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Early biofilm formation could be inhibited by applying a thin biocompatible copper coating to reduce periprosthetic infections. In this study, we deposited crystalline Cu-doped TiO2 films using one-step DC magnetron sputtering in an oxygen atmosphere on a biased Ti6Al4V alloy without external heating. The bias voltage varied from −25 V to −100 V, and the resultant substrate temperature was measured. The deposited coatings were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), microhardness, scratch and hydrophilicity tests, potentiodynamic polarization measurements, and antibacterial assays against S. aureus and E. coli. The findings demonstrated that when a higher negative bias is applied, the substrate temperature drops, and the anatase to rutile transformation is initiated without indicating obvious Cu-containing phases. The SEM images of the films showed spherical agglomerates with homogeneously distributed Cu with decreasing Cu content as the bias value increased. Higher bias results in the grain refinement of the thinning coatings with more lattice microstrain and more defects, together with an increase in water contact angles and hardness values. Samples biased at −75 V exhibited the highest adhesive strength between coatings and substrate, whereas the specimen biased at −50 V demonstrated higher corrosion resistance. Cu-containing TiO2 coatings with pure anatase phase composition and Cu concentrations of 2.62 wt.% demonstrated excellent bactericidal activity against both S. aureus and E. coli. The layers containing 2.34 wt.% Cu exhibited very good antibacterial properties against S. aureus, only. According to these findings, the produced copper-doped TiO2 coatings have high bactericidal qualities in vitro and may be used to prepare orthopaedic and dental implants in the future. [ABSTRACT FROM AUTHOR]

The self-cleaning effect of titanium dioxide coatings is based on the photocatalytic oxidative ability and the phenomenon of photoinduced superhydrophilicity. Doping with metals is used to enhance the photocatalytic activity; however, its influence on the surface hydrophilicity remains to be studied. In this work, the effect of the heterovalent doping of titanium dioxide anatase on its hydrophilic properties has been investigated in detail. Thin xM–TiO2 films, where the M symbol denotes Nb5+, Sc3+, and Al3+, with dopant concentrations of 0.0–1.0 at % have been obtained on glass substrates from solutions of corresponding sols by the deep coating method. The phase composition, surface dopant content, lattice microstress, surface acidity, and electron work function values have been determined and analyzed for three series of doped samples as functions of dopant concentrations. The surface hydrophilicity of xM–TiO2 nanocoatings has been estimated by measuring water contact angle and surface free energy values. It has been shown that doping with niobium ions affects the wettability of titanium dioxide, while its hydrophilic state remains unchanged upon doping with scandium and aluminum ions. It has been found that the incorporation of niobium ions into anatase drastically increases the hydrophilicity of the surface with a simultaneous change in its acidity and work function. At the same time, as Nb content increases, the electronic factor prevails. The kinetic dependences obtained for the photoinduced water contact angles have shown an increase in the surface hydrophilicity of all investigated coatings irrespective of a dopant type within the studied dopant concentration range, thereby indicating their self-cleaning ability. At the same time, the final UV-induced hydrophilic state depends on a dopant type. The maximum surface hydrophilicity is achieved upon UV irradiation of TiO2 doped with Nb regardless of its content. UV-irradiated Al-doped TiO2 coatings exhibit small contact angles, while the photoinduced surface hydrophilicity of Sc-doped titanium dioxide films decreases with increasing scandium concentration. [ABSTRACT FROM AUTHOR]

Photocatalytic coatings have the potential to contribute to the purification of water via an advanced oxidation process (AOP). A commonly used method for analyzing the mechanism of the photocatalytic performance of a given reactor type is to document the degradation behavior in a solution containing methylene blue. However, since methylene blue is rather unstable, the degradation results should be viewed critically. In this work, the degradation behavior of a test solution with methylene blue on quartz glass surfaces coated with photocatalytic titanium dioxide (TiO2) of the anatase modification was investigated through a variety of different light sources. The coating was deposited by physical vapor deposition (PVD) with the reactive pulsed DC magnetron sputtering ion plating (MSIP) method described in the study by Desch and Lake, while the quartz glasses were coated with a 100 nm thick TiO2 coating on the outside. The same glasses were used for all experiments with TiO2. In the determination of the degradation rate, additional experiments were performed using pure quartz glass without any coating, which made it possible to examine the influence of different light sources on the degradation rate of methylene blue in general. Three different light sources, namely UV‐A, UV‐C, and simple fluorescent lamps were used in this study. The concentration of methylene blue was recorded by photo spectrometer in 10‐min increments throughout the experiment and the experiments were performed for 24 h in all cases. Our data indicates that the methylene blue test is a poor method because the degradation rate is not clearly differentiable due to the low stability of the test substance. Without including reference testing in the absence of a catalyst, data may be subject to misinterpretation. [ABSTRACT FROM AUTHOR]

This study investigates the structural and electronic properties of the anatase and rutile TiO2 systems by employing the Quantum Espresso (QE) software using first-principles calculations based on Density Functional Theory (DFT). Optimized lattice constants (a = 3.788, 4.627 a.u. and c = 9.491, 2.979 a.u.) and the internal parameter u (0.209, 0.305), were obtained for anatase and rutile TiO2 phases, respectively. Unit cell volumes were also calculated. Furthermore, the Birch-Murnaghan equation of state was used to obtain the equilibrium volume (937.5, 428.3 a.u.³), the bulk modulus (198.5, 222.5 GPa), and the pressure derivative of the bulk modulus (4.18, 4.37) for both phases. The results are in good agreement with the experimental data and the theoretical results published in other studies. Finally, the energy band gap of both samples was calculated (1.8 and 1.6 eV, respectively) and compared with published results obtained from the Density Of Electron States (DOS). [ABSTRACT FROM AUTHOR]

Titanium dioxide nanoparticles, renowned for their abundance, non-toxicity, and stability, have emerged as indispensable components in various fields such as air purification, healthcare, and industrial processes. Their applications as photocatalysts and antibacterial agents are particularly prominent. The synthesis methods significantly influence the properties and subsequent applications of these nanoparticles. While several techniques exist, the biological approach using plant extracts offers advantages such as simplicity, biocompatibility, and cost-effectiveness. This study focused on the green synthesis of titanium dioxide nanoparticles utilizing spinach leaf extract. Within the scope of this investigation, the green synthesis of titanium dioxide nanoparticles through spinach leaf extract were synthesized and optimized, followed by a comprehensive examination of their morphological, structural, and chemical attributes with UV-visible spectroscopy, FTIR spectroscopy, XRD, FESEM, and EDX. The minimum inhibitory concentration (MIC) against E. coli and S. aureus was determined to evaluate their antibacterial potential. Optimal synthesis conditions were identified at 50 °C, using a 1/30 concentration and 20 ml of spinach leaf extract. Spherical anatase nanoparticles, ranging from 10 to 40 nm, were produced under these conditions. The change in the color of the extract, absorption at 247 nm, change and increase of the peak at 800 − 400 wavelengths, and the maximum intensity of X-ray diffraction at the angle of 25.367 with the crystal plane 101 were indications of the synthesis of these nanoparticles. Notably, the synthesized nanoparticles exhibited antibacterial activity with MIC values of 0.5 mg/ml against E. coli and 2 mg/ml against S. aureus. This research presents a novel, eco-friendly approach to synthesizing titanium dioxide nanoparticles with promising antibacterial properties. [ABSTRACT FROM AUTHOR]

