Rutile Phase Research Articles

Photocatalytic films with high ethylene degradation efficiency for strawberry preservation

The preservation of fruits has always been a research hotspot. In this research, titanium dioxide(TiO2) exhibiting diffraction peaks characteristic of both anatase and rutile phases was synthesized. Subsequently, photocatalytic films loaded with the TiO2 were fabricated using a twin-screw extruder combined with an extrusion casting technique. The films demonstrated a highest ethylene photocatalytic degradation efficiency of 88.57 %. The addition of TiO2 significantly enhanced the hydrophilicity of the films, with a maximum increase of 8.08 %. The tensile strength and elongation at break of the films were also improved. The optical properties, barrier properties and mechanical properties revealed that the film may make contributions to slowing down light aging, reducing weight loss of strawberries and increasing the load-bearing property. Furthermore, fresh-keeping experiment proved that the photocatalytic films could markedly slow down the appearance change, reduce weight loss and TBARS accumulation while decelerating the decline of TSS and antioxidant capacity in strawberries.

Comparative investigation of structural, morphological, mechanical, tribological and electrochemical properties of TiO2 films formed on Cp-Ti, Ti6Al4V and Ti45Nb alloys

This study focuses on the comparison of structural, morphological, mechanical, tribological and electrochemical properties of TiO2 films fabricated on Cp-Ti, Ti6Al4V and Ti45Nb alloys, which are widely used in different industries. For this purpose, TiO2 films were grown on Cp-Ti, Ti6Al4V and Ti45Nb materials by anodization method. Structural, morphological and mechanical properties of the samples were determined using XRD, SEM, Micro Raman, contact angle, surface roughness and micro hardness devices. Afterwards, the samples were subjected to wear and corrosion tests using a pin-on-disc wear device and a corrosion device, respectively. Wear tests were carried out in both dry and liquid environments. In electrochemical corrosion tests, Ringer's solution was used and open circuit potential (OCP) and electrochemical polarization analyzes were performed. According to the results of XRD and Raman analyses, it was determined that TiO2 films were successfully grown on the surface of the samples. Additionally, it was observed that these films were in Rutile and Anatase phases and their peak intensities increased with increasing anodization time. While the thickest films were obtained from Ti45Nb samples, the thinnest films were obtained from Cp-Ti samples. As a result of the increase in surface roughness with anodization, surface wettability increased in all samples. It was seen that electrical resistance of the materials was highly effective on the film thickness, surface roughness and surface structures. Wear coefficients decreased in all samples for both dry and liquid wear conditions due to the increased surface hardness and anodic film thickness and the lowest wear coefficients were obtained from the Ti45Nb sample. Corrosion performance of the samples increased with anodization because TiO2 films acted as protective layers on surface of materials.

Atomic Layer Growth of Rutile TiO2 Films with Ultrahigh Dielectric Constants via Crystal Orientation Engineering.

In general, the electronic and optical properties of oxide films can significantly benefit from highly textured crystallinity. However, oxide films grown by atomic layer deposition (ALD), a powerful technique for the synthesis of high-quality, nanoscale thin films, usually exhibit amorphous or randomly oriented polycrystalline phases. Here, we demonstrate the growth of highly textured rutile phase ALD TiO2 films through rational substrate design. Both a- and c-axis preferentially oriented TiO2 films are obtained by varying the lattice parameters of the initial ALD growth surface. Under optimized conditions, we find that it is possible to deposit high-quality, c-axis preferentially aligned TiO2 films with a bulk dielectric constant approaching 185, rivaling the single crystal limit. These films display a remarkably high dielectric constant of 117 despite thin thickness of 5.2 nm. Moreover, the addition of a single doping sequence of Al2O3 successfully suppresses leakage currents to levels compatible with modern dynamic random access memory cells, all the while maintaining the high bulk dielectric constant of 137. These results clearly highlight the prospect of utilizing crystal orientation engineering in ALD thin films for emerging semiconductor devices.

