characteristics that facilitate CO 2 adsorption/activation and lower the energy barrier for Li 2 CO 3 decomposition (Fig. 1 e). As a result, BTCP photoelectrode delivers outstanding bifunctional photocatalytic activity in photo-assisted Li-CO 2 batteries by accelerating the kinetics of CO 2 RR during the discharge and CO 2 ER during charge, thus enabling superior performance (Fig. 1 d). At a current density of 100 µA cm − 2 , the cell exhibits a high overpotential of 2.66 V and the round-trip efficiency of only 38% under dark conditions. In contrast, under illumination it achieves an ultralow potential hysteresis of only 0.1 V and an exceptionally high round-trip efficiency of 96%, outperforming most reported electrode materials ( Table S1 ). To the best of our knowledge, this study provides the first experimental evidence that light-induced intramolecular bond rotation can substantially boost the photocatalytic activity of conjugated polymer semiconductors in photo-assisted Li-CO 2 batteries, opening new avenues for the design and application in advanced photocatalytic systems. Results and Discussion Morphological characterizations and composition analysis The BTCP samples were prepared through pyrolysis using varying ratios of boric acid and urea as precursors. The resulting samples were labeled as BTCP-1, BTCP-2, BTCP-3, and BTCP-4 according to the increasing ratios, and were systematically investigated. The morphology and composition of the as-prepared borazine/triazine-containing conjugated polymer BTCP samples were investigated using scanning electron microscopy (SEM) and transmission electron microscopy (TEM) characterization. Distinct differences were observed between the as-prepared samples, as shown in Fig. 2 a-d, which revealed significant morphological changes. Notably, BTCP-2 displayed a uniform distribution of porous nanosheet-like structures, as depicted in Fig. 2 b. High-resolution TEM images (inset of Fig. 2 b) reveal that these nanosheets are amorphous, with nanoscale pore diameters of approximately 25 nm and exceptionally high porosity (Fig. 2 e and the inset, indicated by yellow circles in the inset). Supplementary Fig. 3 illustrates that BTCP-1 retained a micron-sized block-like structure akin to that of boron trioxide (B 2 O 3 ), whereas BTCP-2 exhibited a smaller particle-like morphology. In contrast, BTCP-3 and BTCP-4 progressively displayed a sheet-like structure resembling that of graphitic carbon nitride (g-C 3 N 4 ), with BTCP-4 demonstrating a fully sheet-like morphology. Further TEM analyses revealed that the pyrolysis product of boric acid, B 2 O 3 , displays a highly crystalline block-like morphology, whereas the pyrolysis product obtained from urea, C 3 N 4 , presents a weakly crystalline nanosheet-like structure ( see Supplementary Fig. 4 ). High-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM), dark-field TEM images also provide clear information on the pore distribution (Fig. 2 f and Supplementary Fig. 5 ), and elemental mapping (EDX mapping images) verified the homogeneous distribution of B, O, N, and C elements (Fig. 2 g). X-ray diffraction (XRD) results further confirm that, except for BTCP-1, which shows a distinct B 2 O 3 characteristic peak, all other products exhibit an amorphous structure (Fig. 2 h and Supplementary Fig. 6 ). BET analysis indicates that BTCP-2 has the highest specific surface area and the most abundant mesoporous structure, with its surface area significantly surpassing the other three samples, approximately 2 to 50 times greater ( Supplementary Fig. 7 ). This considerable difference is primarily attributed to its uniformly distributed porous nanosheet structure, demonstrating that a porous nanosheet-like conjugated polymer can be successfully synthesized via a template-free, one-step pyrolysis method. The large surface area provides abundant adsorption and catalytic sites, offering clear advantages for photocatalytic applications. X-ray photoelectron spectroscopy (XPS) analysis confirmed that all the BTCP samples contain B, N, C, and O elements ( Supplementary Fig. 8 ). The results of the chemical state analysis for each element reveal that when the boric acid to urea ratio is 1:1, no characteristic peaks corresponding to B-N are observed in the B 1s and N 1s spectra (Fig. 2 i). At this stage, the system mainly consisted a substantial amount of B-O bonds at 193.1 eV, minor B-C bonds at 190.9 eV, and several C-N peaks associated with the triazine ring (N-C = N and N-(C 3 )), and a small amount attributed to N-O bonds (402.5 eV), suggesting that the BN-related conjugated system has not yet formed and may instead be linked through oxygen bridges 35 , 36 . Upon increasing the ratio to 1:5, B-O bonds completely disappeared and were replaced by B-N and B-C bonds in the B 1s spectra as the main components according to both the B 1s and N 1s spectra, indicating the formation of conjugated system 37 . Notably, further increasing the urea content was accompanied by the enhancement of the characteristic peaks corresponding to the 1,3,5-CN triazine ring associated with the C 3 N 4 features, and this trend was also consistent with the SEM and TEM results. The Fourier transform infrared (FT-IR) spectroscopy also highlights differences among the various products ( Supplementary Fig. 9 ). In comparison to the pyrolysis products of the individual precursors, the pyrolysis of the mixture shows distinct N-H absorption peaks at ~ 3456 cm − 1 and B-C absorption peaks at ~ 1105 cm − 1 and ~ 1025 cm − 1 . For the BTCP-1 sample, the B-O bonds remain significantly present, whereas in the other three samples they are completely absent and appear characteristic absorption peaks corresponding to the B-N bonds, with typical peaks at approximately 1248 cm − 1 , 782 cm − 1 , and 695 cm − 1 attributed to the stretching and bending vibrations of B-N 38, 39 . As the nitrogen source content increases during preparation, the intensity of the B-N absorption peaks decreases, while the characteristic peaks corresponding to C-N bonds associated with C 3 N 4 features increase. This is consistent with the XPS results, indicating that the BTCP-1 sample does not have a fully formed conjugated system, while the BTCP-2 sample contains the highest concentration of BN units based on the complete BN conjugated polymer, and in the BTCP-3 and BTCP-4 samples, in addition to the BN units, more CN units resembling C 3 N 4 characteristics are present. Solid-state 11 B, 1 H and 13 C nuclear magnetic resonance (NMR) spectra were collected to provide further structural information. As shown in Fig. 2 j, the 11 B NMR spectrum exhibits two distinct peaks: a broad signal spanning between 10 and 30 ppm, attributed to three-coordinated boron bonds that accounts for a large part, while the sharp peak at ~ 0 ppm corresponds to four-coordinated boron, suggesting the existence of two different coordination environments arising from intramolecular boron atoms 40 . The ¹H NMR spectra showed two single peaks at 6.74 ppm and 2.98 ppm, which were assigned to the intramolecular N-H and NH 2 groups at the edges, respectively. In the 13 C NMR spectra, a peak appeared at 167.5 ppm, indicating a consistent chemical environment for the carbon atoms, with all carbon atoms derived from the triazine ring, suggesting high molecular symmetry 41 . Based on the above morphological characteristics and compositional analysis results, and the relevant reaction processes involved during pyrolysis ( Supplementary Fig. 1 and Fig. 2 ), potential molecular structures of each product were proposed, as shown in Fig. 2 k. Optical property and light-induced structural evolution The optical properties of these BTCP samples are first investigated to assess their potential for photocatalytic applications. Absorption spectra were obtained by using UV/Vis diffuse reflectance spectroscopy (DRS). As depicted in Supplementary Fig. 10a , the absorption characteristics of the samples obtained demonstrate clear variations in the wavelength range of 260–400 nm, with BTCP-2 exhibiting the highest absorption and BTCP-1 showing the lowest. This is mainly because the formation of the conjugated system enhances π-π* transitions, while the creation of the BN-conjugated structure in borazine leads to more delocalized π-electrons, resulting in a noticeable red-shift in the absorption edge 42 . Consequently, the BTCP-1 sample exhibits the weakest light absorption capacity due to its imperfect conjugated system, whereas the BTCP-2 sample demonstrates the broadest light absorption range owing to its highest content of borazine, which aligns with the proposed molecular formula. Based on the UV-vis absorption edge onsets, the optical band gaps (E g ) were calculated to be 4.12, 3.63, 3.87, and 3.76 eV for samples from BTCP-1 to BTCP-4, respectively ( Supplementary Fig. 10b ). The band structure derived from the E g values and the valence bands (VB) positions based on the ultraviolet photoelectron spectroscopy (UPS) tests suggest that all samples exhibit the thermodynamic potential for photocatalytic CO 2 RR and CO 2 ER, making them promising candidates as photoelectrodes for photo-assisted Li-CO 2 battery ( Supplementary Fig. 11 and Fig. 12 ). Among them, BTCP-2 exhibits the smallest band gap, indicating the smallest energy difference between the VB and conduction bands (CB), which facilitates the transition of electrons from the valence band to the CB. The Mott-Schottky plot shows the characteristic behavior of n-type semiconductors, as evidenced by the positive slope of the curve ( Supplementary Fig. 13 ). In the case of n-type semiconductors, the incorporation of B-N units into the π-conjugated system leads to an increase in the electrostatic potential due to the positive charge on the nitrogen atom. This enhances the electron-deficient characteristics of the conjugated system, resulting in a lower LUMO energy level and stronger reductive properties 43 . As shown in Supplementary Fig. 12 , BTCP-2 has the most negative LUMO position. Maintaining charge separation is crucial for photocatalytic activity, as the effective utilization of photogenerated electrons and holes is closely linked to the charge separation state. The charge separation behavior was investigated using photoluminescence spectroscopy (PL) and time-resolved fluorescence decay measurements. Supplementary Fig. 14 presents the PL intensity of BTCP-2, which is notably suppressed relative to the other samples, accompanied by the longest average fluorescence lifetime (τ avg = 5.04 ns), indicating enhanced charge separation efficiency and reduced charge recombination. Furthermore, the transient photocurrent response revealed that BTCP-2 had the highest intensity among all samples ( Supplementary Fig. 15 ), suggesting superior light-induced electron separation and transport efficiency. Light-induced molecular twisting is accompanied by changes in the atomic chemical states. To verify these structural transformations and their impact on optical properties under light exposure, we combined XPS, PL measurements and theoretical calculations. Firstly, we performed in situ photoirradiation XPS analysis to examine the potential changes in the electron density distribution of the BTCP-2 sample after prolonged light exposure, aiming to observe its structural modifications. It is noteworthy that under light irradiation, the B 1s peak shifts noticeably towards a higher binding energy (Fig. 3 a). With increasing irradiation time, the binding energy in the XPS spectra continuously shifts towards higher values and stabilizes after 60 minutes or more of light irradiation. This suggests that during the light irradiation process, the local electronic structure of the B atoms in the sample undergoes a gradual change, with a decrease in electron cloud density, transitioning towards a stronger electron-deficient environment. Interestingly, upon switching off the light source, the binding energy gradually returned to its original position, indicating that the light-induced structural changes are highly reversible and the material’s structure remains intact. This reversible structural change is of significant importance for the material’s potential application as a photocatalyst. Furthermore, no noticeable shift was observed in the N 1s XPS spectrum, but the peak associated with NH gradually diminished with light irradiation and reappeared under dark conditions ( Supplementary Fig. 16 ), likely due to the breaking and regeneration of the hydrogen bonds around N atoms, which are connected via hydrogen bonding within the molecule. This further indicates that the conjugated system undergoes modifications under light irradiation. PL tests were further employed to investigate the impact of light exposure on the structure, with laser intensity adjusted by controlling the slit width during the testing process. Comparative analysis of PL spectra under different laser intensities revealed that the conjugated characteristics of the structure of the BTCP-2 sample underwent significant changes. For highly rigid C 3 N 4 , increasing the excitation light intensity did not cause any shift or intensity change in the PL absorption peak, indicating that variations in light intensity have no significant effect on its molecular configuration (Fig. 3 b). However, regarding the BTCP-2 sample, significant changes were observed in the PL peaks. As shown in Fig. 3 c, the PL emission peak at approximately 460 nm, associated with the strongly conjugated structure, significantly decreases with increasing intensity, while the peak around 360 nm, representing the non-conjugate unit, markedly intensifies. This suggests that light irradiation promotes the transition of the system from a conjugated to a non-conjugated structure, which is consistent with the XPS characterization results. Considering the difficulty in directly comparing fluorescence intensities at different excitation light intensities, a ratio-based (I 323nm /I 467nm ) approach was utilized for reversibility testing. As shown in Fig. 3 d, the I 323nm /I 467nm ratio increased with increasing excitation light intensity and decreased as the intensity was reduced. After six cycles, the I 323nm /I 467nm ratio remained close to its initial value, indicating that the light-induced structural deformation process is highly reversible. Subsequently, a 120-minute continuous test was conducted under the same excitation light intensity (maximum intensity). The results have shown that both the intensity of the 357 nm emission peak and the I 323nm /I 467nm ratio remained stable throughout the test, indicating that the material did not undergo photodegradation during prolonged light exposure, further demonstrating excellent photostability and structural stability ( Supplementary Fig. 17 ). The above results demonstrate a high degree of consistency with the findings from in situ photoirradiation XPS measurements. More importantly, in contrast to the PL intensity of C 3 N 4 that enhance with time, the PL intensities of BCTCP-2 sample display a decreasing trend with increasing illumination time, further confirming that the photogenerated carriers possess longer lifetimes and lower recombination rates (Fig. 3 e and Supplementary Fig. 18 ). The above PL test results demonstrate that the samples we prepared exhibit light-induced reversible and stable structural changes, and after prolonged testing, they maintain excellent structural stability and carrier lifetime. This indicates that the material can operate continuously and efficiently in photocatalytic reactions, underscoring its considerable potential for photocatalytic applications. To elucidate the effect of molecular spatial structure changes on electronic structure and photoelectric properties of materials, density functional theory (DFT) was employed to analyze density of states (DOS), electron density distributions, band structures and the moment of dipole. DOS analysis reveals that the VB of the BTCP-2 planar structure is primarily derived from N and B atoms, and the CB is predominantly derived from C and N atoms (Fig. 3 f). In contrast, in the distorted structure, the VB includes contributions from N atoms and the CB includes support from N and B atoms. This structural change enables the transition of electrons from the top of the VB to the bottom of the CB in boron atoms, thereby activating the boron atoms. According to bader charge analysis, compared to the coplanar conjugated structure, the charge of the B atom in the torsional structure significantly decreases, leads to an asymmetric electron distribution 44 , 45 (Fig. 3 h). We speculate that the main reason for this change is related to the variation in the molecular structure induced by light. When the B atom is coplanar with the triazine