XPS技术分析离子扩散对TiO2薄膜光催化活性的影响

采用溶胶-凝胶浸渍提拉法在不同玻璃基板上制备TiO2薄膜，通过降解浸渍在薄膜表面的甲基蓝来评价其光催化活性．利用X射线光电子能谱分析TiO2薄膜表面元素，采用平行电极法测定TiO2薄膜的光电流，研究薄膜表面离子扩散情况。结果表明，在相同条件下，光催化活性以石英玻璃为基板的TiO2薄膜较高，而以普通玻璃为基板的TiO2薄膜较低．这是由于在煅烧过程中以普通玻璃为基板的TiO2薄膜，其Na^＋扩散到表面成为电子和空穴的复合中心，降低量子效率所致．

The Effects of Diffusion of Ions on Photocatalytic Activity of TiO2 Films via XPS Analytical Method

TiO2 thin films were prepared by sol-gel method on various kinds of glass substrates. The photocatalytic activity of different TiO2 thin films was evaluated by photocatalytic degradation of methyl blue. The TiO2 thin films were characterized by photoeurrent measurement and XPS technology. The photocurrent of TiO2 thin films was identified to investigate the diffused ions from the substrates by parallel electrode method. The results in identical conditions showed that TiO2 thin films had higher activity on quartz glass substrates and lower activity on common glass substrates. It was attributed that the phase is pure anatase, and has little diffused ions from the quartz glass substrates and good stability, diffused Na^＋ from the common glass substrates became electron-hole recombination center.