Effects of Pt-loading on Formation and Visible Light-Induced Photocatalytic Activity of Bismuth Titanate

Abstract

Pt/TiO₂-Bi₂O₃ test catalysts were prepared by impregnating Pt on the sol-gel derived TiO₂-Bi₂O₃ to give these testpieces high photocatalytic activity under visible light irradiation. The optimum Pt support content and TiO₂ content were observed in the ranges 0.05-0.3 wt% and 17-28 wt%, respectively in the photocatalytic activity for Methylene Blue (MB) degradation on Pt/TiO₂-Bi₂O₃. Specifically, those 0.1Pt/17TiO₂-83Bi₂O₃, 0.2Pt/23TiO₂-77Bi₂O₃ and 0.3Pt/28TiO₂-72Bi₂O₃ samples showed relatively higher photocatalytic activity for the MB degradation. The results were closely related to (1) the restriction of recombination of the photo-induced electron and hole pairs by Pt, and (2) the presence of bismuth titanate with such high Ti content as built up by Pt.