Enhanced acetaminophen photodegradation under UV using anatase–rutile TiO2 phase heterojunction – Z-scheme mechanism and factors affecting efficiency

In this work, the commercial Hombikat UV-100 anatase (AH) was calcined at 1000 °C for 4 h to obtain a rutile phase grown on anatase (AR), proven by X-ray diffraction pattern. The dry powder of AH and AR were physically mixed to form AH + AR samples in different ratios. Although the characterization of AR revealed that it had microstructure bigger than AH, lower surface area, lower water-molecule absorption, higher surface states and lower charge separation, all mixed AH + AR samples, which had physically-induced tuning in phase heterojunction, outperformed the commercial TiO2 P25 in acetaminophen (ATM) photodegradation efficiency. This could be due to effective charge separation and more active sites involved in AH + AR samples as seen in the depicted Z-scheme mechanism based on their band-edge positions obtained from Mott-Schottky analysis, scavenger tests and ATM photodegradation efficiency. In addition, this work also showed that band-edge positions, band-gap energy and heterojunction were correlated in determining the ATM photodegradation efficiency.

High-Performance TiO2/ZrO2/TiO2 Thin Film Capacitor by Plasma-Assisted Atomic Layer Annealing.

Although laminate structures are widely used in electrostatic capacitors, unavoidable heterogeneous interfaces often deteriorate the dielectric properties by impeding film crystallization. In this study, a TiO2/ZrO2/TiO2 (TZT) laminate structure, where upper-TiO2 deposited on the heterogeneous interface was crystallized by plasma-assisted atomic layer annealing (ALA), was investigated. ALA effectively induced the phase transition of the upper-TiO2 from the amorphous or anatase phase to the rutile phase, leading to an increase in the dielectric constant, whereas the ZrO2 blocking interlayer maintained the amorphous phase owing to the extremely localized effect of ALA. Consequently, through the layer-by-layer phase control of ALA, the dielectric constant of the upper-TiO2 was enhanced by 25% by applying ALA, leading to an increase in a capacitance density of 27% of the TZT capacitor, whereas a low leakage current density of ∼10-8 A/cm2 was maintained (at 1 V). In addition, the TZT capacitor on three-dimensional structures (aspect ratio of 5:1) shows a high capacitance density of up to 461 nF/mm2 owing to ALA.

Interface engineering of Ti3C2 MXene assisted anatase/rutile TiO2 with hetero-phase junction for enhancing the photocatalytic activity of tetracycline hydrochloride removal and H2 production

The conventional heterojunction formed by combining two different semiconductors is associated with issues of low compatibility, restricted intimate contact, and limited charge anti-recombination process. To address these issues, a simple strategy was adopted to fabricate a hetero-phase junction flanked with two dissimilar crystal phases of a single semiconducting material. This study employed TiB2 as the initial material to fabricate an anatase/rutile TiO2 hetero-phase junction material (AR-TiO2), followed by its combination with highly conductive monolayer Ti3C2 nanosheets to develop an AR-TiO2/Ti3C2 composite photocatalyst. The photocatalyst displayed a wide range of light absorption and a remarkable capability for separating photogenerated carriers. The closely interconnected hetero-phase junction surface, formed by the rutile and anatase phases of AR-TiO2, combined with the incorporation of highly conductive Ti3C2 nanosheets, synergistically increased the availability of multi-dimensional active sites and increased the efficacy of separating photogenerated electron pairs. The optimized AR-TiO2/Ti3C2 achieved a degradation efficiency of 91.49 % for tetracycline hydrochloride (TCH) within 2 h and produced 1005.81 μmol of hydrogen in 6 h. The impacts of initial pH, co-existing anions, initial TCH concentration, initial temperature, and various pollutant species on the catalytic efficiency were also investigated. pH was shown to have the greatest impact on the photocatalytic performance of AR-TiO2/Ti3C2 for TCH degradation. •O2−, and h+ were identified as the primary reactive species that enabled the photocatalytic performance of AR-TiO2/Ti3C2 through trapping experiments. This study presents a novel method to synthesize hetero-phase junction photocatalysts and suggests that Ti3C2 has potential prospects for use in photocatalysis.

