Titanate nanotubes coated with Ag nanoparticles: Effects of Annealing Temperature on Crystalline Structure, Morphology, and Photocatalytic Activity

Titanate nanotubes coated with Ag nanoparticles: Effects of Annealing Temperature on Crystalline Structure, Morphology, and Photocatalytic Activity | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Titanate nanotubes coated with Ag nanoparticles: Effects of Annealing Temperature on Crystalline Structure, Morphology, and Photocatalytic Activity Tarek M. Salama, Ahmed Abd El-Gawad, Ahmed A. El‐Henawy, Ibraheem O. Ali This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-3881461/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract AgNPs were first introduced into the hydrothermally produced sodium titanate nanotubes using a photoreduction method. By gradually raising the temperature of Ag-doped TNTs samples between 100 and 350 ºC, the impact of the annealing temperature was investigated. XRD, HRTEM, FT-IR and UV-visible spectroscopy were used to characterize the nanotubes. Through the interchange of Ag + with extra-framework Na + in TNTs, the XRD demonstrated. The establishment of the Silver Titanate. On the other hand, a partial state transformation from nanotabular Na-TNTs to anatase nanotubes occurred with a rise in temperature. The interaction between Ag and TNT particles was assigned to the FT-IR band that appeared at 1384 cm − 1 . The higher particle size was explained by HRTEM, the investigation demonstrated that the process of annealing resulted in the formation of larger clusters by aggregating small particles. UV-Vis and band gap measurements were used to assess how annealed samples affected the liquid phase of MB dye's capacity to photocatalyzed sunlight. Based on the breakdown of MB dye in an aqueous solution under solar conditions, the Ag/NaTNTs nanostructures with annealing temperatures ranging from 70 to 350◦C were assessed for their photocatalytic activities. The degradation rate increased with increasing annealing. The amorphous cluster's HOMO-LUMO gap and singlet-singlet excited state energies are quite like those of a crystalline Ag/TNTs, according to the calculations. Additionally, our calculations demonstrate that Ag/NaTNTs' computed energetic data values and low energy gap demonstrated strong activity against dye removal. Titania nanotubes Annealing temperature Morphology Photocatalytic activity methylene blue dye Ag nanoparticles Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 1. Introduction In recent years, nanotechnology as well as its research fields and applications has undergone a revolution. Due to its numerous applications in electronics, optics, catalysis, sensors, and energy conversion, titanate (Na x H 1−x Ti 3 O and H 2 Ti 3 O 7 ) and titania (TiO 2 ) nanostructures (nanotubes, nanowires, and nanobelts) have garnered a lot of attention [ 1 – 3 ]. When compared to bulk materials, one of the most significant features of nanotubes is their large specific surface area. Additionally, titanium nanotubes (TNTs) offer enhanced electron transfer channels. As a result, they aid in raising the efficiency of photocatalysis, electrolysis, and solar cells [ 4 ]. According to a prior study, post-synthesis processing of TNTs can be used to modify their electronic structure, concentration of surface local defects, and crystallinity, all of which can affect their photocatalytic activity [ 5 ]. TiO 2 nanotubes can be synthesized through a variety of methods, such as alkaline hydrothermal treatment, electrochemical anodization, and template-assisted fabrication [ 6 ]. The alkaline hydrothermal method has garnered greater attention among these preparation techniques because it is an economical and straightforward way to produce nanotubes on a large scale. Over the last ten years, a lot of earlier research has mostly concentrated on how hydrothermal parameters affect the structure and mechanism of nanotube formation [ 7 ]. Using an anodization process, Yang et al. [ 8 ] synthesized TNTs, which were then calcined to produce the rutile phase (> 500 ◦ C) and anatase phase (> 450 ◦ C). At 800 ◦ C, the TiO 2 nanotube arrays were destroyed, leaving only a dense rutile film visible [ 8 ]. In a different study, Das et al. [ 9 ] observed that the best electrical and photo-electrochemical properties are offered by the anatase structure, which is formed when TNT layers are annealed at 400 ◦ C. The "pillar-effect" technique has been employed recently to safeguard the nanotubular structure at 400°C. According to recent research by Liu et al. [ 10 ], during annealing, O 2 enhanced the local structure and long-range crystallinity, resulting in a reduction of local surface defects such as Ti 3+ and O vacancies. Furthermore, the improvement of the photocatalytic activity also depends critically on the existence of these local defects. The findings of Bai et al. [ 11 ] indicated that the surface structure and characteristics of TNTs are likely to be impacted by the variations in crystallinity brought about by adjusting the annealing temperature. Ag transfers to Ag 2 O at 500 and 600 ◦ C, as shown by Hajakbari et al.'s investigation into the effect of annealing temperature on pure Ag films' ability to crystallize and oxidize [ 12 ]. Furthermore, it has been demonstrated that raising the annealing temperature increases atom mobility, which results in particle agglomeration and the formation of larger particles, both of which raise film roughness [ 12 ]. In a separate investigation, Mosquera et al. [ 13 ] concluded that Ag will aggregate into bigger clusters as a result of the annealing temperature. This prevents Ti and O ions from diffusing in order to form anatase and increases rutile formation by concurrently lowering the transition temperature. It is commonly recognized that the discharge of industrial wastewater into the environment, which contains a broad range of organic hazardous pollutants, poses a potential threat to the environment. As a result, environmental degradation is now a major worldwide concern, and ecosystem maintenance is crucial [ 14 ]. One of the frequently used dyes for dying cotton, silk, and wood is methylene blue (MB) [ 15 , 16 ]. The wastewater released by large manufacturing industries has been linked to a high concentration of dye in water bodies [ 16 ]. A cationic dye with several applications in the dyeing industry is called MB [ 17 ]. These developments indicate that the presence of dyes in aquatic environments is unwanted, unpleasant, and harmful to both human health and the health of plants and animals [ 18 ]. Given that the morphology and crystal structure of Ag/TNTs are directly impacted by the annealing temperature, it is imperative to ascertain and elucidate these effects considering the material's photocatalytic properties. In this w ork, we annealed samples at various temperatures (70 to 350ºC) after synthesizing Ag/TNTs using a photoreduction method. We employ a variety of techniques, including X-ray diffraction (XRD), FT-IR, UV-vis spectroscopy, transmission electron microscopy (HRTEM) to comprehend the physical and chemical properties of the materials. Additionally, the rate at which the methylene blue dye (MB) degraded was used to assess the samples' photocatalytic activity. The investigation was carried out in batches, and the results were assessed using a range of research parameters to ascertain the effectiveness of the nanotubes in eliminating organic pollutants. 2. Experimental 2.1. preparation of sodium titanate nanotubes (NaTNT) The synthesis of sodium titanate nanotubes (NaTNTs) was achieved through the utilization of a hydrothermal technique. Anatase type titanium dioxide powder (BDH Ltd, 98% purity) was used as a starting material. 4.0 g TiO 2 (TiO 2 BDH limited Poole England, 98%) were typically mixed with 200 ml of 10 M NaOH (Merck) solution and vigorously stirred for two hours before being hydrothermally treated for 48 hours at 170 ºC in a stainless autoclave [ 1 ]. After the solid product was filtered, a significant amount of deionized water was used to wash it until the filtrate's pH reached 7.0, which is neutral. The white solid product was dried in an oven for four hours at 100 ◦ C, the sample was referred as NaTNTs-100. 2.2. Preparation of Ag/NaTNTs By photoreducing AgNO 3 (Merck), according to the appropriate process outlined in the literature, AgNPs were created and then loaded into the inner walls of NaTNTs [ 1 , 19 ]. After exposing 1.0 g of NaTNTs-100 in 200 ml of distilled water to UV light while stirring for 10 minutes, organic impurities on the TNT surfaces were removed. Next, 10 ml of 0.1 M AgNO 3 was added dropwise to the suspension, and the treatment with UV light was continued for an additional hour while stirring continuously, during which time the color of the suspension gradually changed to a faint gray. The resulting Ag/NaTNTs was separated from the mother liquor after a 24-hour slow evaporation at 70 ◦ C; this sample was designated Ag/NaTNTs-70. To evaluate the thermal stability of AgNPs on the NaTNT surfaces, 1.0 g of Ag/NaTNTs-70 was then put in a porcelain vessel and heated to 150, 250, and 350 ºC for one hour. Ag/NaTNTs-150, Ag/NaTNTs-250, and Ag/NaTNTs-350 were the designations assigned to these samples, respectively. 2.3. Characterization Using a Philips diffractometer (type PW 3710), the samples' X-ray diffraction (XRD) patterns were measured. The patterns were scanned at a speed of 2θ = 2.5º/min using Ni-filtered copper Kα radiation (λ = 1.5404 Å) at 30 kV and 10 mA. A Perkin Elmer Spectrometer (RXI FT-IR) system was used to record FT-IR spectra with a single beam and a resolution of 2 cm − 1 . The sample was placed on the sample holder within the spectrometer's cavity after being tablet-ground with KBr (1:100). At room temperature, measurements were taken between 4000 − 400 cm − 1 . Using a HRTEM, Tecnai G20, FEI, Netherlands, equipped with an electron source gun made of lanthanum hexaboride (LaB6) and operating at an electron accelerating voltage of 200 kV, the particle size, morphology, and surface topology of the synthesized Ag/NaTNTs samples were examined. The Ag/NaTNTs suspension was dropped onto a carbon-coated Cu grid to create the samples, and the solvent was then allowed to slowly evaporate at room temperature. Reflectance Diffuseness Using a UV-570, JASCO spectrophotometer, the samples were subjected to ultraviolet-visible spectroscopy (UV-vis DRS) at room temperature, covering the wavelength range of 200–1000 nm. Using Microsoft Excel software, the UV-vis spectra were processed. This involved calculating the Kubelka-Monk function, F(R), which was taken out of the UV-vis DRS absorbance. The determination of the edge energy (E g ) for permitted transitions involved locating the straight line's intercept in the low-energy rise of the [F(R)hν] 2 plot of the direct allowed transition vs hν, where hν represents the incident photon energy. 2.4. Evaluation of photocatalytic activity As a cationic probe dye, Methylene Blue (Loba Chemie, purity 85%) was used in the adsorption/degradation investigations. The adsorption tests were conducted in a 200 ml quartz photoreactor (40 mm in diameter and 195 mm in height). After one hour in the dark, 0.05g of the Ag/NaTNTs photocatalyst was suspended in 100 ml MB (10–30 mg L –1 ) with and without H 2 O 2 , and it was exposed to the sun's visible irradiance spectrum while being constantly stirred. Sample aliquots were taken out at predetermined intervals, centrifuged to remove catalyst particles, and the supernatants were removed for spectrophotometric examination. A Perkin-Elmer Lambda 35UV-visible spectrophotometer was used to measure the concentrations of MB in the supernatants at 660 nm, which is the maximum absorption wavelength of MB. The average values were reported, and all measurements were made in triplicate with errors less than 5%. 2.5. Computational model: The Becke3-Lee-Yang-parr (B3LYP) level is applied to perform all the computation, using 6-311G* basis set using Schrödinger [ 20 ]. 3. Results and discussion 3.1. XRD Figure 1 shows the XRD patterns for NaTNTs-100 and Ag/NaTNTs-70-350. A low signal-to-noise ratio, overlapping peak reflections are seen in all patterns; these reflections could be attributed to either the confinement in NaTNTs or the surface curvature effects. The diffraction patterns of NaTNTs100 exhibit peaks at 2θ of 9º, 28.6º, and 48.3º. These positions are most comparable to those of nanosized sodium titanate (Na 2 Ti 3 O 7 /Na 2 Ti 6 O 13 ) whose crystal lattice is oriented towards a monoclinic structure.[ 21 ]. Na 2 Ti 3 O 7 exhibits a lamellar structure with two inter lamellar Na + ions and three adjacent TiO 6 octahedra connected to form Ti 3 O 72 -corrugated layers [ 21 ]. On the other hand, Na 2 Ti 6 O 13 has a structure resembling a tunnel, and the temperature and duration of annealing determine how clear the crystal is. From a structural perspective, the Ti 3 O 72 -units of neighboring layers can be connected to form the tunnels of the Na 2 Ti 6 O 13 phase from lamellar Na 2 Ti 3 O 7 [ 22 ]. Fundamentally, the Na + ions are intercalated into the titanate interlayer framework. [ 23 ]. The XRD pattern of Ag/NaTNTs-70 showed a decrease in intensity of the peaks resulting from the NaTNTs crystal structure, in favor of a newly superimposed peak at 2θ of 29.3º. The formation of silver titanate through the exchange of extra-framework Na + in TNTs with Ag + can be attributed to this new reflection [ 24 ]. The interlayer distance in TNTs can generally vary when ions are removed from an interlayer of a layered material or added to an interlayer from a solution. Ag/NaTNTs-70 showed a shift in the 2θ peak at 9º to a higher angle, 9.3º. This shift was most likely caused by AgNPs being exchanged with extra-framework Na + to transfer into regular lattice positions, which in turn caused the diffraction peak to shift. The spectra the Ag/TNTs-150 and Ag/TNTs-250 samples display a reflection of the silver titanate phase at 29.3° and an enhancement of the nanotabular Ti 6 O 13 -2 phase as well. To further increase the temperature to 350 ºC, i.e. Ag/TNTs-350, the peak at 2θ of 9.3º was shifted to 10º, along with new peaks at 13º, 24.3º, 28.3º and 48.2º were detected. The latter two peaks are indexed to the anatase phase, indicating a partial state transformation with temperatures occurred from nanotabular Na-TNTs to anatase nanotubes. 