Anatase Phase Of TiO2 Research Articles

Novel microbial synthesis of titania nanoparticles using probiotic Bacillus coagulans and its role in enhancing the microhardness of glass ionomer restorative materials

Dental caries is a commonly occurring non-communicable disease throughout the world that might compromise the quality of any individual’s life. Glass ionomer cements (GIC) are the most acceptable restorative materials due to their ease of manipulation, minimal tooth loss and least invasive strategy; however, they lack mechanical stability that has become a point of concern. Nanoparticles (NPs) are an outstanding option for modifying and enhancing the properties of dental materials. The focus of this study was to prepare novel, biocompatible titania dioxide (TiO2) NPs as a dental-restorative material using an efficient probiotic Bacillus coagulans. The prepared NPs were incorporated into glass ionomer restorative material at varying concentrations and investigated for cell viability percentage, microhardness and surface morphology. Results indicated that pure 100% anatase phase TiO2 NPs with particle size of 21.84 nm arranged in smooth, spherical agglomerates and clusters forms. These NPs depicted cell viability > 90%, thus confirming their non-cytotoxic behavior. GIC restorative materials reinforced by 5% titania (TiO2) NPs demonstrated the highest microhardness in comparison to the control group and other experimental groups of the study. Surface morphology analysis revealed a reduction in cracks in this novel dental-restorative material supporting its compatible biological nature with better hardness strength and negligible crack propagation. Overall, these results indicated that TiO2 NPs produced using a biological approach could be easily used as restorative materials in dental applications.Graphical

Metal–oxygen hybridization in Agcluster/TiO2 for selective CO2 photoreduction to CH4

Selective photocatalytic reduction of CO2 to CH4 is one of the most efficient ways to achieve carbon neutralization. However, the formation of methane remains a challenge due to the slow multiple-proton-coupled electron transfer process and the involvement of various C1 intermediates. Herein, an Agcluster/TiO2 catalyst with Ag-O hybridization was synthesized by supporting Ag clusters on anatase phase TiO2 microspheres for photocatalytic CO2 methanation. The Agcluster/TiO2 sample presents an electron selectivity of 86 % for CH4 production with a yield of 25.25 μmol g–1 h−1. Mechanistic study reveals that Ag clusters accelerate the separation and migration of photogenerated carriers, and enhance the adsorption of CO2. Moreover, the Ag-O hybridization promotes the multiple-proton–electron coupling transfer process by effectively stabilizing intermediates and facilitating *CO hydrogenation to *CHO, resulting in selective CO2 reduction to CH4. This work provides a new insight into the development of selective photocatalytic conversion of CO2 to methane by constructing supported cluster catalysts.

Development of an automated and cost-effective apparatus for sol-gel solution deposition using spray coating technique and its application for TiO[formula omitted]-based photocatalytic films

This study presents the development of a novel apparatus for automated sol–gel solution deposition through a cost-effective spray coating technique. The focus was on producing TiO2 films for photocatalytic applications, addressing environmental pollution and energy scarcity issues. The apparatus, constructed using economical materials, facilitated the production of TiO2 films with an anatase-like crystalline structure and uniform surface morphology. The methodology included detailed experimental procedures for solution preparation, substrate cleansing, and deposition process optimization. Characterization techniques such as scanning electron microscope (SEM), energy-dispersive X-ray spectroscopy (EDS), thermogravimetric analysis (TGA), X-ray diffraction analysis (XRD), Fourier-transform infrared spectroscopy (FTIR), and UV–Vis spectroscopy were employed to assess the structural, morphological, and optical properties of the films. The results indicated the successful synthesis of anatase-phase TiO2 thin films with desirable optical properties and efficient photocatalytic activity, as demonstrated through the degradation of methylene blue and methyl orange. The study highlights the apparatus’s efficiency, versatility, and potential for industrial-scale production, thus offering promising prospects for practical applications and commercialization in the field of sustainable environmental solutions.

