Improvement of Photo-functional Properties of TiO2 Thin Film Coated by W Surface Layer

Abstract

TiO2 thin films with a W layer to improve photo-functional properties were prepared by a reactive magnetron sputtering method. The W thin layers with 0.4-2.5 nm in thickness were coated onto the TiO2 thin film by the same magnetron sputtering. The surface chemical state of the W coated TiO2 thin films measured by X-ray photoelectron spectroscopy showed W metal or/and W oxide on the TiO2 thin film. A spectrophotometer was used to investigate UV-Vis absorption of the W coated TiO2 thin films which absorb energy of longer wavelength than the TiO2 thin film without the W surface layer. Visible-ray photocatalysis of the W coated TiO2 thin films was improved by 4 points in the sample with W layer thickness of 1.7 nm and photoconductivity was improved by four times under artificial sun light. It was proved that these improvements of phot-functional properties was achieved by different cause.