3.2. IR spectra Figure 2 displays the FTIR spectra of NaTNTs-100 and Ag/NaTNTs-70-350 in the 4000–400 cm − 1 range. NaTNTs-100 exhibited a spectrum with bands located at 3363, 1638, 1047, 885, 673, and 493 cm − 1 . Since there is a distinct band at 1638 cm − 1 that can be attributed to the bending mode of water molecules in the interlayer space of Na-TNTs, the 3363 cm − 1 band was linked to intermolecular hydrogen bonding at OH groups. This band appeared in all spectra of Ag/NaTNTs70-250 but with comparable intensities. The narrowing width of this band with increasing temperatures suggests perturbation of the complex hydrogen bonding environment, likely as a result of hybridization between the Ag + and Na-TNTs. However, the most pronounced perturbations of the OH-hydrogen bonding occurred for the Ag/NaTNTs-250 sample. For Ag/NaTNTs-350, a symmetrical large band owing to an increase in OH groups were obtained; this could be the result of partial titanate decomposition to highly hydroxylated anatase TiO 2 , which is consistent with information from XRD. The band at 673 cm − 1 in Fig. 2 was assigned to Ti–O–Na vibrations in the tri-titanate wall, the band at 880 cm − 1 to Ti–O bending and stretching vibration involving two-fold oxygen, and the peak at 906 cm − 1 to four-coordinate Ti–O stretching vibrations involving non-bridging oxygen interacting with Na + [ 25 , 26 ]. The band at 494 cm − 1 was assigned to Ti–O–Ti bending vibration involving three-fold oxygen in the edge-shared TiO 6 . In a previous paper [ 27 ], the sodium titanate hydrogel layer was identified as the source of all these peaks. Among these, the intensity of the band at 673 cm − 1 , which was attributed to Ti-O bending vibration involving two-fold oxygen, was reduced in Ag/NaTNTs-250 in favor of the eruption of a new peak at 453 cm − 1 , which was attributed to Ti-O stretching vibration involving three steps. The effects of heat treatments on Ag/NaTNTs' nanostructure can be attributed to the stabilization of the regular, open, dehydrated three-dimensional network structure, which involves coordinations of three oxygen atoms and six titanium atoms [ 26 ]. The interaction between Ag and TNTs particles was tentatively attributed to the band at 1384 cm − 1 [ 28 – 30 ]. 3.3. Transmission electron microscope (TEM) Figure 3 displays the morphology of the Ag/NaTNTs-70, Ag/NaTNTs-250, Ag/NaTNTs-350, and NaTNTs-100. The average diameter of AgNPs increases linearly with increasing annealing temperature. According to Fig. 3 a, the as-synthesized NaTNT nanotubes have hollow inner pores with average outer and inner diameters of 3.32 and 9.41 nm at each tube end, respectively, and lengths of about 265 nm. Diffractions of the titanate/titanium dioxide nanotube phase can be seen in the SAED patterns at (200), (211), and (020). The original nanotube morphology of sodium titanate was unaffected by the addition of Ag NPs, except for the Ag/NaTNTs-350 sample (Fig. 3 -c), which has numerous structural flaws and uneven walls. According to the XRD analysis, these two characteristics point to low crystallinity. It was determined that the annealing temperature caused small particles to combine to form larger clusters, which explained the larger particle size. 3.4. UV-visible diffuse reflectance spectra In Fig. 4 -A, the UV-vis diffuse reflectance spectra (UV-DRS) of Ag/NaTNTs-70, Ag/NaTNTs-150, Ag/NaTNTs-250, and Ag/NaTNTs-350 are displayed along with NaTNTs-100. The sample of NaTNTs (Fig. 4 a) exhibits an absorption band below 380 nm (UV region), as predicted. This absorption band is caused by the charge transfer process from the conduction band, which is formed by the 3d t 2 g orbital of the Ti 4+ cations, to the valence band, which is formed by the 2p orbital of the oxide anions [ 1 , 31 ]. AgNPs that have been photo-deposited in Ag/NaTNTs-70, Ag/NaTNTs-150, Ag/NaTNTs-250, and Ag/NaTNTs-350 (Fig. 4 b, d) cause the maximum absorption to shift red ward from 400 to 430 nm. One possible explanation for this absorption band, which is centered at 416 nm, is that the silver nanoparticles were adsorbed on the surface of the TiO 2 particles and were absorbed [ 1 , 32 ]. Although XRD confirms the presence of metallic silver, the sample lacks the typical surface plasmon band of metallic silver, which is centered around 440 nm [ 33 , 34 ]. This can be explained by the fact that agglomeration causes the Ag nanoparticles over the titanate nanotube to not be of equal size, which can shrink the SPR band [ 35 ]. The HRTEM images show the uneven size distribution of the nanoparticles and their morphology on the nanotube surface (Fig. 3 ). The band-gap values of NaTNTs-100, Ag/NaTNTs-70, Ag/NaTNTs-150, Ag/NaTNTs-250 and Ag/NaTNTs-350 computed using Tauc's method [ 36 ] (Fig. 4 B) were found to be 3.7, 3.4, 3.4, 3.2 and 3.2 eV, respectively. The consequent annealing temperature (70 to 350 ο C) reduces the band gap. Surely, Lower band gap energy Ag/NaTNTs-350 sample (3.2 eV) will function more effectively in photo-induced reactions in the presence of light. Because of the Ag/NaTNTs interface that forms on the TNTs surface, band bending of TNTs causes the shift in the band-gap value. The generated Ag/NaTNTs are anticipated to exhibit effective visible-light-driven plasmonic photocatalytic activity since the TNTs' absorption property has been significantly extended to the visible-light region by the appearance of AgNPs' most advantageous SPR band. In order to better understand the shift in the light absorption band observed in this study from the near UV to the visible light range, we further hypothesize that Ag/NaTNTs-350 should have a lower energy level (3.2 eV) than NaTNTs (3.7 eV). As a result, in the visible spectrum, nanoscale metal colloids like silver exhibit an extremely strong surface plasmon absorption band. 3.5. Photocatalytic performance under sunlight irradiation Before being exposed to direct sunlight to measure the rate of MB photodegradation, the samples were agitated for one hour in the dark to reach the equilibrium of MB adsorption and desorption. The MB photodegradation rate of samples in the presence of sunlight at different times is displayed in Fig. 5 -A. All samples have very high MB photodegradation rates during the first 2.0 minutes of the sunlight irradiation. Ag/NaTNTs-70 (72%) has the slowest MB photodegradation rate compared to NaTNTs (60%) and Ag/NaTNTs-350 (83%) has the fastest. This resulted from an electrostatic interaction between the negatively charged titanate adsorbent and the positively charged MB molecules. Ag/NaTNTs-350 demonstrate a greater capacity for photocatalysis than other materials when exposed to longer periods of sunlight. This indicates that the annealing temperature range of 70 to 350°C had an impact on the photodegradation activity, which could be linked to the Ag/TNTs' structural change. The phase structure, size, and morphology of the adsorbed substrate, as well as the synergistic effect between adsorption and photodegradation, all strongly influence the effectiveness of rapid bleaching of the MB solution. This was further verified by designing a special experiment to soften the adsorption function by thermal treatment. In comparison with Ag/NaTNTs-70, Ag/NaTNT-150 displayed a marginally higher MB removal rate. However, for heat-treated samples at higher temperatures, like Ag/NaTNT-150 and Ag/NaTNT-350, both absorbance capability and photocatalytic degradation of MB were significantly decreased. The morphology and phase transition from titanate nanotubes to anatase particles, as demonstrated by XRD, should be blamed for this subpar MB removal performance. Furthermore, because the MB solution is highly colored due to lower adsorption on these samples, the light-active material was unable to interact with photons as efficiently due to the light shielding effect of the highly concentrated MB dye, which resulted in inferior photocatalytic degradation. Within 20 minutes of exposure to sunlight, the MB photodegradation efficiencies of the Ag/NaTNTs-70, Ag/NaTNTs-150, Ag/NaTNTs-250, and Ag/NaTNTs-350 are 93.6%, 91.4%, 91.2%, 95.8%, and 97.0%, correspondingly. These findings demonstrated that Ag/NaTNTs-350 has the highest photocatalytic activity, whereas Ag/TNTs-70 has the lowest photocatalytic activity. Furthermore, Fig. 5 -B displays the MB absorption spectra on Ag/NaTNTs-350 under varied sunlight irradiation times. The n→π* transition of MB is represented by the UV–visible band of MB monomer in water, which typically appears at 665 nm [ 37 – 39 ]. When silver nanoparticles are not present, the absorption spectrum of MB barely changes after 20 minutes of sunlight irradiation, but for Ag/AgTNTs-350, it significantly changes. In particular, the typical absorption peak of MB at 664 nm strongly decreases after 20 minutes of sunlight irradiation. The relative absorbance of band at 664 nm is plotted as a function of time to evaluate the reduction reaction rate (Fig. 5 -B). This result demonstrated that MB was photodegraded by the catalyst rather than by MB photolysis. These findings demonstrated that Ag/NaTNTs-350 of MB photodegradation capabilities in the presence of sunlight were superior. On the other hand, it is anticipated that Ag/NaTNTs-350 photocatalysis will primarily cause the change in MB concentration (Fig. 5 B). This figure shows hypsochromic effects (blue shifts of spectral bands) in the UV region at λ max = 291 and 246 nm. These effects are caused by N-demethylation of the dimethylamino group in MB, which happened simultaneously with the oxidative degradation under UV irradiation. This effect is associated with the formation of intermediate products, such as benzene and structures resembling naphthalene, as a result of MB breakdown [ 40 ]. 3.5.1. The influence of MB dye concentration A study was conducted to determine the ideal dye concentration for improving the photocatalytic degradation of MB. We measured degradation performance by increasing dye concentration (10, 15, 20, 25, and 30 mg/L) and then withdrawing samples at different time intervals while keeping the photocatalyst concentration (Ag/NaTNTs: 10 mg) constant. Figure 6 showed that when initial dye concentrations are increased from 10 to 30 mg/L, MB degradation decreases. This can be explained by the fact that as the MB concentration increases, the solution's ability to absorb visible light decreases; as a result, as the initial dye concentration is lowered, the photonic efficiency increases. According to [ 41 ], the increase in collision frequency between dye and photons is responsible for the decrease in photonic efficiency as initial dye concentration rises. The extensive dye adsorbed on the photocatalyst surface, which blocks the catalyst's surface, can inhibit the interaction between electron holes and free radicals at high concentrations [ 42 ]. 3.5.2. Langmuir isotherm According to the Langmuir isotherm [ 43 ], the adsorption process occurs at homogeneous sites in the adsorbent. It is considered that monolayer adsorption processes and adsorbate molecules do not interact. The linear form of the following Eq. (1) can be used to represent the Langmuir isotherm model. $$\frac{1}{{\text{q}}_{e}}=\frac{1}{{\text{q}}_{m}}+\frac{1}{{\text{K}}_{L}{\text{q}}_{m}}\left(\frac{1}{{C}_{e}}\right) \left(1\right)$$ where C e is the equilibrium concentration of the adsorbate (mg/L), q m is the Langmuir constant at the monolayer or maximum adsorption capacity (mg/g), K L is the Langmuir adsorption constant related to the adsorption energy (L/mg), and q e is the amount of adsorbate adsorbed per unit mass of adsorbent at equilibrium (mg g − 1 ). The photocatalytic degradation reaction also follows the pseudo first-order reaction, as shown by the K L and q m values, which can be calculated from the slope and intercept of the linear plot of 1/q e versus 1/C e , the apparent rate constants were tabulated in Table 1 . When Ag/NaTNT was used for photocatalytic degradation of MB dye in aqueous solutions, the correlation coefficient R value was less than that of the pseudo-first order model (> 0.99) indicating that the photocatalytic degradation of MB dye in aqueous solutions using Ag/NaTNT follows the pseudo first order kinetic model. 3.5.3. Freundlich isotherm A linear equation that describes the heterogeneous adsorption is the Freundlich isotherm model [ 44 ], which is an empirical relationship: Ln q e = ln K F + \(\frac{1}{\text{n}}\) ln C e (2) where K F is the Freundlich constant and is indicative of the adsorption capacity (mg/g) of titanate nanotubes. The value \(\frac{1}{\text{n}}\) suggests the favorability of adsorption process. The Freundlich isotherm plot of ln q e against ln C e gave straight line and the slope and intercept yield the values of \(\frac{1}{\text{n}}\) and ln K F , respectively. The fitting results for the unmodified and Ag-modified titanate nanotube samples and the isotherm parameters are presented in Table 1 . The adsorbent's adsorption sites have a low-energetic heterogeneous surface, which leads to a high sorption capacity, as indicated by the heterogeneity factor n > 1 (Table 1 ). This may be explained by the sorbate species' molecular interactions with one another and their subsequent aggregation on the surface monolayer. Ag/NaTNTs-150's higher n value indicates that the adsorption of MB is more pronounced for this sample than for Ag/NaTNTs-70, which could be because AgNPs introduced more heterogeneous pores and aggregates, as the TEM micrograph has suggested. 3.6. Mechanism for photodegradation of MB dye Ag/NaTNTs-350 demonstrated increased absorption of visible light, which raised the photocurrent density and improved the efficiency of charge generation and separation. By means of the surface plasmon resonance effect, AgNPs were able to absorb visible light, and electrons were transferred from plasmonically excited AgNPs to the TNTs' CB (Eq. 3). Furthermore, the recombination of photogenerated carriers was inhibited by the heterojunction structure that existed between AgNPs and TNTs [ 45 , 46 ]. O 2 on the sample surface will eventually interact with an electron in the conduction band, reducing O 2 to an O 2 -radical (Eq. 5 ). The primary active species in the MB photodegradation were thought to be the OH * radicals. The radicals represented by the symbol OH * (h + ) may arise from a reaction involving h + in the valence band, H 2 O and OH − in a mode (Eq. 4). Additionally, OH * (e − ), which is the result of reducing O ¬2 with e − in the conduction band, may also be produced (Eqs. 5 –8). The photodegradation of MB would be greatly aided by h + since the formation of OH * radicals is more likely in these circumstances. Eq. 9 shows that the OH * radicals that are generated effectively attack the dye molecule, sever bonds, and ultimately transform the MB into degraded intermediates such as CO 2 and H 2 O. $$\text{A}\text{g}/\text{T}\text{N}\text{T}\text{s}-\text{P}400 +h\nu ⟶{(h}^{+}) +({e}^{-}\left) \right(3)$$ $${h}^{+}+{H}_{2}\text{O} / \text{O}{H}^{-}⟶O{H}_{\left({h}^{+}\right)}^{*} + {H}^{+} \left(4\right)$$ $${e}^{-}+ {O}_{2}⟶{O}_{2}^{-}$$ 5 $${O}_{2}^{-}+2{H}^{+}+OOH⟶{H}_{2}{O}_{2} \left(6\right)$$ $${H}_{2}{O}_{2}+ {O}_{2}^{-}⟶{OH}^{-}\left({e}^{-}\right)+ {OH}^{-} + {O}_{2} \left(7\right)$$ $${H}_{2}{O}_{2}+h\nu ⟶2 {OH}^{*}\left({e}^{-}\right) \left(8\right)$$ $$MB+ {OH}^{*}\left({e}^{-}\right)/ {OH}^{*} /{h}^{+}/{O}_{2 }^{-} ⟶degradation products \left(9\right)$$ 4. Electronic properties Ag atoms imbedded successfully in nanotube templet model. The interaction energy (-880.35Kj/mol.) was calculated, using density functional theory with B3LYP\4-311G* set, as implemented in jauger [ 20 ]. Silver and sodium were optimized in nanotube wall in perpendicular mod with titanium atom before folding configuration (Fig. 7 ). Ag atoms imbedded successfully in nanotube templet model. The attractive/ repulsive attractions played a cyclic function in the holding, folding and stability process of the nanotube. Two interaction forces (attraction & repulsive) are affecting on the nanotube channel conformation. The optimum distances for Na + ….Ti + and Ag + ….Ti + displayed 2.897 and 2.806 Å, respectively. O ـــ …Ti + showed the optimum length 2.190 & 2.087 Å for angular and straight channels, respectively. There are differences in the length of the angular and straight channels as well as the cation-anion and anion-anion lengths. One notice that the (cation→anion or attractive) attractions are preferred than (anion→anion or repulsive) interactions, and the straight channels are more stable than other channels. E HOMO&LUMOs referred to the energetic of the highest-occupied/lowest-unoccupied molecular orbitals of nanotube were calculated (Table 2 ). HOMO& LUMO zones localized over all nanotube skeleton. This information showed that intramolecular charge transfer (ICT) between HOMOs and LUMOs was found. The effectiveness of dye removal is closely linked to the molecular orbitals' spatial distribution, highlighting the most likely sites in the order that dyes will most likely attack. The three factors that were examined to explain the potency against removal dyes were chemical potential (IP), nucleophilicity (χ), and electrophilicty (ω). The promising agent against removing dyes are the particle can accept free electrons from dyes. The low energy gap and the calculated energetic data values for Ag/Ti showed the high activity against removing dye. 4.1. Profile for Molecular electrostatic potential map “MEP” MEP is a useful feature for investigating the reactivity of nanotube species (Fig. 7 ). Its a physical-character able to examine reactivity by quantum chemical approaches, through electronic distribution. High negative potential region that benefit from negative assaults is shown in red. The high positive potential zone is highlighted in blue. The color variation in MEP is lowered by ordering blue > green > red > yellow. The color gradation around whole Skelton’s showing the attraction and repulsive force sharing in the stabilization of Ag in Ti-nanotube. The color variation providing the helpful indication about stabilization between straight and angular molecular sites, that able to balance between attraction and repulsive force in nanotube. Furthermore, raising blue region may be explained by a high repulsive force of angular channel in nanotube, which ability to remove dye based on electrostatic force. 