Silver-Doped Titanium Oxide Layers for Improved Photocatalytic Activity and Antibacterial Properties of Titanium Implants.

Titanium has a long history of clinical use, but the naturally forming oxide is not ideal for bacterial resistance. Anodization processes can modify the crystallinity, surface topography, and surface chemistry of titanium oxides. Anatase, rutile, and mixed phase oxides are known to exhibit photocatalytic activity (PCA)-driven bacterial resistance under UVA irradiation. Silver additions are reported to enhance PCA and reduce bacterial attachment. This study investigated the effects of silver-doping additions to three established anodization processes. Silver doping showed no significant influence on oxide crystallinity, surface topography, or surface wettability. Oxides from a sulfuric acid anodization process exhibited significantly enhanced PCA after silver doping, but silver-doped oxides produced from phosphoric-acid-containing electrolytes did not. Staphylococcus aureus attachment was also assessed under dark and UVA-irradiated conditions on each oxide. Each oxide exhibited a photocatalytic antimicrobial effect as indicated by significantly decreased bacterial attachment under UVA irradiation compared to dark conditions. However, only the phosphorus-doped mixed anatase and rutile phase oxide exhibited an additional significant reduction in bacteria attachment under UVA irradiation as a result of silver doping. The antimicrobial success of this oxide was attributed to the combination of the mixed phase oxide and higher silver-doping uptake levels.

Laser-induced growth of metal oxide films on quartz tubes for photocatalytic water treatments

A solid-state pulsed laser technique was developed to in situ grow arbitrary immobilized catalysts (Fe3O4, CeO2, WO3 etc.) on the inner surface of quartz tube with robust adhering strength. In a case study, anatase/rutile hetero-phase TiO2 film was deposited to serve as immobilized photocatalysts for the effective removal of antibiotics from aqueous environment. The X-ray absorption spectroscopy, low temperature electron paramagnetic resonance and the density functional theory simulation directly confirm a defect-assisted type-II band alignment was established to facilitate the charge transfer at the hereto-interphase. In addition, the oxygen vacancy enriched anatase phase with greater binding energy towards the dissolved oxygen facilitated the O2– generation. Meanwhile, the rutile phase enriched with Ti3+ could effectively activate the antibiotics to promote the direct h+ mediated oxidation. Such integration of unique atomic vacancies prevent defects from becoming electron-hole recombination centers and consequently extend the lifetime of the photoexcited charge carrier. The degradation mechanism of oxytetracycline was thoroughly examined by ultra-high resolution electrospray time-of-flight mass spectrometry and Fukui function, while the ecological structure–activity relationships program assessed the toxicity of contaminant to the environment. Milewhile, a continuous water treatment apparatus employing the catalytic tubes as reactors was established and demonstrated a ∼ 95 % OTC degradation under the natural sunlight adopting river water as the background. The experimental studies also claimed that ∼ 90 % of the initial activity could be retained after 100 cycles reuse, which permits their great potential for the applicational scenarios.

Physical properties of rutile-TiO2 Nanoparticles and effect on PVA/SiO2 hybrid films synthesized by sol-gel method