Herein, we demonstrate an optimization of dye-sensitized solar cells (DSSCs) through the development of single-layer and double-layer configurations. Focusing on the incorporation of brookite and anatase phases in varying ratios, the study aims to determine the optimal composition for enhanced photovoltaic performance. The active layer, composed of anatase- and brookite-TiO2 nanoparticles, is further modified with a scattering layer comprising a mixture of anatase nanoparticles and brookite-TiO2 in the form of nanocube or rice-like particles. The synthesis of TiO2 nanostructures with various morphologies and phase compositions and their subsequent application in single-layer and double-layer DSSCs are presented. The results highlight the superior light-harvesting capabilities achieved through the strategic incorporation of brookite phase into the anatase phase, emphasizing the importance of optimizing the anatase: brookite ratio. The single-layer DSSCs exhibit a peak efficiency of 8.73%, achieved with a composition of 30 wt.% brookite and 70 wt.% anatase at a thickness of 15 μ ms. In the context of double-layer DSSCs, the combined optimization of the active layer composition, scattering layer morphology, and utilization of anatase nanoparticles leads to a remarkable efficiency of 9.18%. These findings underscore the critical role of composition and morphology in enhancing the performance of DSSCs, showcasing the potential for brookite-based DSSCs in solar energy conversion. [ABSTRACT FROM AUTHOR]

A process for creating a macroporous silicon substrate on which a layer of titanium dioxide was deposited using the atomic-layer deposition method is described. Electrochemical etching was used to form the macroporous structure of the substrate. TiO2 was deposited using an SI PEALD setup. The morphology, structure, and optical properties of the deposited TiO2 film were assessed using scanning electron microscopy coupled with energy-dispersive x-ray spectroscopy, spectral ellipsometry in the range 240–1000 nm, and Raman spectroscopy. Raman spectra revealed peaks at 144, 194, 397, and 639 cm–1 that were characteristic of the TiO2 anatase modification. The absorption coefficient and optical band gap width of the deposited film were determined based on the calculated ellipsometric parameters. [ABSTRACT FROM AUTHOR]

Nanoparticles, considered building blocks of nanotechnology, are a topic of widespread research due to their extraordinary properties that are useful in diverse sectors. Among all nanoparticle types, TiO2 (anatase) has drawn the most attention, primarily because of its superhydrophilic properties and effective antibacterial actions. Its applications include self-cleaning of solid surfaces, treatment of water and air, production of clean energy, treatment of microbial infections, pesticide management, etc. making TiO2 a focal point of research in materials science. However, the lack of photosensitivity to visible light (>390 nm) reduces the scope for utilising TiO2 in photocatalytic processes. Therefore, most studies on TiO2 nanoparticles have focused on broadening their spectral sensitivity through band gap manipulation for effective photocatalysis under visible light. Researchers have doped/co-doped metals and non-metals, such as N, C, F, S, B, Cu, Fe, V, Pt, etc. to nano-TiO2 to shorten its band gap with varying degrees of success. This review paper mainly focuses on the mechanism and effectivity of N and Fe co-doped TiO2 nanoparticles. The progress of scientific research on TiO2 photocatalysis has introduced an array of new applications using TiO2 nanoparticles, and these applications have also been discussed in this article. [ABSTRACT FROM AUTHOR]

This research aims to evaluate the efficacy of Mouromtseff's numbers in assessing the thermal transfer performance of titanium oxide (TiO2) nanosized dispersions in convective heat transfer through a pipe. New experimental coefficients of convective heat transfer, thermophysical and rheological characterisation are carried out for TiO2-based nanodispersions in an aqueous propylene glycol 30 vol% mixture at various nanoadditive mass loadings (from 0.25 to 2.0 wt%). Different Mouromtseff's number formulations, including the Dittus–Boelter and Simons expressions, were obtained from experimental data of thermophysical properties, enabling concise analyses on the prospective improvement of heat transfer in cooling and heating systems. The morphology, particle size, and crystallinity of the anatase TiO2 nanopowder were confirmed, and the stability of the nanofluids with various surfactants was evaluated, with PSS at a 1:4 mass ratio being optimal. Slight increments in thermal conductivity (up to 1.5%) and density (up to 1.3%) with nanoparticle loading were observed, while isobaric heat capacity presents a decreasing trend (less than 13%). Dynamic viscosity increases with higher nanoadditive concentrations, 8.8% for the 2.0 wt% A-TiO2/PG:W 30:70 + PSS 1:4 nanofluid. The employed Dittus–Boelter and Simons expressions correctly predict a worsening of the convective heat transfer, but the percentages diverge slightly from experimental data. [ABSTRACT FROM AUTHOR]

The use of multiple wavelengths to excite Titanium Dioxide Raman scattering in the near-infrared was investigated for optical nanothermometry. Indeed, Raman spectroscopy can be a very interesting technique for this purpose, as it offers non-disruptive contactless measurements with a high spatial resolution, down to a few µm. A method based on the ratio between the anti-Stokes and Stokes peaks of Anatase Titanium Dioxide was proposed and tested at three different wavelengths, 785, 800 and 980 nm, falling into the first biological transparency window (BTW-I). Using a temperature-controller stage, the temperature response of the sample was measured between 20 and 50 °C, allowing the thermal sensitivity for this range to be estimated. The use of sufficiently high laser power results in the generation of local heating. A proof of concept of the proposed thermometric method was performed by determining the extent of local heating induced by increasing laser power. By exciting with an 800 nm laser at low power intensities, a temperature equal to room temperature (RT) was found, while a maximum temperature increase of 15 °C was detected using the anti-Stokes/Stokes method. [ABSTRACT FROM AUTHOR]

Introduction. Detonation spraying is an effective method for applying high-quality coatings to various materials, widely used in industry to improve wear resistance and corrosion resistance of surfaces. This article examines the influence of key process parameters, such as gun-to-substrate distance and nozzle velocity, on the structure and properties of the resulting coatings. Materials and methods of research. The Ti–TiO2 coatings on hot-rolled carbon steel are studied. The spray distance and the speed of nozzle passage are varied while the rest spraying parameters are fixed. The obtained coatings were studied using scanning electron microscopy, X-ray diffraction, and energy-dispersive X-ray spectroscopy. Results and discussion. It is found that the phase composition of the coating changes depending on the detonation spray conditions. The fraction of rutile exceeds the fraction of anatase in the obtained samples except for the samples obtained with the fastest nozzle passage. The rutile fraction monotonically decreases with an increase in the spray distance with fixed values of the rest parameters of spraying process. It is found a nonmonotonic changing the rutile fraction with an increase in the speed of nozzle passage and found its optimal values. Two new theoretical models for the spray process based on differential equations are proposed, the solutions of which sufficiently describe the dependencies of the rutile fraction on the distance and speed of the nozzle, respectively. Conclusion. It has been demonstrated that the theoretical values of the parameters, calculated using the formulated equations, are in good agreement with the experimentally measured values