5. Conclusion Due to the presence of AgNPs/NaTNTs have a propensity to undergo phase transformation, and high temperature annealing alters their morphology. The absorption edges of the as-prepared titanate nanotubes and Ag/NaTNTs samples annealed from 70 to 350°C degreased from 3.7 to 3.2 eV, according to UV-vis diffuse reflectance spectra. The presence of functional groups in the titanate product is confirmed by FTIR analysis. The HRTEM images provide the diameter and length of the tube and verify that a tubular structure has formed. Because titanate nanotubes have a larger surface area than nanoparticles, electron percolation through them is easier according to their morphology. Therefore, the findings of this study could provide a broad perspective to the researchers, suggesting that one-dimensional titanate nanotubes could be appropriate for solar cell applications. According to the computed electronic structure, the amorphous TNTs cluster's energy level, HOMO–LUMO gap, and singlet–singlet lowest excited state is extremely similar to those of the anatase TiO2 cluster (crystalline phase). O 2 adsorption on the titania surface is facilitated by the OH group on the catalyst surface, which is primarily related to the photocatalytic activity, according to studies on catalytic activity and characterization measurements. Additionally, the order of the OH group concentration on the surface was maintained by the photocatalytic activity. It is conceivable that Ag/TNTs' structural tunability contributed to its superior photocatalytic MB degradation activity when it was annealed at 350°C compared to other samples. Declarations Author Contribution Prof. Dr . T. M. salama; he is head of research with discussion of analysisDr El‐Henawy is write first paper with discussionEl-Gawad he is preparation of sample with analysisOthman is final write the paper with discussion of analysis References I. O Ali, T. M Salama, A. A. Gawad, A. A El-Henawy, M.B Ghazy, M. F Bakr, Silver nanoparticles @ titanate nanotubes composite: Synthesis, characterization, applications and docking, Inorganic Chem. Comm. 137, (2022), 109187 D.V. Bavykin, F.C. Walsh, Elongated titanate nanostructures and their applications, Eur. J. Inorg. Chem. 2009 (8) (2009) 977–997. H.H. Ou, S.L. Lo, Review of titania nanotubes synthesized via the hydrothermal treatment: fabrication, modification, and application, Sep. Purif. Technol. 58 (1) (2007) 179–191, B. Poudel, W.Z. Wang, C. Dames, J.Y. Huang, S. Kunwar, D.Z. Wang, D. Banerjee, G. Chen, Z.F. Ren, Formation of crystallized titania nanotubes and their transformation into nanowires, Nanotechnology 16 (9) (2005) 1935–1940, doi: J. Liu, P.M. Hosseinpour, S. Luo, D. Heiman, L. Menon, D.A. Arena, L.H. Lewis, TiO 2 nanotube arrays for photocatalysis: effects of crystallinity, local order, and electronic structure, J. Vac. Sci. Technol.: Vac. Surfaces Films 33 (2015) 021202 Y.L. Pang, S. Lim, H.C. Ong, W.T. Chong, A critical review on the recent progress of synthesizing techniques and fabrication of TiO 2 -based nanotubes photocatalysts, Appl. Catal. Gen. 481 (2014) 127–142. D. Wu, J. Liu, X.N. Zhao, A.D. Li, Y.F. Chen, N.B. Min, Sequence of events for the formation of titanate nanotubes, nanofibers, nanowires, and nanobelts, Chem. Mater 18 (2006) 547. L. Yang, M. Zhang, S. Shi, J. Lv, X. Song, G. He, Z. Sun, Effect of annealing temperature on wettability of TiO2 nanotube array films, Nanoscale Res. Lett. 9(2014)621. Das, R. Zazpe, J. Prikryl, P. Knotek, M. Krbal, H. Sopha, V. Podzemna, J.M. Macak, Influence of annealing temperatures on the properties of low aspectratio TiO 2 nanotube layers, Electrochim. Acta 213 (2016) 452–459. J. Liu, P.M. Hosseinpour, S. Luo, D. Heiman, L. Menon, D.A. Arena, L.H. Lewis, TiO 2 nanotube arrays for photocatalysis: effects of crystallinity, local order, and electronic structure, J. Vac. Sci. Technol.: Vac. Surfaces Films 33 (2015) 021202. Y. Bai, I.S. Park, H.H. Park, M.H. Lee, T.S. Bae, W. Duncan, M. Swain, The effect of annealing temperatures on surface properties, hydroxyapatite growth and cell behaviors of TiO 2 nanotubes, Surf. Interface Anal. 43 (2011) 998–1005. F. Hajakbari, M. Ensandoust, Study of thermal annealing effect on the properties of silver thin films prepared by DC magnetron sputtering, Acta Phys. Pol., A 129 (2016) 680–682. A.A. Mosquera, J.M. Albella, V. Navarro, D. Bhattacharyya, J.L. Endrino, Effect of silver on the phase transition and wettability of titanium oxide films, Sci. Rep. 6 (2016) 32171. M. Iqbal, I.A. Bhatti, M. Zia-Ur-Rehman, H.N. Bhatti, M. Shahid, Efficiency of advanced oxidation processes for detoxification of Industrial effluents, Asian J. Chem. 26 (2014) 4291–4296 D. Balarak, et al., Adsorption of acid blue 92 dye from aqueous solutions by singlewalled carbon nanotubes: isothermal, kinetic, and thermodynamic studies, Environ. Proc. 8 (2) (2021) 869–888. S. Karthi, et al., Removal of methylene blue dye using shrimp shell chitin from industrial effluents, Mater. Today Proc. 66 (4) (2022) 1945–1950. T.P.K. Kulasooriya, N. Priyantha, A.N. Navaratne, Removal of textile dyes from industrial effluents using burnt brick pieces: adsorption isotherms, kinetics and desorption, SN Appl. Sci. 2 (11) (2020). L. Hevira, et al., Terminalia catappa shell as low-cost biosorbent for the removal of methylene blue from aqueous solutions, J. Ind. Eng. Chem. 97 (2021) 188–199. M. Basuny, I.O. Ali, A.A. El-Gawad, M.F. Bakr, T.M. Salama, A fast green synthesis of Ag nanoparticles in carboxymethyl cellulose (CMC) through UV irradiation technique for antibacterial applications, J. Sol-Gel Sci. Technol. 75 (2015). Sanderson EW, Redford KH, Chetkiewicz CL, Medellin RA, Rabinowitz AR, Robinson JG, Taber AB. Planning to save a species: the jaguar as a model. Conservation Biology. 16 (1) (2002) 58–72 O. V. Yakubovich, V. V. Kireev, Refinement of the crystal structure of Na 2 Ti 3 O 7 , Crystallogr. Reports. 48 (2003). G.W. Peng, H.S. Liu, FT-IR and XRD characterization of phase transformation of heat-treated synthetic natisite (Na 2 TiOSiO 4 ) powder, Mater. Chem. Phys. 42 (1995). D. V. Bavykin, J.M. Friedrich, F.C. Walsh, Protonated titanates and TiO 2 nanostructured materials: Synthesis, properties, and applications, Adv. Mater. 18 (2006). Y. Inoue, M. Uota, T. Torikai, T. Watari, I. Noda, T. Hotokebuchi, M. Yada, Antibacterial properties of nanostructured silver titanate thin films formed on a titanium plate, J. Biomed. Mater. Res. - Part A. 92 (2010). H.M. Kim, F. Miyaji, T. Kokubo, S. Nishiguchi, T. Nakamura, Graded surface structure of bioactive titanium prepared by chemical treatment, J. Biomed. Mater. Res. 45 (1999). M. Ocaña, J. V. Garcia-Ramos, C.J. Serna, Low‐Temperature Nucleation of Rutile Observed by Raman Spectroscopy during Crystallization of TiO2, J. Am. Ceram. Soc. 75 (1992). H.M. Kim, F. Miyaji, T. Kokubo, T. Nakamura, Apatite-forming ability of alkali-treated Ti metal in body environment, J. Ceram. Soc. Japan. 105 (1997). J. García-Serrano, E. Gómez-Hernández, M. Ocampo-Fernández, U. Pal, Effect of Ag doping on the crystallization and phase transition of TiO2 nanoparticles, Current Applied Physics 9 (2009) 1097–1105 T.M. Salama, M.M. Mohamed, I. Othman A, G.A. El-Shobaky, Structural and textural characteristics of Ce-containing mordenite and ZSM-5 solids and FT-IR spectroscopic investigation of the reactivity of NO gas adsorbed on them, Appl. Catal. A Gen. 286 (2005). C.C. Tsai, H. Teng, Regulation of the physical characteristics of titania nanotube aggregates synthesized from hydrothermal treatment, Chem. Mater. 16 (2004). A. Fuerte, M. D. Hernández-Alonso, A. J. Maira, A. Martínez-Arias, M. Fernández-García, J. C. Conesa, J. Soria and G. Munuera, Nanosize Ti–W Mixed Oxides: Effect of Doping Level in the Photocatalytic Degradation of Toluene Using Sunlight-Type Excitation, J. Catal., 2002, 212, 1 M. Li, Z. Xing, J. Jiang, Z. Li, J. Yin, J. Kuang, S. Tan, Q. Zhu, W. Zhou, Surface plasmon resonance-enhanced visible-light-driven photocatalysis by Ag nanoparticles decorated S-TiO 2 – x nanorods, J. Taiwan Inst. Chem. Eng. 82 (2018). B. Joshi, C. Regmi, D. Dhakal, G. Gyawali, S.W. Lee, Efficient inactivation of Staphylococcus aureus by silver and copper loaded photocatalytic titanate nanotubes, Prog. Nat. Sci-Mater. Int. 28 (2018) 15–23. D. A. Sales, T. M.F. Marques, A. Ghosh, S. B.S. Gusmão, T. L. Vasconcelos, C. Luz-Lima, O. P. Ferreira, L. M. Hollanda, I. S. Lima, E. C. Silva-Filho, D. Dittz, A. O. Lobo, B. C. Viana, Synthesis of silver-cerium titanate nanotubes and their surface properties and antibacterial applications, Materials Science & Engineering C 115 (2020) 111051 N. Sobana, M. Muruganadham, M. Swaminathan, Nano-Ag particles doped TiO2 for efficient photodegradation of direct azo dyes, J. Mol. Catal. A Chem. 258 (2006( 124–132. S.F. Wang, F. Gu, M.K. Lü, X.F. Cheng, W.G. Zou, G.J. Zhou, S.M. Wang, Y.Y. Zhou, Synthesis and photoluminescence characteristics of Dy3+-doped ZnAl2O4 nanocrystals via a combustion process, J. Alloys Compd. 394 (2005) 255–258. Shahwan, T., Sirriah, S.A., Nairat, M., Boyac, E., Eroglu, A.E., Scott, T.B., Hallam, K.R., Green synthesis of iron nanoparticles and their application as a fenton-likecatalyst for the degradation of aqueous cationic and anionic dyes. Chem. Eng. J.172,(2011) 258–266. Rauf, M.A., Meetan, M.A., Khaleel, A., Ahmed, A., Photocatalytic degradationof methylene blue using a mixed catalyst and product analysis by LC/MS. Chem.Eng. J. 157, (2010)373–378. V.K. Vidhu, Daizy Philip, Catalytic degradation of organic dyes using biosynthesized silvernanoparticles, Micron 56 (2014) 54–62 M. Dükkanci, G. Gündüz, S. Yilmaz, R. V. Prihod’ko, Heterogeneous Fenton-like degradation of Rhodamine 6G in water using CuFeZSM-5 zeolite catalyst prepared by hydrothermal synthesis, J. Hazard. Mater. 181 (2010). Dai, K., Lu, L., Dawson, G., 2013. Development of UV-LED/TiO 2 device and their application for photocatalytic degradation of methylene blue. J. Mater. Eng. Perform. 22, 1035–1040 Rauf, M.A., Meetani, M.A., Hisaindee, S., An overview on the photocatalytic degradation of azo dyes in the presence of TiO2 doped with selective transition metals. Desalination 276,(2011) 13–27. I. Langmuir. The constitution and fundamental properties of solids and liquids. Part I. solids. J. Am. Chem. Soc. 38 (11) (1916) 2221–2295. H.M.F. Freundlich, over the adsorption in solution, J. Phys. Chem. 57 (1906) 385–470. D. Yang, Y. Sun, Z. Tong, Y. Tian, Y. Li, Z. Jiang, Synthesis of Ag/TiO2Nanotube heterojunction with improved visible-light photocatalytic performance inspired by bioadhesion, J. Phys. Chem. C 119 (2015) 5827–5835. C. He, D. Shu, M. Su, D. Xia, A. Mudar Abou, L. Lin, Y. Xiong, Photocatalytic activity of metal (Pt, Ag, and Cu)-deposited TiO2 photoelectrodes for degradation of organic pollutants in aqueous solution, Desalination 253 (2010) 88–93. Tables Table 1: Adsorption isotherm of 20 mgl -1 MB adsorbed by1.0 gml -1 of different catalyst at room temperature and PH = 2 Isotherm content Parameter TNTs Ag/TNTs-70 Ag/TNTs-150 Ag /TNTs-250 Ag /TNTs- 350 Langmuir q m ­(mg g -1 ) 12.352 11.169 12.254 11.08 10.52 K L (L mg -1 ) 21.007 23.91759 17.99355 30.71 38.42 R 2 0.9963 0.9886 0.9913 0.983 0.982 Freundlich n 0.3756 2.460152 2.605627 2.36 2.31 K F 0.6101 0.593623 0.603815 0.60 0.59 R 2 0.9834 0.9966 0.9911 0.996 0.997 Table 2. The calculated energy in ev. derived from for Ag/Ti nanotube as calculated at B3LYP/6-311+G(d,p). E HOMO E LUMO D E HOMO/LUMO IP η S χ ω 5 -7.07 -3.91 3.16 7.07 1.58 0.632 -0.122 0.10 Additional Declarations No competing interests reported. Cite Share Download PDF Status: Posted 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. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-3881461","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":268534685,"identity":"5284e40a-29b0-4a4b-b655-ef6f95d28781","order_by":0,"name":"Tarek M. Salama","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAy0lEQVRIiWNgGAWjYNCCAiBmb2BgJkoxD5g0ALEOkKxFIoFILfZiB5g//DCwi+af+cbwc0GFDQN/e3cCflukE9gkewySc2fczjGWnnEmjUHizNkNBLUw8Bgw5zbczjGQ5m07zGAgkUtQC/PHPwb1ufNvnjH+TawWBmkeg8O5G27wmBFpy+0ENmkZg+O5G8+klVnznEnjIegX9tlAh72pqM6dd/zw5ts8FTZy/O29+LUwMPB/gDI4DMDWElCOauEDUlSPglEwCkbBCAIA6UFA27Sjj50AAAAASUVORK5CYII=","orcid":"","institution":"Al-Azhar University","correspondingAuthor":true,"prefix":"","firstName":"Tarek","middleName":"M.","lastName":"Salama","suffix":""},{"id":268534686,"identity":"50ad20c2-3c50-4739-8229-580d2c973ae9","order_by":1,"name":"Ahmed Abd El-Gawad","email":"","orcid":"","institution":"Ministry of Justice","correspondingAuthor":false,"prefix":"","firstName":"Ahmed","middleName":"Abd","lastName":"El-Gawad","suffix":""},{"id":268534687,"identity":"4697723f-38b3-42bc-b0f3-0b7cc3127d43","order_by":2,"name":"Ahmed A. El‐Henawy","email":"","orcid":"","institution":"Al-Azhar University","correspondingAuthor":false,"prefix":"","firstName":"Ahmed","middleName":"A.","lastName":"El‐Henawy","suffix":""},{"id":268534688,"identity":"b89cc2e5-6ec5-4af5-bc0e-a52da2cb2a85","order_by":3,"name":"Ibraheem O. Ali","email":"","orcid":"","institution":"Al-Azhar University","correspondingAuthor":false,"prefix":"","firstName":"Ibraheem","middleName":"O.","lastName":"Ali","suffix":""}],"badges":[],"createdAt":"2024-01-20 11:59:06","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-3881461/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-3881461/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":50096696,"identity":"65c9d498-77f4-42f8-b77a-f3b7f8909700","added_by":"auto","created_at":"2024-01-24 13:40:06","extension":"jpg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":250904,"visible":true,"origin":"","legend":"\u003cp\u003eXRD patterns for (a) TNTs-100, (b) Ag/TNTs-70, (c)Ag/TNTs-150,(d) Ag/TNTs- 250 and (e) Ag/TNTs-350.