ring, the conjugative effect promotes electron sharing, forming a unified π-electronic system that enhances electron delocalization. However, when the triazine ring is no longer coplanar with the B atom, the conjugated system is disrupted. Since the triazine ring is an electron-withdrawing group (EWG), the electron density on the B atom consequently decreases because of the presence of electron-absorbing effects (Fig. 3 g). As presented in Fig. 3 i, calculations of the molecular orbital levels show a significant reduction in the LUMO-HOMO energy gap of the torsional structure, which means that lower energy is required for the transition from HOMO to LUMO, thereby facilitating the generation of electron-hole pairs. Meanwhile, in the planar structure, the HOMO and LUMO are mainly localized on the B and N atoms linking the triazine and borazine rings, as well as on the triazine ring itself, with only minor differences in their orbital distributions. However, in the twisted structure, the HOMO is almost distributed throughout the molecule, while the LUMO orbital is predominantly distributed around the triazine ring that rotates around the B atom and its vicinity, and this significant distribution is more favorable to facilitate more effective charge spatial separation and transmission 46 . The asymmetry in the electronic structure can induce a large dipole moment 33 . The dipole moment (2.88 D) of the distorted structure is significantly higher than that of the planar structure (0.95 D), which will lead to an increased built-in electric field, further accelerating the separation of photogenerated electron-hole pairs 34 , 47 (Fig. 3 j). The above results indicate that light-induced molecular twisting alters the electronic configuration, affecting HOMO/LUMO distributions and dipole moment, which enhances light absorption and improves exciton generation and carrier separation efficiency, ultimately leading to better photocatalytic efficiency. Performance evaluation of photo-assisted Li-CO batteries The photoelectric conversion and energy storage performance of photo-assisted Li-CO 2 batteries assembled with BTCP-x (x = 1–4) as the photocathode were systematically evaluated. Discharge/charge tests of four different samples at a current density of 100 µA cm − 2 are first conducted for evaluating the reaction kinetics of CO 2 redox under both dark and light conditions (Fig. 4 c). Based on the experimental test results, the performance of the BTCP based Li-CO 2 battery under light conditions was significantly better than that observed under dark conditions. Among the tested photoelectrodes, BTCP-2 photoelectrode was demonstrated to display the best performance, achieving an overpotential as low as 0.13 V and a round-trip efficiency as high as 95.5%, with discharge and charging potentials of 2.76 V and 2.89 V ( vs. Li + /Li), respectively, which far surpass those of other samples and the commonly used C 3 N 4 photocatalyst, thereby confirming its remarkable suitability for the photo-assisted Li-CO 2 battery system ( Supplementary Fig. 19 and Fig. 20 ). The exceptional performance of the BTCP-2 photocathode in Li-CO 2 batteries may be attributed to its rapid light response capability and the dynamics of CO 2 redox, as the photo-assisted Li-CO 2 battery systems largely relies on the efficient execution of photocatalytic CO 2 RR and CO 2 ER. The I-t curves in Fig. 4 a show that BTCP-2 photocathode exhibits high photosensitivity and rapid light response capability under conditions of random switching between illumination and darkness. The corresponding EIS results (Fig. 4 b) validate the superior charge separation and transfer efficiency under light exposure. Additionally, the stable variations observed in the I-t curves during repeated cycles of illumination and darkness indicated the high stability and reproducibility of the BTCP-2 photocathode under light conditions. Meanwhile, cyclic voltammetry (CV) measurements were conducted within a potential range of 1.5 to 4.5 V to investigate the activities of CO 2 RR and CO 2 ER. As depicted in Fig. 4 e, two distinct representative reduction and oxidation peaks were observed under illumination compared to dark conditions, suggesting the enhanced activity of CO 2 redox under light. Linear sweep voltammetry (LSV) was performed to further confirm the influence of light on the CO 2 RR and CO 2 ER, revealing that the onset potentials and the limiting current densities for both CO 2 RR and CO 2 ER under illumination are significantly higher than those measured in the absence of light ( Supplementary Fig. 21 ). Therefore, BTCP-2 exhibits rapid charge transfer capability and excellent CO 2 redox kinetics under illumination, ensuring its outstanding bifunctional photocatalytic activity as the photoelectrode in Li-CO 2 batteries. Subsequently, comprehensive assessments of rate capability and cycling stability were carried out to further evaluate the application performance of the Li-CO 2 battery system. The rate profiles of the BTCP-2 photocathode at different current densities of 10, 50, 100, 500, 1000 and 10 µA cm − 2 are shown in Fig. 4 f and Fig. 4 h. Under all current densities, the rate performance of assembled battery in the presence of light significantly exceeds that under dark conditions, with corresponding round-trip efficiencies of 98%, 94%, 88%, 79%, 74% and 98%, respectively. It can be observed that the round-trip efficiency maintains a high level of performance even at a current density of 1000 µA cm − 2 . Notably, even after testing at a high current density of 1000 µA cm − 2 , the battery efficiency can still be reversibly restored when returning to a low current density of 10 µA cm − 2 , maintaining a round-trip efficiency of 98%, which suggests excellent reversibility. The cycling stability was also tested at 100 µA cm − 2 under both light and dark conditions. As shown in Fig. 4 i, the Li-CO 2 battery with BTCP-2 photoelectrode failed after nearly 200 h of testing in the dark. However, under light conditions, it maintained a small voltage gap and high energy efficiency even after over 600 h of testing. The BTCP-2 based photo-assisted Li-CO 2 battery retained high round-trip efficiencies of 73%, 59%, 59%, 53.0%, 50%, 50%, and 48% after 100 h, 200 h, 300 h, 400 h, 500 h, and 600 h of cycling, respectively. Meanwhile, during the initial stage of the light cycling tests, the discharge and charge curves of the BTCP-2 based Li-CO 2 battery presented a significant difference in the discharge and charge potentials of the battery with illumination and without illumination (Fig. 4 h). The stability of the battery was not affected by the light switching, which further verifies the high stability of Li-CO 2 battery system assembled with BTCP-2 photoelectrodes, suggesting that this system possesses good durability and reliability for practical applications. Based on the analysis comparing the recently reported literature, as presented in Fig. 4 k and Supplementary Table 1 , the BTCP-2 photoelectrode demonstrates outstanding Li-CO 2 battery performance, surpassing previously reported cathode photocatalysts under analogous experimental conditions. Specifically, Specifically, it achieved a round-trip efficiency of up to 96% at a current density of 100 µA cm − 2 , demonstrated a battery capacity exceeding 1000 µAh cm − 2 , and exhibited exceptional cycling stability with 323 continuous cycles over a duration of 626 h (27 days). The findings presented above demonstrate that BTCP-2 based photo-assisted Li-CO 2 battery has excellent bifunctional activities for both CO 2 RR and CO 2 ER activities, along with high rate performance and enduring cycling stability. Reaction products monitoring with mechanistic analysis The evolution of products during discharge and charge was investigated to evaluate the reversibility of the CO 2 RR and the CO 2 ER in Li-CO 2 batteries, as well as to gain mechanistic insight into the underlying reactions. EIS measurements of the BTCP-2 photocathode over a 40 h continuous discharge-charge cycle (20 h discharge, 20 h charge) revealed a clear trend ( Supplementary Fig. 22 and Fig. 23 ). During discharge, the charge-transfer resistance increased steadily, indicating the accumulation of poorly conductive products on the photoelectrode surface. In contrast, during charging, the resistance decreased progressively and returned to its initial value, confirming the reversible decomposition of the discharge products. The nature of these discharge products was identified by XRD and XPS. After 20 h discharge, distinct diffraction peaks corresponding to Li 2 CO 3 were observed 17 , which disappeared after 20 h charging ( Supplementary Fig. 24 ). XPS spectra further corroborated these findings. In the C 1s spectrum, a peak characteristic of Li 2 CO 3 at ~ 290.9 eV and an increased C–C signal at 284.8 eV appeared after discharge, while the Li 1s spectrum displayed a Li 2 CO 3 peak at ~ 55.8 eV ( Supplementary Fig. 25 ) 19 . After charging, the peak assigned to Li 2 CO 3 vanished, and the C-C peak intensity decreased. Together, these results confirm that the discharge products are Li 2 CO 3 and carbon, both of which highly reversible. The reversibility of Li 2 CO 3 and carbon was further visually observed through SEM characterization. In contrast to the pristine photoelectrode, the discharged BTCP-2 photocathode exhibited granular deposits that accumulated with extended discharge time and disappear completely after charging ( Supplementary Fig. 26 and Fig. 27 ). To gain a deeper understanding of the catalytic mechanism, quasi-in-situ X-ray photoelectron spectroscopy (QIS-XPS) was used to probe CO 2 adsorption on BTCP-2. Upon CO 2 exposure under illumination, the B 1s peak shifted from 193.34 eV to 193.19 eV (Fig. 5 a ) , indicating charge transfer between adsorbed CO 2 and electron-deficient B atom. B atom experiences a heightened state of electron deficiency as a result of photo-induced structural isomerization, enabling strong interactions with CO 2 molecules. The adsorption of CO 2 donates electrons to the B atom, thereby increasing the electron density of B and lowering its binding energy. DFT calculations elucidated the positive role of photo-induced isomeric structures in the redox reaction processes of Li-CO 2 batteries. Firstly, structural deformation alters the electronic configuration, significantly strengthening reactant-catalyst interactions 11 . As shown in Fig. 5 b, the distorted BTCP-2 structure exhibits much higher adsorption energies for both Li and CO 2 compared to the planar structure, indicating enhanced capability for capturing reactant molecules during CO 2 RR. This facilitates higher surface concentrations of active species, thereby promoting continuous reaction progression. Furthermore, the reversible decomposition of Li 2 CO 3 during charging mitigates catalyst deactivation caused by active sites coverage, thereby sustaining long-term photocatalytic activity. Further calculations indicate that the adsorption energy of Li 2 CO 3 on the distorted structure (2.79 eV) is much weaker than that on the planar structure (4.19 eV). This suggests that the Li 2 CO 3 formed during discharge is more likely to desorb from the distorted structure and diffuse into the electrolyte, thereby exposing more active sites on the cathode surface. Such behavior effectively prevents Li 2 CO 3 accumulation and helps maintain the catalytic activity and stability of the photoelectrode. On the other hand, during the charging process, the sluggish kinetics of Li 2 CO 3 decomposition may also result in the accumulation of poorly conductive Li 2 CO 3 , severely impairing overall battery performance. Therefore, facilitating the decomposition of Li 2 CO 3 during the CO 2 ER process is essential for improving the performance and cycling stability of Li-CO 2 batteries. Theoretical calculations (Fig. 5 c) reveal that the decomposition energy barrier of Li 2 CO 3 is 2.99 eV on the planar structure but reduced to 2.40 eV on the distorted structure, confirming that the distorted structure is more favorable for Li 2 CO 3 decomposition. On the basis of these experimental and theoretical results, we propose a mechanism for the Li-CO 2 battery using the BTCP-2 photoelectrode, as illustrated in Fig. 5 d. Light-induced molecular structural deformation generates an asymmetric electronic configuration, which enhances electron-hole separation and migration. Meanwhile, the increased electron-deficient character of boron atoms after deformation provides highly effective sites for CO 2 adsorption and activation. In addition, the homogeneous porous architecture of BTCP-2, combined with the enhanced CO 2 adsorption and the reduced Li 2 CO 3 decomposition energy barrier, synergistically accelerates both CO 2 RR and CO 2 ER. Overall, this mechanism highlights that the light-induced structural changes in BTCP substantially improve charge separation, facilitate charge transfer, and enhance both oxidation and reduction kinetics of CO 2 in Li-CO 2 batteries. Conclusions In summary, we have developed a borazine/triazine-containing conjugated polymer that exhibits light-induced molecular twisting enabled by the torsional flexibility of B-N, C-B and C-N bonds. Combined experimental and theoretical analyses reveal that this light-driven structural isomerism optimizes the HOMO-LUMO energy levels distribution, broadens light absorption and enhance the photoresponse of BTCP material. In addition, light-induced torsion induces electron cloud around redistribution around B and N atoms, enlarging the dipole moment and strengthening the internal polarization field. These effects synergistically promote separation and migration of photogenerated electrons and holes, enhance CO 2 adsorption, and significantly lower the decomposition energy barrier of Li 2 CO 3 . As a result, the photo-assisted Li-CO₂ battery utilizing BTCP as a photoelectrode achieves exceptional performance, including an ultralow potential hysteresis of 0.1 V, a round-trip efficiency of 96% at 100 µA cm − 2 , and stable cycling over 27 days, surpassing most previously reported photoelectrodes. This work not only expands the scope of research on light-induced torsional molecules and dynamic bonds but also provides a new design strategy for high-performance photoelectrodes in photo-assisted energy storage systems. Methods Materials Chemicals for urea and boric acid used in the material preparation were purchased from Aladdin Reagents. Reagent for N-Methyl-2-pyrrolidone (C 5 H 9 NO, AR) were purchased from Sinopharm Chemical Reagent Co., Ltd. The electrolyte of Lithium bis (trifluoromethane sulfonimide) (1.0 M LiTFSI in TETRAGLYME, 100 Vol%) was purchased from DodoChem. All chemicals were of analytical grade and used without further purification. Preparation of borazine/triazine-containing conjugated polymer Borazine/triazine-containing conjugated polymer samples were prepared using commonly employed methods that involve commercially available boric acid and urea as sources of boron and nitrogen, along with specific modifications, through a simple pyrolysis technique conducted in air at 600°C with a heating rate of 10°C/min in the air, rendering the method suitable for industrial-scale production. Significantly, varying the mass ratio of boric acid to urea induces different degrees of polymerization and crosslinking reactions, resulting in distinct products. (M (boric acid) = 61.83 g/mol, and M (urea) = 60.06 g/mol, means the mass ratio approximately corresponds to the molar ratio). This work conducted experiments using four different mass ratios of boric acid and urea precursors, specifically 1:1, 1:5, 1:10, and 1:20. Four distinct products were successfully synthesized, which were designated as BTCP-1, BTCP-2, BTCP-3, and BTCP-4. Diboron trioxide (B 2 O 3 ) and carbon nitride (C 3 N 4 ) were obtained by pyrolyzing pure boric acid and urea, respectively, under same conditions. Material characterizations The morphologies of BTCP samples were characterized via a field-emission scanning electron microscopy (FE-SEM, SU8020), and a transmission electron microscopy (TEM, Tecnai G2 F20) at an acceleration voltage of 200 kV. The composition and chemical states were determined by XPS (PHI Quantera II) instrument, and the binding energy calibration was referenced to C 1s at 284.6 eV. The crystallographic structures were characterized by using powder X-ray diffractometer (XRD, Rigaku D/Max-3c, Cu Kα radiation with λ = 1.5406 Å) with an operating voltage and current of 40 kV and 15 mA. The chemical bonding behavior of the prepared samples were investigated using a Vertex 70 fourier transform infrared (FT-IR) spectrometer. Experiments were performed at room temperature using solid-state nuclear magnetic resonance (SSNMR) to obtain 1 H, 11 B, and 13 C NMR spectra collected on a Germany Broker Avance Neo 400WB. Ultraviolet photoelectron spectroscopy (UPS) was used to measure valence band value. An ultraviolet-visible spectrophotometer (UV-vis, UV-3600) was applied for characterizing the absorption spectra of the samples at room temperature. The specific surface area and pore size distribution were determined using a surface aperture analyzer (Micromeritics VacPrep 061) by measuring the N 2 adsorption-desorption isotherm at 77 K. Photoluminescence (PL) spectra were acquired on an RF-5301PC fluorescence spectrophotometer (Shimadzu, Tokyo, Japan). Battery assembly and electrochemical performance tests As-prepared BTCP samples, Super-P, and polyvinylidene fluoride (PVDF) were respectively employed as the working materials, conductor and binder, and mixed together at a weight ratio of 8:1:1 with the adding of N-methyl-2-pyrrolidinone (NMP). The prepared slurry was then coated on a clean nickel foam with a diameter of 13 mm. The mass loading of photoelectrode was 1.0 ± 0.5 mg/cm 2 . All the electrodes were dried at 100°C under vacuum for at least 12 h. The CR2032 coin cells with holes on the cathode side were used for testing Li-CO 2 batteries. The batteries were assembled in a glove box and filled at Ar atmosphere with the moisture and oxygen content of below 0.1 ppm. Li foils were used as the counter, BTCP photoelectrode was inserted into the cathode side, and glass fiber (Waterman, GF/A) was applied as the separator. 