Abstract Titanium dioxide nanoparticles, renowned for their abundance, non-toxicity, and stability, have emerged as indispensable components in various fields such as air purification, healthcare, and industrial processes. Their applications as photocatalysts and antibacterial agents are particularly prominent. The synthesis methods significantly influence the properties and subsequent applications of these nanoparticles. While several techniques exist, the biological approach using plant extracts offers advantages such as simplicity, biocompatibility, and cost-effectiveness. This study focused on the green synthesis of titanium dioxide nanoparticles utilizing spinach leaf extract. Within the scope of this investigation, the green synthesis of titanium dioxide nanoparticles through spinach leaf extract were synthesized and optimized, followed by a comprehensive examination of their morphological, structural, and chemical attributes with UV-visible spectroscopy, FTIR spectroscopy, XRD, FESEM, and EDX. The minimum inhibitory concentration (MIC) against E. coli and S. aureus was determined to evaluate their antibacterial potential. Optimal synthesis conditions were identified at 50 °C, using a 1/30 concentration and 20 ml of spinach leaf extract. Spherical anatase nanoparticles, ranging from 10 to 40 nm, were produced under these conditions. The change in the color of the extract, absorption at 247 nm, change and increase of the peak at 800 − 400 wavelengths, and the maximum intensity of X-ray diffraction at the angle of 25.367 with the crystal plane 101 were indications of the synthesis of these nanoparticles. Notably, the synthesized nanoparticles exhibited antibacterial activity with MIC values of 0.5 mg/ml against E. coli and 2 mg/ml against S. aureus. This research presents a novel, eco-friendly approach to synthesizing titanium dioxide nanoparticles with promising antibacterial properties.

Background and Objectives: Nanostructured dispersed semiconductor structures are of some interest as functional materials for modern chemoresistive sensing and photocatalytic chemistry. Among the promising semiconductor materials for such applications is, in particular, titanium dioxide in the modification of anatase. Despite a significant number of experimental and theoretical works devoted to the consideration of electrophysical properties of anatase nanophase and various structures based on it, the features of degradation of electrical conductivity of such systems with time are not fully investigated. The aim of this work was to analyze the behavior of the fluctuation component of the voltage drop on partially conducting systems of interelectrode bridges made of anatase nanoparticles under conditions of direct current flow in the quasi-stationary regime (with a slow increase in the voltage drop) and as it approaches the threshold of flow, characterized by a rapid increase in the voltage drop. Materials and Methods: Experimental studies of the charge transfer fluctuations in disperse structures near the percolation threshold were carried out using specially prepared samples consisting of densely packed titanium oxide nanoparticles (TiO2). The technique is based on the registration of time dependences of the voltage drop across the structures when a constant current flows through the system of anatase bridges. The behavior of fluctuation components during the measurement cycles was analyzed using moving estimates of the Hurst exponent of sample structural functions of intensity fluctuations. In addition to the sample values of the Hurst exponent, the sample normalized autocorrelation functions of the fluctuation component were calculated. To interpret the observed features, we propose a qualitative phenomenologicalmodel that considers the influence of random sequences of acts of blocking and soft breakdown of local conduction channels in the studied structures on the degradation of the effective ohmic conductivity of the structures. Results: It has been established that when approaching the threshold of percolation due to the depletion of the ensemble of free charge carriers (electrons) in bridges, there are qualitative changes in the dynamics of voltage drop fluctuations on bridge systems (in particular, a significant increase in the Hurst exponent of structural functions of voltage drop fluctuations, correlating with a sharp decline in the effective ohmic conductivity of the structures under study). “Soft” breakdowns of previously blocked local conduction channels may be due to the Poole – Frenkel effect, leading to the escape of trapped electrons into the conduction zone due to thermal fluctuations when the depth of traps decreases under the influence of an external electric field. Conclusion: The results obtained are of some interest from the point of view of further development of fundamental ideas about charge transfer mechanisms in dispersed semiconductor materials used in chemoresistive sensing and catalytic chemistry.

Water pollution has emerged as a significant worldwide issue, with organic pollutants being a key contributor. Titanium dioxide (TiO2) has demonstrated promising photocatalytic performance in removing organic pollutants under ultraviolet (UV) irradiation. However, the wide band gap (3.2 eV) of TiO2 results in low absorption capacity of visible light, hindering its overall efficiency in degrading organic pollutants. To address the limitation, this research aimed to synthesize visible light-driven TiO2 photocatalyst with different polymorphs (anatase and rutile) and investigate the effect of various doping combination (Nb, B and Nb,B) and concentrations (0.25, 0.50, 0.75 and 1.00 mol%) on the photodegradation efficiency towards methylene blue (MB) dye solution. Anatase phase was obtained when TiO2-based nanopowders were calcined at 400 °C, while the rutile phase was formed at 900 °C based on XRD analyses. Additionally, the morphology analyses revealed that the particle size of anatase is much smaller than that of rutile. The presence of dopants further reduced the particle size of both anatase and rutile phases. Based on UV-Vis absorbance spectra analyses, the anatase Nb,B-TiO2 with 0.50 mol% of dopant concentration exhibited the best photocatalytic performance towards MB. Moreover, the anatse phase of 0.50 mol% Nb,B-TiO2 showed the narrowest band gap of 2.74 eV compared to the TiO2 (3.4 eV), representing a reduction of 19.41 %, according to UV-Vis analyses. These outcomes suggest the potential application of anatase phase of 0.50 mol% Nb,B-TiO2 in treating organic pollutants in wastewater under visible light conditions in future. 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).

The primary goal of this research outline is the conversion of titanium isopropoxide (TTIP) at 50.0 °C to form a high crystalline preferred oriented predominant (101) with a low crystal strain of 90.0 % anatase-TiO2 phase. With the interval of time, the peptizing agent (IP) reacts to an acidic aqueous medium and preferential growth of anatase-TiO2 has been identified. Exhaustive recombination in X-ray diffraction (XRD) analysis ensures the crystal strain, lattice volume, lattice parameters, d-spacing and crystallite size. UV–vis-NIR showed maximum absorption of 320.0 nm with 0.78 a.u. at blue shift for decreasing nano-size and smaller bandgap 3.0313 eV of larger dimensions anatase-TiO2. The preferred orientation also revealed by nanobeam diffraction (NBD) of TEM enables qualitative lattice type and highly crystal orientated predominant (101) plane 5.60 nm−1 in a diffraction pattern imposed on 200.0 kv parallel electron bean from LaB6 filament.

Doping TiO2 with chalcogen (S, Se, and Te) decreases its band gap and enhances the photocatalytic activity. However, doping TiO2 could create mid‐gap states that trap the electrons and reduce the photocatalytic activity. Therefore, more investigation is needed to extrapolate clear insights for technological development. Density functional theory (DFT) is used to investigate the effects of doping chalcogens (X) (X=S, Se, and Te) in the two layers (2L) and four layers (4L) anatase (101) TiO2 surfaces. The structural and electronic properties as well as the band gap are investigated for the doping of one or two chalcogens in the TiO2 surface. The hybridization between the p chalcogen and 3d Ti as well as the 2p O orbitals causes the narrowing of the band gap. The substitutional doping of chalcogen in the TiO2 surface introduces new states in the band gap region and predicts the enhancement of visible light photoactivity. Among all the substitutional doping chalcogens in TiO2, the Te/TiO2 band gap is significantly lower than in the Se‐ and S‐doping systems. The effects of the chalcogen doping depend on the concentration of the chalcogen as well as the number of layers in TiO2 surfaces. [ABSTRACT FROM AUTHOR]