Development of TiO2/Nb2O5 Films and Evaluation of Corrosion Prevention in AISI 304

The combination of TiO2 and Nb2O5 in thin films has proven promising for preventing the corrosion of AISI 304. The thin films are developed using sol–gel and dip‐coating techniques, followed by heat treatment. Morphological and X‐ray diffraction analyses indicate a predominant anatase phase in TiO2, and isomorphic substitution of up to 20% Nb occurs in the thin‐film composition. Phase segregation above 30% is observed. Electrochemical tests are conducted in a 2 mol L−1 HCl solution. Scanning electron microscopy reveals satisfactory thin film deposition on AISI 304 but shows the presence of regions with discontinuities. Polarization curves show a corrosion current of 128.72 μA for pure AISI 304, an average corrosion current of 0.34 μA for thin films, and an average of 6.44 μA for films with discontinuities. This significant reduction in current demonstrates the efficiency of the corrosion protection of the film at the studied concentrations because of the high corrosion inhibition percentages. Electrochemical impedance spectroscopy results suggest a high charge transfer resistance, indicating a lower corrosion rate in xTiO2 the yNb2O5 films compared to uncoated AISI 304.

Fabrication of new TiO2-SnSe composites with enhanced antibacterial performance against E. coli and S. aureus

In this work, TiO2, SnSe and their composites with different mass ratios of SnSe were fabricated by using cost-effective chemical route. The structural, optical, morphological, and antibacterial properties of the composites were systematically evaluated and compared with those of TiO2 and SnSe. Formation of anatase phase of TiO2 and orthorhombic structure of SnSe were confirmed through their respective X-ray diffraction (XRD) patterns. The results were supported by Raman analysis, which showed the characteristic vibrational modes of TiO2 and SnSe. For the TiO2-SnSe composites, broadening and a systematic shift towards higher wavenumbers was observed with the increase of SnSe concentration. Furthermore, a change in the surface morphology of TiO2-SnSe composites from agglomerated nanoparticles to plates-like nanostructures was observed for varying content of SnSe. Compared to pure TiO2, the TiO2-SnSe composites exhibited a significant shift in the spectral response towards visible region. A red-shift in the energy bandgap values from 3.25 eV (pure TiO2) to 2.42 eV (TiO2-75% SnSe) was observed. The antibacterial performance of TiO2, SnSe and their composites was evaluated against the Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) strains under visible light. Compared to TiO2 and SnSe, the composites revealed a superior antibacterial activity by exhibiting larger zones of inhibition. Furthermore, the minimum inhibitory concentration of TiO2-75% SnSe for S. aureus and E. coli was respectively determined to be 0.25 ± 0.01 and 1.50 ± 0.01 mg/mL, which was substantially lower than the TiO2. Moreover, TiO2-SnSe composites were found to be biocompatible, as more than 80% of RBCs remained viable.

Insights into the Performance of Bimetallic Ru-Co/TiO2 Catalysts Carrying out a Low Temperature C3H8 Oxidation Reaction

The performance of a set of bimetallic Ru-Co catalysts dispersed on the TiO2 anatase phase, synthesized by the co-deposition–precipitation with urea method, was tested in the CO2 production by the entire oxidation of C3H8. The presence of properly dispersed ruthenium nanoparticles on a Co/TiO2-anatase support was notably favorable for enhancing the C3H8 activity/selectivity. Likewise, an increase in the combined acidity (Brönsted and Lewis) was also observed, and the interaction between Ru0-CoOx species stabilized on TiO2 prompted the C3H8 oxidation at low temperature. The performance of bimetallic Ru-Co/TiO2 catalysts was enhanced by increasing Ru0 species and loading, showing more efficient C3H8 oxidation by the combination of Ru0-CoOx, as revealed by DRIFTS, XPS, H2-TPR, and HAADF-STEM characterization outcomes. The higher acidity of the catalysts containing Ru (1.5 wt%) and Co (3 wt%) as well as the reducibility enhancement of the Ru and Co species led to the best capacity of these catalysts for C3H8 oxidation to CO2 under the experimental conditions employed in this study.Graphical