1.0 M LiTFSI in tetraethylene glycol dimethyl ether (Tetraglyme) was employed as the electrolyte, the amount of electrolyte in each battery was about 100 µL. The assembled batteries were stored in a volume capacity of 250 mL sealed glass test device, which was filled with carbon dioxide. The charging and discharging curves were tested on a (Solartron) 1470E CellTest. The EIS curves and GITT curves were measured with a Solartron 1260-1460E machine. DEMS measurements were performed on a quadrupole mass spectrometer (QAS100) with the help of Linglu Instrument Co., Ltd. A GELS500/350 Xe lamp (wavelength range: 200–1200 nm, Ceaulight, Beijing) with a fixed power at 500 W was used as the solar source for illumination. Before the measurement, an optical power meter was utilized for calibrating the photo density on surface of battery electrode to AM1.5 G, which corresponded to the photo density of 100 mW/cm 2 . Theoretical calculation Density functional theory (DFT) calculations were performed using a first-principles approach 48 , 49 within the generalized gradient approximation (GGA) based on the Perdew-Burke-Ernzerhof (PBE) 50 formulation, as implemented in the plane wave set Vienna ab initio Simulation Package (VASP) code. The projected augmented wave (PAW) potentials 51 , 52 to describe the ionic cores and take valence electrons into account using a plane wave basis set with a kinetic energy cutoff of 520 eV. Partial occupancies of the Kohn-Sham orbitals were allowed using the Gaussian smearing method with a width of 0.05 eV. The electronic energy was considered self-consistent when the energy change was smaller than 10 − 6 eV. A geometry optimization was considered convergent when the energy change was smaller than 0.03 eV Å −1 . The vacuum spacing in a direction perpendicular to the plane of the structure is 20 Å for the surfaces. The Brillouin zone integration is performed using 2×2×1 Monkhorst-Pack k-point sampling for a structure. Electrostatic potential analysis was performed the Gaussian 16 software in Multiwfn 53 and VMD 54 packages with the single point calculations under the level of B3LYP-D3BJ/6-311 + G (d, p) 55 . The climbing image-nudge elastic band (CI-NEB) method was used to calculate the diffusion barrier of Li + on the substrates. Finally, the adsorption energies (Eads) were calculated as Eads = Ead/sub - Ead - Esub, where Ead/sub, Ead, and Esub are the total energies of the optimized adsorbate/substrate system, the adsorbate in the structure, and the clean substrate, respectively. The free energy was calculated using the equation: G = Eads + ZPE - TS where G, Eads, ZPE and TS are the free energy, total energy from DFT calculations, zero point energy and entropic contributions, respectively. Declarations Conflict of Interest The authors declare no conflict of interest. Acknowledgements This work was financially supported by the National Natural Science Foundation of China (51772182), The 111 Project, Shaanxi "Three Qin Scholars" Innovation Team, Key Research and Development Program of Shaanxi (2022GY-200), and the Fundamental Research Funds for the Central Universities (GK202302005), the Gansu Provincial University Teachers Innovation Fund Project (2025A-043), Central Government Guidance Fund for Local Science and Technology Development (25ZYJC002). The authors acknowledge the financial support from the Australian Research Council through its Discovery (DP230100572), Future Fellowship (FT200100279) Programs and National Health and Medical Research Council (APP1175808). The authors acknowledge the scientific and technical support from the Australian Microscopy & Microanalysis Research Facility at the Centre for Microscopy and Microanalysis, the University of Queensland. The authors would also like to acknowledge the support received from the UQ-CSC PhD Scholarship and the UQ-CSC Joint PhD Scholarship. L. Li and D. Tian are equal contribution. References Sarkar A et al (2023) Recent advances in rechargeable metal-CO 2 batteries with nonaqueous electrolytes. Chem Rev 123:9497–9564 Wang F et al (2021) Metal-CO 2 electrochemistry: from CO 2 recycling to energy storage. Adv Energy Mater 11:2100667 Liu Y, Wang R, Lyu Y, Li H, Chen L (2014) Rechargeable Li/CO 2 -O 2 (2 : 1) battery and Li/CO 2 battery. Energy Environ Sci 7:677–681 Chen J et al (2023) Recent progress of transition metal-based catalysts as cathodes in O 2 /H 2 O-involved and pure Li-CO 2 batteries. Energy Environ Sci 16:792–829 Baek K et al (2020) Synergistic effect of quinary molten salts and ruthenium catalyst for high-power-density lithium-carbon dioxide cell. Nat Commun 11:456 Sun X et al (2023) Binuclear Cu complex catalysis enabling Li-CO 2 battery with a high discharge voltage above 3.0 V. Nat Commun 14:536 Li W et al (2024) Boosting a practical Li-CO 2 battery through dimerization reaction based on solid redox mediator. Nat Commun 15:803 Liu Y et al (2024) Deciphering the contributing motifs of reconstructed cobalt (II) sulfides catalysts in Li-CO 2 batteries. Nat Commun 15:2167 Cao D, Tan C, Chen Y (2022) Oxidative decomposition mechanisms of lithium carbonate on carbon substrates in lithium battery chemistries. Nat Commun 13:4908 Liu Y et al (2025) Subsurface electron trap enabled long-cycling oxalate‐based Li‐CO 2 Battery. Adv Mater 37:2507871 Lu B et al (2024) Steering the orbital hybridization to boost the redox kinetics for efficient Li-CO 2 batteries. J Am Chem Soc 146:20814–20822 Hu K et al (2025) Photoassisted Li-CO 2 batteries with ultrahigh energy efficiency and cycle stability by a redox mediator. ACS Nano 19:7707–7717 Chang JN et al (2024) Redox molecular junction metal-covalent organic frameworks for light‐assisted CO 2 energy storage. Angew Chem Int Ed 63:e202402458 Hu T et al (2025) Photo-energized MoS 2 /CNT cathode for high-performance Li-CO 2 batteries in a wide-temperature range. Nano-Micro Lett 17:5 Wang JH (2022) ea al. Phthalocyanine based metal-organic framework ultrathin nanosheet for efficient photocathode toward light-assisted Li-CO 2 battery. Adv. Funct. Mater. 32, 2210259 Chang JN et al (2024) Redox molecular junction metal-covalent organic frameworks for light-assisted CO 2 energy storage. Angew Chem Int Ed 63:e202402458 Guan DH et al (2020) Light/electricity energy conversion and storage for a hierarchical porous In 2 S 3 @CNT/SS cathode towards a flexible Li-CO 2 battery. Angew Chem Int Ed 59:19518–19524 Li L et al (2024) High-concentrated electron-deficient boron through dual-function boric acid strategy significantly enhancing reaction kinetics and stability of photoassisted Li-CO 2 batteries. Energy Storage Mater 71:103634 Li J et al (2022) High-efficiency and stable Li-CO 2 battery enabled by carbon nanotube/carbon nitride heterostructured photocathode. Angew Chem Int Ed 61:e202114612 Zhang K et al (2022) Boosting cycling stability and rate capability of Li-CO 2 batteries via synergistic photoelectric effect and plasmonic interaction. Angew Chem Int Ed 61:e202201718 Zhu L, Rabih OA, Christopher JB (2011) Reversible photoinduced twisting of molecular crystal microribbons. J Am Chem Soc 32:12569–12575 Zhu K et al (2024) Limiting molecular twisting: upgrading a donor-acceptor dye to drive H 2 Evolution. Adv Sci 11:2403454 Zhang H, Yu S (2019) Visible light-promoted isomerization of alkenes. Chin J Org Chem 39:95–108 Volarić J, Szymanski W, Simeth NA, Feringa BL (2021) Molecular photoswitches in aqueous environments. Chem Soc Rev 50:12377–12449 Gemen J et al (2023) Disequilibrating azobenzenes by visible-light sensitization under confinement. Science 381:1357–1363 Saltiel J et al (2009) Photoisomerization of all-cis-1,6-diphenyl-1,3,5-hexatriene in the solid state and in solution: a simultaneous three-bond twist process. Angew Chem Int Ed 48:8082–8085 Gerwien A, Schildhauer M, Thumser S, Mayer P, Dube H (2018) Direct evidence for hula twist and single-bond rotation photoproducts. Nat Commun 9:2510 Gerwien A, Jehle B, Irmler M, Mayer P, Dube H (2022) An eight-state molecular sequential switch featuring a dual single-bond rotation photoreaction. J Am Chem Soc 144:3029–3038 Nagami S et al (2024) Photoinduced dual bond rotation of a nitrogen-containing system realized by chalcogen substitution. Nat Chem 16:959–969 Sun K et al (2024) Dynamic structural twist in metal-organic frameworks enhances solar overall water splitting. Nat Chem 16:1638–1646 Chen C, Du CZ, Wang XY (2022) The rise of 1,4-BN-heteroarenes: synthesis, properties, and applications. Adv Sci 9:2200707 Wu Y et al (2024) Aromaticity in isoelectronic analogues of benzene, carborazine and borazine, from electronic structure and magnetic property. Chem Eur J 30:e202403369 Liu J et al (2024) Defects-rich heterostructures trigger strong polarization coupling in sulfides/carbon composites with robust electromagnetic wave absorption. Nano-Micro Lett 17:24 Zhang Q et al (2025) Regulating the built-in electric field in covalent organic frameworks for enhanced CO 2 photoreduction: asymmetry linkage structures. ACS Catal 15:6739–6748 Yuan T et al (2022) Mild and metal-free birch-type hydrogenation of (hetero) arenes with boron carbonitride in water. Nat Catal 5:1157–1168 Li M et al (2023) Construction of boron- and nitrogen‐enriched nanoporous π‐conjugated networks towards enhanced hydrogen activation. Angew Chem Int Ed 135:e202302684 Giusto P et al (2020) Boron carbon nitride thin films: from disordered to ordered conjugated ternary materials. J Am Chem Soc 142:20883–20891 Tang C, Bando Y, Huang Y, Zhi C, Golberg D (2008) Synthetic routes and formation mechanisms of spherical boron nitride nanoparticles. Adv Funct Mater 18:3653–3661 Liang C et al (2022) Band structure engineering within two-dimensional borocarbonitride nanosheets for surface-enhanced raman scattering. Nano Lett 22:6590–6598 Yu H et al (2025) Reversible configurations of 3-coordinate and 4-coordinate boron stabilize ultrahigh-Ni cathodes with superior cycling stability for practical Li-ion batteries. Adv Mater 37:2412360 Wu B et al (2021) Ultrathin porous carbon nitride bundles with an adjustable energy band structure toward simultaneous solar photocatalytic water splitting and selective phenylcarbinol oxidation. Angew Chem Int Ed 60:4815–4822 Dou C et al (2016) An electron-deficient building block based on the B←N unit: An electron acceptor for all-polymer solar cells. Angew Chem Int Ed 55:1436–1440 Dou C, Liu J, Wang L (2017) Conjugated polymers containing B←N unit as electron acceptors for all-polymer solar cells. Sci China Chem 60:450–459 Sun R et al (2025) Unprecedented photocatalytic hydrogen peroxide production via covalent triazine frameworks constructed from fused building blocks. Angew Chem Int Ed 64:e202416350 Liu J et al (2025) Selective ions exchange reactions endow defective heterovalent copper-based selenides with enhanced dielectric polarization response. Adv Funct Mater 35:2420239 Sun R et al (2025) Unprecedented photocatalytic hydrogen peroxide production via covalent triazine frameworks constructed from fused building blocks. Angew Chem Int Ed 137:e202416350 Chen YJ et al (2024) Molecular engineering of perylene diimide polymers with a robust built-in electric field for enhanced solar-driven water splitting. Angew Chem Int Ed 63:e202318224 Kresse G, Furthmüller J (1996) Efficiency of ab-initio total energy calculations for metals and semiconductors using a plane-wave basis set. Comput Mater Sci 6:15–50 Kresse G, Furthmüller J (1996) Efficient iterative schemes for ab initio total-energy calculations using a plane-wave basis set. Phys Rev B 54:11169–11186 Perdew JP, Burke K, Ernzerhof M (1996) Generalized gradient approximation made simple. Phys Rev Lett 77:3865–3868 Kresse G, Joubert D (1999) From ultrasoft pseudopotentials to the projector augmented-wave method. Phys Rev B 59:1758–1775 Blöchl PE (1994) Projector augmented-wave method. Phys Rev B 50:17953–17979 Lu T, Chen F (2012) Multiwfn: a multifunctional wavefunction analyzer. J Comput Chem 33:580–592 Humphrey W, Dalke A, Schulten K (1996) VMD: visual molecular dynamics. J mol graph 14:33–38 Krishnan RBJS, Binkley JS, Seeger R, Pople JA (1980) Self-consistent molecular orbital methods. XX. A basis set for correlated wave functions. J Phys Chem 72:650–654 Additional Declarations There is NO Competing Interest. Supplementary Files SupportingInformation.docx Supporting Information Cite Share Download PDF Status: Under Review Version 1 posted 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. 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02:35:09","extension":"png","order_by":11,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":444479,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage3.png","url":"https://assets-eu.researchsquare.com/files/rs-7907271/v1/4785ee459a0a07e80bbecf21.png"},{"id":95228791,"identity":"e03951ba-1599-4bff-b466-8ea6e831baba","added_by":"auto","created_at":"2025-11-05 16:34:08","extension":"png","order_by":12,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":520554,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage4.png","url":"https://assets-eu.researchsquare.com/files/rs-7907271/v1/4ec1623db688a735868edf3f.png"},{"id":95158259,"identity":"e1eb45c0-cf12-4645-94ad-ef1a02901943","added_by":"auto","created_at":"2025-11-05 02:35:09","extension":"png","order_by":13,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":312818,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage5.png","url":"https://assets-eu.researchsquare.com/files/rs-7907271/v1/8ed875207003cb6d6e3d8568.png"},{"id":95227601,"identity":"ba231181-5b6c-41bb-be61-e2f64d5e66ef","added_by":"auto","created_at":"2025-11-05 16:32:38","extension":"xml","order_by":14,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":136181,"visible":true,"origin":"","legend":"","description":"","filename":"NCOMMS25841300structuring.xml","url":"https://assets-eu.researchsquare.com/files/rs-7907271/v1/ede9a3cfe4519e7e07f82791.xml"},{"id":95225601,"identity":"8f73d1b8-22eb-49be-b222-e586eb16df79","added_by":"auto","created_at":"2025-11-05 16:25:16","extension":"html","order_by":15,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":145433,"visible":true,"origin":"","legend":"","description":"","filename":"earlyproof.html","url":"https://assets-eu.researchsquare.com/files/rs-7907271/v1/bbc21e37f54864efcc99ca7f.html"},{"id":95158255,"identity":"a45b0cfc-c520-4156-92b6-f2dc6a74f45b","added_by":"auto","created_at":"2025-11-05 02:35:09","extension":"jpeg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":935751,"visible":true,"origin":"","legend":"\u003cp\u003e(a) Illustration of the preparation process of BTCP samples. (b) Schematic representation of light-induced rotations of intramolecular bonds in BTCP. (c) Light switch exhibiting conformational isomerism of BTCP caused by the rotation of intramolecular bonds. (d) The discharge-charge profiles of the Li-CO\u003csub\u003e2\u003c/sub\u003e battery with planar and distorted structures under dark and light conditions at a current density of 100 μA cm\u003csup\u003e-2\u003c/sup\u003e. (e) DFT calculations of the adsorption energy of CO\u003csub\u003e2\u003c/sub\u003e and the decomposition energy barriers of Li\u003csub\u003e2\u003c/sub\u003eCO\u003csub\u003e3\u003c/sub\u003e on planar and distorted structures.