We use an ab-initio approach to analyze the structural, electronic band structure, and thermoelectric properties of titanium dioxide (TiO2 in rutile phase), and we then use rutile-TiO2 nanoparticles to determine its effects on sol-gel-produced polyvinyl alcohol/silicon dioxide (PVA/SiO2) hybrid films. The synthesis of hybrid films involved the incorporation of 1 % rutile-TiO2 nanoparticles in the PVA/SiO2 matrix. The thermoelectric properties of the resulting hybrid films were characterized by Seebeck coefficient measurements, as well as electrical and thermal conductivities. The synthesis of PVA/SiO2/Nano-TiO2 films was accomplished with success. The chemical bonds have amply demonstrated that the PVA backbone is connected to the (SiO2-TiO2) network. TGA testing indicates that hybrid films are more resistant to higher temperatures than pure PVA films. SiO2 nanoparticles reveal more effective loading to improve dielectric characteristics compared to TiO2. The best results are obtained in cases of mechanical, thermal and electrical insulation when both nanofillers are integrated into the polymer matrix. The findings show that the thermoelectric performance of PVA/SiO2 hybrid films is improved by the addition of (1 %) rutile-TiO2 nanoparticles in the rutile phase. This study provides insights into the potential applications of rutile-TiO2 nanoparticles in enhancing the thermoelectric properties of hybrid materials and opens up avenues for further research in this area, and contributes to the growing body of knowledge on enhancing the thermoelectric properties of materials by incorporating rutile-TiO2 nanoparticles into hybrid films synthesized by the sol-gel method.

Electrocatalytic Oxidation of Benzaldehyde on Gold Nanoparticles Supported on Titanium Dioxide.

The electrooxidation of organic compounds offers a promising strategy for producing value-added chemicals through environmentally sustainable processes. A key challenge in this field is the development of electrocatalysts that are both effective and durable. In this study, we grow gold nanoparticles (Au NPs) on the surface of various phases of titanium dioxide (TiO2) as highly effective electrooxidation catalysts. Subsequently, the samples are tested for the oxidation of benzaldehyde (BZH) to benzoic acid (BZA) coupled with a hydrogen evolution reaction (HER). We observe the support containing a combination of rutile and anatase phases to provide the highest activity. The excellent electrooxidation performance of this Au-TiO2 sample is correlated with its mixed-phase composition, large surface area, high oxygen vacancy content, and the presence of Lewis acid active sites on its surface. This catalyst demonstrates an overpotential of 0.467 V at 10 mA cm-2 in a 1 M KOH solution containing 20 mM BZH, and 0.387 V in 100 mM BZH, well below the oxygen evolution reaction (OER) overpotential. The electrooxidation of BZH not only serves as OER alternative in applications such as electrochemical hydrogen evolution, enhancing energy efficiency, but simultaneously allows for the generation of high-value byproducts such as BZA.

In-vitro biocompatibility, antibacterial activity, and corrosion resistance of HA-TiO2/ZnO coating fabricated by plasma electrolytic oxidation on Ti6Al4V

The hydroxyapatite/Zinc Oxide (HA-TiO2/ZnO) coatings were grown on the Ti6Al4V substrate by plasma electrolyte oxidation from the CaP-based electrolyte containing 1, 3, and 6 g/L ZnO nanoparticles. XRD results confirmed the presence of ZnO, HA, and rutile phases in all coatings. According to SEM observations, coatings presented the porous morphology as a result of micro-arc discharges during the PEO process, whereas some of the pores in the composite coatings were filled by ZnO proportional to its content. After 7 days of immersion in SBF solution, accumulations of bone-like clusters were visible on the surface, demonstrating a promising bio-mineralization ability for all coatings, although the higher amount of 6 g/L ZnO had partially an inhibitory effect on the apatite nucleation. In-vitro studies demonstrated a time and concentration-dependent impact of ZnO on the viability of MG-63 osteoblast-like cells so that the concentration of 3 and 6 g/L caused the death of some cells after 7 days. The antibacterial tests also showcased that the presence of ZnO decreased the activity of gram-negative bacteria (E. coli) and gram-positive bacteria (S. aureus), while the higher concentration of ZnO particles led to more antibacterial activity of the coating. Finally, evaluating the corrosion behavior of PEO coatings through a potentiodynamic polarization test in Ringer's solution manifested a better protection against corrosion by increasing the ZnO content in the coating, mainly owing to the blocking of the pores by the ZnO particles, and as a result, the greater difficulty of electrolyte to reach the titanium substrate.