Spatial interfacial heterojunctions of TiO2 for photocatalytic degradation of toluene: Effects of interface amorphous region and oxygen vacancy

The catalytic activity of TiO2 is contingent upon its crystal structure and the optoelectronic properties associated with defects. In this study, a one-step method was used to synthesize TiO2 with a spatial interface of rutile/anatase phases, and a simple thermal annealing process was applied to optimize the amorphous regions and oxygen vacancies at the interface between the rutile and anatase phases of TiO2. High-resolution transmission electron microscopy (HRTEM) elucidates the evolution process of the amorphous domain at the interface, skillfully introducing oxygen vacancies at the heterojunction interface by modulating the amorphous domain. The obtained photocatalyst (TiO2–350 °C) after annealing exhibits an optimal interface structure, with its photocatalytic activity and stability in degrading toluene far superior to P25. Photocurrent and photoluminescence (PL) measurements affirm that the existence of interfacial oxygen vacancies heightens the efficiency of electron transfer at the interface, while surface oxygen vacancies significantly enhance the stability and mineralization rate of toluene degradation. The improved photocatalytic properties were attributed to the combined effects of surface/interface oxygen vacancies and spatial interface heterojunctions. The one-step synthesis method developed in this work provides a novel perspective on combining spatially interfaced anatase/rutile phases with surface/interfacial oxygen vacancies.

Effect of TiN thin films deposited by oblique angle sputter deposition on sol-gel coated TiO2 layers for photocatalytic applications

TiO2 monolayer and TiN/TiO2 bilayer coatings were deposited on soda-lime glass prepared by mixing two techniques, TiO2 was deposited by sol-gel dip-coating and TiN film was deposited by oblique angle deposition using reactive magnetron sputtering at α=45° Structural analysis showed typical peaks of TiO2 anatase phase and cubic (Na-Cl type) structure of TiN. Roughness value of 3 nm was obtained for the TiN/TiO2 bilayer film with a rise and elongated grains size. It was found that the optical band gap energy decreases after coupling the TiN sub-layer which is explained by the incorporation of N atoms into TiO2 structure. At constant UV irradiation time, the photo-degradation of methylene blue rate increased for TiN/TiO2 film by 4 % compared to TiO2 film.

Electrochemical deposition of hydrothermally pretreated TiO2 on aluminium substrate through the formation of peroxotitanium complex and their application towards visible light assisted photocurrent generation

Herein, we report a novel method for the electrochemical deposition of TiO2 on Al substrate through the formation of peroxotitanium complex without any post heat treatment process. The alkaline treated titanium precursors were used as an electrolyte and TiO2 was deposited onto aluminium substrate by both cathodic reduction and electrophoretic deposition through the formation of peroxotitanium complex. The electrodeposition process was optimized by varying the pH, concentration of the electrolyte, deposition voltage, time and area of the electrode respectively. The optimized condition to obtain a maximum yield is as follows: voltage (4.5 V), time (2.5 h), pH (5) and area of the electrode 3 × 3 cm2. The deposits were then characterized using various material characterization techniques such as high-resolution transmission electron microscopy (HR-TEM), scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray diffraction (XRD) and Raman spectroscopy respectively. The morphological analysis showed the deposition of nanocrystalline TiO2 with irregular morphology on Al substrate. The AFM revealed a non-uniform deposition of TiO2 with high surface roughness (average roughness: 44.60 nm). The XRD pattern and Raman spectrum confirmed the presence of anatase phase of TiO2. The obtained TiO2 were then subjected to photoelectrochemical studies by coating over an ITO electrode. The nanocrystalline TiO2 showed excellent photocurrent response which could be due to the short hole retrieval and fast electron transport across the electrode-electrolyte interface. The proposed method can be promising towards the industrial application for the extraction and recovery of TiO2 from the mineral ore residues and spent mining waste.