\u003c/p\u003e","description":"","filename":"floatimage1.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-7907271/v1/cc48c3a1dcbac1b4d57636fb.jpeg"},{"id":95226022,"identity":"bade8217-07a9-4858-9d1d-7eb84f9dc42a","added_by":"auto","created_at":"2025-11-05 16:26:02","extension":"jpeg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":1845211,"visible":true,"origin":"","legend":"\u003cp\u003e(a-d) TEM images of BTCP samples. The insets show the corresponding HRTEM and FFT patterns, respectively. (e) TEM image of BTCP-2 sample with an inset showing HRTEM. The yellow circle highlights the distribution of nanopores, accompanied by a statistical diagram that illustrates the pore diameter distribution. (f, g) HAADF-STEM image and EDX elemental mapping. (h) XRD patterns of BTCP samples. (i) B 1s, O 1s, N 1s, and C 1s XPS spectra of B\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e3\u003c/sub\u003e, C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e and BTCP samples. (j) Solid-state NMR and the corresponding molecular structure unit of BTCP-2 sample. (k) Molecular structure representation of BTCP samples.\u003c/p\u003e","description":"","filename":"floatimage2.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-7907271/v1/f1edd5493e7d9a901e11481b.jpeg"},{"id":95158252,"identity":"7f961786-b825-4e39-8d7f-7ee2ed7ff0df","added_by":"auto","created_at":"2025-11-05 02:35:09","extension":"jpeg","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":1070080,"visible":true,"origin":"","legend":"\u003cp\u003e(a) In situ photoirradiation B1s XPS spectra of BTCP-2 sample. (b, c) PL spectra of C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e and BTCP-2 samples with varying fluorescence intensities. (d) Reversible PL spectrum test of the ratio signal for the BTCP-2 sample. (e) Continuous measurement of PL spectra for the BTCP-2 sample over a duration of 30 min. (f) DOS of planar structure and distorted structure of BTCP-2 sample. (g) Schematic diagram of light-induced reversible intramolecular single bond cooperative rotation (the yellow represents borazine and the blue corresponds to triazine). (h) Bader charge values obtained from DFT calculations. (i) Frontier molecular orbital energy levels (HOMO and LUMO). (j) Electrostatic potential distribution of planar structure (above) and distorted structure (below) of BTCP-2 sample.\u003c/p\u003e","description":"","filename":"floatimage3.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-7907271/v1/8b7734c44fb06d3529334d6c.jpeg"},{"id":95158254,"identity":"e36f160d-8d4c-4c1c-aaca-391632ea40ca","added_by":"auto","created_at":"2025-11-05 02:35:09","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":6702169,"visible":true,"origin":"","legend":"\u003cp\u003e(a, b) Amperometric I-t curves of the BTCP-2 photocathode without applying a bias voltage under illumination with 200 s light on/off cycles and the corresponding EIS curves. (c, d) Discharged and charged curves of four photocathodes at 100 μA cm\u003csup\u003e-2\u003c/sup\u003e and the corresponding voltage gaps and round-trip efficiencies. (e) CV curves at a scanning rate of 0.5 mV s\u003csup\u003e-1\u003c/sup\u003e of the BTCP-2 photocathode. (f) Discharge-charge curves for the BTCP-2 photocathode at different current densities with and without illumination. (g) Corresponding round-trip efficiency under different current densities. (h) Cycling performance of BTCP-2 photocathode at 100 μA cm\u003csup\u003e-2\u003c/sup\u003e with and without illumination (gray dashed lines and arrows indicate the partial enlarged areas). (i) Round-trip efficiency of the battery corresponding to different cycle test times. (j) Comparison chart of capacity, voltage gaps and efficiencies for the rechargeable Li-CO\u003csub\u003e2\u003c/sub\u003e batteries with BTCP-2 photocathode and other reported catalysts from the last three years.\u003c/p\u003e","description":"","filename":"floatimage4.png","url":"https://assets-eu.researchsquare.com/files/rs-7907271/v1/ed88b863fe6e9ffb3ab4d4e0.png"},{"id":95225561,"identity":"bf8a0b7f-1ed0-473f-b395-d30cafb3b69b","added_by":"auto","created_at":"2025-11-05 16:25:13","extension":"jpeg","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":607010,"visible":true,"origin":"","legend":"\u003cp\u003e(a) B 1s XPS spectra of light in vacuum and with CO\u003csub\u003e2\u003c/sub\u003e atmospheric of the BTCP-2 sample. (b) Adsorption energies of Li, CO\u003csub\u003e2\u003c/sub\u003e, and Li\u003csub\u003e2\u003c/sub\u003eCO\u003csub\u003e3\u003c/sub\u003e on BTCP-2 sample, featuring a planar and a distorted structure, respectively (blue represents planar structure and yellow represents distorted structure). (c) Detailed decomposition paths (embedding graph) and decomposition energy barriers of Li\u003csub\u003e2\u003c/sub\u003eCO\u003csub\u003e3\u003c/sub\u003e on BTCP-2 sample with planar and distorted structure. (d) Schematic diagram of the reversible discharge and charge reaction mechanisms of the BTCP-2 photocathode in the photo-assisted\u003cstrong\u003e \u003c/strong\u003eLi-CO\u003csub\u003e2\u003c/sub\u003e battery.\u003c/p\u003e","description":"","filename":"floatimage5.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-7907271/v1/8e2b4e37e69f9cb7628ec5fa.jpeg"},{"id":95523497,"identity":"52f200bb-4e67-4b3a-a7e0-fdcc46580389","added_by":"auto","created_at":"2025-11-10 09:57:08","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":10359255,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7907271/v1/df20c75c-07d5-4727-884b-daebd7d1e169.pdf"},{"id":95158265,"identity":"94421e1c-d276-4a35-aee6-4d37f634f0bc","added_by":"auto","created_at":"2025-11-05 02:35:09","extension":"docx","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":16548193,"visible":true,"origin":"","legend":"Supporting Information","description":"","filename":"SupportingInformation.docx","url":"https://assets-eu.researchsquare.com/files/rs-7907271/v1/35c519dfcd8ed347238ddeb0.docx"}],"financialInterests":"There is \u003cb\u003eNO\u003c/b\u003e Competing Interest.","formattedTitle":"Light-induced borazine/triazine-containing conjugated polymers spatial twist boosting high-performance photo-assisted Li-CO2 batteries","fulltext":[{"header":"Introduction","content":"\u003cp\u003eLithium-carbon dioxide battery (Li-CO\u003csub\u003e2\u003c/sub\u003e) has been considered as a unique solution for realizing sustainable energy storage and recycling CO\u003csub\u003e2\u003c/sub\u003e utilization\u003csup\u003e\u003cspan additionalcitationids=\"CR2\" citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e\u003c/sup\u003e. This system enables CO\u003csub\u003e2\u003c/sub\u003e conversion in energy storage through the reversible reaction 4Li\u0026thinsp;+\u0026thinsp;3CO\u003csub\u003e2\u003c/sub\u003e ⇌ 2Li\u003csub\u003e2\u003c/sub\u003eCO\u003csub\u003e3\u003c/sub\u003e\u0026thinsp;+\u0026thinsp;C, providing a superior theoretical energy density of 1876 Wh kg\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e and an output potential of 2.8 V (\u003cem\u003evs.\u003c/em\u003e Li\u003csup\u003e+\u003c/sup\u003e/Li)\u003csup\u003e4, \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e\u003c/sup\u003e. However, the sluggish reaction kinetics of CO\u003csub\u003e2\u003c/sub\u003e reduction reactions (CO\u003csub\u003e2\u003c/sub\u003eRR) and CO\u003csub\u003e2\u003c/sub\u003e evolution reactions (CO\u003csub\u003e2\u003c/sub\u003eER), along with incomplete dissociation of discharge products (Li\u003csub\u003e2\u003c/sub\u003eCO\u003csub\u003e3\u003c/sub\u003e), resulted in high overpotentials with low round-trip efficiency, limited rate capability and poor reversibility\u003csup\u003e\u003cspan additionalcitationids=\"CR7 CR8 CR9 CR10\" citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e\u003c/sup\u003e. To tackle these challenges, photo-assisted Li-CO\u003csub\u003e2\u003c/sub\u003e battery strategies have been proposed to incorporate semiconductor materials with appropriate band structures into the cathode for accelerating the kinetics of CO\u003csub\u003e2\u003c/sub\u003eRR and CO\u003csub\u003e2\u003c/sub\u003eER by utilizing photoexcited high-energy electrons and holes\u003csup\u003e\u003cspan additionalcitationids=\"CR13\" citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e\u003c/sup\u003e. Therefore, semiconductor material serving as photoelectrode is crucial to the performance of the Li-CO\u003csub\u003e2\u003c/sub\u003e battery. Extensive research has demonstrated that photoelectrode efficiency can be enhanced through various strategies, such as designing porous structures, optimizing defect energy levels, constructing heterojunctions, and applying external fields. For instance, Lan\u0026rsquo;s group recently prepared porous structures with rich porosity phthalocyanine based metal-organic frameworks (CoPc-Mn-O)\u003csup\u003e15\u003c/sup\u003e and metal-covalent organic frameworks (Cu\u003csub\u003e3\u003c/sub\u003e-BTDE-COF)\u003csup\u003e\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e\u003c/sup\u003e, achieving outstanding round-trip efficiencies of 99% at 0.01 mA cm\u003csup\u003e\u0026minus;\u0026thinsp;2\u003c/sup\u003e and 95% at 200 mA g\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, respectively. A In\u003csub\u003e2\u003c/sub\u003eS\u003csub\u003e3\u003c/sub\u003e@CNT/SS\u003csup\u003e17\u003c/sup\u003e photoelectrode materials with hierarchical porous structure has been proposed in Xu\u0026rsquo;s group, achieving an impressive round-trip efficiency of 98% at 0.01 mA cm\u003csup\u003e\u0026minus;\u0026thinsp;2\u003c/sup\u003e. Our group also prepared a boric acid coated boron (B@BA\u003csub\u003e2\u003c/sub\u003e)\u003csup\u003e\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e\u003c/sup\u003e photoelectrode that achieved an overpotential as low as 0.07 V and a round-trip efficiency of 98% at 0.01 mA cm\u003csup\u003e\u0026minus;\u0026thinsp;2\u003c/sup\u003e, with a low charging potential of 2.80 V by utilizing unique dissociation-exposure strategy to introduce defect-rich electron-deficient boron for efficient Li-CO\u003csub\u003e2\u003c/sub\u003e batteries. In addition, Peng\u0026rsquo;s group developed a heterostructure (CNT@C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e)\u003csup\u003e\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e\u003c/sup\u003e photoelectrode by leveraging the defect properties of C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e and favorable interfacial charge transfer mechanisms, demonstrating a round-trip efficiency of 89% and excellent cycling stability with 86% after 100 cycles. They also designed a nano-Ag modified TiO\u003csub\u003e2\u003c/sub\u003e nanotubes (TNAs@AgNPs)\u003csup\u003e\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e\u003c/sup\u003e photoelectrode applied into the dual-field assisted Li-CO\u003csub\u003e2\u003c/sub\u003e battery, which reduced the overpotential to 0.37 V and achieved a round-trip efficiency of 87% at 0.1 mA cm\u003csup\u003e\u0026minus;\u0026thinsp;2\u003c/sup\u003e. Nevertheless, conventional photoelectrode materials still suffer from the limited in-plane molecular carrier separation and transport capabilities based on the static molecular conformation, resulting in the confined polarization electric fields that hinder the improvement of photoelectric conversion and storage performance.\u003c/p\u003e\u003cp\u003ePhotoinduced molecular twisting harnesses light to drive molecular isomerization, thereby enabling precise modulation of optoelectronic and chemical properties. Upon photoexcitation, the separation of electrons and holes alters the molecular dipole moment, causing the molecular framework to undergo a reversible conformational twist to stabilize the excited state, primarily achieved through the rotation of intramolecular bonds\u003csup\u003e\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e, \u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e\u003c/sup\u003e. Most commonly facilitated by single-bond rotations, as observed in the twisting of C\u0026thinsp;=\u0026thinsp;C, C\u0026thinsp;=\u0026thinsp;N, or N\u0026thinsp;=\u0026thinsp;N bonds in alkenes or aromatic organic molecules\u003csup\u003e\u003cspan additionalcitationids=\"CR24\" citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e\u003c/sup\u003e. More recently, coupled photoisomerization involving multi-bond rotations has been demonstrated to be feasible as well. Studies by Jack Saltiel et al.\u003csup\u003e26\u003c/sup\u003e and Aaron Gerwien et al.\u003csup\u003e27\u003c/sup\u003e reported the discovery of simultaneous three-bond twist in conjugated hexane system and hula twist in hemithioindigo, respectively, confirming that C\u0026thinsp;=\u0026thinsp;C and adjacent C-C bonds can rotate simultaneously under light irradiation. Henry Dube et al.\u003csup\u003e28\u003c/sup\u003e introduced two asymmetric aryl substituents in hemithioindigo and presented both hula-twist and dual single-bond rotation photoactivated reactions, enabling the interconversion of eight different isomers under light conditions. Akira Katsuyama\u0026rsquo;s group\u003csup\u003e\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e\u003c/sup\u003e constructed a chalcogen-substituted benzamide system that achieves light-induced C-N/C-C concerted bond rotation by introducing a chalcogen substituent into a sterically hindered benzamide system. In addition, the Hai-long Jiang team\u003csup\u003e\u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e\u003c/sup\u003e discovered an asymmetric metal-organic framework (MOF) with electronically insulated Zn\u003csup\u003e2+\u003c/sup\u003e nodes, where two chemically equivalent yet crystallographically independent linkers contain entirely different orbitals. Upon photoexcitation, it experiences a dynamic excited-state structural twist, resulting in orbital rearrangements that inhibits radiative relaxation and foster a long-lived charge-separated state. However, to date, most studies on photoisomerization behaviors have primarily focused on biomolecules or small organic molecules. There is no definitive conclusion as to whether this photoisomerization mechanism can be successfully extended to non-metallic polymer semiconductors. Especially, the relationship between light-induced molecular twisting of semiconductor photocatalyst and variations in optical properties remains limited and requires further in-depth exploration.\u003c/p\u003e\u003cp\u003eIn this work, we report a borazine/triazine-containing conjugated polymer semiconductor (BTCP) that exhibits light-induced conformational isomerism and demonstrates highly efficient bifunctional photocatalytic activity in photo-assisted Li-CO\u003csub\u003e2\u003c/sub\u003e batteries. Unlike conventional rigid conjugated systems, the coexistence of borazine and triazine rings imparts greater molecular flexibility and torsional freedom due to variations in bond lengths and π-electron delocalization\u003csup\u003e\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e, \u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e32\u003c/span\u003e\u003c/sup\u003e. Motivated by this, BTCPs were synthesized to investigate their structural evolutions and photoelectronic behavior under light irradiation (synthetic procedure and mechanism are shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003ea, and \u003cb\u003eSupplementary Fig.\u0026nbsp;1 and\u003c/b\u003e Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). As illustrated in Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003eb and \u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003ec, cooperative bond rotation occurs upon illumination, leading to structural distortion that is fully reversible once the light source is removed. Combined experimental and density functional theory (DFT) calculations reveal that light-induced deformation promotes electron cloud redistribution within BTCP, generating electronic asymmetry that enhances the built-in electric field and optimizes HOMO-LUMO (the highest occupied molecular orbital-the lowest unoccupied molecular orbital) energy level alignment\u003csup\u003e\u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e33\u003c/span\u003e, \u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e34\u003c/span\u003e\u003c/sup\u003e. These effects significantly improve photogenerated charge separation and migration efficiency. Notably, the electron cloud density around the B atom decreases, further strengthening electron-deficient characteristics that facilitate CO\u003csub\u003e2\u003c/sub\u003e adsorption/activation and lower the energy barrier for Li\u003csub\u003e2\u003c/sub\u003eCO\u003csub\u003e3\u003c/sub\u003e decomposition (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003ee). As a result, BTCP photoelectrode delivers outstanding bifunctional photocatalytic activity in photo-assisted Li-CO\u003csub\u003e2\u003c/sub\u003e batteries by accelerating the kinetics of CO\u003csub\u003e2\u003c/sub\u003eRR during the discharge and CO\u003csub\u003e2\u003c/sub\u003eER during charge, thus enabling superior performance (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003ed). At a current density of 100 \u0026micro;A cm\u003csup\u003e\u0026minus;\u0026thinsp;2\u003c/sup\u003e, the cell exhibits a high overpotential of 2.66 V and the round-trip efficiency of only 38% under dark conditions. In contrast, under illumination it achieves an ultralow potential hysteresis of only 0.1 V and an exceptionally high round-trip efficiency of 96%, outperforming most reported electrode materials (\u003cb\u003eTable \u003cspan refid=\"MOESM1\" class=\"InternalRef\"\u003eS1\u003c/span\u003e\u003c/b\u003e). To the best of our knowledge, this study provides the first experimental evidence that light-induced intramolecular bond rotation can substantially boost the photocatalytic activity of conjugated polymer semiconductors in photo-assisted Li-CO\u003csub\u003e2\u003c/sub\u003e batteries, opening new avenues for the design and application in advanced photocatalytic systems.