The development of systems capable of efficiently eliminating organic dyes from wastewater is crucial for the environment. In this context, TiO2-based photocatalytic systems are of particular interest. However, the development of eco-friendly and single-step methods for the fabrication of such systems remains a challenge to their practical use. Here, we demonstrate a fabrication approach for a catalytic system composed of TiO2 nanocoating created on the surface of a bulk titanium plate by exposure to a nanosecond laser. The exposure conditions affect the relief and phase composition of the nanocoating, as revealed by a combination of scanning electron microscopy (SEM), contact profilometry, Raman, High-resolution X-ray photoelectron spectroscopy (HR XPS), and grazing incidence X-ray diffraction (GIXRD) methods. Using the GIXRD method, we establish that nanocoatings consist of a mixture of anatase and rutile grains with sizes of 22.7–24.4 and 29.8–32.2 nm, respectively. HR XPS analysis demonstrates that changes in the number of pulses per spot modify the anatase surface content from 40.6 to 70.4%. The samples with a higher anatase content exhibit up to 6.3 times higher catalytic activity, which is confirmed by methylene blue degradation when exposed to UV light and can be related to the synergistic effect of the anatase–rutile heterojunction. The reusability of the samples is supported by repeated degradation experiments. The photocatalytic activity of the obtained TiO2 nanocoatings is improved by Au nanoparticles deposited on their surface by magnetron sputtering. The proposed approach lays the foundation for the application of nanosecond laser-assisted technologies in the eco-friendly fabrication of catalytic systems. [ABSTRACT FROM AUTHOR]

Agarose/micrometer titanium dioxide (TiO2) beads were essayed to test the photocatalytic capacity of two of the most widely prescribed drugs worldwide: paracetamol and ibuprofen. Although the initial tests demonstrated promising degradation rates for both drugs, the presence of turbidity, due to TiO2 leakage, during the photocatalytic essays induced to improve the stability of the photocatalytic composites. Among the different strategies adopted to strengthen such materials, crosslinking with citric acid and the use of alternative gelling agents: gellan, agargel™, and agar were chosen. Composites obtained by merging both strategies were characterized and employed to degrade both drugs under a simulated light that mimics the solar spectrum (indoor). Considering the superior degradation rates obtained when agar and agarose were used to shape the titanium oxide particles (up to 70–75% of drug destruction), such composites were subjected to a more realistic experiment (outdoor): solar illumination, tap water, and higher volumes, that should facilitate its ulterior scale up as a real wastewater depollution procedure. Degradation rates between 80 and 90% are attained under such conditions for both drugs. [ABSTRACT FROM AUTHOR]

TiO 2 -based photoelectrocatalysts are synthesized by anodization at 90, 70 and 50V, using ethylenediamine to incorporate C and N elements (i.e. formation of coordinated complexes). The analysis is focused on determining the effects of oxygen vacancies, crystallite size, phase type, band gap size, elemental surface composition, roughness, and thickness of the photoelectrodes, to establish those influencing the photoelectroactivity of H 2 production. H 2 is generated with irradiations simulating solar conditions, and only visible-light. The photoelectrode formed at 70V develops the largest photocurrent, and consequently the largest H 2 production. It is revealed that the lowest content of oxygen vacancies, the highest amount of elemental C and O at the surface, and the reduction of the main band gap in this photoelectrode substantially control the photoactivity of this reaction. While the roughness and thickness of the coatings, the crystallite size, the specific surface area, and the surface compositions of elemental Ti and N are found to be negligible. [Display omitted] • Ethylenediamine was effective to incorporate C and N species into anodized TiO 2. • C and N incorporations reduced the main band gaps of all (CN)–TiO 2 photoanodes. • Oxygen vacancies, surface contents of C and O, and band gap size control H 2 yield. • Roughness, thickness, and crystallite size of catalysts do not impact H 2 activity. • Specific area and surface compositions of Ti and N are negligible for H 2 generation. [ABSTRACT FROM AUTHOR]

Water pollution has emerged as a significant worldwide issue, with organic pollutants being a key contributor. Titanium dioxide (TiO2) has demonstrated promising photocatalytic performance in removing organic pollutants under ultraviolet (UV) irradiation. However, the wide band gap (3.2 eV) of TiO2 results in low absorption capacity of visible light, hindering its overall efficiency in degrading organic pollutants. To address the limitation, this research aimed to synthesize visible light-driven TiO2 photocatalyst with different polymorphs (anatase and rutile) and investigate the effect of various doping combination (Nb, B and Nb,B) and concentrations (0.25, 0.50, 0.75 and 1.00 mol%) on the photodegradation efficiency towards methylene blue (MB) dye solution. Anatase phase was obtained when TiO2-based nanopowders were calcined at 400 °C, while the rutile phase was formed at 900 °C based on XRD analyses. Additionally, the morphology analyses revealed that the particle size of anatase is much smaller than that of rutile. The presence of dopants further reduced the particle size of both anatase and rutile phases. Based on UV-Vis absorbance spectra analyses, the anatase Nb,B-TiO2 with 0.50 mol% of dopant concentration exhibited the best photocatalytic performance towards MB. Moreover, the anatse phase of 0.50 mol% Nb,B-TiO2 showed the narrowest band gap of 2.74 eV compared to the TiO2 (3.4 eV), representing a reduction of 19.41 %, according to UV-Vis analyses. These outcomes suggest the potential application of anatase phase of 0.50 mol% Nb,B-TiO2 in treating organic pollutants in wastewater under visible light conditions in future. [ABSTRACT FROM AUTHOR]

Surface modification is a special feature in the textile industry. The end use performance of a textile product is greatly influenced by its final properties. A new concept has been developed based on the 'lotus leaf' principle, namely, 'selfcleaning textiles', i.e. textile surfaces that can clean themselves, without any washing process. The use of superfine materials made by means of nanotechnologies has received attention in the process of finishing textiles in recent years. Nanomaterials or nanoscale nanomaterials are used to endow textiles with various properties, such as radiation resistance, antimicrobial properties, self-cleaning, amortization, and others. In this study, titanium dioxide nanoparticles were simultaneously sono-synthesized and coated onto cotton fabric. For the synthesis of titanium dioxide nanoparticles, two different precursors, namely, titanium isopoxide (TTIP) and titanium butoxide (TTIB) have been used. Several analytical methods, including field emission scanning electron microscopy (FESEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), energy dispersive X-ray (EDX), dynamic light scattering (DLS), ultraviolet visible (UV-Vis) spectroscopy, were used to confirm the presence of TiO2 nanoparticles and investigate the self-cleaning property of treated fabrics. [ABSTRACT FROM AUTHOR]

Titania nanoparticles (NPs) find wide application in photocatalysis, photovoltaics, gas sensing, lithium batteries, etc. One of the most important synthetic challenges is maintaining control over the polymorph composition of the prepared nanomaterial. In the present work, TiO2 NPs corresponding to anatase, rutile, or an anatase/rutile/brookite mixture were obtained at 80 °C by an inverse microemulsion method in a ternary system of water/cetyltrimethylammonium bromide/1-hexanol in a weight ratio of 17:28:55. The only synthesis variables were the preparation of the aqueous component and the nature of the Ti precursor (Ti(IV) ethoxide, isopropoxide, butoxide, or chloride). The materials were characterized with X-ray diffraction, scanning/transmission electron microscopy, N2 adsorption–desorption isotherms, FTIR and Raman vibrational spectroscopies, and diffuse reflectance spectroscopy. The synthesis products differed significantly not only in phase composition, but also in crystallinity, textural properties, and adsorption properties towards water. All TiO2 NPs were active in the photocatalytic decomposition of rhodamine B, a model dye pollutant of wastewater streams. The mixed-phase anatase/rutile/brookite nanopowders obtained from alkoxy precursors showed the best photocatalytic performance, comparable to or better than the P25 reference. The exceptionally high photoactivity was attributed to the advantageous electronic effects known to accompany multiphase titania composition, namely high specific surface area and strong surface hydration. Among the single-phase materials, anatase samples showed better photoactivity than rutile ones, and this effect was associated, primarily, with the much higher specific surface area of anatase photocatalysts. [ABSTRACT FROM AUTHOR]

