Anatase Phase Of TiO2 Research Articles

High-Performance Hydrogen Sensing at Room Temperature via Nb-Doped Titanium Oxide Thin Films Fabricated by Micro-Arc Oxidation.

Metal oxide semiconductor (MOS) hydrogen sensors offer advantages, such as high sensitivity and fast response, but their challenges remain in achieving low-cost fabrication and stable operation at room temperature. This study investigates Nb-doped TiO2 (NTO) thin films prepared via a one-step micro-arc oxidation (MAO) with the addition of Nb2O5 nanoparticles into the electrolyte for room-temperature hydrogen sensing. The characterization results revealed that the incorporation of Nb2O5 altered the film's morphology and phase composition, increasing the Nb content and forming a homogeneous composite thin film. Hydrogen sensing tests demonstrated that the NTO samples exhibited significantly improved sensitivity, selectivity, and stability compared to undoped TiO2. Among the fabricated samples, NTO thin film prepared at Nb2O5 concentration of 6 g/L (NTO-6) showed the best performance, with a broad detection range, excellent sensitivity, rapid response, and good specificity to hydrogen. A strong linear relationship between response values and hydrogen concentration (10-1000 ppm) highlights its potential for precise hydrogen detection. The enhanced hydrogen sensing mechanism of NTO thin films primarily stems from the influence of Nb2O5; nanoparticles doping in the anatase-phase TiO2 structure on the semiconductor surface depletion layer, as well as the improved charge transfer and additional adsorption sites provided by the Nb/Ti composite metal oxides, such as TiNb2O7 and Ti0.95Nb0.95O4. This study demonstrates the potential of MAO-fabricated Nb-doped TiO2 thin films as efficient and reliable hydrogen sensors operating at room temperature, offering a pathway for novel gas-sensing technologies to support clean energy applications.

Bio-synthesis of TiO2 photocatalyst: a reduced step approach using leaf extract

ABSTRACT This study demonstrated the effectiveness of a green synthesis approach for TiO2, utilizing basil (Ocimum basilicum) leaf extract as a reducing agent. This method eliminated the need for additional precipitating agents and calcination in the preparation process. TiO2 was synthesized through traditional precipitation (TiO2–P) and biosynthesis with Holy Basil extract (TiO2–B), both resulting in anatase-phase TiO2 as the primary phase. FESEM images revealed that TiO2–P particles (200–250 nm) showed significant agglomeration, while TiO2–B particles were smaller. BET analysis indicated a higher specific surface area for TiO2–B (245.51 m2/g) compared to TiO2–P (19.55 m2/g), enhancing its suitability for photocatalytic applications. The band gap energies were determined to be 3.28 eV for TiO2–B and 3.35 eV for TiO2–P, with both exhibiting similar UV light responses. Photocatalytic testing revealed that TiO2–B achieved 90.4% degradation of tetracycline (TC) within 120 min, outperforming TiO2–P, which achieved 73.0% under the same conditions. Kinetic analysis indicated that the reaction rate constant for TiO2–B (0.015 min−1) was twice that of TiO2–P (0.0075 min−1). Hydroxyl radical generation was also confirmed, and TiO2–B showed reusability over three cycles, highlighting its sustainability and effectiveness for environmental use.

Energy-efficient Carbon-doped TiO2 for Visible Light Degradation of Methyl Orange: Preparation, Performance, and Mechanism

Water pollution caused by textile dyes has become a serious issue, making the treatment of sewage urgent. Carbon-doped TiO2 (C-doped TiO2), using alkanes and polyols as carbon sources, has been found to be light-responsive in degrading dyes. However, there is a lack of studies on the interfacial interaction between carboxylic acids and TiO2. Therefore, citric acid, a triprotic, hexadentate carboxylic acid, was used to dope TiO2 through solvothermal-calcination. The effects of carbon content and calcination temperature on the photodegradation performance of C-doped TiO2 were investigated. The band gap energy of C-doped TiO2 was found to be narrower (2.67 eV) than that of undoped TiO2 (2.88 eV). After carbon doping, the absorption band extended from the UV to the visible regions, lowering the energy required for electron excitation. The functional groups present on C-doped TiO2 assisted in the adsorption of methyl orange (MO), assisting in photodegradation. Only the anatase phase of TiO2 was observed at calcination temperatures between 250 and 400 °C. Photoluminescence analysis revealed that a lower carbon content and slightly higher calcination temperature resulted in better interfacial charge separation and transfer efficiency. The 10 wt% C-doped TiO2 calcined at 300 °C demonstrated the best MO photodegradation efficiency of 62.1% under visible light illumination. Copyright © 2024 by Authors, Published by BCREC Publishing Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