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e"},{"header":"Results and Discussion","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e\u003ch2\u003eMorphological characterizations and composition analysis\u003c/h2\u003e\u003cp\u003eThe BTCP samples were prepared through pyrolysis using varying ratios of boric acid and urea as precursors. The resulting samples were labeled as BTCP-1, BTCP-2, BTCP-3, and BTCP-4 according to the increasing ratios, and were systematically investigated. The morphology and composition of the as-prepared borazine/triazine-containing conjugated polymer BTCP samples were investigated using scanning electron microscopy (SEM) and transmission electron microscopy (TEM) characterization. Distinct differences were observed between the as-prepared samples, as shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003ea-d, which revealed significant morphological changes. Notably, BTCP-2 displayed a uniform distribution of porous nanosheet-like structures, as depicted in Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003eb. High-resolution TEM images (inset of Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003eb) reveal that these nanosheets are amorphous, with nanoscale pore diameters of approximately 25 nm and exceptionally high porosity (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003ee and the inset, indicated by yellow circles in the inset). \u003cb\u003eSupplementary Fig.\u0026nbsp;3\u003c/b\u003e illustrates that BTCP-1 retained a micron-sized block-like structure akin to that of boron trioxide (B\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e3\u003c/sub\u003e), whereas BTCP-2 exhibited a smaller particle-like morphology. In contrast, BTCP-3 and BTCP-4 progressively displayed a sheet-like structure resembling that of graphitic carbon nitride (g-C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e), with BTCP-4 demonstrating a fully sheet-like morphology. Further TEM analyses revealed that the pyrolysis product of boric acid, B\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e3\u003c/sub\u003e, displays a highly crystalline block-like morphology, whereas the pyrolysis product obtained from urea, C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e, presents a weakly crystalline nanosheet-like structure (\u003cb\u003esee Supplementary Fig.\u0026nbsp;4\u003c/b\u003e). High-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM), dark-field TEM images also provide clear information on the pore distribution (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003ef and \u003cb\u003eSupplementary Fig.\u0026nbsp;5\u003c/b\u003e), and elemental mapping (EDX mapping images) verified the homogeneous distribution of B, O, N, and C elements (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003eg). X-ray diffraction (XRD) results further confirm that, except for BTCP-1, which shows a distinct B\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e3\u003c/sub\u003e characteristic peak, all other products exhibit an amorphous structure (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003eh and \u003cb\u003eSupplementary Fig.\u0026nbsp;6\u003c/b\u003e). BET analysis indicates that BTCP-2 has the highest specific surface area and the most abundant mesoporous structure, with its surface area significantly surpassing the other three samples, approximately 2 to 50 times greater (\u003cb\u003eSupplementary Fig.\u0026nbsp;7\u003c/b\u003e). This considerable difference is primarily attributed to its uniformly distributed porous nanosheet structure, demonstrating that a porous nanosheet-like conjugated polymer can be successfully synthesized via a template-free, one-step pyrolysis method. The large surface area provides abundant adsorption and catalytic sites, offering clear advantages for photocatalytic applications.\u003c/p\u003e\u003cp\u003eX-ray photoelectron spectroscopy (XPS) analysis confirmed that all the BTCP samples contain B, N, C, and O elements (\u003cb\u003eSupplementary Fig.\u0026nbsp;8\u003c/b\u003e). The results of the chemical state analysis for each element reveal that when the boric acid to urea ratio is 1:1, no characteristic\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003epeaks corresponding to B-N are observed in the B 1s and N 1s spectra (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003ei). At this stage, the system mainly consisted a substantial amount of B-O bonds at 193.1 eV, minor B-C bonds at 190.9 eV, and several C-N peaks associated with the triazine ring (N-C\u0026thinsp;=\u0026thinsp;N and N-(C\u003csub\u003e3\u003c/sub\u003e)), and a small amount attributed to N-O bonds (402.5 eV), suggesting that the BN-related conjugated system has not yet formed and may instead be linked through oxygen bridges\u003csup\u003e\u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e35\u003c/span\u003e, \u003cspan citationid=\"CR36\" class=\"CitationRef\"\u003e36\u003c/span\u003e\u003c/sup\u003e. Upon increasing the ratio to 1:5, B-O bonds completely disappeared and were replaced by B-N and B-C bonds in the B 1s spectra as the main components according to both the B 1s and N 1s spectra, indicating the formation of conjugated system\u003csup\u003e\u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e37\u003c/span\u003e\u003c/sup\u003e. Notably, further increasing the urea content was accompanied by the enhancement of the characteristic peaks corresponding to the 1,3,5-CN triazine ring associated with the C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e features, and this trend was also consistent with the SEM and TEM results. The Fourier transform infrared (FT-IR) spectroscopy also highlights differences among the various products (\u003cb\u003eSupplementary Fig.\u0026nbsp;9\u003c/b\u003e). In comparison to the pyrolysis products of the individual precursors, the pyrolysis of the mixture shows distinct N-H absorption peaks at ~\u0026thinsp;3456 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e and B-C absorption peaks at ~\u0026thinsp;1105 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e and ~\u0026thinsp;1025 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e. For the BTCP-1 sample, the B-O bonds remain significantly present, whereas in the other three samples they are completely absent and appear characteristic absorption peaks corresponding to the B-N bonds, with typical peaks at approximately 1248 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, 782 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, and 695 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e attributed to the stretching and bending vibrations of B-N\u003csup\u003e38, 39\u003c/sup\u003e. As the nitrogen source content increases during preparation, the intensity of the B-N absorption peaks decreases, while the characteristic peaks corresponding to C-N bonds associated with C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e features increase. This is consistent with the XPS results, indicating that the BTCP-1 sample does not have a fully formed conjugated system, while the BTCP-2 sample contains the highest concentration of BN units based on the complete BN conjugated polymer, and in the BTCP-3 and BTCP-4 samples, in addition to the BN units, more CN units resembling C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e characteristics are present. Solid-state \u003csup\u003e\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e\u003c/sup\u003eB, \u003csup\u003e1\u003c/sup\u003eH and \u003csup\u003e\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e\u003c/sup\u003eC nuclear magnetic resonance (NMR) spectra were collected to provide further structural information. As shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003ej, the \u003csup\u003e\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e\u003c/sup\u003eB NMR spectrum exhibits two distinct peaks: a broad signal spanning between 10 and 30 ppm, attributed to three-coordinated boron bonds that accounts for a large part, while the sharp peak at ~\u0026thinsp;0 ppm corresponds to four-coordinated boron, suggesting the existence of two different coordination environments arising from intramolecular boron atoms\u003csup\u003e\u003cspan citationid=\"CR40\" class=\"CitationRef\"\u003e40\u003c/span\u003e\u003c/sup\u003e. The \u0026sup1;H NMR spectra showed two single peaks at 6.74 ppm and 2.98 ppm, which were assigned to the intramolecular N-H and NH\u003csub\u003e2\u003c/sub\u003e groups at the edges, respectively. In the \u003csup\u003e\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e\u003c/sup\u003eC NMR spectra, a peak appeared at 167.5 ppm, indicating a consistent chemical environment for the carbon atoms, with all carbon atoms derived from the triazine ring, suggesting high molecular symmetry\u003csup\u003e\u003cspan citationid=\"CR41\" class=\"CitationRef\"\u003e41\u003c/span\u003e\u003c/sup\u003e. Based on the above morphological characteristics and compositional analysis results, and the relevant reaction processes involved during pyrolysis (\u003cb\u003eSupplementary Fig.\u0026nbsp;1\u003c/b\u003e and Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e), potential molecular structures of each product were proposed, as shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003ek.\u003c/p\u003e\u003c/div\u003e\n\u003ch3\u003eOptical property and light-induced structural evolution\u003c/h3\u003e\n\u003cp\u003eThe optical properties of these BTCP samples are first investigated to assess their potential for photocatalytic applications. Absorption spectra were obtained by using UV/Vis diffuse reflectance spectroscopy (DRS). As depicted in \u003cb\u003eSupplementary Fig.\u0026nbsp;10a\u003c/b\u003e, the absorption characteristics of the samples obtained demonstrate clear variations in the wavelength range of 260\u0026ndash;400 nm, with BTCP-2 exhibiting the highest absorption and BTCP-1 showing the lowest. This is mainly because the formation of the conjugated system enhances π-π* transitions, while the creation of the BN-conjugated structure in borazine leads to more delocalized π-electrons, resulting in a noticeable red-shift in the absorption edge\u003csup\u003e\u003cspan citationid=\"CR42\" class=\"CitationRef\"\u003e42\u003c/span\u003e\u003c/sup\u003e. Consequently, the BTCP-1 sample exhibits the weakest light absorption capacity due to its imperfect conjugated system, whereas the BTCP-2 sample demonstrates the broadest light absorption range owing to its highest content of borazine, which aligns with the proposed molecular formula. Based on the UV-vis absorption edge onsets, the optical band gaps (E\u003csub\u003eg\u003c/sub\u003e) were calculated to be 4.12, 3.63, 3.87, and 3.76 eV for samples from BTCP-1 to BTCP-4, respectively (\u003cb\u003eSupplementary Fig.\u0026nbsp;10b\u003c/b\u003e). The band structure derived from the E\u003csub\u003eg\u003c/sub\u003e values and the valence bands (VB) positions based on the ultraviolet photoelectron spectroscopy (UPS) tests suggest that all samples exhibit the thermodynamic potential for photocatalytic CO\u003csub\u003e2\u003c/sub\u003eRR and CO\u003csub\u003e2\u003c/sub\u003eER, making them promising candidates as photoelectrodes for photo-assisted Li-CO\u003csub\u003e2\u003c/sub\u003e battery (\u003cb\u003eSupplementary Fig.\u0026nbsp;11\u003c/b\u003e and \u003cb\u003eFig.\u0026nbsp;12\u003c/b\u003e). Among them, BTCP-2 exhibits the smallest band gap, indicating the smallest energy difference between the VB and conduction bands (CB), which facilitates the transition of electrons from the valence band to the CB. The Mott-Schottky plot shows the characteristic behavior of n-type semiconductors, as evidenced by the positive slope of the curve (\u003cb\u003eSupplementary Fig.\u0026nbsp;13\u003c/b\u003e). In the case of n-type semiconductors, the incorporation of B-N units into the π-conjugated system leads to an increase in the electrostatic potential due to the positive charge on the nitrogen atom. This enhances the electron-deficient characteristics of the conjugated system, resulting in a lower LUMO energy level and stronger reductive properties\u003csup\u003e\u003cspan citationid=\"CR43\" class=\"CitationRef\"\u003e43\u003c/span\u003e\u003c/sup\u003e. As shown in \u003cb\u003eSupplementary Fig.\u0026nbsp;12\u003c/b\u003e, BTCP-2 has the most negative LUMO position. Maintaining charge separation is crucial for photocatalytic activity, as the effective utilization of photogenerated electrons and holes is closely linked to the charge separation state. The charge separation behavior was investigated using photoluminescence spectroscopy (PL) and time-resolved fluorescence decay measurements. \u003cb\u003eSupplementary Fig.\u0026nbsp;14\u003c/b\u003e presents the PL intensity of BTCP-2, which is notably suppressed relative to the other samples, accompanied by the longest average fluorescence lifetime (τ\u003csub\u003eavg\u003c/sub\u003e\u0026thinsp;=\u0026thinsp;5.04 ns), indicating enhanced charge separation efficiency and reduced charge recombination. Furthermore, the transient photocurrent response revealed that BTCP-2 had the highest intensity among all samples (\u003cb\u003eSupplementary Fig.\u0026nbsp;15\u003c/b\u003e), suggesting superior light-induced electron separation and transport efficiency.\u003c/p\u003e\u003cp\u003eLight-induced molecular twisting is accompanied by changes in the atomic chemical states. To verify these structural transformations and their impact on optical properties under light exposure, we combined XPS, PL measurements and theoretical calculations. Firstly, we performed in situ photoirradiation XPS analysis to examine the potential changes in the electron density distribution of the BTCP-2 sample after prolonged light exposure, aiming to observe its structural modifications. It is noteworthy that under light irradiation, the B 1s peak shifts noticeably towards a higher binding energy (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003ea). With increasing irradiation time, the binding energy in the XPS spectra continuously shifts towards higher values and stabilizes after 60 minutes or more of light irradiation. This suggests that during the light irradiation process, the local electronic structure of the B atoms in the sample undergoes a gradual change, with a decrease in electron cloud density, transitioning towards a stronger electron-deficient environment. Interestingly, upon switching off the light source, the binding energy gradually returned to its original position, indicating that the light-induced structural changes are highly reversible and the material\u0026rsquo;s structure remains intact. This reversible structural change is of significant importance for the material\u0026rsquo;s potential application as a photocatalyst. Furthermore, no noticeable shift was observed in the N 1s XPS spectrum, but the peak associated with NH gradually diminished with light irradiation and reappeared under dark conditions (\u003cb\u003eSupplementary Fig.