Study On The Photocatalytic Properties Of TiO_2-xS_x Films Induced By Visible Light

Exploiting and researching visible-light-induced photocatalyzer TiO₂ is the key point of the industrialization of photocatalysis. Meanwhile, it's one of the challenging subjects in reducing the indoor-energy consumption. In this paper, review was first made on machenism, and then TiO₂ films was conceived to be modified by means of doping, in order to acquire solar-controlled and easy-cleaning films.In order to improve the photocatalytic activity and make full use of the solar rays, as well as considering its industrialization, the nano TiO₂ films and S doped TiO_2-xS_x films were synthesized by APCVD method using TTIP as a precursor on two kinds of substrates. The deposition process imitated the float glass line.This paper systematically analyzed the relations between the technical parameters such as substrate temperature, substrate moving rate and substrate coatings and the crystallization and surface morphology, optical properties, photocalysis and hydrophilicity of TiO₂ films. Cross experiments method was applied for synthetically analyzing the great effect of the factors. Considering the the integrative properties of the films, a suit of optimized technical parameters was acquired by range analysis. Underlay films was used to prevent alkali metal ions from separating out. When the substrate which has a basic coating moved in 6m/min at the temperature of 600℃, the films behaved well in photo-induced decomposition with best density and crystallization, as well as the solar controlled effect in some extent.This paper contrasted the photocatalytic activity and optical properties of TiO₂ films with those of TiO_2-xS_x films. In the visible waveband, the transmittance of TiO_2-xS_x films was as good as TiO₂ films. The slope of linear part of transmittance curve increased with increasing S doping. In other words, the optical absorption-edge obviously shifted to the longer wavelength in some extent. While the reflectivity of TiO_2-xS_x films behaved worse than undoped samples. The refractive index of all the doped samples was lower than the undoped. Only the 10% doped sample got a peak in the visible waveband which represents a high absorbtion to visible light. TiO_2-xS_x films prepared by APCVD played well in easy-cleaning at a certain extent. For a lack of raw material in Si films manufacture, TiO_2-xS_x films is expected to be the substitute with easy-cleaning, solar-controlling and commercial prospect.