抄録
A porous, nanocrystalline TiO2 photocatalytic thin film was prepared by r. f. magnetron reactive sputtering technique, with the optimum sputtering parameters searched. Furthermore, the surface modification of the thin films was carried out to improve the photocatalytic activity by Au particle embedding methods. It was found that the photocatalytic activity of the TiO2 thin films in a pure anatase was improved with the increasing concentration of the Au particles. However there exists a critical concentration of the embedded Au particles that the photocatalytic activity decreases above the critical concentration. The electron (hole) trapping states are formed in the Schottky barrier at the Au/TiO2 interface. This suppresses the recombination of the photogenerated e--h+ pairs when the metal-doped concentration is below the critical value. The photocatalytic activity decreases with the formation of the e--h+ pair recombination centers by excess metal doping concentration.