\u0026nbsp;16\u003c/b\u003e), likely due to the breaking and regeneration of the hydrogen bonds around N atoms, which are connected via hydrogen bonding within the molecule. This further indicates that the conjugated system undergoes modifications under light irradiation. PL tests were further employed to investigate the impact of light exposure on the structure, with laser intensity adjusted by controlling the slit width during the testing process. Comparative analysis of PL spectra under different laser intensities revealed that the conjugated\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003echaracteristics of the structure of the BTCP-2 sample underwent significant changes. For highly rigid C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e, increasing the excitation light intensity did not cause any shift or intensity change in the PL absorption peak, indicating that variations in light intensity have no significant effect on its molecular configuration (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003eb). However, regarding the BTCP-2 sample, significant changes were observed in the PL peaks. As shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003ec, the PL emission peak at approximately 460 nm, associated with the strongly conjugated structure, significantly decreases with increasing intensity, while the peak around 360 nm, representing the non-conjugate unit, markedly intensifies. This suggests that light irradiation promotes the transition of the system from a conjugated to a non-conjugated structure, which is consistent with the XPS characterization results. Considering the difficulty in directly comparing fluorescence intensities at different excitation light intensities, a ratio-based (I\u003csub\u003e323nm\u003c/sub\u003e/I\u003csub\u003e467nm\u003c/sub\u003e) approach was utilized for reversibility testing. As shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003ed, the I\u003csub\u003e323nm\u003c/sub\u003e/I\u003csub\u003e467nm\u003c/sub\u003e ratio increased with increasing excitation light intensity and decreased as the intensity was reduced. After six cycles, the I\u003csub\u003e323nm\u003c/sub\u003e/I\u003csub\u003e467nm\u003c/sub\u003e ratio remained close to its initial value, indicating that the light-induced structural deformation process is highly reversible. Subsequently, a 120-minute continuous test was conducted under the same excitation light intensity (maximum intensity). The results have shown that both the intensity of the 357 nm emission peak and the I\u003csub\u003e323nm\u003c/sub\u003e/I\u003csub\u003e467nm\u003c/sub\u003e ratio remained stable throughout the test, indicating that the material did not undergo photodegradation during prolonged light exposure, further demonstrating excellent photostability and structural stability (\u003cb\u003eSupplementary Fig.\u0026nbsp;17\u003c/b\u003e). The above results demonstrate a high degree of consistency with the findings from \u003cem\u003ein situ\u003c/em\u003e photoirradiation XPS measurements. More importantly, in contrast to the PL intensity of C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e that enhance with time, the PL intensities of BCTCP-2 sample display a decreasing trend with increasing illumination time, further confirming that the photogenerated carriers possess longer lifetimes and lower recombination rates (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003ee and \u003cb\u003eSupplementary Fig.\u0026nbsp;18\u003c/b\u003e). The above PL test results demonstrate that the samples we prepared exhibit light-induced reversible and stable structural changes, and after prolonged testing, they maintain excellent structural stability and carrier lifetime. This indicates that the material can operate continuously and efficiently in photocatalytic reactions, underscoring its considerable potential for photocatalytic applications.\u003c/p\u003e\u003cp\u003eTo elucidate the effect of molecular spatial structure changes on electronic structure and photoelectric properties of materials, density functional theory (DFT) was employed to analyze density of states (DOS), electron density distributions, band structures and the moment of dipole. DOS analysis reveals that the VB of the BTCP-2 planar structure is primarily derived from N and B atoms, and the CB is predominantly derived from C and N atoms (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003ef). In contrast, in the distorted structure, the VB includes contributions from N atoms and the CB includes support from N and B atoms. This structural change enables the transition of electrons from the top of the VB to the bottom of the CB in boron atoms, thereby activating the boron atoms. According to bader charge analysis, compared to the coplanar conjugated structure, the charge of the B atom in the torsional structure significantly decreases, leads to an asymmetric electron distribution\u003csup\u003e\u003cspan citationid=\"CR44\" class=\"CitationRef\"\u003e44\u003c/span\u003e, \u003cspan citationid=\"CR45\" class=\"CitationRef\"\u003e45\u003c/span\u003e\u003c/sup\u003e (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003eh). We speculate that the main reason for this change is related to the variation in the molecular structure induced by light. When the B atom is coplanar with the triazine ring, the conjugative effect promotes electron sharing, forming a unified π-electronic system that enhances electron delocalization. However, when the triazine ring is no longer coplanar with the B atom, the conjugated system is disrupted. Since the triazine ring is an electron-withdrawing group (EWG), the electron density on the B atom consequently decreases because of the presence of electron-absorbing effects (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003eg). As presented in Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003ei, calculations of the molecular orbital levels show a significant reduction in the LUMO-HOMO energy gap of the torsional structure, which means that lower energy is required for the transition from HOMO to LUMO, thereby facilitating the generation of electron-hole pairs. Meanwhile, in the planar structure, the HOMO and LUMO are mainly localized on the B and N atoms linking the triazine and borazine rings, as well as on the triazine ring itself, with only minor differences in their orbital distributions. However, in the twisted structure, the HOMO is almost distributed throughout the molecule, while the LUMO orbital is predominantly distributed around the triazine ring that rotates around the B atom and its vicinity, and this significant distribution is more favorable to facilitate more effective charge spatial separation and transmission\u003csup\u003e\u003cspan citationid=\"CR46\" class=\"CitationRef\"\u003e46\u003c/span\u003e\u003c/sup\u003e. The asymmetry in the electronic structure can induce a large dipole moment\u003csup\u003e\u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e33\u003c/span\u003e\u003c/sup\u003e. The dipole moment (2.88 D) of the distorted structure is significantly higher than that of the planar structure (0.95 D), which will lead to an increased built-in electric field, further accelerating the separation of photogenerated electron-hole pairs\u003csup\u003e\u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e34\u003c/span\u003e, \u003cspan citationid=\"CR47\" class=\"CitationRef\"\u003e47\u003c/span\u003e\u003c/sup\u003e (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003ej). The above results indicate that light-induced molecular twisting alters the electronic configuration, affecting HOMO/LUMO distributions and dipole moment, which enhances light absorption and improves exciton generation and carrier separation efficiency, ultimately leading to better photocatalytic efficiency.\u003c/p\u003e\n\u003ch3\u003ePerformance evaluation of photo-assisted Li-CO batteries\u003c/h3\u003e\n\u003cp\u003eThe photoelectric conversion and energy storage performance of photo-assisted Li-CO\u003csub\u003e2\u003c/sub\u003e batteries assembled with BTCP-x (x\u0026thinsp;=\u0026thinsp;1\u0026ndash;4) as the photocathode were systematically evaluated. Discharge/charge tests of four different samples at a current density of 100 \u0026micro;A cm\u003csup\u003e\u0026minus;\u0026thinsp;2\u003c/sup\u003e are first conducted for evaluating the reaction kinetics of CO\u003csub\u003e2\u003c/sub\u003e redox under both dark and light conditions (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003ec). Based on the experimental test results, the performance of the BTCP based Li-CO\u003csub\u003e2\u003c/sub\u003e battery under light conditions was significantly better than that observed under dark conditions. Among the tested photoelectrodes, BTCP-2 photoelectrode was demonstrated to display the best performance, achieving an overpotential as low as 0.13 V and a round-trip efficiency as high as 95.5%, with discharge and charging potentials of 2.76 V and 2.89 V (\u003cem\u003evs.\u003c/em\u003e Li\u003csup\u003e+\u003c/sup\u003e/Li), respectively, which far surpass those of other samples and the commonly used C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e photocatalyst, thereby confirming its remarkable suitability for the photo-assisted Li-CO\u003csub\u003e2\u003c/sub\u003e battery system (\u003cb\u003eSupplementary Fig.\u0026nbsp;19 and Fig.\u0026nbsp;20\u003c/b\u003e). The exceptional performance of the BTCP-2 photocathode in Li-CO\u003csub\u003e2\u003c/sub\u003e batteries may be attributed to its rapid light response capability and the dynamics of CO\u003csub\u003e2\u003c/sub\u003e redox, as the photo-assisted Li-CO\u003csub\u003e2\u003c/sub\u003e battery systems largely relies on the efficient execution of photocatalytic CO\u003csub\u003e2\u003c/sub\u003eRR and CO\u003csub\u003e2\u003c/sub\u003eER. The I-t curves in Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003ea show that BTCP-2 photocathode exhibits high photosensitivity and rapid light response capability under conditions of random switching between illumination and darkness. The corresponding EIS results (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003eb) validate the superior charge separation and transfer efficiency under light exposure. Additionally, the stable variations observed in the I-t curves during repeated cycles of illumination and darkness indicated the high stability and reproducibility of the BTCP-2 photocathode under light conditions. Meanwhile, cyclic voltammetry (CV) measurements were conducted within a potential range of 1.5 to 4.5 V to investigate the activities of CO\u003csub\u003e2\u003c/sub\u003eRR and CO\u003csub\u003e2\u003c/sub\u003eER. As depicted in Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003ee, two distinct representative reduction and oxidation peaks were observed under illumination compared to dark conditions, suggesting the enhanced activity of CO\u003csub\u003e2\u003c/sub\u003e redox under light. Linear sweep voltammetry (LSV) was performed to further confirm the influence of light on the CO\u003csub\u003e2\u003c/sub\u003eRR and CO\u003csub\u003e2\u003c/sub\u003eER, revealing that the onset potentials and the limiting current densities for both CO\u003csub\u003e2\u003c/sub\u003eRR and CO\u003csub\u003e2\u003c/sub\u003eER under illumination are significantly higher than those measured in the absence of light (\u003cb\u003eSupplementary Fig.\u0026nbsp;21\u003c/b\u003e). Therefore, BTCP-2 exhibits rapid charge transfer capability and excellent CO\u003csub\u003e2\u003c/sub\u003e redox kinetics under illumination, ensuring its outstanding bifunctional photocatalytic activity as the photoelectrode in Li-CO\u003csub\u003e2\u003c/sub\u003e batteries.\u003c/p\u003e\u003cp\u003eSubsequently, comprehensive assessments of rate capability and cycling stability were carried out to further evaluate the application performance of the Li-CO\u003csub\u003e2\u003c/sub\u003e battery system. The rate\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003eprofiles of the BTCP-2 photocathode at different current densities of 10, 50, 100, 500, 1000 and 10 \u0026micro;A cm\u003csup\u003e\u0026minus;\u0026thinsp;2\u003c/sup\u003e are shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003ef and Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003eh. Under all current densities, the rate performance of assembled battery in the presence of light significantly exceeds that under dark conditions, with corresponding round-trip efficiencies of 98%, 94%, 88%, 79%, 74% and 98%, respectively. It can be observed that the round-trip efficiency maintains a high level of performance even at a current density of 1000 \u0026micro;A cm\u003csup\u003e\u0026minus;\u0026thinsp;2\u003c/sup\u003e. Notably, even after testing at a high current density of 1000 \u0026micro;A cm\u003csup\u003e\u0026minus;\u0026thinsp;2\u003c/sup\u003e, the battery efficiency can still be reversibly restored when returning to a low current density of 10 \u0026micro;A cm\u003csup\u003e\u0026minus;\u0026thinsp;2\u003c/sup\u003e, maintaining a round-trip efficiency of 98%, which suggests excellent reversibility. The cycling stability was also tested at 100 \u0026micro;A cm\u003csup\u003e\u0026minus;\u0026thinsp;2\u003c/sup\u003e under both light and dark conditions. As shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003ei, the Li-CO\u003csub\u003e2\u003c/sub\u003e battery with BTCP-2 photoelectrode failed after nearly 200 h of testing in the dark. However, under light conditions, it maintained a small voltage gap and high energy efficiency even after over 600 h of testing. The BTCP-2 based photo-assisted Li-CO\u003csub\u003e2\u003c/sub\u003e battery retained high round-trip efficiencies of 73%, 59%, 59%, 53.0%, 50%, 50%, and 48% after 100 h, 200 h, 300 h, 400 h, 500 h, and 600 h of cycling, respectively. Meanwhile, during the initial stage of the light cycling tests, the discharge and charge curves of the BTCP-2 based Li-CO\u003csub\u003e2\u003c/sub\u003e battery presented a significant difference in the discharge and charge potentials of the battery with illumination and without illumination (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003eh). The stability of the battery was not affected by the light switching, which further verifies the high stability of Li-CO\u003csub\u003e2\u003c/sub\u003e battery system assembled with BTCP-2 photoelectrodes, suggesting that this system possesses good durability and reliability for practical applications. Based on the analysis comparing the recently reported literature, as presented in Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003ek and \u003cb\u003eSupplementary Table\u0026nbsp;1\u003c/b\u003e, the BTCP-2 photoelectrode demonstrates outstanding Li-CO\u003csub\u003e2\u003c/sub\u003e battery performance, surpassing previously reported cathode photocatalysts under analogous experimental conditions. Specifically, Specifically, it achieved a round-trip efficiency of up to 96% at a current density of 100 \u0026micro;A cm\u003csup\u003e\u0026minus;\u0026thinsp;2\u003c/sup\u003e, demonstrated a battery capacity exceeding 1000 \u0026micro;Ah cm\u003csup\u003e\u0026minus;\u0026thinsp;2\u003c/sup\u003e, and exhibited exceptional cycling stability with 323 continuous cycles over a duration of 626 h (27 days). The findings presented above demonstrate that BTCP-2 based photo-assisted Li-CO\u003csub\u003e2\u003c/sub\u003e battery has excellent bifunctional activities for both CO\u003csub\u003e2\u003c/sub\u003eRR and CO\u003csub\u003e2\u003c/sub\u003eER activities, along with high rate performance and enduring cycling stability.\u003c/p\u003e\n\u003ch3\u003eReaction products monitoring with mechanistic analysis\u003c/h3\u003e\n\u003cp\u003eThe evolution of products during discharge and charge was investigated to evaluate the reversibility of the CO\u003csub\u003e2\u003c/sub\u003eRR and the CO\u003csub\u003e2\u003c/sub\u003eER in Li-CO\u003csub\u003e2\u003c/sub\u003e batteries, as well as to gain mechanistic insight into the underlying reactions. EIS measurements of the BTCP-2 photocathode over a 40 h continuous discharge-charge cycle (20 h discharge, 20 h charge) revealed a clear trend (\u003cb\u003eSupplementary Fig.\u0026nbsp;22 and Fig.\u0026nbsp;23\u003c/b\u003e). During discharge, the charge-transfer resistance increased steadily, indicating the accumulation of poorly conductive products on the photoelectrode surface. In contrast, during charging, the resistance decreased progressively and returned to its initial value, confirming the reversible decomposition of the discharge products. The nature of these discharge products was identified by XRD and XPS. After 20 h discharge, distinct diffraction peaks corresponding to Li\u003csub\u003e2\u003c/sub\u003eCO\u003csub\u003e3\u003c/sub\u003e were observed\u003csup\u003e\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e\u003c/sup\u003e, which disappeared after 20 h charging (\u003cb\u003eSupplementary Fig.