Photocatalytic Properties of TiO_2/ WO_3/ FTO Multi-layer Structures Prepared by Spray Pyrolysis Deposition

摘要

Visible-light photocatalytic property of TiO_2 / WO_3 / FTO multi-layer structure was investigated. In this structure, the visible-light absorption takes place in the WO_3 layer, and generated electrons and holes diffuse into the FTO and TiO_2 layers, respectively. The holes diffused into the valence band of the TiO_2 layer produce the hydroxyl radicals due to oxidation of H_2O and/or OH~- adsorbed on the TiO_2 surface. The FTO bottom layer, which acts as a scavenger of electrons, contributes to an effective charge separation. As a result, the visible-light photocatalysis is enhanced in this structure.