Photocatalytic Properties of Ag Surface Doped Nanocrystalline TiO₂-SiO₂ Composite Films

Ag surface doped TiO2-SiO2 composite films had been synthesized by the sol-gel method and doping processes, in which tetrabutyl titanate (Ti(OC4H9)4) and tetraethylorthosilicate (TEOS) were chosen as the precursors and silver nitrate (AgNO3) was chosen as silver source. The experimental results revealed that the Ag surface doped TiO2-SiO2 composite film was composed of uniform round-like nano-particles or aggregates with the size range of 4–10 nm. Compared with pure TiO2 film, Ag surface doped TiO2-SiO2 composite film exhibited excellent photocatalytic activity. It is believed that the microstructure of the composite film is responsible for improving the photocatalytic activity.