不同掺铁方式对TiO_2薄膜光催化活性的影响

Effects of iron impurities on photo-catalytic activity of TiO_2 thin films

采用溶胶凝胶工艺在普通玻璃表面制备出表面掺铁与体相掺铁的TiO2 薄膜。运用SEM ,XRD和AES等技术研究了复合薄膜的表面特征。以光催化降解甲基橙溶液为模型反应 ,表征薄膜的光催化活性。结果表明 :体相掺铁时 ,薄膜的最佳n(Fe) /n(Ti)为 0 .12 %;表面掺铁时 ,薄膜的最佳n(Fe) /n(Ti)为 1.5 %。表面掺铁薄膜的最佳光催化表观速率常数比体相掺铁的最佳值要高 1.5倍。并从载流子分离效率等方面进行了机理探讨。

Surface iron-doped and bulk iron-doped TiO 2 composite thin films deposited on glass substrates were prepared by sol-gel technology. The properties of the films were investigated by means of SEM, XRD and AES. The photo-catalytic activity of films was investigated by using the model reaction of the photo-catalytic degradation of methyl orange. The results show that the optimal n(Fe)/n(Ti) of bulk iron-doped TiO 2 thin films is 0.12%, while that of surface iron-doped TiO 2 thin films is 1.5%. Moreover, the maximum first-order kinetic rate constant, k, of surface iron-doped TiO 2 thin films is more 1.5 times than that of bulk iron-doped TiO 2 thin films. The doping mechanisms were discussed based on the charge carriers separated efficiency theory.