\u0026nbsp;24\u003c/b\u003e). XPS spectra further corroborated these findings. In the C 1s spectrum, a peak characteristic of Li\u003csub\u003e2\u003c/sub\u003eCO\u003csub\u003e3\u003c/sub\u003e at ~\u0026thinsp;290.9 eV and an increased C\u0026ndash;C signal at 284.8 eV appeared after discharge, while the Li 1s spectrum displayed a Li\u003csub\u003e2\u003c/sub\u003eCO\u003csub\u003e3\u003c/sub\u003e peak at ~\u0026thinsp;55.8 eV (\u003cb\u003eSupplementary Fig.\u0026nbsp;25\u003c/b\u003e)\u003csup\u003e\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e\u003c/sup\u003e. After charging, the peak assigned to Li\u003csub\u003e2\u003c/sub\u003eCO\u003csub\u003e3\u003c/sub\u003e vanished, and the C-C peak intensity decreased. Together, these results confirm that the discharge products are Li\u003csub\u003e2\u003c/sub\u003eCO\u003csub\u003e3\u003c/sub\u003e and carbon, both of which highly reversible. The reversibility of Li\u003csub\u003e2\u003c/sub\u003eCO\u003csub\u003e3\u003c/sub\u003e and carbon was further visually observed through SEM characterization. In contrast to the pristine photoelectrode, the discharged BTCP-2 photocathode exhibited granular deposits that accumulated with extended discharge time and disappear completely after charging (\u003cb\u003eSupplementary Fig.\u0026nbsp;26 and Fig.\u0026nbsp;27\u003c/b\u003e).\u003c/p\u003e\u003cp\u003eTo gain a deeper understanding of the catalytic mechanism, quasi-in-situ X-ray photoelectron spectroscopy (QIS-XPS) was used to probe CO\u003csub\u003e2\u003c/sub\u003e adsorption on BTCP-2. Upon CO\u003csub\u003e2\u003c/sub\u003e exposure under illumination, the B 1s peak shifted from 193.34 eV to 193.19 eV (Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003ea\u003cb\u003e)\u003c/b\u003e, indicating charge transfer between adsorbed CO\u003csub\u003e2\u003c/sub\u003e and electron-deficient B atom. B atom experiences a heightened state of electron deficiency as a result of photo-induced structural isomerization, enabling strong interactions with CO\u003csub\u003e2\u003c/sub\u003e molecules. The adsorption of CO\u003csub\u003e2\u003c/sub\u003e donates electrons to the B atom, thereby increasing the electron density of B and lowering its binding energy. DFT calculations elucidated the positive role of photo-induced isomeric structures in the redox reaction processes of Li-CO\u003csub\u003e2\u003c/sub\u003e batteries. Firstly, structural deformation alters the electronic configuration, significantly strengthening reactant-catalyst interactions \u003csup\u003e\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e\u003c/sup\u003e. As shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003eb, the distorted BTCP-2 structure exhibits much higher adsorption energies for both Li and CO\u003csub\u003e2\u003c/sub\u003e compared to the planar structure, indicating enhanced capability for capturing reactant molecules during CO\u003csub\u003e2\u003c/sub\u003eRR. This facilitates higher surface concentrations of active species, thereby promoting continuous reaction progression. Furthermore, the reversible\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003edecomposition of Li\u003csub\u003e2\u003c/sub\u003eCO\u003csub\u003e3\u003c/sub\u003e during charging mitigates catalyst deactivation caused by active sites coverage, thereby sustaining long-term photocatalytic activity.\u003c/p\u003e\u003cp\u003eFurther calculations indicate that the adsorption energy of Li\u003csub\u003e2\u003c/sub\u003eCO\u003csub\u003e3\u003c/sub\u003e on the distorted structure (2.79 eV) is much weaker than that on the planar structure (4.19 eV). This suggests that the Li\u003csub\u003e2\u003c/sub\u003eCO\u003csub\u003e3\u003c/sub\u003e formed during discharge is more likely to desorb from the distorted structure and diffuse into the electrolyte, thereby exposing more active sites on the cathode surface. Such behavior effectively prevents Li\u003csub\u003e2\u003c/sub\u003eCO\u003csub\u003e3\u003c/sub\u003e accumulation and helps maintain the catalytic activity and stability of the photoelectrode. On the other hand, during the charging process, the sluggish kinetics of Li\u003csub\u003e2\u003c/sub\u003eCO\u003csub\u003e3\u003c/sub\u003e decomposition may also result in the accumulation of poorly conductive Li\u003csub\u003e2\u003c/sub\u003eCO\u003csub\u003e3\u003c/sub\u003e, severely impairing overall battery performance. Therefore, facilitating the decomposition of Li\u003csub\u003e2\u003c/sub\u003eCO\u003csub\u003e3\u003c/sub\u003e during the CO\u003csub\u003e2\u003c/sub\u003eER process is essential for improving the performance and cycling stability of Li-CO\u003csub\u003e2\u003c/sub\u003e batteries. Theoretical calculations (Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003ec) reveal that the decomposition energy barrier of Li\u003csub\u003e2\u003c/sub\u003eCO\u003csub\u003e3\u003c/sub\u003e is 2.99 eV on the planar structure but reduced to 2.40 eV on the distorted structure, confirming that the distorted structure is more favorable for Li\u003csub\u003e2\u003c/sub\u003eCO\u003csub\u003e3\u003c/sub\u003e decomposition.\u003c/p\u003e\u003cp\u003eOn the basis of these experimental and theoretical results, we propose a mechanism for the Li-CO\u003csub\u003e2\u003c/sub\u003e battery using the BTCP-2 photoelectrode, as illustrated in Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003ed. Light-induced molecular structural deformation generates an asymmetric electronic configuration, which enhances electron-hole separation and migration. Meanwhile, the increased electron-deficient character of boron atoms after deformation provides highly effective sites for CO\u003csub\u003e2\u003c/sub\u003e adsorption and activation. In addition, the homogeneous porous architecture of BTCP-2, combined with the enhanced CO\u003csub\u003e2\u003c/sub\u003e adsorption and the reduced Li\u003csub\u003e2\u003c/sub\u003eCO\u003csub\u003e3\u003c/sub\u003e decomposition energy barrier, synergistically accelerates both CO\u003csub\u003e2\u003c/sub\u003eRR and CO\u003csub\u003e2\u003c/sub\u003eER. Overall, this mechanism highlights that the light-induced structural changes in BTCP substantially improve charge separation, facilitate charge transfer, and enhance both oxidation and reduction kinetics of CO\u003csub\u003e2\u003c/sub\u003e in Li-CO\u003csub\u003e2\u003c/sub\u003e batteries.\u003c/p\u003e"},{"header":"Conclusions","content":"\u003cp\u003eIn summary, we have developed a borazine/triazine-containing conjugated polymer that exhibits light-induced molecular twisting enabled by the torsional flexibility of B-N, C-B and C-N bonds. Combined experimental and theoretical analyses reveal that this light-driven structural isomerism optimizes the HOMO-LUMO energy levels distribution, broadens light absorption and enhance the photoresponse of BTCP material. In addition, light-induced torsion induces electron cloud around redistribution around B and N atoms, enlarging the dipole moment and strengthening the internal polarization field. These effects synergistically promote separation and migration of photogenerated electrons and holes, enhance CO\u003csub\u003e2\u003c/sub\u003e adsorption, and significantly lower the decomposition energy barrier of Li\u003csub\u003e2\u003c/sub\u003eCO\u003csub\u003e3\u003c/sub\u003e. As a result, the photo-assisted Li-CO₂ battery utilizing BTCP as a photoelectrode achieves exceptional performance, including an ultralow potential hysteresis of 0.1 V, a round-trip efficiency of 96% at 100 µA cm\u003csup\u003e− 2\u003c/sup\u003e, and stable cycling over 27 days, surpassing most previously reported photoelectrodes. This work not only expands the scope of research on light-induced torsional molecules and dynamic bonds but also provides a new design strategy for high-performance photoelectrodes in photo-assisted energy storage systems.\u003c/p\u003e\u003cdiv id=\"Sec8\" class=\"Section2\"\u003e\u003cdiv id=\"Sec9\" class=\"Section3\"\u003e\u003c/div\u003e\u003c/div\u003e\n\n"},{"header":"Methods","content":"\u003ch2\u003eMaterials\u003c/h2\u003e\u003cp\u003eChemicals for urea and boric acid used in the material preparation were purchased from Aladdin Reagents. Reagent for N-Methyl-2-pyrrolidone (C\u003csub\u003e5\u003c/sub\u003eH\u003csub\u003e9\u003c/sub\u003eNO, AR) were purchased from Sinopharm Chemical Reagent Co., Ltd. The electrolyte of Lithium bis (trifluoromethane sulfonimide) (1.0 M LiTFSI in TETRAGLYME, 100 Vol%) was purchased from DodoChem. All chemicals were of analytical grade and used without further purification.\u003c/p\u003e\u003ch3\u003ePreparation of borazine/triazine-containing conjugated polymer\u003c/h3\u003e\u003cp\u003eBorazine/triazine-containing conjugated polymer samples were prepared using commonly employed methods that involve commercially available boric acid and urea as sources of boron and nitrogen, along with specific modifications, through a simple pyrolysis technique conducted in air at 600°C with a heating rate of 10°C/min in the air, rendering the method suitable for industrial-scale production. Significantly, varying the mass ratio of boric acid to urea induces different degrees of polymerization and crosslinking reactions, resulting in distinct products. (M\u003csub\u003e(boric acid)\u003c/sub\u003e = 61.83 g/mol, and M\u003csub\u003e(urea)\u003c/sub\u003e = 60.06 g/mol, means the mass ratio approximately corresponds to the molar ratio). This work conducted experiments using four different mass ratios of boric acid and urea precursors, specifically 1:1, 1:5, 1:10, and 1:20. Four distinct products were successfully synthesized, which were designated as BTCP-1, BTCP-2, BTCP-3, and BTCP-4. Diboron trioxide (B\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e3\u003c/sub\u003e) and carbon nitride (C\u003csub\u003e3\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003e) were obtained by pyrolyzing pure boric acid and urea, respectively, under same conditions.\u003c/p\u003e\u003ch2\u003eMaterial characterizations\u003c/h2\u003e\u003cp\u003eThe morphologies of BTCP samples were characterized via a field-emission scanning electron microscopy (FE-SEM, SU8020), and a transmission electron microscopy (TEM, Tecnai G2 F20) at an acceleration voltage of 200 kV. The composition and chemical states were determined by XPS (PHI Quantera II) instrument, and the binding energy calibration was referenced to C 1s at 284.6 eV. The crystallographic structures were characterized by using powder X-ray diffractometer (XRD, Rigaku D/Max-3c, Cu Kα radiation with λ = 1.5406 Å) with an operating voltage and current of 40 kV and 15 mA. The chemical bonding behavior of the prepared samples were investigated using a Vertex 70 fourier transform infrared (FT-IR) spectrometer. Experiments were performed at room temperature using solid-state nuclear magnetic resonance (SSNMR) to obtain \u003csup\u003e\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u003c/sup\u003eH, \u003csup\u003e11\u003c/sup\u003eB, and \u003csup\u003e\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e\u003c/sup\u003eC NMR spectra collected on a Germany Broker Avance Neo 400WB. Ultraviolet photoelectron spectroscopy (UPS) was used to measure valence band value. An ultraviolet-visible spectrophotometer (UV-vis, UV-3600) was applied for characterizing the absorption spectra of the samples at room temperature. The specific surface area and pore size distribution were determined using a surface aperture analyzer (Micromeritics VacPrep 061) by measuring the N\u003csub\u003e2\u003c/sub\u003e adsorption-desorption isotherm at 77 K. Photoluminescence (PL) spectra were acquired on an RF-5301PC fluorescence spectrophotometer (Shimadzu, Tokyo, Japan).\u003c/p\u003e\u003ch2\u003eBattery assembly and electrochemical performance tests\u003c/h2\u003e\u003cp\u003eAs-prepared BTCP samples, Super-P, and polyvinylidene fluoride (PVDF) were respectively employed as the working materials, conductor and binder, and mixed together at a weight ratio of 8:1:1 with the adding of N-methyl-2-pyrrolidinone (NMP). The prepared slurry was then coated on a clean nickel foam with a diameter of 13 mm. The mass loading of photoelectrode was 1.0 ± 0.5 mg/cm\u003csup\u003e2\u003c/sup\u003e. All the electrodes were dried at 100°C under vacuum for at least 12 h. The CR2032 coin cells with holes on the cathode side were used for testing Li-CO\u003csub\u003e2\u003c/sub\u003e batteries. The batteries were assembled in a glove box and filled at Ar atmosphere with the moisture and oxygen content of below 0.1 ppm. Li foils were used as the counter, BTCP photoelectrode was inserted into the cathode side, and glass fiber (Waterman, GF/A) was applied as the separator. 1.0 M LiTFSI in tetraethylene glycol dimethyl ether (Tetraglyme) was employed as the electrolyte, the amount of electrolyte in each battery was about 100 µL. The assembled batteries were stored in a volume capacity of 250 mL sealed glass test device, which was filled with carbon dioxide. The charging and discharging curves were tested on a (Solartron) 1470E CellTest. The EIS curves and GITT curves were measured with a Solartron 1260-1460E machine. DEMS measurements were performed on a quadrupole mass spectrometer (QAS100) with the help of Linglu Instrument Co., Ltd. A GELS500/350 Xe lamp (wavelength range: 200–1200 nm, Ceaulight, Beijing) with a fixed power at 500 W was used as the solar source for illumination. Before the measurement, an optical power meter was utilized for calibrating the photo density on surface of battery electrode to AM1.5 G, which corresponded to the photo density of 100 mW/cm\u003csup\u003e2\u003c/sup\u003e.\u003c/p\u003e\u003ch2\u003eTheoretical calculation\u003c/h2\u003e\u003cp\u003eDensity functional theory (DFT) calculations were performed using a first-principles approach\u003csup\u003e\u003cspan citationid=\"CR48\" class=\"CitationRef\"\u003e48\u003c/span\u003e, \u003cspan citationid=\"CR49\" class=\"CitationRef\"\u003e49\u003c/span\u003e\u003c/sup\u003e within the generalized gradient approximation (GGA) based on the Perdew-Burke-Ernzerhof (PBE)\u003csup\u003e\u003cspan citationid=\"CR50\" class=\"CitationRef\"\u003e50\u003c/span\u003e\u003c/sup\u003e formulation, as implemented in the plane wave set Vienna ab initio Simulation Package (VASP) code. The projected augmented wave (PAW) potentials\u003csup\u003e\u003cspan citationid=\"CR51\" class=\"CitationRef\"\u003e51\u003c/span\u003e, \u003cspan citationid=\"CR52\" class=\"CitationRef\"\u003e52\u003c/span\u003e\u003c/sup\u003e to describe the ionic cores and take valence electrons into account using a plane wave basis set with a kinetic energy cutoff of 520 eV. Partial occupancies of the Kohn-Sham orbitals were allowed using the Gaussian smearing method with a width of 0.05 eV. The electronic energy was considered self-consistent when the energy change was smaller than 10\u003csup\u003e− 6\u003c/sup\u003e eV. A geometry optimization was considered convergent when the energy change was smaller than 0.03 eV Å\u003csup\u003e−1\u003c/sup\u003e. The vacuum spacing in a direction perpendicular to the plane of the structure is 20 Å for the surfaces. The Brillouin zone integration is performed using 2×2×1 Monkhorst-Pack k-point sampling for a structure. Electrostatic potential analysis was performed the Gaussian 16 software in Multiwfn\u003csup\u003e\u003cspan citationid=\"CR53\" class=\"CitationRef\"\u003e53\u003c/span\u003e\u003c/sup\u003e and VMD\u003csup\u003e\u003cspan citationid=\"CR54\" class=\"CitationRef\"\u003e54\u003c/span\u003e\u003c/sup\u003e packages with the single point calculations under the level of B3LYP-D3BJ/6-311 + G (d, p)\u003csup\u003e55\u003c/sup\u003e. The climbing image-nudge elastic band (CI-NEB) method was used to calculate the diffusion barrier of Li\u003csup\u003e+\u003c/sup\u003e on the substrates. Finally, the adsorption energies (Eads) were calculated as Eads = Ead/sub - Ead - Esub, where Ead/sub, Ead, and Esub are the total energies of the optimized adsorbate/substrate system, the adsorbate in the structure, and the clean substrate, respectively. The free energy was calculated using the equation:\u003c/p\u003e\u003cp\u003eG = Eads + ZPE - TS\u003c/p\u003e\u003cp\u003ewhere G, Eads, ZPE and TS are the free energy, total energy from DFT calculations, zero point energy and entropic contributions, respectively.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003ch2\u003eConflict of Interest\u003c/h2\u003e\u003cp\u003eThe authors declare no conflict of interest.