Synthesis and UV-Visible-Light Photoactivity of Noble-Metal-SrTiO3 Composites

The photocatalytic activity of strontium titanate (SrTiO3) perovskite films has been examined and compared with that of commercially available titania (TiO2, Degussa P25) in the degradation of a model pollutant, Victoria Blue dye. The effects of pH, synthesis temperature, and Sr/Ti ratio in the synthesis of the perovskite were examined. SrTiO3 was prepared using Ag, Pt, or Au and characterized using optical and surface analysis methods. We found no clear evidence of substitution of the noble metal into the SrTiO3 lattice, and most metal existed as zerovalent metal deposits. Addition of Ag to SrTiO3 showed the most promising catalytic activity toward dye degradation. Degradation of the dye under UV-visible light was also observed to be enhanced only for Ag-SrTiO3.