TiO2-Phase-Mediated Size Effect of Rh Nanoparticles on Photothermal Catalytic CO2 Hydrogenation.

Photothermal catalytic CO2 hydrogenation on TiO2-based catalysts has drawn extensive attention. However, few reports have focused on the impact of particle size of the active sites by altering TiO2 crystal phase on the CO2 hydrogenation activity. Herein, we successfully regulated Rh nanoparticle size by adjusting the crystal phases of TiO2 at different calcination temperatures and obtained impressive photothermal catalytic CO2 hydrogenation performance. Notably, the anatase-phase TiO2 loaded with Rh nanoparticles achieved a CH4 production rate of 2.7 mmol h-1 with nearly 100 % selectivity and a single-pass CO2 conversion rate of 69.4 %. Given the anatase-phase TiO2 is more favorable for the presence of surface hydroxyl groups and oxygen vacancies, which can facilitate the distribution of Rh cations, Rh nanoparticles on the anatase-phase TiO2 exhibited the smallest sizes. Small Rh particle size further enhanced CO2 adsorption and activation, leading to high photothermal CO2 hydrogenation performance. Furthermore, the optimized Rh nanoparticle-loaded anatase-phase TiO2 catalyst exhibited high structural stability and resistance to coke accumulation, maintaining stability during long-term performance tests. This work investigated the particle size effect of active sites adjusted by crystal phase of light-harvesting materials on the photothermal catalytic performance, providing guidance for the preparation of effective catalysts for CO2 hydrogenation to CH4.

Photocatalytic performance and solar cell simulations of TiO2–SnO2:F mixed oxide thin films grown by spray pyrolysis method

Mixed oxide titanium dioxide (TiO2) and fluorine doped tin oxide (SnO2:F) thin films have been grown, using spray pyrolysis technique, at various substrate temperatures (Ts) ranging from 250 to 400 °C with a step of 50 °C. Samples were examined using X-ray diffraction (XRD), optical microscopy, spectrophotometry and spectrofluorimetry, with special emphasis on the evolution of their physico-chemical properties versus substrate temperature. In fact, X-ray diffraction analysis showed that a substrate temperature of about 350 °C exhibits the presence of both anatase phase of TiO2 and tetragonal structure of SnO2:F compounds. A direct band gap of about 3.91 eV was obtained. Envelope method, based on transmission spectrum, was investigated in order to estimate the film thickness and some optical parameters such as real and imaginary parts of dielectric constant. Wemple Di-Dominico and Spizer Fan models were applied in order to determine the effect of substrate temperature on some dispersion parameters. Photoluminescence spectra showed different emissions in the visible region. The photodegradation mechanism of both Rhodamine B (RhB) and Malachite Green (MG) pollutants using TiO2–SnO2:F coupled oxide layer, grown at 350 °C, was discussed and an efficiency of about 90 %, after 3 h of sun irradiation, was achieved. Additionally, the layer exhibits good stability, recoverability and reusability after a cyclic test of 9 h, making it suitable for industrial applications. As a secondary application, a numerical simulation of TiO2–SnO2:F/CdS/CIGS solar cell, using SCAPS-1D software, was investigated for the first time. An open circuit voltage of about 613 mV was obtained, the current density Jsc was in the order of 33.49 mA/cm2, the Fill Factor FF and the efficiency were in the order of 79.13, 16.23 %, respectively.

