Preparation of a TiO2 based multiple layer thin film photocatalyst

A TiO 2 thin film semiconductor is expected to show high photocatalytic activity because of the short diffusion distances of photoexcited electrons and holes to the surface as well as the short spatial separation of reducing and oxidizing sites. The multiple layer photocatalyst, reported herein, which consists of a TiO 2 thin film, platinum electrode and porous alumina substrate, was prepared by spin-coating a TiO 2 sol and sputter-coating of a platinum electrode on a porous substrate. After adequate heat treatment, this multi-layered photocatalyst showed a high efficiency for H 2 generation from ethanol aqueous solution under UV illumination as compared with platinized TiO 2 fine particles.