In the last few years, an increasing interest has developed regarding the application of different techniques for the identification of pollutants inside the tissues deriving from patients affected by benign or neoplastic diseases. Particular attention was paid to neoplasia linked to particular exposures, e.g., heavy metals, carbon dusts, silica, asbestos. As regards the last pollutant, a wide body of scientific literature has been collected, considering the severe effects caused by mineral fibers on human health. Optical and electronic microscopies were widely applied to identify the fibers in respiratory and extra-respiratory organs to detect the minerals and to link their presence to an exposure source and to understand their role in cancer development. The main advantage of electron microscopy lies in the possibility of coupling the microscopes with energy dispersive spectrometers and also collecting data on the elemental composition of various inorganic phases. In term of sample preparation and time of analysis, the most utilized microscope technique is Scanning Electron Microscopy with an annexed energy dispersive spectrometer (SEM/EDS), allowing for the morphological and chemical characterization of the observed particles/fibers. Moreover, this technique is envisaged by Italian Law for asbestos identification in air and bulk samples. On the other hand, this technique does not allow a reliable identification of the mineral phase in the case of polymorphs with the same chemical formula but different crystal structures. In this work, the coupling of a spectroscopical technique—micro-Raman spectroscopy—to SEM/EDS is proposed for a sure phase identification of particles, showing EDS spectra with ambiguous phase identification, observed in samples of tissues from patients affected by colorectal cancer and living in an asbestos-polluted area. In these tissues, different particles with EDS spectra that do not allow a sure identification of the phase—in particular calcium-rich particles and titanium oxides—were successively analyzed by micro-Raman spectroscopy. Thanks to this last technique, it was possible to ascribe the mineral phases associated to these particles to "aragonite" (a calcium carbonate polymorph) and to "anatase" (a Ti dioxide polymorph). [ABSTRACT FROM AUTHOR]

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The mixture of TiO2-Al-C with stoichiometric ratio was prepared then ball milling process was done in a planetary ball mill in different times. The evidence of a chemical reaction was not detected in the 1 h milled sample however, the sign of an exothermic peak was detected at ~690ºC in the DTA results for this mixture. The XRD results of the as-milled samples indicated that the chemical reaction progresses as MSR model in the mixture with stoichiometric ratio. The decreasing of the particles size and the traces of amorphization were observed after increasing the milling time to 7 hours. The products of rection (i.e., Al2O3 and TiC) were well crystallized after isothermal heating of the 5 h milled sample at 1000ºC for 1 h under argon atmosphere. The signs of these phases were also observed in the XRD patterns of the solid residues after DTA analysis. The evolution of the microstructures indicated the decreasing in the particle size due to ball milling and the changing of morphology of the microstructure due to occurrence of chemical reaction. The assessments of the lattice parameter of the TiC in the final products indicated that the lattice parameter changes and reaches to amount of the stoichiometric composition due to isothermal heating. Thermodynamics assessments were done for the mixture of TiO2-Al-C and the feasibility of the reactions was studied using HSC thermodynamics software. The XRD results of the milled and the isothermally heated samples were accordance with the thermodynamics assessments. [ABSTRACT FROM AUTHOR]

This work deals with phytochemical synthesis of TiO2 nanoparticles by using leaf extract of Ficus benghalensis tree and evaluation of their antibacterial and photocatalytic activities. The synthesized TiO2 nanoparticles were characterized by using X-ray diffraction, Attenuated total reflectance Infrared, UV visible spectroscopy and transmission electron microscopy as well as scanning electron microscopy techniques. The characterizations revealed formation of stable, spherical nanoparticles of anatase phase of TiO2 with average diameter of 21 nm. The particles showed excellent antibacterial activity against Bacillus cereus (Gram-positive) and Escherichia coli (Gram-negative) bacteria. The photocatalytic testing showed complete degradation of model pollutants from cationic and anionic dye family namely methylene blue (cationic dye) and methyl orange (anionic dye) that confirmed the excellent photocatalytic activity of the particles. [ABSTRACT FROM AUTHOR]

Photocatalytically active ceramic flat sheet membranes based on a nanostructured titanium dioxide (TiO2) coating were produced for photocatalytic water treatment. The nano-TiO2 layer was produced by a novel combination of magnetron sputtering of a thin titanium layer on silicon carbide (SiC) membranes, followed by electrochemical oxidation (anodization) and subsequent heat treatment (HT). Characterization by Raman spectra and field emission scanning electron microscopy proved the presence of a nanostructured anatase layer on the membranes. The influence of the titanium layer thickness on the TiO2 formation process and the photocatalytic properties were investigated using anodization curves, by using cyclovoltammetry measurements, and by quantifying the generated hydroxyl radicals (OH•) under UV-A irradiation in water. Promising photocatalytic activity and permeability of the nano-TiO2-coated membranes could be demonstrated. A titanium layer of at least 2 μm was necessary for significant photocatalytic effects. The membrane sample with a 10 μm Ti/TiO2 layer had the highest photocatalytic activity showing a formation rate of 1.26 × 10−6 mmol OH• s−1. Furthermore, the membranes were tested several times, and a decrease in radical formation was observed. Assuming that these can be attributed to adsorption processes of the reactants, initial experiments were carried out to reactivate the photocatalyzer. HIGHLIGHTS TiO2-coated membranes for photocatalytic wastewater treatment are promising to overcome the drawbacks of photocatalysis.; A novel coating method for ceramic flat sheet membranes with nanostructured TiO2 is described.; Nano-TiO2 coating is adhesive, permeable, has a high reaction surface, and shows favorable photocatalytic activity.; A decreasing photocatalytic effect with repeated membrane use is discussed.;

Introduction. The use of building materials with photocatalytically active additives is considered as a promising solution to environmental and economic problems of the urban environment. In the field of building materials science the necessity of studying the microstructure of self-cleaning building materials and the influence of impurities on the efficiency of self-cleaning of materials with photocatalytically active additives is determined.Materials and methods. Red gypsum (production waste with photocatalytically active impurities), cement, building gypsum, microsilica, synthesized photocatalytically active titanium oxide – silicon oxide additive, and iron-based pigments were used. Tablet specimens of gypsum-cement-pozzolanic binder with various photocatalytically active components were made: photocatalyst additive, pigments, photocatalytically active oxide impurities. The microstructure of the specimens and the distribution of titanium and iron elements were studied using scanning electron microscopy. The efficiency of self-cleaning was determined by the change in the contact angle of a water drop on a surface coated with oleic acid.Results. The efficiency of self-cleaning of specimens with added and impurity photocatalytically active components was determined. The influence of added impurities on the structure of the material and the influence of the type and concentration of impurities on the efficiency of self-cleaning were revealed.Conclusions. Titanium oxide photocatalyst additive at a concentration of 4.4 % provides high self-cleaning efficiency, evenly distributed throughout the material without affecting the structure of the forming binder stone. Pigment (iron (III) oxide) provides sufficient self-cleaning efficiency at a concentration of 2–9 %, at concentrations of more than 2 % it is distributed unevenly, providing a small increase in self-cleaning efficiency indicators. With the joint introduction of titanium and iron oxides, deterioration in self-purification is observed due to the high degree of recombination of electron – hole pairs. Red gypsum with impurity oxides of titanium and iron has shown a high efficiency of self-cleaning, has a uniform distribution of impurities that do not have a clear effect on the structure of the material.