Zinc doped TiO2 thin films for ethanol detection

TiO2 and Zn-doped TiO2 thin films were prepared by sol gel spin coating technique on glass substrates and their structural, optical and ethanol sensing properties were studied. The films were crystallized into the anatase TiO2 phase after annealing at 500 °C for 2 h. The crystallite size of TiO2 and Zn-doped TiO2 films were in the range of 4–18 nm. The band gaps were in the range: 3.55–3.65 eV. The surface electrical resistivity TiO2 decreased drastically by 1.36 × 10−4 Ω−1 cm−1 on doping with 2 at% of Zn. The ethanol response of films was measured at room temperature (30 °C) and it is found that Zn doping produces a large enhancement in ethanol response. The sample 1.5 at% Zn-TiO2 shows peak response of 44.18 for 500 ppm ethanol. The response and recovery time improve significantly with Zn doping in TiO2.

Unique properties of titanium dioxide quantum dots assisted regulation of growth and biochemical parameters of Hibiscus sabdariffa plants

Owing to the uniqueness of quantum dots (QDs) as a potential nanomaterial for agricultural application, hence in the present study, titanium dioxide quantum dots (TiO2 QDs) were successfully synthesized via sol-gel technique and the physico-chemical properties of the prepared TiO2 QDs were analyzed. Based on the results, the TiO2 QDs showed the presence of anatase phase of TiO2. TEM examination revealed spherical QDs morphology with an average size of 7.69 ± 1.22 nm. The large zeta potential value (-20.9 ± 2.3 mV) indicate greater stability of the prepared TiO2 QDs in aqueous solutions. Moreover, in this work, the application of TiO2 QDs on Hibiscus sabdariffa plants was conducted, where H. sabdariffa plants were foliar sprayed twice a week in the early morning with different concentrations of TiO2 QDs (0, 2, 5, 10, 15 and 30 ppm) to evaluate their influence on these plants in terms of morphological indexes and biochemical parameters. The results exhibited an increasing impact of the different used concentrations of TiO2 QDs on morphological indexes, such as fresh weight, dry weight, shoot length, root length, and leaf number, and physio-biochemical parameters like chlorophyll a, chlorophyll b, carotenoid contents, total pigments and total phenolic contents. Remarkably, the most prominent result was recorded at 15 ppm TiO2 QDs where plant height, total protein and enzymatic antioxidants like catalase and peroxidase were noted to increase by 47.6, 20.5, 29.5 and 38.3%, respectively compared to control. Therefore, foliar spraying with TiO2 QDs positively serves as an effective strategy for inducing optimistic effects in H. sabdariffa plants.

An Ultrasensitive Room-Temperature H2 Sensor Based on a TiO2 Rutile–Anatase Homojunction

Metal oxide semiconductor hetero- and homojunctions are commonly constructed to improve the performance of hydrogen sensors at room temperature. In this study, a simple two-step hydrothermal method was employed to prepare TiO2 films with homojunctions of rutile and anatase phases (denoted as TiO2-R/A). Then, the microstructure of anatase-phase TiO2 was altered by controlling the amount of hydrochloric acid to realize a more favorable porous structure for charge transport and a larger surface area for contact with H2. The sensor used a Pt interdigital electrode. At an optimal HCl dosage (25 mL), anatase-phase TiO2 uniformly covered rutile-phase TiO2 nanorods, resulting in a greater response to H2 at 2500 ppm compared with that of a rutile TiO2 nanorod sensor by a factor of 1153. The response time was 21 s, mainly because the homojunction formed by the TiO2 rutile and anatase phases increased the synergistic effect of the charge transfer and potential barrier between the two phases, resulting in the formation of more superoxide (O2−) free radicals on the surface. Furthermore, the porous structure increased the surface area for H2 adsorption. The TiO2-R/A-based sensor exhibited high selectivity, long-term stability, and a fast response. This study provides new insights into the design of commercially competitive hydrogen sensors.

