Ion engineering techniques for the preparation of the highly effective TiO2 photocatalysts operating under visible light irradiation

Evaluation of Solar-Driven Photocatalytic Activity of Thermal Treated TiO₂ under Various Atmospheres

In this report, the photocatalytic activity of P25 has been explored and the influence of thermal treatment under various atmospheres (air, vacuum and hydrogen) were discussed. The samples’ characteristics were disclosed by means of various instruments including X-ray diffraction (XRD), Electron paramagnetic resonance (EPR), X-ray photoelectron spectroscopy (XPS) and UV–vis. This study also accentuates various states of the oxygen vacancy density formed inside the samples as well as the colour turning observed in treated P25 under various atmospheres. Produced coloured TiO₂ samples were then exploited for their photocatalytic capability concerning photodegradation of methylene blue (MB) using air mass (AM) 1.5 G solar light irradiation. Our findings revealed that exceptional photocatalytic activity of P25 is related to the thermal treatment. Neither oxygen vacancy formation nor photocatalytic activity enhancement was observed in the air-treated sample. H₂-treated samples have shown better photoactivity which even could be further improved by optimizing treatment conditions to achieve the advantages of the positive role of oxygen vacancy (O-vacancy at higher concentration than optimum acts as electron trapping sites). The chemical structure and stability of the samples were also studied. There was no sign of deteriorating of O₂-vacancies inside the samples after 6 months. High stability of thermal treated samples in terms of both long and short-term time intervals is another significant feature of the produced photocatalyst.

Facile preparation of C-modified TiO2 supported on MCF for high visible-light-driven photocatalysis

This study developed a facile approach for preparing C-modified TiO₂/MCF with high visible light photocatalytic activity by a hydrothermal and thermal treatment method.

Preparation and characterization of SiO2/BiOX (X = Cl, Br, I) films with high visible-light activity

SiO₂/BiOX (X = Cl, Br, I) thin films with layered structures were prepared using a convenient sol–gel method. The films show a high and stable photocatalytic activity under visible-light irradiation.

Fabrication and properties of TiO2 nanofilms on different substrates by a novel and universal method of Ti-ion implantation and subsequent annealing

We report a new, novel and universal method to fabricate high-quality titanium dioxide (TiO2) nanofilms on different substrates by a solid phase growth process of ion implantation and subsequent annealing in oxygen atmosphere. Ti ions were implanted into fused silica, soda lime glass, Z-cut quartz, or (0001) α-sapphire by a metal vapor vacuum arc (MEVVA) ion source implanter to fluences of 0.75, 1.5 and 3 × 10(17) ions cm(-2) with a nominal accelerating voltage of 20 kV. To understand the influence of the annealing temperature, time, and substrate on the formation and phase transformation of the TiO2 nanofilms, the Ti-ion-implanted substrates were annealed in oxygen atmosphere from 500 to 1000 °C for 1-6 h. The formation of TiO2 nanofilms resulted from the slow out-diffusion of implanted Ti ions from the substrates which were then oxidized at the surfaces. The thickness and phase of the nanofilms can be tailored by controlling the implantation and annealing parameters. Since the TiO2 nanofilms are formed under high temperature and low growth rate, they show good crystallinity and antibacterial properties, with good film adhesion and stability, suggesting that the TiO2 nanofilms formed by this method have great potential in applications such as antibacterial and self-cleaning transparent glass.