Colloidal TiO₂ solid spheres as high-performance anodes for Lithium-ion batteries: Synthesis, characterization, and optimization

Anatase phase TiO2 nanoparticles were successfully synthesized by annealing amorphous colloidal TiO2 spheres. The colloidal TiO2 nanoparticles exhibited enhanced specific discharge capacities ∼296 (0.1C), 185 (1C), 127 (2C), 101 (5C) and 82 mAh g-1 (10C) in contrast to their amorphous counterparts ∼182 (0.1C), 119 (1C), 81 (2 C), 43 (5 C) and 18 mAh g-1 (∼10C rates). Amorphous TiO2 nanoparticles developed a layer of solid electrolyte interface (SEI) comprising lithium carbonate, lithium alkyl carbonates, and organic phosphates, leading to heightened intrinsic resistance of cells and diminished performance in terms of rate and cycling. Conversely, annealing at high temperatures effectively eliminates chemisorbed water and hydroxyl groups, resulting in improved stability under varying rates and during cycling for lithium-ion batteries based on titanium dioxide. The annealed colloidal TiO2 demonstrated notably elevated specific discharge capacities and capacity retention of 93.5 % compared to amorphous titanium dioxide spheres of 42.1 %.

Enhanced Photodegradation of Sulfamethoxazole Through Cutting-Edge Titania-Zirconia-Based Materials

ZrO2, TiO2, ZrO2-TiO2, and TiO2-ZrO2 were successfully prepared using the sol–gel method and fully characterized to check their physico-chemical features. X-ray diffraction showed the co-existence of monoclinic and tetragonal ZrO2 in addition to the Anatase phase for TiO2. The formation of mixed oxides led to a reduction in the band gap values and a modification of the textural characteristics, while the XPS evidenced an oxygen vacancy-rich surface. The ability of the synthesized materials to eliminate drug contaminants was checked using Sulfamethoxazole (SMX) as a model molecule under UV and BLUE-LED irradiation. The materials’ potential to decrease wastewater toxicity was also studied. The best photocatalyst was TiO2-ZrO2 with 76 and 100% conversion under visible and UV irradiation, respectively.

Breaking new grounds: Solid-state synthesis of TiO2–La2O3–CuO nanocomposites for degrading brilliant green dye under visible light

Environmental pollution, particularly from industrial dyes and chemicals, poses a significant threat to ecosystems and human health. Traditional pollution mitigation methods are often inefficient and costly. Photocatalysis has emerged as a promising solution for degrading pollutants using light energy. Titanium dioxide (TiO2) is a widely studied photocatalyst due to its stability, non-toxicity, and strong oxidative power. However, its efficiency is limited by a wide bandgap, restricting absorption to the UV region, and rapid electron-hole recombination. To address these limitations, doping TiO2 with materials (La2O3 and CuO) can enhance its photocatalytic activity under visible light. This study investigates the enhancement of TiO2 nanocomposites by incorporating La2O3 and CuO. X-ray diffraction (XRD) revealed that the nanocomposites retained the TiO2 anatase and rutile phases with their improved crystallinity. Scanning electron microscopy (SEM) displayed spherical nanoparticles forming agglomerates, typically due to high surface energy. Energy-dispersive X-ray spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS) confirmed the presence of La and Cu in the TiO2 matrix. Fourier-transform infrared (FTIR) spectroscopy identified characteristic vibrational modes of Ti–O, La–O, and Cu–O bonds, suggesting strong interactions between dopants and TiO2 lattice. Ultraviolet–visible (UV–vis) spectroscopy showed a red shift in absorption spectra with La2O3 and CuO addition, reducing the bandgap energy from 3.23 eV (pure TiO2) to 2.27 eV for the TiO2–0.1La2O3–0.2CuO composite. Photoluminescence (PL) spectroscopy indicated improved charge separation and reduced electron-hole recombination rates in the synthesized nanocomposites. Photocatalytic performance was evaluated by degrading brilliant green (BG) dye under visible light. The TiO2–0.1La2O3–0.2CuO (TLC0.2) nanocomposite achieved the highest dye degradation of over 95% after 204 min under optimal conditions (Co = 17 mg/L and 1 g/L). Adding the inorganic agent Na2SO4 to this process significantly enhanced the photocatalytic activity, increasing degradation from 56% to 95% after 180 min of visible light irradiation. TLC0.2 exhibited a high stability of dye degradation efficiency after six consecutive photocatalysis cycles. La2O3 and CuO doping significantly enhance TiO2 nanocomposites' crystalline structure, morphology, optical property, and photocatalytic efficiency. TLC0.2 has a potential use for environmental remediation and solar energy conversion.