\u003c/p\u003e","description":"","filename":"Figs1.jpg","url":"https://assets-eu.researchsquare.com/files/rs-3881461/v1/38445c47c8fe0b21c57114f4.jpg"},{"id":50096700,"identity":"e1a9d010-9083-4a2a-9553-e9af45a8748b","added_by":"auto","created_at":"2024-01-24 13:40:06","extension":"jpg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":226590,"visible":true,"origin":"","legend":"\u003cp\u003eIR spectra of (a) TNTs-100, (b) Ag/TNTs-70, (c) Ag/TNTs-150, (d) Ag/TNTs-250 and (e) Ag/TNTs-350.\u003c/p\u003e","description":"","filename":"Figs2.jpg","url":"https://assets-eu.researchsquare.com/files/rs-3881461/v1/9ce03c5b5cecd85f4fcd64a5.jpg"},{"id":50096965,"identity":"f4d28f42-f354-459c-9dba-7f6a238b1bfb","added_by":"auto","created_at":"2024-01-24 13:48:06","extension":"jpg","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":395830,"visible":true,"origin":"","legend":"\u003cp\u003eHR-TEM images for (a) TNTs-100, (b) Ag/TNTs-70 and (c) Ag/TNT-350.\u003c/p\u003e","description":"","filename":"Figs3.jpg","url":"https://assets-eu.researchsquare.com/files/rs-3881461/v1/ce5e2ecbc222442a5428025d.jpg"},{"id":50096964,"identity":"4b668a72-8e0b-4774-985a-de967385c3fc","added_by":"auto","created_at":"2024-01-24 13:48:06","extension":"jpg","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":326425,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eA: \u003c/strong\u003eUV–vis diffuse reflectance absorption spectra of (a) TNTs-100, (b) Ag/TNTs-70, (c) Ag/TNTs-150, (d) Ag/TNTs-250 and (e) Ag/TNTs-350.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eB: \u003c/strong\u003eEstimated band gaps of the prepared samples\u003c/p\u003e","description":"","filename":"Figs4.jpg","url":"https://assets-eu.researchsquare.com/files/rs-3881461/v1/5f4219a263e32f44fe21377f.jpg"},{"id":50096702,"identity":"472e06fe-0745-4039-a9ca-245a918c9859","added_by":"auto","created_at":"2024-01-24 13:40:06","extension":"jpg","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":319468,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eA:\u003c/strong\u003e Photocatalytic degradation of 10 ppm MB dye over the unmodified and Ag-modified titanate NTs as a function of contact time.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eB:\u003c/strong\u003e plot of I\u003csub\u003ed\u003c/sub\u003e/I\u003csub\u003em \u003c/sub\u003eratio versus contact time for photo degradation of MB by (a) TNTs-100, (b) Ag/TNTs-350.\u003c/p\u003e","description":"","filename":"Figs5.jpg","url":"https://assets-eu.researchsquare.com/files/rs-3881461/v1/7dbcc76c7e7ca5c74fcc7a6d.jpg"},{"id":50097691,"identity":"95916730-6b18-48c7-abd5-7f24bf1ae9c5","added_by":"auto","created_at":"2024-01-24 13:56:06","extension":"jpg","order_by":6,"title":"Figure 6","display":"","copyAsset":false,"role":"figure","size":177187,"visible":true,"origin":"","legend":"\u003cp\u003eAmount of MB removed in different concentration (10:30) \u0026nbsp;by Ag/TNTs-350 catalyst\u003c/p\u003e","description":"","filename":"Figs6.jpg","url":"https://assets-eu.researchsquare.com/files/rs-3881461/v1/8d7bceae8eaaffcdcd017b7f.jpg"},{"id":50096701,"identity":"9692a2e8-84cd-4493-8742-c6dc8035fb7f","added_by":"auto","created_at":"2024-01-24 13:40:06","extension":"jpg","order_by":7,"title":"Figure 7","display":"","copyAsset":false,"role":"figure","size":346761,"visible":true,"origin":"","legend":"\u003cp\u003eThe optimization geometry and MEP with HOMO\u0026amp;LUMO maps for Ag/Ti-nanotube, where O, Ti, Na and Ag, respectively, represented in red, green, yellow and cyan, respectively.\u003c/p\u003e","description":"","filename":"Figs7.jpg","url":"https://assets-eu.researchsquare.com/files/rs-3881461/v1/74219973c39547cb738dcc03.jpg"},{"id":51496776,"identity":"c61242e9-894e-451b-9f8b-4fbfd61b1019","added_by":"auto","created_at":"2024-02-22 15:52:48","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":796553,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-3881461/v1/982c83f2-fab2-43ba-ae62-265d70aeeae1.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Titanate nanotubes coated with Ag nanoparticles: Effects of Annealing Temperature on Crystalline Structure, Morphology, and Photocatalytic Activity","fulltext":[{"header":"1. Introduction","content":"\u003cp\u003eIn recent years, nanotechnology as well as its research fields and applications has undergone a revolution. Due to its numerous applications in electronics, optics, catalysis, sensors, and energy conversion, titanate (Na\u003csub\u003ex\u003c/sub\u003eH\u003csub\u003e1\u0026minus;x\u003c/sub\u003eTi\u003csub\u003e3\u003c/sub\u003eO and H\u003csub\u003e2\u003c/sub\u003eTi\u003csub\u003e3\u003c/sub\u003eO\u003csub\u003e7\u003c/sub\u003e) and titania (TiO\u003csub\u003e2\u003c/sub\u003e) nanostructures (nanotubes, nanowires, and nanobelts) have garnered a lot of attention [\u003cspan additionalcitationids=\"CR2\" citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]. When compared to bulk materials, one of the most significant features of nanotubes is their large specific surface area. Additionally, titanium nanotubes (TNTs) offer enhanced electron transfer channels. As a result, they aid in raising the efficiency of photocatalysis, electrolysis, and solar cells [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eAccording to a prior study, post-synthesis processing of TNTs can be used to modify their electronic structure, concentration of surface local defects, and crystallinity, all of which can affect their photocatalytic activity [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]. TiO\u003csub\u003e2\u003c/sub\u003e nanotubes can be synthesized through a variety of methods, such as alkaline hydrothermal treatment, electrochemical anodization, and template-assisted fabrication [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]. The alkaline hydrothermal method has garnered greater attention among these preparation techniques because it is an economical and straightforward way to produce nanotubes on a large scale. Over the last ten years, a lot of earlier research has mostly concentrated on how hydrothermal parameters affect the structure and mechanism of nanotube formation [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]. Using an anodization process, Yang et al. [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e] synthesized TNTs, which were then calcined to produce the rutile phase (\u0026gt;\u0026thinsp;500 \u003csup\u003e◦\u003c/sup\u003eC) and anatase phase (\u0026gt;\u0026thinsp;450 \u003csup\u003e◦\u003c/sup\u003eC). At 800 \u003csup\u003e◦\u003c/sup\u003eC, the TiO\u003csub\u003e2\u003c/sub\u003e nanotube arrays were destroyed, leaving only a dense rutile film visible [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. In a different study, Das et al. [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e] observed that the best electrical and photo-electrochemical properties are offered by the anatase structure, which is formed when TNT layers are annealed at 400 \u003csup\u003e◦\u003c/sup\u003eC. The \"pillar-effect\" technique has been employed recently to safeguard the nanotubular structure at 400\u0026deg;C. According to recent research by Liu et al. [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e], during annealing, O\u003csub\u003e2\u003c/sub\u003e enhanced the local structure and long-range crystallinity, resulting in a reduction of local surface defects such as Ti\u003csup\u003e3+\u003c/sup\u003e and O vacancies. Furthermore, the improvement of the photocatalytic activity also depends critically on the existence of these local defects. The findings of Bai et al. [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e] indicated that the surface structure and characteristics of TNTs are likely to be impacted by the variations in crystallinity brought about by adjusting the annealing temperature.\u003c/p\u003e \u003cp\u003eAg transfers to Ag\u003csub\u003e2\u003c/sub\u003eO at 500 and 600 \u003csup\u003e◦\u003c/sup\u003eC, as shown by Hajakbari et al.'s investigation into the effect of annealing temperature on pure Ag films' ability to crystallize and oxidize [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]. Furthermore, it has been demonstrated that raising the annealing temperature increases atom mobility, which results in particle agglomeration and the formation of larger particles, both of which raise film roughness [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]. In a separate investigation, Mosquera et al. [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e] concluded that Ag will aggregate into bigger clusters as a result of the annealing temperature. This prevents Ti and O ions from diffusing in order to form anatase and increases rutile formation by concurrently lowering the transition temperature.\u003c/p\u003e \u003cp\u003eIt is commonly recognized that the discharge of industrial wastewater into the environment, which contains a broad range of organic hazardous pollutants, poses a potential threat to the environment. As a result, environmental degradation is now a major worldwide concern, and ecosystem maintenance is crucial [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. One of the frequently used dyes for dying cotton, silk, and wood is methylene blue (MB) [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e, \u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]. The wastewater released by large manufacturing industries has been linked to a high concentration of dye in water bodies [\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]. A cationic dye with several applications in the dyeing industry is called MB [\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e]. These developments indicate that the presence of dyes in aquatic environments is unwanted, unpleasant, and harmful to both human health and the health of plants and animals [\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eGiven that the morphology and crystal structure of Ag/TNTs are directly impacted by the annealing temperature, it is imperative to ascertain and elucidate these effects considering the material's photocatalytic properties. In this w ork, we annealed samples at various temperatures (70 to 350\u0026ordm;C) after synthesizing Ag/TNTs using a photoreduction method. We employ a variety of techniques, including X-ray diffraction (XRD), FT-IR, UV-vis spectroscopy, transmission electron microscopy (HRTEM) to comprehend the physical and chemical properties of the materials. Additionally, the rate at which the methylene blue dye (MB) degraded was used to assess the samples' photocatalytic activity. The investigation was carried out in batches, and the results were assessed using a range of research parameters to ascertain the effectiveness of the nanotubes in eliminating organic pollutants.\u003c/p\u003e"},{"header":"2. Experimental","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003e2.1. preparation of sodium titanate nanotubes (NaTNT)\u003c/h2\u003e \u003cp\u003eThe synthesis of sodium titanate nanotubes (NaTNTs) was achieved through the utilization of a hydrothermal technique. Anatase type titanium dioxide powder (BDH Ltd, 98% purity) was used as a starting material. 4.0 g TiO\u003csub\u003e2\u003c/sub\u003e (TiO\u003csub\u003e2\u003c/sub\u003e BDH limited Poole England, 98%) were typically mixed with 200 ml of 10 M NaOH (Merck) solution and vigorously stirred for two hours before being hydrothermally treated for 48 hours at 170 \u0026ordm;C in a stainless autoclave [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. After the solid product was filtered, a significant amount of deionized water was used to wash it until the filtrate's pH reached 7.0, which is neutral. The white solid product was dried in an oven for four hours at 100 \u003csup\u003e◦\u003c/sup\u003eC, the sample was referred as NaTNTs-100.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec4\" class=\"Section2\"\u003e \u003ch2\u003e2.2. Preparation of Ag/NaTNTs\u003c/h2\u003e \u003cp\u003eBy photoreducing AgNO\u003csub\u003e3\u003c/sub\u003e (Merck), according to the appropriate process outlined in the literature, AgNPs were created and then loaded into the inner walls of NaTNTs [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e]. After exposing 1.0 g of NaTNTs-100 in 200 ml of distilled water to UV light while stirring for 10 minutes, organic impurities on the TNT surfaces were removed. Next, 10 ml of 0.1 M AgNO\u003csub\u003e3\u003c/sub\u003e was added dropwise to the suspension, and the treatment with UV light was continued for an additional hour while stirring continuously, during which time the color of the suspension gradually changed to a faint gray. The resulting Ag/NaTNTs was separated from the mother liquor after a 24-hour slow evaporation at 70 \u003csup\u003e◦\u003c/sup\u003eC; this sample was designated Ag/NaTNTs-70. To evaluate the thermal stability of AgNPs on the NaTNT surfaces, 1.0 g of Ag/NaTNTs-70 was then put in a porcelain vessel and heated to 150, 250, and 350 \u0026ordm;C for one hour. Ag/NaTNTs-150, Ag/NaTNTs-250, and Ag/NaTNTs-350 were the designations assigned to these samples, respectively.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec5\" class=\"Section2\"\u003e \u003ch2\u003e2.3. Characterization\u003c/h2\u003e \u003cp\u003eUsing a Philips diffractometer (type PW 3710), the samples' X-ray diffraction (XRD) patterns were measured. The patterns were scanned at a speed of 2θ\u0026thinsp;=\u0026thinsp;2.5\u0026ordm;/min using Ni-filtered copper Kα radiation (λ\u0026thinsp;=\u0026thinsp;1.5404 \u0026Aring;) at 30 kV and 10 mA.\u003c/p\u003e \u003cp\u003eA Perkin Elmer Spectrometer (RXI FT-IR) system was used to record FT-IR spectra with a single beam and a resolution of 2 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e. The sample was placed on the sample holder within the spectrometer's cavity after being tablet-ground with KBr (1:100). At room temperature, measurements were taken between 4000\u0026thinsp;\u0026minus;\u0026thinsp;400 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eUsing a HRTEM, Tecnai G20, FEI, Netherlands, equipped with an electron source gun made of lanthanum hexaboride (LaB6) and operating at an electron accelerating voltage of 200 kV, the particle size, morphology, and surface topology of the synthesized Ag/NaTNTs samples were examined. The Ag/NaTNTs suspension was dropped onto a carbon-coated Cu grid to create the samples, and the solvent was then allowed to slowly evaporate at room temperature.\u003c/p\u003e \u003cp\u003eReflectance Diffuseness Using a UV-570, JASCO spectrophotometer, the samples were subjected to ultraviolet-visible spectroscopy (UV-vis DRS) at room temperature, covering the wavelength range of 200\u0026ndash;1000 nm. Using Microsoft Excel software, the UV-vis spectra were processed. This involved calculating the Kubelka-Monk function, F(R), which was taken out of the UV-vis DRS absorbance. The determination of the edge energy (E\u003csub\u003eg\u003c/sub\u003e) for permitted transitions involved locating the straight line's intercept in the low-energy rise of the [F(R)hν]\u003csup\u003e2\u003c/sup\u003e plot of the direct allowed transition vs hν, where hν represents the incident photon energy.