The thin films of TiO₂ doped by Pt with different distribution were prepared by sol-gel method. The photocatalyst film was characterized by UV-vis spectrophotometer and electrochemical workstation. The activity of photocatalyst was evaluated by photocatalytic degradation of aqueous methyl orange under UV radiation. The results show that the photocatalytic activity of TiO₂ thin film could be evidently enhanced by Pt doping with non-uniform distribution. And the optimal dopant amount was 0.3 mol%. The higher open circuit potential, the less electrochemical impedance, and the better activity of the TiO₂ doped non-uniformly by Pt, which demonstrated that the charge of hole and electron has been effectively separated. The photocatalytic activity mechanism of TiO₂ non-uniformly doped by Pt was discussed by semiconductor PN junction theory.

Key words: photocatalysis, TiO₂, Pt, doped, non-uniformity