Synthesis of titanium dioxide and the study of photocatalytic activity

Abstract The preparation of titanium dioxide (TiO2) particles is optimized by two different methods based on the sol-gel method. The degradation experiment of methyl orange showed that sample B prepared by the two-step ethanol method had better catalytic performance than sample A prepared by the one-step ethanol method. In addition, X-ray diffraction (XRD) testing revealed there was a rutile phase in sample B in addition to the anatase phase, and the catalytic degradation experiment proved that the existence of a rutile phase was conducive to improving the photocatalytic efficiency of TiO2.

Doping of photoactive TiO2 films by DC plasma electrolytic oxidation: Effect of transition metals

Several beneficial features maintain TiO2 in the top list of viable materials for photocatalytic purposes. However, its relatively large band-gap (3.0–3.2 eV) still hampers practical applications under sunlight. This work explores Direct Current (DC) Plasma Electrolytic Oxidation (PEO) of titanium as a fast, easily-scalable and single-step tool to synthesise doped TiO2 photoanodes with controlled morphology, crystalline structure and thickness. Zn-, Cu- and Fe-doped crystalline TiO2 films were obtained in H2SO4 aqueous solutions containing ZnSO4, CuSO4 and FeSO4 precursors, respectively. As-prepared TiO2 films showed a porous and homogeneous sponge-like surface morphology, typical of PEO-produced oxides, and a crystalline phase structure consisting of a mixture of anatase and rutile phases. The anatase content varied in the 54–100 % range and correspondingly the band-gap energy was in the 2.85–3.07 eV range. Doped oxides prepared with a low concentration of the metal precursors showed monochromatic incident-photon-to-current-efficiency (IPCE) values exceeding those obtained with pristine TiO2 by up to 24 %, best performing in the order Zn- > Cu- > Fe-doped TiO2. Photocurrent under polychromatic UV-Vis irradiation showed an analogous trend and the estimated efficiency of solar-light harvesting was in the 0.3–4 % range, with Zn- ≈ Cu- > Fe-doped TiO2. Although the superior performance of the PEO-prepared metal-doped TiO2 could not be fully confirmed by photoelectrocatalytic oxidation tests of organics, the present investigation showed the viability of DC PEO for the synthesis of metal-doped TiO2 photoanodes.

Low density phases of TiO2 by cluster self-assembly

The interest in titanium dioxide (TiO2\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$_2$$\\end{document}) phases is growing due to the number of applications in cosmetics, food industry and photocatalysis, an increase that is driven by its exceptional properties when engineered at the nanoscale like in the form of nanoparticles. Our goal is to discover unknown low-density phases of TiO2\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$_2$$\\end{document}, with potential for applications in various fields. We then use well-known TiO2\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$_2$$\\end{document} clusters as fundamental building blocks to be self-assembled into unique structures to study their distinct characteristics. Density functional calculations are employed to relax the structures and identify the most stable TiO2\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$_2$$\\end{document} structures within an energy range of 0.1 eV per atom from the rutile and anatase phases, which are confirmed, validating our methodology. Going beyond conventional phases, we found two-dimensional TiO2\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$_2$$\\end{document} structures, previously explored in separate studies, and showing typical structures of transition metal dichalcogenide layers, that forge a bridge between different TiO2\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$_2$$\\end{document} structures. It is noteworthy that our investigation uncovered an entirely novel class of TiO2\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$_2$$\\end{document} structures featuring hexagonal cages like beehive channels, opening novel phases with huge potential. These discovered low-density phases are interesting, particularly the hexagonal cage structures with remarkable large gaps, because they introduce other dimensions for uncharted applications in the ever-growing TiO2\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$_2$$\\end{document} landscape.

Facile Preparation Method of TiO2/Activated Carbon for Photocatalytic Degradation of Methylene Blue.

