Preparation and properties of TiO/sub 2/-SiO/sub 2/ thin films by sol-gel process

We prepared TiO/sub 2/-SiO/sub 2/ thin films by sol-gel process and examined their optical, structural and photocatalytic properties as a function of film composition. The XRD results show that pure TiO/sub 2/ thin films are amorphous at 400/spl deg/C, transform into anatase at 500/spl deg/C, and further transform into rutile at 1000/spl deg/C. The grain size of TiO/sub 2/ thin films increases with increasing calcination temperature. Refractive indices of the pure TiO/sub 2/ and SiO/sub 2/ thin films are 2.10 and 1.40, respectively at 550 nm, and they decrease with increasing SiO/sub 2/ content in composite TiO/sub 2/-SiO/sub 2/ films. Photocatalytic activity of TiO/sub 2/-SiO/sub 2/ composite thin films decreases with increasing SiO/sub 2/ content.