Fabrication and Photocatalytic Activities of TiO_2 Nano-films deposited at Different Ar/O_2 Flow Ratios by DC Magnetron Sputtering

摘要

Polycrystalline TiO_2 nano-films were prepared by DC magnetron sputtering at different Ar/O_2 flow ratios. The thicknesses of all the prepared films were about 200 nm. The prepared films consist of a mixture of anatase and rutile phase. The TiO_2 nano-films deposited at Ar/O_2 flow ratio (1:1) have the best crystallinity and the mixture phase of anatase and rutile. SEM images show that the film surface composed of polygonal particles about 100 nm in diameter. UV-Vis transmission measurements reveal that the band gap of the deposited TiO_2 nano-films changed from 3.01 to 3.12 eV. The photocatalytic activities of the TiO_2 films were investigated by the decomposition of IPA under UV irradiation. The IPA can be oxidized to acetone and further to CO_2. The maximal acetone concentration and CO_2 concentration can reach to 29.2 ppm and 4 ppm after 120 min.