The development of nanocomposite photocatalysts with high photocatalytic activity, cost-effectiveness, a simple preparation process, and scalability for practical applications is of great interest. In this study, nanocomposites of TiO2 Degussa P25 nanoparticles/activated carbon (TiO2/AC) were prepared at various mass ratios of (4:1), (3:2), (2:3), and (1:4) by a facile process involving manual mechanical pounding, ultrasonic-assisted mixing in an ethanol solution, paper filtration, and mild thermal annealing. The characterization methods included XRD, SEM-EDS, Raman, FTIR, XPS, and UV-Vis spectroscopies. The effects of TiO2/AC mass ratios on the structural, morphological, and photocatalytic properties were systematically studied in comparison with bare TiO2 and bare AC. TiO2 nanoparticles exhibited dominant anatase and minor rutile phases and a crystallite size of approximately 21 nm, while AC had XRD peaks of graphite and carbon and a crystallite size of 49 nm. The composites exhibited tight decoration of TiO2 nanoparticles on micron-/submicron AC particles, and uniform TiO2/AC composites were obtained, as evidenced by the uniform distribution of Ti, O, and C in an EDS mapping. Moreover, Raman spectra show the typical vibration modes of anatase TiO2 (e.g., E1g(1), B1g(1), Eg(3)) and carbon materials with D and G bands. The TiO2/AC with (4:1), (3:2), and (2:3) possessed higher reaction rate constants (k) in photocatalytic degradation of methylene blue (MB) than that of either TiO2 or AC. Among the investigated materials, TiO2/AC = 4:1 achieved the highest photocatalytic activity with a high k of 55.2 × 10-3 min-1 and an MB removal efficiency of 96.6% after 30 min of treatment under UV-Vis irradiation (120 mW/cm2). The enhanced photocatalytic activity for TiO2/AC is due to the synergistic effect of the high adsorption capability of AC and the high photocatalytic activity of TiO2. Furthermore, TiO2/AC promotes the separation of photoexcited electron/hole (e-/h+) pairs to reduce their recombination rate and thus enhance photocatalytic activity. The optimal TiO2/AC composite with a mass ratio of 4/1 is suggested for treating industrial or household wastewater with organic pollutants.

Boosting the visible-light-driven photocatalytic efficiency in porous Cu/TiO2 ceramic coatings

In this study, we examined how current density, sodium phosphate concentration, and the addition of copper sulfate to the supporting electrolyte affect PEO coatings on pure titanium. The chemical composition, morphology, and optical behavior of PEO coatings were extensively analyzed using scanning electron microscopy (SEM), X-ray diffraction (XRD), and UV–Vis diffuse reflectance spectroscopy (DRS). With an increase in current density from 6 to 18 A/dm2, the coating's pore size enlarges and the rutile phase content within the coatings increases. The coating created at 12 A/dm2 shows the highest photocatalytic activity and triggers a unique three-stage behavior in the voltage-time diagram. Adding 4 g/l of CuSO4 to the electrolyte resulted in the formation of an unwanted Cu-based precipitates, causing electrolyte instability. To stabilize it, potassium hydroxide was removed, and the base electrolyte concentration was adjusted. To address this issue, potassium hydroxide was eliminated from the supporting electrolyte. Subsequently, the concentration of the base electrolyte was optimized. Also, the synergistic influence of CuSO4 addition (4 g/l) to the supporting electrolyte at different concentrations of 5, 10, and, 15 g/l of trisodium phosphate on PA was investigated. The superior photocatalytic performance of the optimum coating created in the electrolyte containing 5 g/l trisodium phosphate and 4 g/l CuSO4 is attributed to its enhanced porous structure, along with the heterojunction between the anatase and rutile phases. These features significantly boost the available surface area and facilitate the efficient separation and transfer of photogenerated charge carriers. Ultimately, a mechanism for MB photodegradation was proposed based on the findings from Mott-Schottky analysis and DRS.

