Visible-Light-Sensitive TiO₂ Photocatalysts Initiated by Interfacial Charge Transfer

Abstract

We have designed and fabricated TiO₂ photocatalysts sensitive to visible light, after the suggestions made in the literature as to the photo-induced interfacial charge transfer between a semiconductor and an adsorbed molecular species. Among them, Cu (II)/TiO₂ decomposed 2-propanol to CO₂ via acetone under visible light (>400 nm) with a high quantum efficiency of 8.8%. We speculate that the high performance of the photocatalyst is derived from the photo-produced holes that are generated in the valence band of TiO₂ and contribute to the oxidative decomposition of 2-propanol, and the catalytic reduction of oxygen (presumably multi-electron reduction) by photo-produced Cu (I) species on TiO₂.