Photoinduced hydrophilicity of TiO2 film as the effect of H2O2 addition

Abstract

TiO2 thin film photocatalysts coated onto glass plates were prepared by thermal decomposition of tetraisopropyl orthotitanate with a dip-coating process. In this Letter, the mechanism for photoinduced hydrophilicity of TiO2 film is clarified by adding the extra H2O2 on TiO2 surface. Results show that the photoinduced hydrophilicity of TiO2 film is inhibited with the presence of H2O2. The amount of Ti-OH bonds on the surface oppositely increased by the addition of H2O2. It indicates the photoinduced hydrophilicity of TiO2 results from surface oxygen vacancy, not Ti-OH bonds.