Synthesis and Evaluation of Novel Ternary MgFe2O4/CuO/TiO2 Nanocomposite for Visible Light Photodegradation of Malachite Green Dye

Novel ternary MgFe2O4/CuO/TiO2 nanocomposite was synthesized using the sol-gel method at low temperatures. The XRD, FTIR, SEM-EDX, TEM, UV-visible DRS and VSM techniques were used to characterize the structure, shape, optical, morphology and magnetic properties. The XRD examination revealed typical peaks in nanocomposites, including the anatase phase of TiO2 with an average diameter of 9 nm, consistent with the TEM data. The SEM morphology examinations revealed spherical particles, while EDAX analysis indicated the corresponding components (Fe, Ti, O, Mg and Cu) in the prepared nanocomposites. The UV-DRS measurements revealed that the synthesized nanocomposite has a band-gap energy of 2.30 eV. The vibrating sample magnetometer (VSM) was used to trace the M-H loop of MgFe2O4, yielding magnetic parameters such as saturation magnetization (Ms). The catalytic activity of the as-prepared sample was examined by the degradation of malachite green dye under visible light and UV irradiations. The photocatalytic studies demonstrated that MgFe2O4/CuO/TiO2 nanocomposite showed 100% degradation efficiency towards malachite green dye. Under visible light and UV irradiations, the synthesized MgFe2O4/CuO/TiO2 sample with a molar ratio of 0.8:0.1:0.1 demonstrated good catalytic efficiency. The antibacterial activity investigations were done against Gram-negative Escherichia coli, Klebsiella pneumonia, Gram-positive Staphylococcus aureus and Bacillus subtilis bacteria utilizing nanocomposites.

Synthesis and Characterization of TiO2 -CQDs Nanocomposites and Testing of Their Anticancer Potential

This work used a green approach to produce carbon quantum dots (CQDs). TiO2 nanoparticles (NPs) and TiO2–CQDs nanocomposites with different weight ratios of CQDs were organized through a facile sol-gel method. XRD showed that the anatase and rutile phases of TiO2 were polycrystalline with a tetragonal structure and that the CQDs exhibited a broad peak at (002) and a hexagonal structure. High resolution-transmission-electron microscopy revealed that the TiO2 NPs agglomerated in mostly spherical shapes and that the anatase and rutile phases of TiO2 had sizes of less than 15 and 25 nm, respectively. The CQDs had a relatively uniform diameter, a spherical shape with a highly crystalline structure, and a size below 2 nm. UV–visible spectroscopy revealed that the absorbance of the TiO2- CQDs nanocomposites increased with the increase in CQD ratio. The energy band gaps of the anatase and rutile phases were 3.07 and 2.7 eV, respectively, whereas that of CQDs was 3.14 eV. Meanwhile, the energy band gaps of the TiO2–CQDs nanocomposites decreased with the increase in CQDs ratio. The growth inhibition rates of the liver cancer HepG2 cell line and the normal cell line RD were measured after 24 hours of experience to the two TiO2 phases and TiO2–CQDs nanocomposites. The cytotoxicity test presented that the tested substances were extremely harmful to cells in cancer. Inhibition rates increased with the increase in CQDs ratio. The inhibition rate of growth in cancer cells, including the liver cancer HepG2 cell line and the normal cell line (RD), was measured for 24 hours after they were exposed to TiO2 (two phases) and TiO2-CQDs nanocomposites. The samples showed a slight effect on the normal line (RD) compared to HepG2 cancer. The highest inhibition rate was 12.11% for the CQD 0.7 sample.