Polymorphous nanotitania samples were prepared from titanium butoxide (TTB) as a precursor using sol-gel processing in ethanol as a solvent, without and with monoethanolamine (MEA). The experiments used 5.25 mL TTB and MEA with varied volumes of 0.5, 1.0, 1.5, and 2.0 mL. The sample without MEA was specified as sample A, and the samples produced using MEA were specified as samples B, C, D, and E, respectively. All samples were calcined at 500 °C for 4 h and then collected data by X-ray Diffraction (XRD), the Brunauer-Emmett-Teller (BET) method used to analyze Surface Area Analyzer (SAA), Transmission Electron Microscopy (TEM), Raman Spectroscopy, and UV-Visible Diffuse Reflectance Spectroscopy (UV-Vis DRS). The results of XRD characterization indicate that samples A and B form anatase phase, while samples C and D are composed of anatase, brookite, and rutile phases, and sample E is consisted of anatase and brookite phases with weight percentages of (94.53 ± 1.72) % and (5.47 ± 0.36) %, respectively. The presence of the three phases of titania is also confirmed by Raman spectroscopy analysis, which showed anatase peaks at 146, 197, 398, and 513 cm-1, brookite peaks at 245 and 402 cm-1, and rutile peaks at 319, 436, and 612 cm-1. According to XRD, the samples have the particle size in the range of 14-19 nm. A representative sample (sample C) was also characterized using TEM, revealing a particle size of 16.0 ± 0.3 nm. This representative sample revealed the largest surface area of 172.2 m2/g, as seen by BET, and the lowest energy gap of 3.03 eV.

The two largest deposits of Russia – Yaregskoye and Pizhemskoye belong to the same genetic type; hydrothermal-metamorphic indigenous deposits. They are located in the same Timan structure at a distance of no more than 230 km from each other. According to the total approved reserves and forecast resources of titanium dioxide, they are approaching 60% of the all-Russian and will form the basis of industrial titanium raw materials used in Russia in the near future. In the interests of technological mineralogy, morphological features, internal structure, chemical composition of grains of the two main titanium mineral phases ‒ leucoxene and pseudorutile, TiO2 polymorphs, as well as the composition of mineral microinclusions in these phases have been studied in detail. The compositions of all mineral phases in polished preparations of leucoxene and pseudorutile were analyzed by SEM-EDS method at the Institute of Geology and Geochronology of the Precambrian of the RAS, 147 chemical analyses were obtained at the point (3 µk) and many images of polished grains of anatase, leucoxene and pseudorutile were scanned over the area (20×20 µk). In the leucoxene grains themselves, 12 mineral phases were diagnosed and characterized in the form of inclusions: pseudorutile, rutile, anatase, quartz, hydromuscovite-illite, kaolinite, siderite, zircon, xenotime, pyrite, florencite, monazite and kularite. TiO2 polymorphs are verified by Raman spectroscopy and X-ray diffraction analysis. New evidence has been obtained that the transformation of ilmenite into leucoxene occurs hydrothermally through intermediate phases ‒ Fe-rutile and pseudorutile; the enlargement of rutile crystals in the leucoxene grain itself is shown; the presence of secondary crystals of siderite, florencite and others inside the studied grains.

TiO2-Al2O3 supports with different incorporation methods of titania were synthesized via three methods: impregnation (TA-I), co-precipitation (TA-CP), and co-precipitation–hydrothermal treatment (TA-HT). And the NiMoP catalysts prepared on the corresponding supports were evaluated for hydrodesulfurization (HDS) reactions. The results demonstrated that the Ti atoms in TA-I are attached to alumina through hydroxyl groups, while the Ti atoms in TA-CP and TA-HT can be dispersed in the alumina skeleton. Variations in the incorporation modes of TiO2 affect the support properties, consequently influencing the nature of the active metal on the supports. The Ti atoms dispersed in the Al2O3 skeleton allow an increase in the basic hydroxyl groups. Meanwhile, TiO2 in TA-CP and TA-HT can absorb hydrogen molecules and be partially reduced. Furthermore, metal species supported on the TA-CP and TA-HT are more easily reduced and better dispersed. For the NiMoP catalysts prepared with TA-CP and TA-HT, the Ti element promotes the sulfidation degree of Mo, besides shortening the average (Ni)MoS2 slab. The catalysts prepared with TA-CP exhibited superior activity for 4,6-DMDBT hydrodesulfurization. This can be ascribed not only to the relatively high sulfidation degree of Mo and proportion of the NiMoS active phase but also to the well-dispersed (Ni)MoS2 slabs. Moreover, the Ti4+ ions dispersed in the Al2O3 skeleton can be partially reduced to act as electron donors, enhancing the metallic character of the S layers in MoS2, which facilitates the improvement of the hydrogenation desulfurization activity. [ABSTRACT FROM AUTHOR]

This study investigates the impact of calcination temperature and the use of monochloroacetic acid (MCAA) as a complexing agent during the synthesis of TiO2 heterojunctions on the photocatalytic performance of TiO2 containing a heterojunction of anatase (A) and brookite (B). The TiO2 samples were dried at 100 °C and subjected to calcination in the temperature range of 200–500 °C. As the calcination temperature increased, changes in chemical composition, phase composition, specific surface area, pore size distribution, and band gap energy were observed, influencing the photocatalytic behavior during Acid Orange (AO7) photodegradation. With increasing calcination temperature, the anatase content slightly increased to 81.8 wt.%, while the brookite content decreased. Additionally, the anatase crystallite size increased from 5 to 7 nm, and the brookite crystallite size increased from 8 to 11 nm. These phase changes were characterized by a slight decrease in the brookite/anatase (B/A) molar ratio from 0.27 to 0.22. Concurrently, the specific surface area of TiO2 samples decreased from 180 to 70 m2 g−1, accompanied by alterations in the pore size distribution. The decrease in photocatalytic activity was evident, as the apparent rate constant kapp of AO7 photodegradation declined from 2.1 × 10–3 min−1 (100 °C) to 0.7 × 10–3 min−1 (500 °C). This reduction was attributed to the partial destruction of anatase/brookite heterojunctions on the photocatalyst surface, which underwent changes in size and surface structure due to sintering. Moreover, the presence of Ti3+, Ti4+, Ti–O, and Ti–OH hydroxyl groups played a significant role in the degradation process. Overall, this investigation sheds light on the crucial role of calcination temperature in modulating the photocatalytic properties of TiO2 heterojunctions and highlights the importance of heterojunction in enhancing photocatalytic activity. [ABSTRACT FROM AUTHOR]