Co-sputtered CuO/TiO2 coatings with varying copper content deposited on Ti6Al4V alloy

In this study, mosaic target material of titanium (Ti) and copper (Cu) was used to deposit CuO/TiO2 coatings on Ti6Al4V alloy. The aim was to examine the change in composition, structure and adhesion of the deposited films on titanium alloy when varying the titanium/copper (20:1, 41:1, 179:1, 418:1 and 837:1) ratio of the target material. The coatings were obtained by sputtering in a glow-discharge in a pure O2 atmosphere for a deposition time of 240 min. All coatings showed homogenous Cu distribution and the film thickness decreased with the reduction of Cu content in the composite target. Cu content in the coatings followed a power function of decrease with reduction of Ti-Cu content in the target while the increase of Ti showed logarithmic dependence. In all coatings, anatase and rutile TiO2 phases were detected whereas Cu atoms participated only in the formation of monoclinic CuO. TiO2-rich coatings demonstrated better adhesion to the Ti6Al4V alloy, whereas the critical loads of CuO-rich films were dependent on coating thickness.

Electrical properties of TiO2 films synthetized by sol-gel process

Titanium oxide (TiO2) is one of the most used metal oxides for its multiple applications due to its high sensitivity, fast response, low cost, no toxicity and used in hostile environments. In this work was deposited TiO2 film on 304 stainless steel substrates using the spin coating technique. The synthesis of the deposited solution was with the sol-gel method a temperature environment, obtained TiO2 films on different thermal treatments. The results of the experiment show film: with a thickness from 0.6 to 1μm, anatase phase at the plane (101). The Raman spectroscopy confirms the TiO2 anatase phase. The resistivity decreases, and conductivity increases with increasing temperature. The micrograph SEM observes a compact and smooth homogeneous surface with an average size of 18.40nm to 7nm.

Photocatalytically active Ag-doped TiO2 coatings developed by plasma electrolytic oxidation in the presence of colloidal Ag nanoparticles

The plasma electrolytic oxidation process of Ti foil in the presence of a colloidal solution of Ag nanoparticles was used for the synthesis of exceptionally photocatalytically active Ag-doped TiO2 coatings. UV–Vis absorption spectroscopy was applied to follow the changes in the surface plasmon resonance band of the Ag nanoparticles as a function of the Ag:PO43− ratio in a phosphate-based electrolyte solution. Transmission electron microscopy revealed the size of the Ag nanoparticles in the range of 3–12 nm. The XRD patterns of the Ag-doped TiO2 coatings confirmed the crystalline anatase TiO2 phase regardless of the dopant concentration and without metallic Ag or crystalline Ag oxide forms. The typical porous morphology of the Ag–TiO2 coatings was observed by scanning electron microscopy. A significantly improved photocatalytic activity of the Ag–TiO2 coatings in the degradation process of the insecticide lindane (gamma isomer of benzene hexachloride) and test molecule methyl orange compared to pure TiO2 was determined using the GC technique. The degradation efficiency of Ag-doped TiO2 coatings is higher for lindane than for methyl orange.

Monitoring of UV-A radiation by TiO2/CdS nanohybrid along with the high on-off ratio

Exposure to UV-A light can have detrimental effects on human health, leading to skin damage and an increased risk of skin cancer. In this study, we employed a hydrothermal-assisted method to cultivate TiO2-decorated CdS nanorods for use in UV photodetectors. Our research culminated in the fabrication of an exceptionally responsive and rapid photodetector based on the TiO2/CdS nanohybrid. X-ray diffraction analysis revealed the hexagonal phase of CdS nanorods, predominantly oriented along the (002) plane, and the presence of the anatase phase of TiO2. Scanning electron microscopy (SEM) measurements confirmed the nanorod structure of TiO2/CdS. Optical properties of the TiO2/CdS nanohybrid were investigated through UV–visible absorbance analysis. Additionally, X-ray photoelectron spectroscopy (XPS) provided insights into the surface composition of the prepared nanohybrid, with peaks corresponding to Cd 3d3/2 and Cd 3d5/2 at binding energies of 411.47 eV and 404.73 eV, respectively, and confirming the presence of titanium through peaks of Ti 2p3/2 and 2p1/2 at binding energies of 458.31 eV and 463.8 eV, respectively. Raman analysis indicated the presence of the anatase phase of TiO2 in the composite. Our device exhibited an impressive detectivity of 9.9 × 1012 Jones, an EQE (external quantum efficiency) of 971.36%, and a high photoresponsivity of 2.86 A/W. These results suggest that TiO2/CdS nanohybrids, prepared using a cost-effective and straightforward method, hold promise for UV photodetection applications.

