Vanadium-Doped WO ₃ /TiO ₂ Microporous Film as Visible-Light Photocatalyst

Abstract

Vanadium (V)-doped WO3/TiO2 microporous film on a titanium (Ti) plate was prepared by using the micro-arc oxidation process. Incorporating V and tungsten (W) species into the TiO2 lattice in one step yields band gap narrowing and strong visible-light (Vis) photoactivity, dominated mostly by incorporation of WO3 and V2O5 oxides, and possibly WxTi1−xO2. Photoactivity under ultraviolet light (UV) irradiation was likely attributable to its WO3-loaded microporous structure, which favored cationic molecule adsorption on its active sites. Although post annealing enhanced film crystallinity, photocatalytic ability was decreased largely because of changes in doping levels. This suggests that the as-oxidized microporous film is feasible for photocatalytic cationic dye degradation under UV and Vis irradiation.