Enhanced photocatalytic performance of TiO2 with tunable oxygen vacancies induced by H2/N2 mixture treatment

Surface treatment can effectively modulate the surface properties of a photocatalyst to hasten the separation and transfer of photoinduced charges, ultimately achieving high photocatalytic performance. Herein, surface treatment of anatase-phase TiO2 prepared by a hydrothermal method was performed under H2/N2 mixed atmosphere. The experimental results demonstrate that roasting TiO2 in a H2/N2 atmosphere can effectively reduce partial Ti4+ to Ti3+, thereby facilitating the production of tunable oxygen vacancies (OVs) by disrupting Ti-O-Ti bonds. OVs can construct defective energy levels to bring about a decrease in the bandgap of TiO2 and an extension of light absorption range. Moreover, OVs remarkedly improve the separation of photoinduced charges of TiO2 and accelerate the photocatalytic reaction as active sites. The photocatalytic experimental results demonstrate that TiO2 exhibits the highest performance when roasting TiO2 in a H2/N2 atmosphere for 2 h, and the photocatalytic degradation rate constant of rhodamine B (RhB) and tetracycline (TC) on this sample under simulated solar light irradiation is 2.24 and 1.11 times higher than that on the reference TiO2, respectively. These findings provide valuable insights for designing highly efficient photocatalysts for effective water pollution treatment.

Enhanced efficiency, electron lifetime, and eco-friendliness of dye-sensitized solar cells using nanofibrous TiO2/ZnO composite photoanodes and natural anthocyanin sensitizer

Semiconductor is the main part of the photoanode in dye-sensitized solar cells (DSSCs). In this study, an evaluation was conducted on two different morphological shapes of TiO2/ZnO semiconductors, namely nanoparticles (NPs) and nanofibers (NFs), to enhance the efficiency of DSSCs. The nanofibrous semiconductors were fabricated using the electrospinning technique. Furthermore, a natural sensitizer, anthocyanin dye, was used to promote the environmental friendliness of the fabricated cells. These cells were then compared to those that used a synthetic dye known as N719 to determine their efficiencies. The UV–vis results confirmed the extraction of anthocyanin from black plum fruits (Syzygium cumini). The structural characteristics of the composites were examined using XRD, FE-SEM, and BET experiments. The XRD results revealed that the anatase phase of TiO2 was dominant in the crystal structure of the semiconductors, while the crystallite sizes of the composites were 25.04 nm and 12.24 nm in NPs and NFs forms, respectively. The FE-SEM analysis revealed the formation of quasi-spherical NPs with an average diameter of 48.26 ± 17.75 nm and NFs with an average diameter of 153.99 ± 26.18 nm. The BET results showed that the surface characteristics of the nanocomposite were enhanced by changing the shape from NPs to NFs. Photovoltaic studies showed that utilizing NFs semiconductors in the photoanodes of DSSCs resulted in increased conversion efficiency of light to electricity. The results of the sun simulator studies confirmed that the use of natural dye led to a decrease in the effectiveness of the DSSCs. This phenomenon can be attributed to the weaker binding of the natural dye to the photoanodes. Furthermore, the EIS investigations illustrated that the electron lifetime in the natural dye is more than twice that of N719, leading to a reduced rate of electron recombination in the Syzygium cumini extract. The TiO2/ZnO NFs photoanodes exhibited superior performance compared to their nanoparticle counterparts in DSSCs. Their high surface area promoted superior dye adsorption and light absorption. Moreover, the interconnected nanofiber network facilitated efficient electron transport, minimizing recombination losses. Increasing the binding strength of the chosen natural dye to the photoanode will also make the cells more environmentally friendly and improve their ability to produce electricity.

Influence of Temperature and Nanoparticle Concentration on the Electrical Conductivity of Water-Based TiO2 Nanofluids: Experimental Study, Correlation, and Model Assessment

Different volume fractions of TiO2/water nanofluids were created using TiO2 nanoparticles synthesized via the chemical coprecipitation technique. The electrical conductivity (EC) of each nanofluid was then measured at specific temperatures, ranging from 10 to 60 °C. X-ray diffraction (XRD) analysis confirmed the presence of the TiO2 anatase phase and a minor presence of the rutile phase. Measurements from dynamic light scattering (DLS) and UV-Vis spectroscopy revealed that the nanoparticles exhibit an average diameter close to 26 nm, with an optical band gap estimated to be about 3.8 eV. Experimental findings demonstrated that both temperature and volume fraction play significant roles in enhancing the EC of nanofluids. These findings were evaluated compared to an earlier model for nanofluid conductivity that includes nanoparticle Brownian motion and electrophoretic effects, demonstrating a close alignment between the predicted and observed values. Furthermore, the long-term stability of the nanofluids was validated, and a reliable correlation was established between the nanofluid’s EC, temperature, and volume fraction.

