掺铅TiO2薄膜的光催化活性及电化学性能

采用溶胶凝胶烧结工艺在玻璃表面制备铅离子多层掺杂的光催化复合TiO2薄膜，用XRD技术表征了该薄膜的晶型，并用电化学方法测定了该薄膜电极的伏安特性及交流阻抗性能．以光催化降解甲基橙溶液为模型反应，采用两种不同方式制备的铅离子多层掺杂TiO2薄膜具有很好的光催化活性，最佳掺杂浓度均为0．5％(Pb／Ti原子百分比)，PbD0.5掺铅薄膜的最佳光催化降解甲基橙表观速率常数约是纯TiO2的2．52倍．铅离子掺杂TiO2薄膜表现出近表面处捕获光生电子或空穴，随后被捕获的电子或空穴迁移到TiO2薄膜表向参与光催化反应。

THE PHOTO-CATALYTIC ACTIVITY AND ELECTRO-CHEMICAL PROPERTY OF LEAD ION DOPED TiO2 FILM

The non-uniform lead ion doped TiO 2 composite thin films deposited on glass substrates have prepared by sol-gel technology.The crystal properties of the films were investigated by means of XRD techniques.The photo electro chemistry of TiO 2 film was measured by electro chemical method.The films photo-catalytic activity was investigated by using the model reaction,the photo-catalytic degradation of methyl orange.The results showed that the lead ion doped TiO 2 composite thin films prepared by two different methods had good photo catalytic activity.The optimum doping concentrations are all 0.5% (Pb/Ti atom%).The maximum apparent degradation rate constant,k,of PbD 0.5 films is 2.52 times of that in pure TiO 2 thin films.Primary,the optimum doping effect is that the electron hold were trapped by the dopant ion near the catalyst surface,then moved to the surface to take the photo catalytic reaction.