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec6\" class=\"Section2\"\u003e \u003ch2\u003e2.4. Evaluation of photocatalytic activity\u003c/h2\u003e \u003cp\u003eAs a cationic probe dye, Methylene Blue (Loba Chemie, purity 85%) was used in the adsorption/degradation investigations. The adsorption tests were conducted in a 200 ml quartz photoreactor (40 mm in diameter and 195 mm in height). After one hour in the dark, 0.05g of the Ag/NaTNTs photocatalyst was suspended in 100 ml MB (10\u0026ndash;30 mg L\u003csup\u003e\u0026ndash;1\u003c/sup\u003e) with and without H\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e2\u003c/sub\u003e, and it was exposed to the sun's visible irradiance spectrum while being constantly stirred. Sample aliquots were taken out at predetermined intervals, centrifuged to remove catalyst particles, and the supernatants were removed for spectrophotometric examination. A Perkin-Elmer Lambda 35UV-visible spectrophotometer was used to measure the concentrations of MB in the supernatants at 660 nm, which is the maximum absorption wavelength of MB. The average values were reported, and all measurements were made in triplicate with errors less than 5%.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec7\" class=\"Section2\"\u003e \u003ch2\u003e2.5. Computational model:\u003c/h2\u003e \u003cp\u003eThe Becke3-Lee-Yang-parr (B3LYP) level is applied to perform all the computation, using 6-311G* basis set using \u003cb\u003eSchr\u0026ouml;dinger\u003c/b\u003e [\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e].\u003c/p\u003e \u003c/div\u003e"},{"header":"3. Results and discussion","content":"\u003cdiv id=\"Sec9\" class=\"Section2\"\u003e\n \u003ch2\u003e3.1. XRD\u003c/h2\u003e\n \u003cp\u003eFigure \u003cspan class=\"InternalRef\"\u003e1\u003c/span\u003e shows the XRD patterns for NaTNTs-100 and Ag/NaTNTs-70-350. A low signal-to-noise ratio, overlapping peak reflections are seen in all patterns; these reflections could be attributed to either the confinement in NaTNTs or the surface curvature effects. The diffraction patterns of NaTNTs100 exhibit peaks at 2\u0026theta; of 9\u0026ordm;, 28.6\u0026ordm;, and 48.3\u0026ordm;. These positions are most comparable to those of nanosized sodium titanate (Na\u003csub\u003e2\u003c/sub\u003eTi\u003csub\u003e3\u003c/sub\u003eO\u003csub\u003e7\u003c/sub\u003e/Na\u003csub\u003e2\u003c/sub\u003eTi\u003csub\u003e6\u003c/sub\u003eO\u003csub\u003e13\u003c/sub\u003e) whose crystal lattice is oriented towards a monoclinic structure.[\u003cspan class=\"CitationRef\"\u003e21\u003c/span\u003e]. Na\u003csub\u003e2\u003c/sub\u003eTi\u003csub\u003e3\u003c/sub\u003eO\u003csub\u003e7\u003c/sub\u003e exhibits a lamellar structure with two inter lamellar Na\u003csup\u003e+\u003c/sup\u003e ions and three adjacent TiO\u003csub\u003e6\u003c/sub\u003e octahedra connected to form Ti\u003csub\u003e3\u003c/sub\u003eO\u003csub\u003e72\u003c/sub\u003e-corrugated layers [\u003cspan class=\"CitationRef\"\u003e21\u003c/span\u003e]. On the other hand, Na\u003csub\u003e2\u003c/sub\u003eTi\u003csub\u003e6\u003c/sub\u003eO\u003csub\u003e13\u003c/sub\u003e has a structure resembling a tunnel, and the temperature and duration of annealing determine how clear the crystal is. From a structural perspective, the Ti\u003csub\u003e3\u003c/sub\u003eO\u003csub\u003e72\u003c/sub\u003e-units of neighboring layers can be connected to form the tunnels of the Na\u003csub\u003e2\u003c/sub\u003eTi\u003csub\u003e6\u003c/sub\u003eO\u003csub\u003e13\u003c/sub\u003e phase from lamellar Na\u003csub\u003e2\u003c/sub\u003eTi\u003csub\u003e3\u003c/sub\u003eO\u003csub\u003e7\u003c/sub\u003e [\u003cspan class=\"CitationRef\"\u003e22\u003c/span\u003e]. Fundamentally, the Na\u003csup\u003e+\u003c/sup\u003e ions are intercalated into the titanate interlayer framework. [\u003cspan class=\"CitationRef\"\u003e23\u003c/span\u003e].\u003c/p\u003e\n \u003cp\u003eThe XRD pattern of Ag/NaTNTs-70 showed a decrease in intensity of the peaks resulting from the NaTNTs crystal structure, in favor of a newly superimposed peak at 2\u0026theta; of 29.3\u0026ordm;. The formation of silver titanate through the exchange of extra-framework Na\u003csup\u003e+\u003c/sup\u003e in TNTs with Ag\u003csup\u003e+\u003c/sup\u003e can be attributed to this new reflection [\u003cspan class=\"CitationRef\"\u003e24\u003c/span\u003e]. The interlayer distance in TNTs can generally vary when ions are removed from an interlayer of a layered material or added to an interlayer from a solution. Ag/NaTNTs-70 showed a shift in the 2\u0026theta; peak at 9\u0026ordm; to a higher angle, 9.3\u0026ordm;. This shift was most likely caused by AgNPs being exchanged with extra-framework Na\u003csup\u003e+\u003c/sup\u003e to transfer into regular lattice positions, which in turn caused the diffraction peak to shift.\u003c/p\u003e\n \u003cp\u003eThe spectra the Ag/TNTs-150 and Ag/TNTs-250 samples display a reflection of the silver titanate phase at 29.3\u0026deg; and an enhancement of the nanotabular Ti\u003csub\u003e6\u003c/sub\u003eO\u003csub\u003e13\u003c/sub\u003e\u003csup\u003e-2\u003c/sup\u003e phase as well. To further increase the temperature to 350 \u0026ordm;C, i.e. Ag/TNTs-350, the peak at 2\u0026theta; of 9.3\u0026ordm; was shifted to 10\u0026ordm;, along with new peaks at 13\u0026ordm;, 24.3\u0026ordm;, 28.3\u0026ordm; and 48.2\u0026ordm; were detected. The latter two peaks are indexed to the anatase phase, indicating a partial state transformation with temperatures occurred from nanotabular Na-TNTs to anatase nanotubes.\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec10\" class=\"Section2\"\u003e\n \u003ch2\u003e3.2. IR spectra\u003c/h2\u003e\n \u003cp\u003eFigure \u003cspan class=\"InternalRef\"\u003e2\u003c/span\u003e displays the FTIR spectra of NaTNTs-100 and Ag/NaTNTs-70-350 in the 4000\u0026ndash;400 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e range. NaTNTs-100 exhibited a spectrum with bands located at 3363, 1638, 1047, 885, 673, and 493 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e. Since there is a distinct band at 1638 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e that can be attributed to the bending mode of water molecules in the interlayer space of Na-TNTs, the 3363 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e band was linked to intermolecular hydrogen bonding at OH groups. This band appeared in all spectra of Ag/NaTNTs70-250 but with comparable intensities. The narrowing width of this band with increasing temperatures suggests perturbation of the complex hydrogen bonding environment, likely as a result of hybridization between the Ag\u003csup\u003e+\u003c/sup\u003e and Na-TNTs. However, the most pronounced perturbations of the OH-hydrogen bonding occurred for the Ag/NaTNTs-250 sample. For Ag/NaTNTs-350, a symmetrical large band owing to an increase in OH groups were obtained; this could be the result of partial titanate decomposition to highly hydroxylated anatase TiO\u003csub\u003e2\u003c/sub\u003e, which is consistent with information from XRD.\u003c/p\u003e\n \u003cp\u003eThe band at 673 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e in Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e2\u003c/span\u003e was assigned to Ti\u0026ndash;O\u0026ndash;Na vibrations in the tri-titanate wall, the band at 880 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e to Ti\u0026ndash;O bending and stretching vibration involving two-fold oxygen, and the peak at 906 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e to four-coordinate Ti\u0026ndash;O stretching vibrations involving non-bridging oxygen interacting with Na\u003csup\u003e+\u003c/sup\u003e[\u003cspan class=\"CitationRef\"\u003e25\u003c/span\u003e, \u003cspan class=\"CitationRef\"\u003e26\u003c/span\u003e]. The band at 494 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e was assigned to Ti\u0026ndash;O\u0026ndash;Ti bending vibration involving three-fold oxygen in the edge-shared TiO\u003csub\u003e6\u003c/sub\u003e. In a previous paper [\u003cspan class=\"CitationRef\"\u003e27\u003c/span\u003e], the sodium titanate hydrogel layer was identified as the source of all these peaks.\u003c/p\u003e\n \u003cp\u003eAmong these, the intensity of the band at 673 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, which was attributed to Ti-O bending vibration involving two-fold oxygen, was reduced in Ag/NaTNTs-250 in favor of the eruption of a new peak at 453 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, which was attributed to Ti-O stretching vibration involving three steps. The effects of heat treatments on Ag/NaTNTs\u0026apos; nanostructure can be attributed to the stabilization of the regular, open, dehydrated three-dimensional network structure, which involves coordinations of three oxygen atoms and six titanium atoms [\u003cspan class=\"CitationRef\"\u003e26\u003c/span\u003e]. The interaction between Ag and TNTs particles was tentatively attributed to the band at 1384 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e [\u003cspan class=\"CitationRef\"\u003e28\u003c/span\u003e\u0026ndash;\u003cspan class=\"CitationRef\"\u003e30\u003c/span\u003e].\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec11\" class=\"Section2\"\u003e\n \u003ch2\u003e3.3. Transmission electron microscope (TEM)\u003c/h2\u003e\n \u003cp\u003eFigure \u003cspan class=\"InternalRef\"\u003e3\u003c/span\u003e displays the morphology of the Ag/NaTNTs-70, Ag/NaTNTs-250, Ag/NaTNTs-350, and NaTNTs-100. The average diameter of AgNPs increases linearly with increasing annealing temperature. According to Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e3\u003c/span\u003ea, the as-synthesized NaTNT nanotubes have hollow inner pores with average outer and inner diameters of 3.32 and 9.41 nm at each tube end, respectively, and lengths of about 265 nm. Diffractions of the titanate/titanium dioxide nanotube phase can be seen in the SAED patterns at (200), (211), and (020). The original nanotube morphology of sodium titanate was unaffected by the addition of Ag NPs, except for the Ag/NaTNTs-350 sample (Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e3\u003c/span\u003e-c), which has numerous structural flaws and uneven walls. According to the XRD analysis, these two characteristics point to low crystallinity. It was determined that the annealing temperature caused small particles to combine to form larger clusters, which explained the larger particle size.\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec12\" class=\"Section2\"\u003e\n \u003ch2\u003e3.4. UV-visible diffuse reflectance spectra\u003c/h2\u003e\n \u003cp\u003eIn Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e4\u003c/span\u003e-A, the UV-vis diffuse reflectance spectra (UV-DRS) of Ag/NaTNTs-70, Ag/NaTNTs-150, Ag/NaTNTs-250, and Ag/NaTNTs-350 are displayed along with NaTNTs-100. The sample of NaTNTs (Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e4\u003c/span\u003ea) exhibits an absorption band below 380 nm (UV region), as predicted. This absorption band is caused by the charge transfer process from the conduction band, which is formed by the 3d t\u003csub\u003e2\u003c/sub\u003eg orbital of the Ti\u003csup\u003e4+\u003c/sup\u003ecations, to the valence band, which is formed by the 2p orbital of the oxide anions [\u003cspan class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan class=\"CitationRef\"\u003e31\u003c/span\u003e]. AgNPs that have been photo-deposited in Ag/NaTNTs-70, Ag/NaTNTs-150, Ag/NaTNTs-250, and Ag/NaTNTs-350 (Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e4\u003c/span\u003eb, d) cause the maximum absorption to shift red ward from 400 to 430 nm. One possible explanation for this absorption band, which is centered at 416 nm, is that the silver nanoparticles were adsorbed on the surface of the TiO\u003csub\u003e2\u003c/sub\u003e particles and were absorbed [\u003cspan class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan class=\"CitationRef\"\u003e32\u003c/span\u003e].\u003c/p\u003e\n \u003cp\u003eAlthough XRD confirms the presence of metallic silver, the sample lacks the typical surface plasmon band of metallic silver, which is centered around 440 nm [\u003cspan class=\"CitationRef\"\u003e33\u003c/span\u003e, \u003cspan class=\"CitationRef\"\u003e34\u003c/span\u003e]. This can be explained by the fact that agglomeration causes the Ag nanoparticles over the titanate nanotube to not be of equal size, which can shrink the SPR band [\u003cspan class=\"CitationRef\"\u003e35\u003c/span\u003e]. The HRTEM images show the uneven size distribution of the nanoparticles and their morphology on the nanotube surface (Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e3\u003c/span\u003e).\u003c/p\u003e\n \u003cp\u003eThe band-gap values of NaTNTs-100, Ag/NaTNTs-70, Ag/NaTNTs-150, Ag/NaTNTs-250 and Ag/NaTNTs-350 computed using Tauc\u0026apos;s method [\u003cspan class=\"CitationRef\"\u003e36\u003c/span\u003e] (Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e4\u003c/span\u003eB) were found to be 3.7, 3.4, 3.4, 3.2 and 3.2 eV, respectively. The consequent annealing temperature (70 to 350 \u003csup\u003e\u0026omicron;\u003c/sup\u003eC) reduces the band gap. Surely, Lower band gap energy Ag/NaTNTs-350 sample (3.2 eV) will function more effectively in photo-induced reactions in the presence of light. Because of the Ag/NaTNTs interface that forms on the TNTs surface, band bending of TNTs causes the shift in the band-gap value. The generated Ag/NaTNTs are anticipated to exhibit effective visible-light-driven plasmonic photocatalytic activity since the TNTs\u0026apos; absorption property has been significantly extended to the visible-light region by the appearance of AgNPs\u0026apos; most advantageous SPR band. In order to better understand the shift in the light absorption band observed in this study from the near UV to the visible light range, we further hypothesize that Ag/NaTNTs-350 should have a lower energy level (3.2 eV) than NaTNTs (3.7 eV). As a result, in the visible spectrum, nanoscale metal colloids like silver exhibit an extremely strong surface plasmon absorption band.\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec13\" class=\"Section2\"\u003e\n \u003ch2\u003e3.5. Photocatalytic performance under sunlight irradiation\u003c/h2\u003e\n \u003cp\u003eBefore being exposed to direct sunlight to measure the rate of MB photodegradation, the samples were agitated for one hour in the dark to reach the equilibrium of MB adsorption and desorption. The MB photodegradation rate of samples in the presence of sunlight at different times is displayed in Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e5\u003c/span\u003e-A. All samples have very high MB photodegradation rates during the first 2.0 minutes of the sunlight irradiation. Ag/NaTNTs-70 (72%) has the slowest MB photodegradation rate compared to NaTNTs (60%) and Ag/NaTNTs-350 (83%) has the fastest. This resulted from an electrostatic interaction between the negatively charged titanate adsorbent and the positively charged MB molecules. Ag/NaTNTs-350 demonstrate a greater capacity for photocatalysis than other materials when exposed to longer periods of sunlight. This indicates that the annealing temperature range of 70 to 350\u0026deg;C had an impact on the photodegradation activity, which could be linked to the Ag/TNTs\u0026apos; structural change. The phase structure, size, and morphology of the adsorbed substrate, as well as the synergistic effect between adsorption and photodegradation, all strongly influence the effectiveness of rapid bleaching of the MB solution. This was further verified by designing a special experiment to soften the adsorption function by thermal treatment.