The surface modification of the TiO2 with selective narrow band gap of metal or metal sulfide is an attractive attention in recent years. Herein, tiny Ag2S nanoparticles are well anchored on the TiO2 surface by a cost‐effective chemical precipitation method for efficient photocatalytic activity. The decoration of Ag2S nanoparticles is clearly identified through electron microscopy studies. The UV‐Vis diffuse reflection spectra (DRS) revealed that TiO2/Ag2S composites absorbed broad spectrum in the visible region. The reduced band‐gap of 2.41 eV by anchored the Ag2S on TiO2 may boosted the photocatalytic activity. Particularly, incorporation of Ag2S nanoparticles increased charge separation efficiency, lowering recombination, and improving photocatalytic performance. Because of their unique structural and optical properties, TiO2/Ag2S composites have increased photocatalytic activity. The photocatalytic performance of the pristine Ag2S and Ag2S anchored TiO2 are Crystal violet (CV) and Methyl orange (MO) dye molecules under same experimental condition. As expected, the TiO2/Ag2S showed highest photocatalytic degradation efficiency than alone TiO2. [ABSTRACT FROM AUTHOR]

TiO2 nanoparticles are effective alternative to the antibiotics. The quick recombination of the photogenerated charges and the inefficient exploitation of visible light remain the major problems limiting their large‐scale applications. Modifying the TiO2 with Silver that acting as an electron trap, plays an important role in reducing the recombination of TiO2 charges and shift its photo‐response to the visible light region. The present work aims to synthesize AgTiO2 nanoparticles using sol‐gel and coprecipitation methods and evaluating the antimicrobial behavior of them. Also, to find the optimal conditions based on the anatase phase of TiO2 due to its higher antimicrobial activity than the rutile form. Among Ag‐TiO2 nanoparticles obtained, the one prepared by sol‐gel method at 450 °C and PH=8–8.5 exhibits the best antimicrobial property. AgTiO2 nanoparticles have been characterized by means X‐ray Diffraction (XRD), Fourier transform infrared spectroscopy (FTIR),scanning electron microscope (SEM), ζ‐potential, dynamic light scattering (DLS) that showing promising results. Zeta potential values −103 mV has been reported that is considered as a stable colloidal suspension system that prevents nanoparticles aggregation. Antimicrobial behavior of them were evaluated using Diffusion (Agar disk‐diffusion), Dilution (MIC) and Bacterial colony counting methods and diameter of the inhibitory zone 15 mm and minimum inhibitory concentration 5 mg/ml was observed.Colony count results indicated that AgTiO2 able to kill bacteria at the lowest concentration of 5 mg/ml. Outcomes of MTT assay (measure cell cytoxicity) suggesting the absence of toxicity in living Hfff cells (as a normal human fibroblast) while surviving L929 cells (as a cancer cell line originated from mouse fibroblast cells). After 24 and 48 h incubation from 100 % to 77.3 % and 57.2 % was reduced respectively. This indicates that Ag/TiO2 nanoparticles act as a anticancer drug and have inherent selective toxicity nature towards cancer cells while posing no effect to normal cells. AgTiO2 nanoparticles are synthesized using sol‐gel and coprecipitation methods. The sample prepared by the sol‐gel method at a temperature of 450 °C and pH=8.5, which corresponds to the anatase phase of TiO2 synthesis, shows the best antimicrobial properties and acts as an anticancer drug with inherent selective toxicity nature towards cancer cells while posing no effect on normal cells. [ABSTRACT FROM AUTHOR]

TNAs have been synthesized using a two-step anodization method by increasing the second-step voltages. The titanium (Ti) foil was used as the anode, and the first step of anodization layer was removed by sonication in the deionized water. The second anodization step was conducted using the same electrolyte but at a higher potential. The modification of the second-step voltage was discussed with correlation for the morphology and photoelectrochemical performance of TNAs. Increasing the second voltage of two-step anodization leads to a decrease in the bandgap of the anatase phase of TNAs at 3.09 eV. The highly ordered TNAs were formed by increasing the second-step voltage based on the Fast Fourier Transform (FFT) images with a higher regularity ratio (RR) with 30 V for 30 min in the first step and 40 V for 30 min in the second step. The tube length of TNAs was produced in a short time of anodization. The photocurrent density of TNAs prepared by increasing voltage in the second step is higher than that of the one-step anodization. [ABSTRACT FROM AUTHOR]

The emerging reverse microemulsion technique offers a precise nanofabrication method for intricate nanostructures. Surfactant provides a stable microemulsion, wherein precursors are dissolved. Subsequent resin assisting results in finely patterned nanostructures. This study focuses on creating copper nanoparticles evenly dispersed on titania using varying copper loadings (5%, 10%, and 15% wt) and Brij-35 as the surfactant. Characterization via XRD, FESEM, EDAX, HRTEM, and physisorption reveals CuO/TiO2 nanospheres with different copper loadings. The catalysts were used for the liquid-phase selective oxidation of toluene, producing benzoic acid as the major product. The CuO/TiO2 nanocomposite displayed exceptional performance, with the highest toluene conversion rate (97.02%) and benzoic acid selectivity (98.14%) compared to other nanocomposites. The catalyst's stability and recyclability across five cycles were attributed to the strong copper oxide-titania interaction. The findings suggest this nanocomposite material as a promising candidate for catalytic applications, offering high selectivity and consistent toluene conversion rates. [ABSTRACT FROM AUTHOR]

The processing of anatase ores by sulphuric acid digestion is well known for its low titanium dissolution yields, which makes the process economically and technically unfeasible. Anatase is considered much less reactive than other forms of titanium such as ilmenite and rutile. Generally, to enhance its dissolution, thermal processes along with acid and/or alkaline leaching processes are necessary. Studies of direct sulphuric acid digestion are few and the reported yields of titanium dissolution are <48%. This study investigated the main parameters of sulphuric digestion of anatase such as temperature, anatase:acid ratio, and time of reaction. Dissolution of titanium of around 86% were obtained at relatively mild conditions such as, temperature at 220 °C, grain size of 62 µm, an anatase:sulphuric acid ratio of 1:2, and 4 h of reaction. A comprehensive characterization of the resulting material indicated a content of 56.5% of TiO2 and 15% iron oxide—the main impurity. It also contained silica, aluminum, phosphorus, calcium, and rare earth elements (REE) in concentrations that varied from 1.61% to 6.01%. [ABSTRACT FROM AUTHOR]

This study investigates the synthesis of TiO2 using the rind of Aloe vera (L.) Burm extract as a green-capping agent. It was discovered that adding the studied extract up to 10 % (TOAv10) increased the surface area and pore volume while maintaining the spherical shape of the nanoparticles. Overall, the TOAv4 sample has the highest photocatalytic activity compared to other samples and a good photocatalytic activity compared to TiO2 prepared without extract. The current findings provide an environmentally friendly and low-cost protocol for the synthesis of TiO2 nanoparticles in the application of wastewater treatment.

The processing of anatase ores by sulphuric acid digestion is well known for its low titanium dissolution yields, which makes the process economically and technically unfeasible. Anatase is considered much less reactive than other forms of titanium such as ilmenite and rutile. Generally, to enhance its dissolution, thermal processes along with acid and/or alkaline leaching processes are necessary. Studies of direct sulphuric acid digestion are few and the reported yields of titanium dissolution are 2 and 15% iron oxide—the main impurity. It also contained silica, aluminum, phosphorus, calcium, and rare earth elements (REE) in concentrations that varied from 1.61% to 6.01%.

