Photocatalysis and characterization of the gel-derived TiO_2 and P-TiO_2 transparent thin films

摘要

The gel-derived TiO_2 and P-TiO_2 transparent films coated on fused-SiO_2 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-0 framework, the growth of anatase crystallites was hindered and the crystal structure of anatase-TiO_2 could withstand temperature up to 900 ℃. The photocatalytic activities of the prepared films were characterized using the characteristic time constant (t) for the photocatalytic reaction. The titania film with a smaller t value possesses a higher photocatalytic ability. After exposing to 365-nm UV light for 12 h, the P-TiO_2 films calcined between 600 ℃ and 900 ℃ can photocatalytically decomposed > 84 mol% of the methylene blue in water with corresponding t < 7.1 h, which were better than the pure TiO_2 films prepared at the same calcination temperature.