\u003c/p\u003e\n \u003cp\u003eIn comparison with Ag/NaTNTs-70, Ag/NaTNT-150 displayed a marginally higher MB removal rate. However, for heat-treated samples at higher temperatures, like Ag/NaTNT-150 and Ag/NaTNT-350, both absorbance capability and photocatalytic degradation of MB were significantly decreased. The morphology and phase transition from titanate nanotubes to anatase particles, as demonstrated by XRD, should be blamed for this subpar MB removal performance. Furthermore, because the MB solution is highly colored due to lower adsorption on these samples, the light-active material was unable to interact with photons as efficiently due to the light shielding effect of the highly concentrated MB dye, which resulted in inferior photocatalytic degradation. Within 20 minutes of exposure to sunlight, the MB photodegradation efficiencies of the Ag/NaTNTs-70, Ag/NaTNTs-150, Ag/NaTNTs-250, and Ag/NaTNTs-350 are 93.6%, 91.4%, 91.2%, 95.8%, and 97.0%, correspondingly. These findings demonstrated that Ag/NaTNTs-350 has the highest photocatalytic activity, whereas Ag/TNTs-70 has the lowest photocatalytic activity.\u003c/p\u003e\n \u003cp\u003eFurthermore, Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e5\u003c/span\u003e-B displays the MB absorption spectra on Ag/NaTNTs-350 under varied sunlight irradiation times. The n\u0026rarr;\u0026pi;* transition of MB is represented by the UV\u0026ndash;visible band of MB monomer in water, which typically appears at 665 nm [\u003cspan class=\"CitationRef\"\u003e37\u003c/span\u003e\u0026ndash;\u003cspan class=\"CitationRef\"\u003e39\u003c/span\u003e]. When silver nanoparticles are not present, the absorption spectrum of MB barely changes after 20 minutes of sunlight irradiation, but for Ag/AgTNTs-350, it significantly changes. In particular, the typical absorption peak of MB at 664 nm strongly decreases after 20 minutes of sunlight irradiation. The relative absorbance of band at 664 nm is plotted as a function of time to evaluate the reduction reaction rate (Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e5\u003c/span\u003e-B). This result demonstrated that MB was photodegraded by the catalyst rather than by MB photolysis. These findings demonstrated that Ag/NaTNTs-350 of MB photodegradation capabilities in the presence of sunlight were superior. On the other hand, it is anticipated that Ag/NaTNTs-350 photocatalysis will primarily cause the change in MB concentration (Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e5\u003c/span\u003eB). This figure shows hypsochromic effects (blue shifts of spectral bands) in the UV region at \u0026lambda;\u003csub\u003emax\u003c/sub\u003e\u0026thinsp;=\u0026thinsp;291 and 246 nm. These effects are caused by N-demethylation of the dimethylamino group in MB, which happened simultaneously with the oxidative degradation under UV irradiation. This effect is associated with the formation of intermediate products, such as benzene and structures resembling naphthalene, as a result of MB breakdown [\u003cspan class=\"CitationRef\"\u003e40\u003c/span\u003e].\u003c/p\u003e\n \u003cdiv id=\"Sec14\" class=\"Section3\"\u003e\n \u003ch2\u003e3.5.1. The influence of MB dye concentration\u003c/h2\u003e\n \u003cp\u003eA study was conducted to determine the ideal dye concentration for improving the photocatalytic degradation of MB. We measured degradation performance by increasing dye concentration (10, 15, 20, 25, and 30 mg/L) and then withdrawing samples at different time intervals while keeping the photocatalyst concentration (Ag/NaTNTs: 10 mg) constant. Figure\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e6\u003c/span\u003e showed that when initial dye concentrations are increased from 10 to 30 mg/L, MB degradation decreases. This can be explained by the fact that as the MB concentration increases, the solution\u0026apos;s ability to absorb visible light decreases; as a result, as the initial dye concentration is lowered, the photonic efficiency increases. According to [\u003cspan class=\"CitationRef\"\u003e41\u003c/span\u003e], the increase in collision frequency between dye and photons is responsible for the decrease in photonic efficiency as initial dye concentration rises. The extensive dye adsorbed on the photocatalyst surface, which blocks the catalyst\u0026apos;s surface, can inhibit the interaction between electron holes and free radicals at high concentrations [\u003cspan class=\"CitationRef\"\u003e42\u003c/span\u003e].\u003c/p\u003e\n \u003c/div\u003e\n \u003cdiv id=\"Sec15\" class=\"Section3\"\u003e\n \u003ch2\u003e3.5.2. Langmuir isotherm\u003c/h2\u003e\n \u003cp\u003eAccording to the Langmuir isotherm [\u003cspan class=\"CitationRef\"\u003e43\u003c/span\u003e], the adsorption process occurs at homogeneous sites in the adsorbent. It is considered that monolayer adsorption processes and adsorbate molecules do not interact. The linear form of the following Eq.\u0026nbsp;(1) can be used to represent the Langmuir isotherm model.\u003c/p\u003e\n \u003cdiv id=\"Equa\" class=\"Equation\"\u003e\n \u003cdiv class=\"mathdisplay\" id=\"FileID_Equa\" name=\"EquationSource\"\u003e$$\\frac{1}{{\\text{q}}_{e}}=\\frac{1}{{\\text{q}}_{m}}+\\frac{1}{{\\text{K}}_{L}{\\text{q}}_{m}}\\left(\\frac{1}{{C}_{e}}\\right) \\left(1\\right)$$\u003c/div\u003e\n \u003c/div\u003e\n \u003cp\u003ewhere C\u003csub\u003ee\u003c/sub\u003e is the equilibrium concentration of the adsorbate (mg/L), q\u003csub\u003em\u003c/sub\u003e is the Langmuir constant at the monolayer or maximum adsorption capacity (mg/g), K\u003csub\u003eL\u003c/sub\u003e is the Langmuir adsorption constant related to the adsorption energy (L/mg), and q\u003csub\u003ee\u003c/sub\u003e is the amount of adsorbate adsorbed per unit mass of adsorbent at equilibrium (mg g\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e). The photocatalytic degradation reaction also follows the pseudo first-order reaction, as shown by the K\u003csub\u003eL\u003c/sub\u003e and q\u003csub\u003em\u003c/sub\u003e values, which can be calculated from the slope and intercept of the linear plot of 1/q\u003csub\u003ee\u003c/sub\u003e versus 1/C\u003csub\u003ee\u003c/sub\u003e, the apparent rate constants were tabulated in Table \u003cspan class=\"InternalRef\"\u003e1\u003c/span\u003e. When Ag/NaTNT was used for photocatalytic degradation of MB dye in aqueous solutions, the correlation coefficient R value was less than that of the pseudo-first order model (\u0026gt;\u0026thinsp;0.99) indicating that the photocatalytic degradation of MB dye in aqueous solutions using Ag/NaTNT follows the pseudo first order kinetic model.\u003c/p\u003e\n \u003c/div\u003e\n \u003cdiv id=\"Sec16\" class=\"Section3\"\u003e\n \u003ch2\u003e3.5.3. Freundlich isotherm\u003c/h2\u003e\n \u003cp\u003eA linear equation that describes the heterogeneous adsorption is the Freundlich isotherm model [\u003cspan class=\"CitationRef\"\u003e44\u003c/span\u003e], which is an empirical relationship:\u003c/p\u003e\n \u003cp\u003eLn q\u003csub\u003ee\u003c/sub\u003e = ln K\u003csub\u003eF\u003c/sub\u003e + \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\frac{1}{\\text{n}}\\)\u003c/span\u003e\u003c/span\u003e ln C\u003csub\u003ee\u003c/sub\u003e (2)\u003c/p\u003e\n \u003cp\u003ewhere K\u003csub\u003eF\u003c/sub\u003e is the Freundlich constant and is indicative of the adsorption capacity (mg/g) of titanate nanotubes. The value \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\frac{1}{\\text{n}}\\)\u003c/span\u003e\u003c/span\u003esuggests the favorability of adsorption process. The Freundlich isotherm plot of ln q\u003csub\u003ee\u003c/sub\u003e against ln C\u003csub\u003ee\u003c/sub\u003e gave straight line and the slope and intercept yield the values of\u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\frac{1}{\\text{n}}\\)\u003c/span\u003e\u003c/span\u003e and ln K\u003csub\u003eF\u003c/sub\u003e, respectively. The fitting results for the unmodified and Ag-modified titanate nanotube samples and the isotherm parameters are presented in Table\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e1\u003c/span\u003e.\u003c/p\u003e\n \u003cp\u003eThe adsorbent\u0026apos;s adsorption sites have a low-energetic heterogeneous surface, which leads to a high sorption capacity, as indicated by the heterogeneity factor n\u0026thinsp;\u0026gt;\u0026thinsp;1 (Table\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e1\u003c/span\u003e). This may be explained by the sorbate species\u0026apos; molecular interactions with one another and their subsequent aggregation on the surface monolayer. Ag/NaTNTs-150\u0026apos;s higher n value indicates that the adsorption of MB is more pronounced for this sample than for Ag/NaTNTs-70, which could be because AgNPs introduced more heterogeneous pores and aggregates, as the TEM micrograph has suggested.\u003c/p\u003e\n \u003c/div\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec17\" class=\"Section2\"\u003e\n \u003ch2\u003e3.6. Mechanism for photodegradation of MB dye\u003c/h2\u003e\n \u003cp\u003eAg/NaTNTs-350 demonstrated increased absorption of visible light, which raised the photocurrent density and improved the efficiency of charge generation and separation. By means of the surface plasmon resonance effect, AgNPs were able to absorb visible light, and electrons were transferred from plasmonically excited AgNPs to the TNTs\u0026apos; CB (Eq.\u0026nbsp;3). Furthermore, the recombination of photogenerated carriers was inhibited by the heterojunction structure that existed between AgNPs and TNTs [\u003cspan class=\"CitationRef\"\u003e45\u003c/span\u003e, \u003cspan class=\"CitationRef\"\u003e46\u003c/span\u003e]. O\u003csub\u003e2\u003c/sub\u003e on the sample surface will eventually interact with an electron in the conduction band, reducing O\u003csub\u003e2\u003c/sub\u003e to an O\u003csub\u003e2\u003c/sub\u003e-radical (Eq.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e5\u003c/span\u003e). The primary active species in the MB photodegradation were thought to be the OH\u003csup\u003e*\u003c/sup\u003e radicals. The radicals represented by the symbol OH\u003csup\u003e*\u003c/sup\u003e(h\u003csup\u003e+\u003c/sup\u003e) may arise from a reaction involving h\u003csup\u003e+\u003c/sup\u003e in the valence band, H\u003csub\u003e2\u003c/sub\u003eO and OH\u003csup\u003e\u0026minus;\u003c/sup\u003e in a mode (Eq.\u0026nbsp;4). Additionally, OH\u003csup\u003e*\u003c/sup\u003e(e\u003csup\u003e\u0026minus;\u003c/sup\u003e), which is the result of reducing O\u003csup\u003e\u0026not;2\u003c/sup\u003e with e\u003csup\u003e\u0026minus;\u003c/sup\u003e in the conduction band, may also be produced (Eqs.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e5\u003c/span\u003e\u0026ndash;8). The photodegradation of MB would be greatly aided by h\u003csup\u003e+\u003c/sup\u003e since the formation of OH\u003csup\u003e*\u003c/sup\u003e radicals is more likely in these circumstances. Eq.\u0026nbsp;9 shows that the OH\u003csup\u003e*\u003c/sup\u003e radicals that are generated effectively attack the dye molecule, sever bonds, and ultimately transform the MB into degraded intermediates such as CO\u003csub\u003e2\u003c/sub\u003e and H\u003csub\u003e2\u003c/sub\u003eO.\u003c/p\u003e\n \u003cdiv id=\"Equb\" class=\"Equation\"\u003e\n \u003cdiv class=\"mathdisplay\" id=\"FileID_Equb\" name=\"EquationSource\"\u003e$$\\text{A}\\text{g}/\\text{T}\\text{N}\\text{T}\\text{s}-\\text{P}400 +h\\nu ⟶{(h}^{+}) +({e}^{-}\\left) \\right(3)$$\u003c/div\u003e\n \u003c/div\u003e\n \u003cdiv id=\"Equc\" class=\"Equation\"\u003e\n \u003cdiv class=\"mathdisplay\" id=\"FileID_Equc\" name=\"EquationSource\"\u003e$${h}^{+}+{H}_{2}\\text{O} / \\text{O}{H}^{-}⟶O{H}_{\\left({h}^{+}\\right)}^{*} + {H}^{+} \\left(4\\right)$$\u003c/div\u003e\n \u003c/div\u003e\n \u003cdiv id=\"Equ1\" class=\"Equation\"\u003e\n \u003cdiv class=\"mathdisplay\" id=\"FileID_Equ1\" name=\"EquationSource\"\u003e$${e}^{-}+ {O}_{2}⟶{O}_{2}^{-}$$\u003c/div\u003e\n \u003cdiv class=\"EquationNumber\"\u003e5\u003c/div\u003e\n \u003c/div\u003e\n \u003cdiv id=\"Equd\" class=\"Equation\"\u003e\n \u003cdiv class=\"mathdisplay\" id=\"FileID_Equd\" name=\"EquationSource\"\u003e$${O}_{2}^{-}+2{H}^{+}+OOH⟶{H}_{2}{O}_{2} \\left(6\\right)$$\u003c/div\u003e\n \u003c/div\u003e\n \u003cdiv id=\"Eque\" class=\"Equation\"\u003e\n \u003cdiv class=\"mathdisplay\" id=\"FileID_Eque\" name=\"EquationSource\"\u003e$${H}_{2}{O}_{2}+ {O}_{2}^{-}⟶{OH}^{-}\\left({e}^{-}\\right)+ {OH}^{-} + {O}_{2} \\left(7\\right)$$\u003c/div\u003e\n \u003c/div\u003e\n \u003cdiv id=\"Equf\" class=\"Equation\"\u003e\n \u003cdiv class=\"mathdisplay\" id=\"FileID_Equf\" name=\"EquationSource\"\u003e$${H}_{2}{O}_{2}+h\\nu ⟶2 {OH}^{*}\\left({e}^{-}\\right) \\left(8\\right)$$\u003c/div\u003e\n \u003c/div\u003e\n \u003cdiv id=\"Equg\" class=\"Equation\"\u003e\n \u003cdiv class=\"mathdisplay\" id=\"FileID_Equg\" name=\"EquationSource\"\u003e$$MB+ {OH}^{*}\\left({e}^{-}\\right)/ {OH}^{*} /{h}^{+}/{O}_{2 }^{-} ⟶degradation products \\left(9\\right)$$\u003c/div\u003e\n \u003c/div\u003e\n\u003c/div\u003e"},{"header":"4. Electronic properties","content":"\u003cdiv class=\"BlockQuote\"\u003e\n \u003cp\u003eAg atoms imbedded successfully in nanotube templet model. The interaction energy (-880.35Kj/mol.) was calculated, using density functional theory with B3LYP\\4-311G* set, as implemented in jauger [\u003cspan class=\"CitationRef\"\u003e20\u003c/span\u003e]. Silver and sodium were optimized in nanotube wall in perpendicular mod with titanium atom before folding configuration (Fig. \u003cspan class=\"InternalRef\"\u003e7\u003c/span\u003e). Ag atoms imbedded successfully in nanotube templet model.\u003c/p\u003e\n \u003cp\u003eThe attractive/ repulsive attractions played a cyclic function in the holding, folding and stability process of the nanotube. Two interaction forces (attraction \u0026amp; repulsive) are affecting on the nanotube channel conformation. The optimum distances for Na\u003csup\u003e+\u003c/sup\u003e\u0026hellip;.Ti\u003csup\u003e+\u003c/sup\u003e and Ag\u003csup\u003e+\u003c/sup\u003e\u0026hellip;.Ti\u003csup\u003e+\u003c/sup\u003e displayed 2.897 and 2.806 \u0026Aring;, respectively. O\u003csup\u003eـــ\u003c/sup\u003e\u0026hellip;Ti\u003csup\u003e+\u003c/sup\u003e showed the optimum length 2.190 \u0026amp; 2.087 \u0026Aring; for angular and straight channels, respectively. There are differences in the length of the angular and straight channels as well as the cation-anion and anion-anion lengths. One notice that the (cation\u0026rarr;anion or attractive) attractions are preferred than (anion\u0026rarr;anion or repulsive) interactions, and the straight channels are more stable than other channels.