Crystal structure and photocatalytic activities of TiO₂-SiO₂ composite oxide

The TiO₂ and TiO₂-SiO₂ composite oxide were prepared by Sol-gel method and characterized by XRD, BET and DRS. The photocatalytic activity was investigated by the photocatalytic degradation of methyl orange. The results show that adding silicon could inhibite the crystal transformation from anatase to rutile, restrain the increase of grain size and refine grains. It could also broad band gap, which could improve the ability of reduction-oxidation. It is found that the samples calcined at 900°C and doped with 20 mol% Si possess the highest photocatalytic activity among of all the prepared samples.