Semi-transparent dye-sensitized solar cells (DSSC) for energy-efficient windows with microwave-prepared TiO2 nanoparticles as photoanodes

Here in this work semi-transparent Dye-Sensitized Solar Cells (DSSC) was constructed using TiO2 nanoparticles prepared by Microwave assisted method as photoanode and its performance was studied. The structural studies of the synthesized TiO2 nanoparticles exhibited anatase phase of TiO2. Optical characteristics were studied through UV–Visible and Photoluminescence spectroscopy (PL) analysis respectively. Further the morphological analysis through Field emission scanning electron microscopy (FESEM) and High-resolution transmission electron microscopy (HRTEM) shows the near spherical shaped particles. The chemical states were analysed through X-Ray Photoelectron Spectroscopy (XPS) analysis.

A mesoporous Mo and N Co-doped TiO2 nanocomposite with enhanced photocatalytic efficiency.

This study reports the synthesis of a mesoporous Mo and N codoped anatase TiO2 nanocomposite with many oxygen vacancies using a simple one-step hydrothermal method and subsequent calcination treatment. Both Mo and N were effectively co-incorporated into the anatase phase of TiO2 without MoOx phase segregation. The codoped catalyst demonstrated a mesoporous architecture with a surface area of 107.48 m2 g-1 and a pore volume of 0.2974 cm3 g-1. X-ray photoelectron spectroscopy confirmed that both Mo and N dissolved in the TiO2 lattice and created induced oxygen vacancies. The interaction of the dopants (Mo and N) and oxygen vacancies clearly affected TiO2 crystal formation. Photocatalytic performance of the nanocomposite was investigated in terms of the decomposition of methyl orange at a concentration of 50 mg L-1 in an aqueous solution. The results revealed a significant methyl orange degradation of up to 99.6% after 30 min irradiation under a UV light. The impressive performance of the nanocomposite is assigned to the synergetic effect of important factors, including the co-doping of metallic (Mo) and non-metallic (N) elements, oxygen vacancy defects, bandgap, crystallite size, mesoporous structure, and BET surface area.

Synthesis and characterization of anatase phase TiO2 thin films for formaldehyde detection

Synthesis and characterization of anatase phase TiO2 thin films for formaldehyde detection

Physical Properties of Cu, Co, and Zn doped TiO2 nanocrystalline thin films prepared using spray pyrolysis

This research focuses on the preparation and characterization of TiO2 thin films in both pure and doped forms. The films were deposited onto glass substrates using the spray pyrolysis technique. The pure film was doped with Cu, Co, and Zn at a constant ratio of 3 wt% in the starting solution. XRD analysis revealed the presence of anatase TiO2 phase in all deposited films. The crystallite size of the pure film was determined using Scherer’s equation and found to be 8.3 nm, while the doped films had sizes of 11.3 nm (Cu), 13.8 nm (Co), and 11.3 nm (Zn). SEM images showed the formation of fine grains with a normal distribution, with average sizes of 27.02 nm (pure), 39.37 nm (Cu), 33.4 nm (Co), and 29.37 nm (Zn) for the respective doped TiO2 films. EDX analysis confirmed the presence of the dopant elements in the deposited films. It was observed that all films exhibited a direct band gap, with a value of 3.79 eV for the pure film, which slightly decreased upon doping. Additionally, various optical constants such as refractive index, extinction coefficient, dielectric constant, relaxation time, and optical mobility were estimated and presented in this study.