\u003c/p\u003e\n \u003cp\u003e\u003cem\u003eE\u003c/em\u003e \u003csub\u003e\u0026nbsp;\u003cstrong\u003eHOMO\u0026amp;LUMOs\u003c/strong\u003e\u0026nbsp;\u003c/sub\u003e referred to the energetic of the highest-occupied/lowest-unoccupied molecular orbitals of nanotube were calculated (Table \u003cspan class=\"InternalRef\"\u003e2\u003c/span\u003e). HOMO\u0026amp; LUMO zones localized over all nanotube skeleton. This information showed that intramolecular charge transfer (ICT) between HOMOs and LUMOs was found. The effectiveness of dye removal is closely linked to the molecular orbitals\u0026apos; spatial distribution, highlighting the most likely sites in the order that dyes will most likely attack. The three factors that were examined to explain the potency against removal dyes were chemical potential (IP), nucleophilicity (\u0026chi;), and electrophilicty (\u0026omega;). The promising agent against removing dyes are the particle can accept free electrons from dyes. The low energy gap and the calculated energetic data values for Ag/Ti showed the high activity against removing dye.\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec19\" class=\"Section2\"\u003e\n \u003ch2\u003e4.1. Profile for Molecular electrostatic potential map \u0026ldquo;MEP\u0026rdquo;\u003c/h2\u003e\n \u003cdiv class=\"BlockQuote\"\u003e\n \u003cp\u003eMEP is a useful feature for investigating the reactivity of nanotube species (Fig. \u003cspan class=\"InternalRef\"\u003e7\u003c/span\u003e). Its a physical-character able to examine reactivity by quantum chemical approaches, through electronic distribution. High negative potential region that benefit from negative assaults is shown in red. The high positive potential zone is highlighted in blue. The color variation in MEP is lowered by ordering blue\u0026thinsp;\u0026gt;\u0026thinsp;green\u0026thinsp;\u0026gt;\u0026thinsp;red\u0026thinsp;\u0026gt;\u0026thinsp;yellow. The color gradation around whole Skelton\u0026rsquo;s showing the attraction and repulsive force sharing in the stabilization of Ag in Ti-nanotube. The color variation providing the helpful indication about stabilization between straight and angular molecular sites, that able to balance between attraction and repulsive force in nanotube. Furthermore, raising blue region may be explained by a high repulsive force of angular channel in nanotube, which ability to remove dye based on electrostatic force.\u003c/p\u003e\n \u003c/div\u003e\n\u003c/div\u003e"},{"header":"5. Conclusion","content":"\u003cp\u003eDue to the presence of AgNPs/NaTNTs have a propensity to undergo phase transformation, and high temperature annealing alters their morphology. The absorption edges of the as-prepared titanate nanotubes and Ag/NaTNTs samples annealed from 70 to 350\u0026deg;C degreased from 3.7 to 3.2 eV, according to UV-vis diffuse reflectance spectra. The presence of functional groups in the titanate product is confirmed by FTIR analysis. The HRTEM images provide the diameter and length of the tube and verify that a tubular structure has formed. Because titanate nanotubes have a larger surface area than nanoparticles, electron percolation through them is easier according to their morphology. Therefore, the findings of this study could provide a broad perspective to the researchers, suggesting that one-dimensional titanate nanotubes could be appropriate for solar cell applications. According to the computed electronic structure, the amorphous TNTs cluster's energy level, HOMO\u0026ndash;LUMO gap, and singlet\u0026ndash;singlet lowest excited state is extremely similar to those of the anatase TiO2 cluster (crystalline phase). O\u003csub\u003e2\u003c/sub\u003e adsorption on the titania surface is facilitated by the OH group on the catalyst surface, which is primarily related to the photocatalytic activity, according to studies on catalytic activity and characterization measurements. Additionally, the order of the OH group concentration on the surface was maintained by the photocatalytic activity. It is conceivable that Ag/TNTs' structural tunability contributed to its superior photocatalytic MB degradation activity when it was annealed at 350\u0026deg;C compared to other samples.\u003c/p\u003e"},{"header":"Declarations","content":"\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eProf. Dr . T. M. salama; he is head of research with discussion of analysisDr El‐Henawy is write first paper with discussionEl-Gawad he is preparation of sample with analysisOthman is final write the paper with discussion of analysis\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eI. O Ali, T. M Salama, A. A. Gawad, A. A El-Henawy, M.B Ghazy, M. F Bakr, Silver nanoparticles @ titanate nanotubes composite: Synthesis, characterization, applications and docking, Inorganic Chem. Comm. 137, (2022), 109187\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eD.V. Bavykin, F.C. Walsh, Elongated titanate nanostructures and their applications, Eur. J. Inorg. Chem. 2009 (8) (2009) 977\u0026ndash;997.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eH.H. Ou, S.L. Lo, Review of titania nanotubes synthesized via the hydrothermal treatment: fabrication, modification, and application, Sep. Purif. Technol. 58 (1) (2007) 179\u0026ndash;191,\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eB. Poudel, W.Z. Wang, C. Dames, J.Y. Huang, S. Kunwar, D.Z. Wang, D. Banerjee, G. Chen, Z.F. Ren, Formation of crystallized titania nanotubes and their transformation into nanowires, Nanotechnology 16 (9) (2005) 1935\u0026ndash;1940, doi:\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eJ. Liu, P.M. Hosseinpour, S. Luo, D. Heiman, L. Menon, D.A. Arena, L.H. Lewis, TiO\u003csub\u003e2\u003c/sub\u003e nanotube arrays for photocatalysis: effects of crystallinity, local order, and electronic structure, J. Vac. Sci. Technol.: Vac. Surfaces Films 33 (2015) 021202\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eY.L. Pang, S. Lim, H.C. Ong, W.T. Chong, A critical review on the recent progress of synthesizing techniques and fabrication of TiO\u003csub\u003e2\u003c/sub\u003e-based nanotubes photocatalysts, Appl. Catal. Gen. 481 (2014) 127\u0026ndash;142.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eD. Wu, J. Liu, X.N. Zhao, A.D. Li, Y.F. Chen, N.B. Min, Sequence of events for the formation of titanate nanotubes, nanofibers, nanowires, and nanobelts, Chem. Mater 18 (2006) 547.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eL. Yang, M. Zhang, S. Shi, J. Lv, X. Song, G. He, Z. Sun, Effect of annealing temperature on wettability of TiO2 nanotube array films, Nanoscale Res. Lett. 9(2014)621.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDas, R. Zazpe, J. Prikryl, P. Knotek, M. Krbal, H. Sopha, V. Podzemna, J.M. Macak, Influence of annealing temperatures on the properties of low aspectratio TiO\u003csub\u003e2\u003c/sub\u003e nanotube layers, Electrochim. Acta 213 (2016) 452\u0026ndash;459.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eJ. Liu, P.M. Hosseinpour, S. Luo, D. Heiman, L. Menon, D.A. Arena, L.H. Lewis, TiO\u003csub\u003e2\u003c/sub\u003e nanotube arrays for photocatalysis: effects of crystallinity, local order, and electronic structure, J. Vac. Sci. Technol.: Vac. Surfaces Films 33 (2015) 021202.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eY. Bai, I.S. Park, H.H. Park, M.H. Lee, T.S. Bae, W. Duncan, M. Swain, The effect of annealing temperatures on surface properties, hydroxyapatite growth and cell behaviors of TiO\u003csub\u003e2\u003c/sub\u003e nanotubes, Surf. Interface Anal. 43 (2011) 998\u0026ndash;1005.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eF. Hajakbari, M. Ensandoust, Study of thermal annealing effect on the properties of silver thin films prepared by DC magnetron sputtering, Acta Phys. Pol., A 129 (2016) 680\u0026ndash;682.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eA.A. Mosquera, J.M. Albella, V. Navarro, D. Bhattacharyya, J.L. Endrino, Effect of silver on the phase transition and wettability of titanium oxide films, Sci. Rep. 6 (2016) 32171.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eM. Iqbal, I.A. Bhatti, M. Zia-Ur-Rehman, H.N. Bhatti, M. Shahid, Efficiency of advanced oxidation processes for detoxification of Industrial effluents, Asian J. Chem. 26 (2014) 4291\u0026ndash;4296\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eD. Balarak, et al., Adsorption of acid blue 92 dye from aqueous solutions by singlewalled carbon nanotubes: isothermal, kinetic, and thermodynamic studies, Environ. Proc. 8 (2) (2021) 869\u0026ndash;888.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eS. Karthi, et al., Removal of methylene blue dye using shrimp shell chitin from industrial effluents, Mater. Today Proc. 66 (4) (2022) 1945\u0026ndash;1950.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eT.P.K. Kulasooriya, N. Priyantha, A.N. Navaratne, Removal of textile dyes from industrial effluents using burnt brick pieces: adsorption isotherms, kinetics and desorption, SN Appl. Sci. 2 (11) (2020).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eL. Hevira, et al., Terminalia catappa shell as low-cost biosorbent for the removal of methylene blue from aqueous solutions, J. Ind. Eng. Chem. 97 (2021) 188\u0026ndash;199.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eM. Basuny, I.O. Ali, A.A. El-Gawad, M.F. Bakr, T.M. Salama, A fast green synthesis of Ag nanoparticles in carboxymethyl cellulose (CMC) through UV irradiation technique for antibacterial applications, J. Sol-Gel Sci. Technol. 75 (2015).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSanderson EW, Redford KH, Chetkiewicz CL, Medellin RA, Rabinowitz AR, Robinson JG, Taber AB. Planning to save a species: the jaguar as a model. Conservation Biology. 16 (1) (2002) 58\u0026ndash;72\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eO. V. Yakubovich, V. V. Kireev, Refinement of the crystal structure of Na\u003csub\u003e2\u003c/sub\u003eTi\u003csub\u003e3\u003c/sub\u003eO\u003csub\u003e7\u003c/sub\u003e, Crystallogr. Reports. 48 (2003).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eG.W. Peng, H.S. Liu, FT-IR and XRD characterization of phase transformation of heat-treated synthetic natisite (Na\u003csub\u003e2\u003c/sub\u003eTiOSiO\u003csub\u003e4\u003c/sub\u003e) powder, Mater. Chem. Phys. 42 (1995).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eD. V. Bavykin, J.M. Friedrich, F.C. Walsh, Protonated titanates and TiO\u003csub\u003e2\u003c/sub\u003e nanostructured materials: Synthesis, properties, and applications, Adv. Mater. 18 (2006).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eY. Inoue, M. Uota, T. Torikai, T. Watari, I. Noda, T. Hotokebuchi, M. Yada, Antibacterial properties of nanostructured silver titanate thin films formed on a titanium plate, J. Biomed. Mater. Res. - Part A. 92 (2010).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eH.M. Kim, F. Miyaji, T. Kokubo, S. Nishiguchi, T. Nakamura, Graded surface structure of bioactive titanium prepared by chemical treatment, J. Biomed. Mater. Res. 45 (1999).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eM. Oca\u0026ntilde;a, J. V. Garcia-Ramos, C.J. Serna, Low‐Temperature Nucleation of Rutile Observed by Raman Spectroscopy during Crystallization of TiO2, J. Am. Ceram. Soc. 75 (1992).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eH.M. Kim, F. Miyaji, T. Kokubo, T. Nakamura, Apatite-forming ability of alkali-treated Ti metal in body environment, J. Ceram. Soc. Japan. 105 (1997).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eJ. Garc\u0026iacute;a-Serrano, E. G\u0026oacute;mez-Hern\u0026aacute;ndez, M. Ocampo-Fern\u0026aacute;ndez, U. Pal, Effect of Ag doping on the crystallization and phase transition of TiO2 nanoparticles, Current Applied Physics 9 (2009) 1097\u0026ndash;1105\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eT.M. Salama, M.M. Mohamed, I. Othman A, G.A. El-Shobaky, Structural and textural characteristics of Ce-containing mordenite and ZSM-5 solids and FT-IR spectroscopic investigation of the reactivity of NO gas adsorbed on them, Appl. Catal. A Gen. 286 (2005).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eC.C. Tsai, H. Teng, Regulation of the physical characteristics of titania nanotube aggregates synthesized from hydrothermal treatment, Chem. Mater. 16 (2004).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eA. Fuerte, M. D. Hern\u0026aacute;ndez-Alonso, A. J. Maira, A. Mart\u0026iacute;nez-Arias, M. Fern\u0026aacute;ndez-Garc\u0026iacute;a, J. C. Conesa, J. Soria and G. Munuera, Nanosize Ti\u0026ndash;W Mixed Oxides: Effect of Doping Level in the Photocatalytic Degradation of Toluene Using Sunlight-Type Excitation, J. Catal., 2002, 212, 1\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eM. Li, Z. Xing, J. Jiang, Z. Li, J. Yin, J. Kuang, S. Tan, Q. Zhu, W. Zhou, Surface plasmon resonance-enhanced visible-light-driven photocatalysis by Ag nanoparticles decorated S-TiO\u003csub\u003e2\u003c/sub\u003e \u0026ndash;\u0026thinsp;x nanorods, J. Taiwan Inst. Chem. Eng. 82 (2018).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eB. Joshi, C. Regmi, D. Dhakal, G. Gyawali, S.W. Lee, Efficient inactivation of Staphylococcus aureus by silver and copper loaded photocatalytic titanate nanotubes, Prog. Nat. Sci-Mater. Int. 28 (2018) 15\u0026ndash;23.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eD. A. Sales, T. M.F. Marques, A. Ghosh, S. B.S. Gusm\u0026atilde;o, T. L. Vasconcelos, C. Luz-Lima, O. P. Ferreira, L. M. Hollanda, I. S. Lima, E. C. Silva-Filho, D. Dittz, A. O. Lobo, B. C. Viana, Synthesis of silver-cerium titanate nanotubes and their surface properties and antibacterial applications, Materials Science \u0026amp; Engineering C 115 (2020) 111051\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eN. Sobana, M. Muruganadham, M. Swaminathan, Nano-Ag particles doped TiO2 for efficient photodegradation of direct azo dyes, J. Mol. Catal. A Chem. 258 (2006( 124\u0026ndash;132.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eS.F. Wang, F. Gu, M.K. L\u0026uuml;, X.F. Cheng, W.G. Zou, G.J. Zhou, S.M. Wang, Y.Y. Zhou, Synthesis and photoluminescence characteristics of Dy3+-doped ZnAl2O4 nanocrystals via a combustion process, J. Alloys Compd. 394 (2005) 255\u0026ndash;258.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eShahwan, T., Sirriah, S.A., Nairat, M., Boyac, E., Eroglu, A.E., Scott, T.B., Hallam, K.R., Green synthesis of iron nanoparticles and their application as a fenton-likecatalyst for the degradation of aqueous cationic and anionic dyes. Chem. Eng. J.172,(2011) 258\u0026ndash;266.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRauf, M.A., Meetan, M.A., Khaleel, A., Ahmed, A., Photocatalytic degradationof methylene blue using a mixed catalyst and product analysis by LC/MS. Chem.Eng. J. 157, (2010)373\u0026ndash;378.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eV.K. Vidhu, Daizy Philip, Catalytic degradation of organic dyes using biosynthesized silvernanoparticles, Micron 56 (2014) 54\u0026ndash;62\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eM. D\u0026uuml;kkanci, G. G\u0026uuml;nd\u0026uuml;z, S. Yilmaz, R. V. Prihod\u0026rsquo;ko, Heterogeneous Fenton-like degradation of Rhodamine 6G in water using CuFeZSM-5 zeolite catalyst prepared by hydrothermal synthesis, J. Hazard. Mater. 181 (2010).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDai, K., Lu, L., Dawson, G., 2013. Development of UV-LED/TiO 2 device and their application for photocatalytic degradation of methylene blue. J. Mater. Eng. Perform. 