Photoelectrochemical properties of doped TiO2 nanowires grown by seed-assisted thermal oxidation

Titanium dioxide Nanowires (NWs) are particularly interesting because of their very high surface/volume ratio and their photocatalytic activity allows them to be used in a myriad of applications. This manuscript presents a study of nanowires grown on a conductive substrate making use of a seed-assisted thermal oxidation process. To obtain doped NWs, before the oxidation, metallic titanium was doped with Fe (or Cr) by ion implantation technology. Analyses showed good quality Rutile phase and light absorption in the visible range. Transport properties of the NWs/electrolyte junction were investigated by using linear sweep voltammetry and electrochemical impedance spectroscopy. They allowed us to measure the photovoltage and the barrier height of the junction. We also evaluated the density of hole trap states at the interface during illumination. Electrical results indicate that the formation of deep levels, induced by doping, influences the electron concentration in the TiO2 and the transport properties.Graphical abstract

Influence of growth temperature on structural, optical, morphological and photoelectrochemical characteristics of vertically aligned hydrothermally synthesized TiO2 nanorods

Herein, vertically oriented TiO2 nanorods were prepared on FTO substrate using hydrothermal synthesis. The influence of growth temperature on structural, optical, morphological and photoelectrochemical characteristics were analyzed. The FESEM and AFM results validated the formation of TiO2 nanorods. XRD spectra revealed the formation TiO2 tetragonal crystal structure with the rutile phase. UV–vis data showed an increase in the visible light absorption and a narrowing of the energy band gap with increasing in reaction temperature. Based on PEC studies, all the samples showed good light response and pronounced photocurrent density under light conditions. The highest possible photocurrent density of 78.8 μA/cm2 at 1.2V vs Ag/AgCl was recorded from TiO2 film with hydrothermal growth temperature of 200°C for 3 h s. This performance is attributed to narrow bandgap (2.89eV) and longer lifetime of carriers (0.3s). This result was validated by data from EIS, whereby the fast separation and transfer of photogenerated charge carriers were demonstrated.

Formation of Diamond Films with Different Grain Sizes on TiO2 Nanotubes and Its Field Emission Properties

Diamond films with different grain sizes are deposited on TiO2 nanotube (TNT) arrays prepared by anodic oxidation using a microwave plasma chemical vapor deposition reactor. The scanning electron microscope, X‐Ray diffractometer, and Raman results indicate that the diamond film is successfully deposited and that the substrate undergoes a phase transition due to the diamond deposition temperature, resulting in the rutile phase becoming dominant with lower energy bandgap and work function. Notably, after 5 h of deposition, a relatively continuous microcrystalline film is formed on the TNTs, and the diamond grains change from spherical to pyramidal and show excellent electron field emission behavior, with a low turn‐on field of 0.5 V μm−1 and a current density of 85.9 μA cm−2. In addition, the deposition environment of the nanocrystalline diamond has a large impact on the substrate morphology, resulting in a blocked electron transport path, which reduces the overall field emission performance. The enhanced performance is attributed to the synergistic effect between the highly efficient 1D electron path of the TNTs, the negative electron affinity of the diamond surface, and the lower work function of rutile TiO2.

Exploring the Impact of Potential, Ammonium Fluoride Concentration, and Anodization Time on the Structure, Surface Characteristics, and Corrosion Resistance of Nanotubular Titanium Oxide Coatings on Biomedical Alloy Ti-6Al-4V ELI

The current research delves into assessing the impact of applied potential, ammonium fluoride concentration, and anodization duration on the structural, phase compositional, microhardness, and surface roughness attributes of nanotubular titanium oxide coatings on anodized Ti-6Al-4V ELI. A meticulous experimental design was executed to systematically investigate the varied effects of these factors. Scanning electron microscopy (SEM) unveiled the presence of well-defined titania nanotubes on the surfaces of the anodized specimens. X-ray diffraction (XRD) analysis discerned the composition of the nanotubular oxide layer, revealing the presence of both anatase and a mixture of anatase and rutile phases contingent upon the anodization parameters. Notably, surface microhardness, surface roughness, and corrosion resistance manifested noticeable variations in response to alterations in applied voltage, NH4F concentration, and anodization duration within the designated experimental ranges.