Early biofilm formation could be inhibited by applying a thin biocompatible copper coating to reduce periprosthetic infections. In this study, we deposited crystalline Cu-doped TiO2 films using one-step DC magnetron sputtering in an oxygen atmosphere on a biased Ti6Al4V alloy without external heating. The bias voltage varied from −25 V to −100 V, and the resultant substrate temperature was measured. The deposited coatings were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), microhardness, scratch and hydrophilicity tests, potentiodynamic polarization measurements, and antibacterial assays against S. aureus and E. coli. The findings demonstrated that when a higher negative bias is applied, the substrate temperature drops, and the anatase to rutile transformation is initiated without indicating obvious Cu-containing phases. The SEM images of the films showed spherical agglomerates with homogeneously distributed Cu with decreasing Cu content as the bias value increased. Higher bias results in the grain refinement of the thinning coatings with more lattice microstrain and more defects, together with an increase in water contact angles and hardness values. Samples biased at −75 V exhibited the highest adhesive strength between coatings and substrate, whereas the specimen biased at −50 V demonstrated higher corrosion resistance. Cu-containing TiO2 coatings with pure anatase phase composition and Cu concentrations of 2.62 wt.% demonstrated excellent bactericidal activity against both S. aureus and E. coli. The layers containing 2.34 wt.% Cu exhibited very good antibacterial properties against S. aureus, only. According to these findings, the produced copper-doped TiO2 coatings have high bactericidal qualities in vitro and may be used to prepare orthopaedic and dental implants in the future.

The use of multiple wavelengths to excite Titanium Dioxide Raman scattering in the near-infrared was investigated for optical nanothermometry. Indeed, Raman spectroscopy can be a very interesting technique for this purpose, as it offers non-disruptive contactless measurements with a high spatial resolution, down to a few µm. A method based on the ratio between the anti-Stokes and Stokes peaks of Anatase Titanium Dioxide was proposed and tested at three different wavelengths, 785, 800 and 980 nm, falling into the first biological transparency window (BTW-I). Using a temperature-controller stage, the temperature response of the sample was measured between 20 and 50 °C, allowing the thermal sensitivity for this range to be estimated. The use of sufficiently high laser power results in the generation of local heating. A proof of concept of the proposed thermometric method was performed by determining the extent of local heating induced by increasing laser power. By exciting with an 800 nm laser at low power intensities, a temperature equal to room temperature (RT) was found, while a maximum temperature increase of 15 °C was detected using the anti-Stokes/Stokes method.

Photocatalytic hydrogen production is of great significance for the transformation of energy system. To improve the hydrogen production performance, nano-photocatalysts including pure TiO 2 and NiO-TiO 2 were prepared by sol-gel method in this paper. To unravel reaction intermediates and pathways, the adsorption experiments and photocatalytic reaction of ethanol over the photocatalysts were carried out in combination with in situ DRIFTS technique, and the main products in the photocatalytic process were detected through gas chromatography. The results showed that 2NiO-TiO 2 as the optimum photocatalyst can yield the maximum H 2 rate at 20.10 mmol g−1 h−1. For the adsorption of ethanol on TiO 2 and 2NiO-TiO 2 , the molecular form of ethanol is more dominant than the dissociated form, and CH 3 CH 2 OTi is more easily generated on 2NiO-TiO 2 than pure TiO 2. The hydrogen production pathway changes by doping with NiO, reducing the production of acetic acid and aldehydes and producing the important intermediate CH 2 CHOTi. [Display omitted] • The H 2 production using anatase doping different amount of NiO was compared. • 2 % NiO-TiO 2 exhibited the optimum activity of hydrogen production and stability. • The selectivity (organic products) of ethanol photocatalysis was investigated. • The mode of adsorption and surface species was ensured by in situ DRIFTS. [ABSTRACT FROM AUTHOR]

The inclusion of particles in a polymeric substrate to achieve certain properties is a well-known practice. In the case of textile substrates, this practice may deeply affect the structure of the produced yarns, as even a filament with no textile applications can be obtained. In this manuscript, titanium dioxide (TiO2) particles were incorporated into polyester (PET) chips and the influence of these fillers on the properties of yarn and fabric, and the ultraviolet protection factor (UPF) was assessed. For this purpose, rutile and anatase crystalline forms of TiO2, as well as the size of the particles, were evaluated. Moreover, parameters such as mechanical properties, orientation of the macromolecules and thermal behavior were analyzed to ensure that the textile grade is maintained throughout the production process. The results showed that the inclusion of micro- and nanoparticles of TiO2 decreases the molecular weight and tenacity of PET. Also, although orientation and crystallinity varied during the textile process, the resulting heatset fabrics did not present important differences in those parameters. Finally, the attainment of textile-grade PET-TiO2 fabrics with UPF indexes of 50+ with both rutile and anatase and micro- and nano-sized TiO2 forms was demonstrated. [ABSTRACT FROM AUTHOR]

TiO2 is the most important and remarkable material in photocatalytic applications. In the present work, pure and doped TiO2 nanoparticles were fabricated by the sol‐gel synthesis route. The impact of the metal and nonmetal dopants on the performance of the photocatalysts was examined systematically. X‐ray diffraction (XRD) analysis affirmed the existence of anatase and rutile phases in the fabricated nanoparticles. The diffuse reflectance spectroscopy (DRS) analysis confirmed that all doped TiO2 nanoparticles have a lower bandgap than undoped TiO2, and (N, Cu, Ag)‐doped TiO2 nanoparticles having the lowest bandgap (2.38 eV), demonstrating that metal‐metal‐nonmetal multidoping improves TiO2′s sensitivity towards visible light. In comparison to pure and other doped TiO2 nanoparticles, methylene blue (MB) photodegrades at a faster rate (rate constant of 0.04878 min−1) with the highest photocatalytic activity (99.61 % MB degradation) on the surface of (N, Cu, Ag)‐doped TiO2. The photocatalytic activities of TiO2 nanoparticles have been improved by multidoping in the following sequence: TiO2

Most studies have theoretically and experimentally investigated the effects of single‐element C/N/S doping on the magnetic and photocatalytic properties of three‐dimensional TiO2. However, only a few comparative studies are available on the magnetic and photocatalytic properties of two‐dimensional anatase TiO2 doped with C, N, or S. Based on the density functional theory framework, generalized gradient approximation + U method of the first principles is used to investigate the effects of doping three nonmetallic elements (C/N/S) on the magnetic and photocatalytic properties of bilayer anatase TiO2. The bilayer Ti24O47N (001) is found to have the lowest formation energy, the largest cohesion energy, is relatively stable, and exhibits magnetic property with a magnetic moment of −1.0 μB. The holes and electrons of Ti24O47N (001) system have longest carrier lifetime. The ratio of their average effective masses is 1.28, and the carrier separation in this system is good. The system is most favorable for the preparation of H2 and O2 from water decomposition. Within the 420–790 nm wavelength range, the Ti24O47N (001) system shows the strongest absorption spectrum intensity, the most prominent redshift, and the best activity. Thus, the bilayer Ti24O47N (001) system is an optimal photocatalyst. [ABSTRACT FROM AUTHOR]