Photocatalytic Properties of TiO2 Thin Films Prepared by RF Sputtering

Abstract

Titanium dioxide films were prepared by RF sputtering method on glass for various oxygen partial pressures at power 270 W. The crystal structure, photocatalytic property and the hydrophilicity of <TEX>$TiO_2$</TEX>thin film the deposition conditions were investigated. Crystallized anatase phase was observed in <TEX>$TiO_2$</TEX>film deposited at the ratio of oxygen partial pressure 10% and 20% for 2 hrs. As the increase of deposition time, the grain size and void size of <TEX>$TiO_2$</TEX>film have increased and also <TEX>$V_2$</TEX>films have been good crystallinity. The ultraviolet-visible light absorption of <TEX>$TiO_2$</TEX>films was increased with increasing of deposition time and occured chiefly at the wavelength between 280 and 340 nm. The absorption band was shifted to a longer wave length as deposition time increased. Water contact angle on the X<TEX>$TiO_2$</TEX>film of anatase structure was decreased with increasing ultraviolet illumination time and became lower than <TEX>$11^{\circ}$</TEX> from <TEX>$83^{\circ}$</TEX>. When hydrophilic <TEX>$TiO_2$</TEX>film changed by enough ultraviolet illumination was stored in the dark, the film surface gradually turned to hydrophobic state.