22, 1035\u0026ndash;1040\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRauf, M.A., Meetani, M.A., Hisaindee, S., An overview on the photocatalytic degradation of azo dyes in the presence of TiO2 doped with selective transition metals. Desalination 276,(2011) 13\u0026ndash;27.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eI. Langmuir. The constitution and fundamental properties of solids and liquids. Part I. solids. J. Am. Chem. Soc. 38 (11) (1916) 2221\u0026ndash;2295.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eH.M.F. Freundlich, over the adsorption in solution, J. Phys. Chem. 57 (1906) 385\u0026ndash;470.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eD. Yang, Y. Sun, Z. Tong, Y. Tian, Y. Li, Z. Jiang, Synthesis of Ag/TiO2Nanotube heterojunction with improved visible-light photocatalytic performance inspired by bioadhesion, J. Phys. Chem. C 119 (2015) 5827\u0026ndash;5835.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eC. He, D. Shu, M. Su, D. Xia, A. Mudar Abou, L. Lin, Y. Xiong, Photocatalytic activity of metal (Pt, Ag, and Cu)-deposited TiO2 photoelectrodes for degradation of organic pollutants in aqueous solution, Desalination 253 (2010) 88\u0026ndash;93.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"},{"header":"Tables","content":"\u003cp\u003e\u003cstrong\u003eTable 1:\u003c/strong\u003e Adsorption isotherm of \u003cspan dir=\"LTR\"\u003e20 mgl\u003csup\u003e-1\u0026nbsp;\u003c/sup\u003eMB\u003c/span\u003e\u003cspan dir=\"LTR\"\u003e\u0026nbsp;adsorbed by1.0 gml\u003csup\u003e-1\u003c/sup\u003e of different catalyst at room temperature and PH = 2\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n\u003cdiv\u003e\n \u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"83%\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd width=\"20.61855670103093%\"\u003e\n \u003cp dir=\"RTL\"\u003e\u003cstrong\u003e\u003cspan dir=\"LTR\"\u003eIsotherm content\u003c/span\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003cp dir=\"RTL\"\u003e\u003cstrong\u003e\u003cspan dir=\"LTR\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"13.402061855670103%\"\u003e\n \u003cp dir=\"RTL\"\u003e\u003cstrong\u003e\u003cspan dir=\"LTR\"\u003eParameter\u003c/span\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.309278350515465%\"\u003e\n \u003cp dir=\"RTL\"\u003e\u003cstrong\u003e\u003cspan dir=\"LTR\"\u003eTNTs\u003c/span\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.371134020618557%\"\u003e\n \u003cp dir=\"RTL\"\u003e\u003cstrong\u003e\u003cspan dir=\"LTR\"\u003eAg/TNTs-70\u003c/span\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"13.402061855670103%\"\u003e\n \u003cp dir=\"RTL\"\u003e\u003cstrong\u003e\u003cspan dir=\"LTR\"\u003eAg/TNTs-150\u003c/span\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.43298969072165%\"\u003e\n \u003cp dir=\"RTL\"\u003e\u003cstrong\u003e\u003cspan dir=\"LTR\"\u003eAg /TNTs-250\u003c/span\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.463917525773196%\"\u003e\n \u003cp dir=\"RTL\"\u003e\u003cstrong\u003e\u003cspan dir=\"LTR\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003cp dir=\"RTL\"\u003e\u003cstrong\u003e\u003cspan dir=\"LTR\"\u003eAg /TNTs- 350\u003c/span\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003cp dir=\"RTL\"\u003e\u003cstrong\u003e\u003cspan dir=\"LTR\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"20.61855670103093%\" rowspan=\"3\"\u003e\n \u003cp dir=\"RTL\"\u003e\u003cstrong\u003e\u003cspan dir=\"LTR\"\u003eLangmuir\u003c/span\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"13.402061855670103%\" valign=\"top\"\u003e\n \u003cp dir=\"RTL\"\u003e\u003cspan dir=\"LTR\"\u003eq\u003csub\u003em\u0026nbsp;\u003c/sub\u003e\u0026shy;(mg g \u003csup\u003e-1\u003c/sup\u003e)\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.309278350515465%\"\u003e\n \u003cp dir=\"RTL\"\u003e\u003cspan dir=\"LTR\"\u003e12.352\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.371134020618557%\"\u003e\n \u003cp dir=\"RTL\"\u003e\u003cspan dir=\"LTR\"\u003e11.169\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"13.402061855670103%\"\u003e\n \u003cp dir=\"RTL\"\u003e\u003cspan dir=\"LTR\"\u003e12.254\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.43298969072165%\"\u003e\n \u003cp dir=\"RTL\"\u003e\u003cspan dir=\"LTR\"\u003e11.08\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.463917525773196%\"\u003e\n \u003cp dir=\"RTL\"\u003e\u003cspan dir=\"LTR\"\u003e10.52\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"16.883116883116884%\" valign=\"top\"\u003e\n \u003cp dir=\"RTL\"\u003e\u003cspan dir=\"LTR\"\u003eK\u003csub\u003eL\u0026nbsp;\u003c/sub\u003e(L mg \u003csup\u003e-1\u003c/sup\u003e)\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.987012987012987%\"\u003e\n \u003cp dir=\"RTL\"\u003e\u003cspan dir=\"LTR\"\u003e21.007\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.584415584415584%\"\u003e\n \u003cp dir=\"RTL\"\u003e\u003cspan dir=\"LTR\"\u003e23.91759\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.883116883116884%\"\u003e\n \u003cp dir=\"RTL\"\u003e\u003cspan dir=\"LTR\"\u003e17.99355\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.181818181818183%\"\u003e\n \u003cp dir=\"RTL\"\u003e\u003cspan dir=\"LTR\"\u003e30.71\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"19.48051948051948%\"\u003e\n \u003cp dir=\"RTL\"\u003e\u003cspan dir=\"LTR\"\u003e38.42\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"16.883116883116884%\" valign=\"top\"\u003e\n \u003cp dir=\"RTL\"\u003e\u003cspan dir=\"LTR\"\u003eR\u003csup\u003e2\u003c/sup\u003e\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.987012987012987%\"\u003e\n \u003cp dir=\"RTL\"\u003e\u003cspan dir=\"LTR\"\u003e0.9963\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.584415584415584%\"\u003e\n \u003cp dir=\"RTL\"\u003e\u003cspan dir=\"LTR\"\u003e0.9886\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.883116883116884%\"\u003e\n \u003cp dir=\"RTL\"\u003e\u003cspan dir=\"LTR\"\u003e0.9913\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.181818181818183%\"\u003e\n \u003cp dir=\"RTL\"\u003e\u003cspan dir=\"LTR\"\u003e0.983\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"19.48051948051948%\"\u003e\n \u003cp dir=\"RTL\"\u003e\u003cspan dir=\"LTR\"\u003e0.982\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"20.61855670103093%\" rowspan=\"3\"\u003e\n \u003cp dir=\"RTL\"\u003e\u003cstrong\u003e\u003cspan dir=\"LTR\"\u003eFreundlich\u003c/span\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003cp dir=\"RTL\"\u003e\u003cstrong\u003e\u003cspan dir=\"LTR\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"13.402061855670103%\" valign=\"top\"\u003e\n \u003cp dir=\"RTL\"\u003e\u003cspan dir=\"LTR\"\u003en\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.309278350515465%\"\u003e\n \u003cp dir=\"RTL\"\u003e\u003cspan dir=\"LTR\"\u003e0.3756\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.371134020618557%\"\u003e\n \u003cp dir=\"RTL\"\u003e\u003cspan dir=\"LTR\"\u003e2.460152\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"13.402061855670103%\"\u003e\n \u003cp dir=\"RTL\"\u003e\u003cspan dir=\"LTR\"\u003e2.605627\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.43298969072165%\"\u003e\n \u003cp dir=\"RTL\"\u003e\u003cspan dir=\"LTR\"\u003e2.36\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.463917525773196%\"\u003e\n \u003cp dir=\"RTL\"\u003e\u003cspan dir=\"LTR\"\u003e2.31\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"16.883116883116884%\" valign=\"top\"\u003e\n \u003cp dir=\"RTL\"\u003e\u003cspan dir=\"LTR\"\u003eK\u003csub\u003eF\u003c/sub\u003e\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.987012987012987%\"\u003e\n \u003cp dir=\"RTL\"\u003e\u003cspan dir=\"LTR\"\u003e0.6101\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.584415584415584%\"\u003e\n \u003cp dir=\"RTL\"\u003e\u003cspan dir=\"LTR\"\u003e0.593623\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.883116883116884%\"\u003e\n \u003cp dir=\"RTL\"\u003e\u003cspan dir=\"LTR\"\u003e0.603815\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.181818181818183%\"\u003e\n \u003cp dir=\"RTL\"\u003e\u003cspan dir=\"LTR\"\u003e0.60\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"19.48051948051948%\"\u003e\n \u003cp dir=\"RTL\"\u003e\u003cspan dir=\"LTR\"\u003e0.59\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"16.883116883116884%\" valign=\"top\"\u003e\n \u003cp dir=\"RTL\"\u003e\u003cspan dir=\"LTR\"\u003eR\u003csup\u003e2\u003c/sup\u003e\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.987012987012987%\"\u003e\n \u003cp dir=\"RTL\"\u003e\u003cspan dir=\"LTR\"\u003e0.9834\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.584415584415584%\"\u003e\n \u003cp dir=\"RTL\"\u003e\u003cspan dir=\"LTR\"\u003e0.9966\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.883116883116884%\"\u003e\n \u003cp dir=\"RTL\"\u003e\u003cspan dir=\"LTR\"\u003e0.9911\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.181818181818183%\"\u003e\n \u003cp dir=\"RTL\"\u003e\u003cspan dir=\"LTR\"\u003e0.996\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"19.48051948051948%\"\u003e\n \u003cp dir=\"RTL\"\u003e\u003cspan dir=\"LTR\"\u003e0.997\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003c/table\u003e\n\u003c/div\u003e\n\u003cp\u003e\u003cstrong\u003eTable 2.\u003c/strong\u003e The calculated energy in ev. derived from for Ag/Ti nanotube as calculated at B3LYP/6-311+G(d,p).\u003c/p\u003e\n\u003cdiv\u003e\n \u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp dir=\"RTL\"\u003e\u003cstrong\u003e\u003cem\u003e\u003cspan dir=\"LTR\"\u003eE\u003c/span\u003e\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003cp dir=\"RTL\"\u003e\u003cstrong\u003e\u003cem\u003e\u003csub\u003e\u003cspan dir=\"LTR\"\u003eHOMO\u003c/span\u003e\u003c/sub\u003e\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp dir=\"RTL\"\u003e\u003cstrong\u003e\u003cem\u003e\u003cspan dir=\"LTR\"\u003eE\u003c/span\u003e\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003cp dir=\"RTL\"\u003e\u003cstrong\u003e\u003cem\u003e\u003csub\u003e\u003cspan dir=\"LTR\"\u003eLUMO\u003c/span\u003e\u003c/sub\u003e\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp dir=\"RTL\"\u003e\u003cstrong\u003e\u003cem\u003e\u003cspan dir=\"LTR\"\u003eD\u003c/span\u003e\u003c/em\u003e\u003c/strong\u003e\u003cstrong\u003e\u003cem\u003e\u003cspan dir=\"LTR\"\u003eE\u003c/span\u003e\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003cp dir=\"RTL\"\u003e\u003cstrong\u003e\u003cem\u003e\u003csub\u003e\u003cspan dir=\"LTR\"\u003eHOMO/LUMO\u003c/span\u003e\u003c/sub\u003e\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp dir=\"RTL\"\u003e\u003cstrong\u003e\u003cem\u003e\u003cspan dir=\"LTR\"\u003eIP\u003c/span\u003e\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp dir=\"RTL\"\u003e\u003cstrong\u003e\u003cem\u003e\u003cspan dir=\"LTR\"\u003e\u0026eta;\u003c/span\u003e\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp dir=\"RTL\"\u003e\u003cstrong\u003e\u003cem\u003e\u003cspan dir=\"LTR\"\u003eS\u003c/span\u003e\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp dir=\"RTL\"\u003e\u003cstrong\u003e\u003cem\u003e\u003cspan dir=\"LTR\"\u003e\u0026chi;\u003c/span\u003e\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp dir=\"RTL\"\u003e\u003cstrong\u003e\u003cem\u003e\u003cspan dir=\"LTR\"\u003e\u0026omega;\u003c/span\u003e\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp dir=\"RTL\"\u003e\u003cstrong\u003e\u003cem\u003e\u003cspan dir=\"LTR\"\u003e5\u003c/span\u003e\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp dir=\"RTL\"\u003e\u003cspan dir=\"LTR\"\u003e-7.07\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp dir=\"RTL\"\u003e\u003cspan dir=\"LTR\"\u003e-3.91\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp dir=\"RTL\"\u003e\u003cspan dir=\"LTR\"\u003e3.16\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp dir=\"LTR\"\u003e7.07\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp dir=\"RTL\"\u003e\u003cspan dir=\"LTR\"\u003e1.58\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp dir=\"RTL\"\u003e\u003cspan dir=\"LTR\"\u003e0.632\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp dir=\"LTR\"\u003e-0.122\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\"\u003e\n \u003cp dir=\"LTR\"\u003e0.10\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003c/table\u003e\n\u003c/div\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"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":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Titania nanotubes, Annealing temperature, Morphology, Photocatalytic activity, methylene blue dye, Ag nanoparticles","lastPublishedDoi":"10.21203/rs.3.rs-3881461/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-3881461/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eAgNPs were first introduced into the hydrothermally produced sodium titanate nanotubes using a photoreduction method. By gradually raising the temperature of Ag-doped TNTs samples between 100 and 350 \u0026ordm;C, the impact of the annealing temperature was investigated. XRD, HRTEM, FT-IR and UV-visible spectroscopy were used to characterize the nanotubes. Through the interchange of Ag\u003csup\u003e+\u003c/sup\u003e with extra-framework Na\u003csup\u003e+\u003c/sup\u003e in TNTs, the XRD demonstrated. The establishment of the Silver Titanate. On the other hand, a partial state transformation from nanotabular Na-TNTs to anatase nanotubes occurred with a rise in temperature. The interaction between Ag and TNT particles was assigned to the FT-IR band that appeared at 1384 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e. The higher particle size was explained by HRTEM, the investigation demonstrated that the process of annealing resulted in the formation of larger clusters by aggregating small particles. UV-Vis and band gap measurements were used to assess how annealed samples affected the liquid phase of MB dye's capacity to photocatalyzed sunlight. Based on the breakdown of MB dye in an aqueous solution under solar conditions, the Ag/NaTNTs nanostructures with annealing temperatures ranging from 70 to 350◦C were assessed for their photocatalytic activities. The degradation rate increased with increasing annealing. The amorphous cluster's HOMO-LUMO gap and singlet-singlet excited state energies are quite like those of a crystalline Ag/TNTs, according to the calculations. Additionally, our calculations demonstrate that Ag/NaTNTs' computed energetic data values and low energy gap demonstrated strong activity against dye removal.\u003c/p\u003e","manuscriptTitle":"Titanate nanotubes coated with Ag nanoparticles: Effects of Annealing Temperature on Crystalline Structure, Morphology, and Photocatalytic Activity","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-01-24 13:40:01","doi":"10.21203/rs.3.rs-3881461/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"81c9ba26-1b03-429d-bb98-7a8fdc2ac54d","owner":[],"postedDate":"January 24th, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2024-02-22T15:52:20+00:00","versionOfRecord":[],"versionCreatedAt":"2024-01-24 13:40:01","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-3881461","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-3881461","identity":"rs-3881461","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}