The effect of the H2 flow rate on the structure and optical properties of TiO2 films deposited by inductively coupled plasma assisted chemical vapor deposition

The optical and photocatalytic properties of TiO2 are closely related to crystalline structures, such as rutile and anatase. In this paper, TiO2 films were produced by inductively coupled plasma (ICP) assisted chemical vapor deposition (CVD) without extra heating of the substrate, and the effect of H2 addition on the structure and optical properties of the films was investigated. After increasing the partial pressure of H2, the structure of the TiO2 films changed from anatase to rutile, which usually appears at high temperatures (>600 °C). The light transmittance decreased with increasing the H2 flow rate due to the increased surface roughness. The photocatalytic activity of the anatase TiO2 film was better than that of the rutile TiO2 film.