铂非均匀掺杂二氧化钛薄膜的光催化性能

Photocatalytic Activity of TiO_2 Thin Film Doped by Pt with Different Distribution

采用溶胶-凝胶法制备了铂非均匀掺杂的二氧化钛薄膜,并用UV-vis分光光度计及电化学工作站表征了薄膜的光吸收性能和光电化学行为,通过对甲基橙的光催化降解动力学来表征催化剂的光催化活性.结果表明Pt非均匀掺杂可以明显增强二氧化钛的光催化活性,而均匀掺杂的效果较差;Pt非均匀掺杂的最佳量为0.3mol%.催化剂薄膜的电化学行为显示:Pt非均匀掺杂二氧化钛薄膜的开路电压高,交流阻抗小.并从半导体的PN结原理探讨了Pt非均匀掺杂二氧化钛的催化活性机理.

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.