Photocatalysis and characterization of the gel-derived TiO2 and P–TiO2 transparent thin films

Abstract: The gel-derived TiO2 and P–TiO2 transparent films coated on fused-SiO2 substrates were prepared using a spin-coating technique. Effects of phosphorus dopants and calcination temperature on crystal structure, crystallite size, microstructure, light transmittance and photocatalytic activity of the films were investigated. By introducing P atoms to Ti–O framework, the growth of anatase crystallites was hindered and the crystal structure of anatase-TiO2 could withstand temperature up to 900°C. The photocatalytic activities of the prepared films were characterized using the characteristic time constant (τ) for the photocatalytic reaction. The titania film with a smaller τ value possesses a higher photocatalytic ability. After exposing to 365-nm UV light for 12h, the P–TiO2 films calcined between 600°C and 900°C can photocatalytically decomposed ≥84mol% of the methylene blue in water with corresponding τ≤7.1h, which were better than the pure TiO2 films prepared at the same calcination temperature. [Copyright &y& Elsevier]