A Comparison Study of Photocatalytic Performance of TiO2 Anatase Phase Prepared from Different Procedures

In this work, three TiO2 anatase phase samples, labeled as S1, S2, and S3, were synthesized using varying titanium precursors, solvents, and conditions to compare their photocatalytic performances. The structural and morphological properties of the synthesized samples were characterized through X-ray diffraction (XRD), Raman scattering, field emission scanning electron microscopy (FESEM), and transmission electron microscopy (TEM). The obtained results indicated that all samples exhibited an anatase crystalline phase. Sample S1 notably featured nanowires with an average diameter of 38.6 nm. Meanwhile, samples S2 and S3 comprised nanoparticles, each exhibiting unique average sizes of 12.76 nm and 10.11 nm, respectively. The diffuse reflectance spectra reveal that the S3 sample possesses the lowest bandgap, suggesting its potential as the most promising photocatalyst. Additionally, photocurrent response and electrochemical impedance spectroscopy (EIS) were characterized to elucidate the charge transfer mechanisms within the materials. The degradation efficiencies of Rhodamine B (RhB) for samples S1, S2, and S3 were determined to be 17.40%, 17.93%, and 33.04%, respectively, under visible light irradiation. This study provides valuable insights into the criteria for choosing efficient TiO2 photocatalysts.

Biosynthesis of TiO2/CuO and Its Application for the Photocatalytic Removal of the Methylene Blue Dye.

In this study, we successfully synthesized a TiO2/CuO nanocomposite using the aqueous extract of Impatiens tinctoria A.rich. leaf extract as a capping, reducing, and stabilizing agent for the first time in an environmentally friendly, low-cost, straightforward, and sustainable technique. Numerous characterization techniques such as ultraviolet-visible diffuse reflectance spectroscopy (UV-vis-DRS), photoluminescence (PL), Raman spectroscopy, Fourier-transform infrared (FTIR), energy dispersive X-ray (EDX), transmission electron microscopy (TEM), X-ray diffraction (XRD), scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET), and high resolution TEM (HRTEM) were used to characterize the obtained TiO2/CuO nanocomposite. XRD verified that the TiO2/CuO nanocomposite has an average crystallite size of about 21 nm. The TEM result revealed an average particle size of 29 nm for the biosynthesized TiO2/CuO NC. The HRTEM analysis showed the presence of polycrystalline structures with the predominant lattice fringes 0.352 and 0.19 which were attributed to anatase phase TiO2 in the crystal plane of (101) and (200), respectively. The lattice fringes for monoclinic CuO were observed with values of 0.213 and 0.252 for the lattice planes of (111) and (111̅), respectively. The photoluminescence spectroscopic analysis revealed that the TiO2/CuO NC showed the lowest intensity compared to the pristine TiO2 and CuO indicating the reduction of exciton recombination in the case of the TiO2/CuO NC. The BET analysis showcased the formation of mesoporous materials with a surface area of 87.5 m2/g. The photocatalytic degradation performance of the biosynthesized TiO2, CuO, and TiO2/CuO nanomaterials against the potentially harmful MB dye was tested using the light source of a 150 tungsten-halogen lamp with a wavelength range of 360-2800 nm. The factors affecting photodegradation efficiencies like catalyst dose (20 mg), dye concentration(15 ppm), pH (9), and reaction time (90 min) were optimized for the degradation of the MB dye. The TiO2/CuO catalyst showed the highest degradation efficiency of 99% under the optimized conditions. The degradation rate of the MB dye in the presence of the TiO2/CuO NC was evaluated and found to be fitted to the pseudo-first-order kinetics with a rate constant of 0.03 min-1. The reusability test of the TiO2/CuO catalyst showed its good stability.