\u003c/p\u003e\u003c/p\u003e\u003ch2\u003eAcknowledgements\u003c/h2\u003e\u003cp\u003eThis work was financially supported by the National Natural Science Foundation of China (51772182), The 111 Project, Shaanxi \"Three Qin Scholars\" Innovation Team, Key Research and Development Program of Shaanxi (2022GY-200), and the Fundamental Research Funds for the Central Universities (GK202302005), the Gansu Provincial University Teachers Innovation Fund Project (2025A-043), Central Government Guidance Fund for Local Science and Technology Development (25ZYJC002). The authors acknowledge the financial support from the Australian Research Council through its Discovery (DP230100572), Future Fellowship (FT200100279) Programs and National Health and Medical Research Council (APP1175808). The authors acknowledge the scientific and technical support from the Australian Microscopy \u0026amp; Microanalysis Research Facility at the Centre for Microscopy and Microanalysis, the University of Queensland. The authors would also like to acknowledge the support received from the UQ-CSC PhD Scholarship and the UQ-CSC Joint PhD Scholarship.\u003c/p\u003e\u003cp\u003eL. Li and D. Tian are equal contribution.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eSarkar A et al (2023) Recent advances in rechargeable metal-CO\u003csub\u003e2\u003c/sub\u003e batteries with nonaqueous electrolytes. Chem Rev 123:9497\u0026ndash;9564\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eWang F et al (2021) Metal-CO\u003csub\u003e2\u003c/sub\u003e electrochemistry: from CO\u003csub\u003e2\u003c/sub\u003e recycling to energy storage. Adv Energy Mater 11:2100667\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eLiu Y, Wang R, Lyu Y, Li H, Chen L (2014) Rechargeable Li/CO\u003csub\u003e2\u003c/sub\u003e-O\u003csub\u003e2\u003c/sub\u003e (2 : 1) battery and Li/CO\u003csub\u003e2\u003c/sub\u003e battery. Energy Environ Sci 7:677\u0026ndash;681\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eChen J et al (2023) Recent progress of transition metal-based catalysts as cathodes in O\u003csub\u003e2\u003c/sub\u003e/H\u003csub\u003e2\u003c/sub\u003eO-involved and pure Li-CO\u003csub\u003e2\u003c/sub\u003e batteries. Energy Environ Sci 16:792\u0026ndash;829\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eBaek K et al (2020) Synergistic effect of quinary molten salts and ruthenium catalyst for high-power-density lithium-carbon dioxide cell. Nat Commun 11:456\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eSun X et al (2023) Binuclear Cu complex catalysis enabling Li-CO\u003csub\u003e2\u003c/sub\u003e battery with a high discharge voltage above 3.0 V. Nat Commun 14:536\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eLi W et al (2024) Boosting a practical Li-CO\u003csub\u003e2\u003c/sub\u003e battery through dimerization reaction based on solid redox mediator. Nat Commun 15:803\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eLiu Y et al (2024) Deciphering the contributing motifs of reconstructed cobalt (II) sulfides catalysts in Li-CO\u003csub\u003e2\u003c/sub\u003e batteries. Nat Commun 15:2167\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eCao D, Tan C, Chen Y (2022) Oxidative decomposition mechanisms of lithium carbonate on carbon substrates in lithium battery chemistries. Nat Commun 13:4908\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eLiu Y et al (2025) Subsurface electron trap enabled long-cycling oxalate‐based Li‐CO\u003csub\u003e2\u003c/sub\u003e Battery. Adv Mater 37:2507871\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eLu B et al (2024) Steering the orbital hybridization to boost the redox kinetics for efficient Li-CO\u003csub\u003e2\u003c/sub\u003e batteries. J Am Chem Soc 146:20814\u0026ndash;20822\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eHu K et al (2025) Photoassisted Li-CO\u003csub\u003e2\u003c/sub\u003e batteries with ultrahigh energy efficiency and cycle stability by a redox mediator. ACS Nano 19:7707\u0026ndash;7717\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eChang JN et al (2024) Redox molecular junction metal-covalent organic frameworks for light‐assisted CO\u003csub\u003e2\u003c/sub\u003e energy storage. Angew Chem Int Ed 63:e202402458\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eHu T et al (2025) Photo-energized MoS\u003csub\u003e2\u003c/sub\u003e/CNT cathode for high-performance Li-CO\u003csub\u003e2\u003c/sub\u003e batteries in a wide-temperature range. Nano-Micro Lett 17:5\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eWang JH (2022) ea al. Phthalocyanine based metal-organic framework ultrathin nanosheet for efficient photocathode toward light-assisted Li-CO\u003csub\u003e2\u003c/sub\u003e battery. \u003cem\u003eAdv. Funct. Mater.\u003c/em\u003e 32, 2210259\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eChang JN et al (2024) Redox molecular junction metal-covalent organic frameworks for light-assisted CO\u003csub\u003e2\u003c/sub\u003e energy storage. Angew Chem Int Ed 63:e202402458\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eGuan DH et al (2020) Light/electricity energy conversion and storage for a hierarchical porous In\u003csub\u003e2\u003c/sub\u003eS\u003csub\u003e3\u003c/sub\u003e@CNT/SS cathode towards a flexible Li-CO\u003csub\u003e2\u003c/sub\u003e battery. Angew Chem Int Ed 59:19518\u0026ndash;19524\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eLi L et al (2024) High-concentrated electron-deficient boron through dual-function boric acid strategy significantly enhancing reaction kinetics and stability of photoassisted Li-CO\u003csub\u003e2\u003c/sub\u003e batteries. Energy Storage Mater 71:103634\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eLi J et al (2022) High-efficiency and stable Li-CO\u003csub\u003e2\u003c/sub\u003e battery enabled by carbon nanotube/carbon nitride heterostructured photocathode. Angew Chem Int Ed 61:e202114612\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eZhang K et al (2022) Boosting cycling stability and rate capability of Li-CO\u003csub\u003e2\u003c/sub\u003e batteries via synergistic photoelectric effect and plasmonic interaction. Angew Chem Int Ed 61:e202201718\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eZhu L, Rabih OA, Christopher JB (2011) Reversible photoinduced twisting of molecular crystal microribbons. J Am Chem Soc 32:12569\u0026ndash;12575\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eZhu K et al (2024) Limiting molecular twisting: upgrading a donor-acceptor dye to drive H\u003csub\u003e2\u003c/sub\u003e Evolution. Adv Sci 11:2403454\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eZhang H, Yu S (2019) Visible light-promoted isomerization of alkenes. Chin J Org Chem 39:95\u0026ndash;108\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eVolarić J, Szymanski W, Simeth NA, Feringa BL (2021) Molecular photoswitches in aqueous environments. Chem Soc Rev 50:12377\u0026ndash;12449\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eGemen J et al (2023) Disequilibrating azobenzenes by visible-light sensitization under confinement. Science 381:1357\u0026ndash;1363\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eSaltiel J et al (2009) Photoisomerization of all-cis-1,6-diphenyl-1,3,5-hexatriene in the solid state and in solution: a simultaneous three-bond twist process. Angew Chem Int Ed 48:8082\u0026ndash;8085\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eGerwien A, Schildhauer M, Thumser S, Mayer P, Dube H (2018) Direct evidence for hula twist and single-bond rotation photoproducts. Nat Commun 9:2510\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eGerwien A, Jehle B, Irmler M, Mayer P, Dube H (2022) An eight-state molecular sequential switch featuring a dual single-bond rotation photoreaction. J Am Chem Soc 144:3029\u0026ndash;3038\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eNagami S et al (2024) Photoinduced dual bond rotation of a nitrogen-containing system realized by chalcogen substitution. Nat Chem 16:959\u0026ndash;969\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eSun K et al (2024) Dynamic structural twist in metal-organic frameworks enhances solar overall water splitting. Nat Chem 16:1638\u0026ndash;1646\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eChen C, Du CZ, Wang XY (2022) The rise of 1,4-BN-heteroarenes: synthesis, properties, and applications. Adv Sci 9:2200707\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eWu Y et al (2024) Aromaticity in isoelectronic analogues of benzene, carborazine and borazine, from electronic structure and magnetic property. Chem Eur J 30:e202403369\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eLiu J et al (2024) Defects-rich heterostructures trigger strong polarization coupling in sulfides/carbon composites with robust electromagnetic wave absorption. Nano-Micro Lett 17:24\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eZhang Q et al (2025) Regulating the built-in electric field in covalent organic frameworks for enhanced CO\u003csub\u003e2\u003c/sub\u003e photoreduction: asymmetry linkage structures. ACS Catal 15:6739\u0026ndash;6748\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eYuan T et al (2022) Mild and metal-free birch-type hydrogenation of (hetero) arenes with boron carbonitride in water. Nat Catal 5:1157\u0026ndash;1168\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eLi M et al (2023) Construction of boron- and nitrogen‐enriched nanoporous π‐conjugated networks towards enhanced hydrogen activation. Angew Chem Int Ed 135:e202302684\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eGiusto P et al (2020) Boron carbon nitride thin films: from disordered to ordered conjugated ternary materials. J Am Chem Soc 142:20883\u0026ndash;20891\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eTang C, Bando Y, Huang Y, Zhi C, Golberg D (2008) Synthetic routes and formation mechanisms of spherical boron nitride nanoparticles. Adv Funct Mater 18:3653\u0026ndash;3661\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eLiang C et al (2022) Band structure engineering within two-dimensional borocarbonitride nanosheets for surface-enhanced raman scattering. Nano Lett 22:6590\u0026ndash;6598\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eYu H et al (2025) Reversible configurations of 3-coordinate and 4-coordinate boron stabilize ultrahigh-Ni cathodes with superior cycling stability for practical Li-ion batteries. Adv Mater 37:2412360\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eWu B et al (2021) Ultrathin porous carbon nitride bundles with an adjustable energy band structure toward simultaneous solar photocatalytic water splitting and selective phenylcarbinol oxidation. Angew Chem Int Ed 60:4815\u0026ndash;4822\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eDou C et al (2016) An electron-deficient building block based on the B\u0026larr;N unit: An electron acceptor for all-polymer solar cells. Angew Chem Int Ed 55:1436\u0026ndash;1440\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eDou C, Liu J, Wang L (2017) Conjugated polymers containing B\u0026larr;N unit as electron acceptors for all-polymer solar cells. Sci China Chem 60:450\u0026ndash;459\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eSun R et al (2025) Unprecedented photocatalytic hydrogen peroxide production via covalent triazine frameworks constructed from fused building blocks. Angew Chem Int Ed 64:e202416350\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eLiu J et al (2025) Selective ions exchange reactions endow defective heterovalent copper-based selenides with enhanced dielectric polarization response. Adv Funct Mater 35:2420239\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eSun R et al (2025) Unprecedented photocatalytic hydrogen peroxide production via covalent triazine frameworks constructed from fused building blocks. Angew Chem Int Ed 137:e202416350\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eChen YJ et al (2024) Molecular engineering of perylene diimide polymers with a robust built-in electric field for enhanced solar-driven water splitting. Angew Chem Int Ed 63:e202318224\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eKresse G, Furthm\u0026uuml;ller J (1996) Efficiency of ab-initio total energy calculations for metals and semiconductors using a plane-wave basis set. Comput Mater Sci 6:15\u0026ndash;50\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eKresse G, Furthm\u0026uuml;ller J (1996) Efficient iterative schemes for ab initio total-energy calculations using a plane-wave basis set. Phys Rev B 54:11169\u0026ndash;11186\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003ePerdew JP, Burke K, Ernzerhof M (1996) Generalized gradient approximation made simple. Phys Rev Lett 77:3865\u0026ndash;3868\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eKresse G, Joubert D (1999) From ultrasoft pseudopotentials to the projector augmented-wave method. Phys Rev B 59:1758\u0026ndash;1775\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eBl\u0026ouml;chl PE (1994) Projector augmented-wave method. Phys Rev B 50:17953\u0026ndash;17979\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eLu T, Chen F (2012) Multiwfn: a multifunctional wavefunction analyzer. J Comput Chem 33:580\u0026ndash;592\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eHumphrey W, Dalke A, Schulten K (1996) VMD: visual molecular dynamics. J mol graph 14:33\u0026ndash;38\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eKrishnan RBJS, Binkley JS, Seeger R, Pople JA (1980) Self-consistent molecular orbital methods. XX. A basis set for correlated wave functions. J Phys Chem 72:650\u0026ndash;654\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":true,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"nature-portfolio","isNatureJournal":true,"hasQc":false,"allowDirectSubmit":false,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"","title":"Nature Portfolio","twitterHandle":"","acdcEnabled":false,"dfaEnabled":false,"editorialSystem":"ejp","reportingPortfolio":"","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"Photo-assisted batteries, spatial twist, borazine/triazine-containing conjugated polymer, Li-CO2 battery, photocatalytic kinetics of CO2RR and CO2ER","lastPublishedDoi":"10.21203/rs.3.rs-7907271/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7907271/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003ePhotoelectrode materials are essential in facilitating the kinetics of CO\u003csub\u003e2\u003c/sub\u003e redox reaction in photo-assisted Li-CO\u003csub\u003e2\u003c/sub\u003e batteries. However, conventional rigid photoelectrodes suffer from limited in-plane charge carrier separation and transport, leading to poor photoelectric conversion and storage efficiency. Herein, we report a borazine/triazine-containing conjugated polymer (BTCP) with flexible conformational isomerism. Under light exposure, cooperative rotation of the bonds involving B-N, C-B, and C-N induce molecular twisting that redistributes electron cloud and enhances polarized electric field, thereby promoting efficient charge separation and migration, while also enhancing CO\u003csub\u003e2\u003c/sub\u003e adsorption and lowering the Li\u003csub\u003e2\u003c/sub\u003eCO\u003csub\u003e3\u003c/sub\u003e compositional energy barrier. Consequently, the BTCP photoelectrode delivers an ultra-low voltage gap of 0.1 V at 100 \u0026micro;A cm\u003csup\u003e\u0026minus;\u0026thinsp;2\u003c/sup\u003e, a round-trip efficiency of 96% and outstanding cycling stability for 27 days. This work highlights a novel strategy of exploiting light-induced molecular torsion to boost photocatalytic activity, offering new insights into the design of high-performance photoelectrodes for light-driven energy storage systems.\u003c/p\u003e","manuscriptTitle":"Light-induced borazine/triazine-containing conjugated polymers spatial twist boosting high-performance photo-assisted Li-CO2 batteries","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-11-05 02:35:03","doi":"10.21203/rs.3.rs-7907271/v1","editorialEvents":[],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"nature-communications","isNatureJournal":true,"hasQc":false,"allowDirectSubmit":false,"externalIdentity":"NCOMMS","sideBox":"Learn more about [Nature Communications](http://www.nature.com/ncomms/)","snPcode":"","submissionUrl":"https://mts-ncomms.nature.com/","title":"Nature Communications","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"ejp","reportingPortfolio":"Nature Communications","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"08abc865-becb-40e4-8c92-5d06ae8d549f","owner":[],"postedDate":"November 5th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[{"id":57436381,"name":"Physical sciences/Energy science and technology/Energy storage/Batteries"},{"id":57436382,"name":"Physical sciences/Materials science/Materials for energy and catalysis/Photocatalysis"}],"tags":[],"updatedAt":"2026-03-19T16:06:30+00:00","versionOfRecord":[],"versionCreatedAt":"2025-11-05 02:35:03","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-7907271","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7907271","identity":"rs-7907271","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}