The encapsulation of noble metal over metal oxide semiconductor TiO2@Ag for the degradation of sulphur dye in effluent water by photocatalysis and electrochemical water splitting

Metal Oxide Semiconductor - Metal core-shell nanostructure with TiO2 as core and Ag nanoparticles as shell (TiO2@Ag) have been synthesized by a simple, environmentally friendly room temperature wet chemical method. The prepared TiO2@Ag core-shell nanoparticle was characterized by using various analytic techniques. X-ray diffraction analysis confirms the formation of tetragonal bcc structure anatase phase of TiO2 and Face-Centred Cubic structure (fcc) of silver in core-shell nanostructure. Fourier Transform Infrared Spectroscopy (FTIR) study proved the presence of characteristic peaks of both TiO2 and Ag. XPS study revealed the existence Ti4+ and metallic silver in core-shell nanostructure, High - Resolution Transmission Electron Microscopy (HR–TEM) and High - Resolution Scanning Electron Microscopy (HR–SEM) revealed the covering of Ag nanoparticles at the surface of TiO2 spheres. The TiO2@Ag core-shell nanoparticles exhibit a high residual mass of 95.9 % and stability to withstand up to 1000 °C. The prepared TiO2@Ag core-shell nanoparticles as photocatalyst showed enhanced photocatalytic degradation (240 min) of sulphur dye in effluent water with a degradation efficiency of 81 % and capable of employing in wastewater treatment to eliminate toxic elements present in it. In the current study, we have used core-shell nanoparticles prepared using the wet chemical method at room temperature. The prepared core-shell nanoparticles were used to study the photocatalytic degradation of sulphur black dye directly collected from textile effluent water. They were also used for the production of oxygen and hydrogen through the electrolysis process. The synthesized TiO2@Ag core-shell nanoparticles act as effective electrocatalyst for the production of oxygen and hydrogen through oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) using the electrolysis process.

Tweaking the structural, micro–structural, optical and dielectric properties of anatase titanium dioxide via doping of nitrogen ions

The pure nanostructured anatase titanium dioxide (TiO2) and subsequent nitrogen–doped derivatives (TiO2–xNx; where, x = 0.005, 0.01, 0.05) were synthesized by sol–gel auto–combustion technique. XRD analysis confirms the formation of pure anatase phase of TiO2 up to doping of 1 mol% (x = 0.01) of nitrogen having tetragonal structure with space group of I41/amd whereas an additional monoclinic phase of TiO2–B was observed at 5 mol% of nitrogen doping in TiO2. This sample has smallest crystallite size of ∼4.7 ± 0.2 nm corresponding to TiO2–B phase and ∼12.0 ± 0.1 nm corresponding to anatase phase. XRD also reveals that the crystallite size of all other samples having pure anatase phase ranges between ∼8.7 ± 0.1 nm & 13.9 ± 0.1 nm. The crystalline phase revealed from XRD of all samples was further supported by the Raman analysis. The direct optical band gap of pure TiO2 (∼3.4 eV) was reduced non–monotonically after nitrogen doping in the ranges from ∼2.8 eV (TiO1.95N0.05) to ∼2.0 eV (TiO1.99N0.01). FTIR spectra confirm the metal oxide bond formation, surface adsorption of water molecules and presence of residual hydroxyl group in all crystalline samples. HRTEM analysis validates the coexistence of secondary phase of TiO2–B along with anatase phase of TiO2 in studied highest doped sample (TiO1.95N0.05) including its broader particle size distribution as compared to pure TiO2. The electrical studies reveal that the highest values of dielectric constant and ac conductivity can be realized for pure TiO2 and at 1 mol% (x = 0.01) of nitrogen doping, among all the studied nitrogen doped samples.

Integrating machine learning with experimental investigation for optimizing photocatalytic degradation of Rhodamine B using neodymium-doped titanium dioxide: a comprehensive approach with toxicity assessment.

In this study, neodymium-doped titanium dioxide (Nd-TiO2) nanoparticles were synthesized via a hydrothermal method for the photocatalytic degradation of Rhodamine B (RhB) under UV and sunlight conditions. The properties of these NPs were comprehensively characterized. And optimization of RhB degradation was conducted using control-variable experiment and artificial neural networks (ANN) under various operational conditions and in the presence of competing compounds. The acute toxicity of both NPs, RhB, and the environmental impact of the photocatalytic treatment effluent on Danio rerio were evaluated. The Nd modification increased the catalyst's specific surface area and thermal stability. X-ray diffraction confirmed the tetragonal anatase phase in undoped TiO2, while Nd-doped TiO2 exhibited shifts in peaks and the presence of brookite and rutile phases. Nd (1mol%) doped TiO2 demonstrated superior RhB photocatalytic degradation efficiency, achieving 95% degradation and 82% total organic carbon (TOC) removal within 60min under UV irradiation. Optimization under sunlight conditions yielded 95.14% RhB removal with 0.28g/L photocatalyst and 1% doping. Under UV light, 98.12% RhB removal was optimized with 0.97% doping, along with the presence of humic acid and CaCl2. ANN modeling achieved high precision (R2 of 0.99) in modeling environmental photocatalysis. Toxicity assessments indicated that the 96-h LC50 values were 681.59mg L-1 for both NPs, and 23.02mg L-1 for RhB. The treated dye solution exhibited a significant decline in toxicity, emphasizing the potential of 1% Nd-TiO2 in wastewater treatment.

Influence of Ag doping on structural, morphological, and optical characteristics of sol-gel spin-coated TiO2 thin films

Pure and Ag-doped Titanium dioxide (TiO2) thin films have been synthesized via the sol-gel spin coating method, and their structural, morphological, and optical properties have been investigated. X-ray diffraction analysis verifies that the polycrystalline anatase TiO2 phase is retained up to 2 % Ag doping. However, lattice expansion and grain refinement down to 25.345 nm are observed with increasing Ag content. Scanning electron microscopy (SEM) reveals the formation of large, isolated TiO2 aggregates separated by drying-induced cracks across the film surface. Optical studies show the undoped TiO2 films demonstrate excellent visible transparency (>75 % transmittance) that slightly decreases upon Ag doping, though it remains suitably high for device applications. Meanwhile, optical absorption and defect states improve with more Ag incorporation, narrowing the TiO2 bandgap from 3.83 eV (undoped) to 3.51 eV (2 % Ag-doping) due to the incorporation of Ag-induced electronic states just below the conduction band minimum. The capability to control optical and structural properties through Ag doping highlights the potential of these TiO2 films suitably tailored for photovoltaic devices or self-cleaning coatings.

X-ray characterization, structural analysis, antibacterial activity, and self-cleaning property of Cu-doped TiO2-SiO2 nanocomposite prepared by sonochemical process

TiO2-SiO2 nanocomposites with different copper (Cu) precursor loadings were prepared by a one-step sonochemical process. The mole ratio of Cu precursor in TiO2-SiO2 composite was varied at 0.004, 0.008, 0.020, and 0.040, respectively. The specific X-ray characterization techniques on crystalline structure, chemical composition, and chemical states of Cu-doped TiO2-SiO2 composite were carried out by X-ray diffraction technique (XRD), X-ray fluorescence (XRF), and X-ray photoelectron spectroscopy (XPS), respectively. Surface morphology and chemical bonding of Cu-doped TiO2-SiO2 composite were monitored by field emission scanning electron microscope (FE-SEM) and Fourier transform infrared spectrophotometer (FTIR). For antibacterial properties, the inhibition zone of antimicrobial activity was investigated by varying amounts of Cu precursors in the TiO2-SiO2 composite. After that, Cu-doped TiO2-SiO2 composite powder with different Cu precursor ratios was mixed in PMMA solution and deposited on glass slides to study the optical property and hydrophilicity by UV-VIS-NIR spectrophotometer and contact angle method. XRD patterns of Cu-doped TiO2-SiO2 nanocomposites show the formation of the main TiO2 anatase phase with the ultrafine particles observed by FE-SEM images. FT-IR spectra of the composites are assigned to the prominent peaks of the Ti-O-Ti and Ti-O-Si bond relating to the TiO2-SiO2 host matrix. Meanwhile, TiO2-SiO2 composites with Cu precursor at 0.004 mol ratio can significantly enhance the antibacterial activity with a large inhibition zone. The contact angle value of Cu-doped TiO2-SiO2 nanocomposite film at 0.040 Cu precursor mole ratio in the TiO2-SiO2 matrix resulted in the optimized composite ratio for achieving a hydrophilic surface on the substrate.