Ag担载对TiO2光催化活性的影响

 采用光化学沉积法合成了Ag/TiO2光催化剂,以苯酚降解反应考察了光催化剂活性随Ag担载量的变化,用TEM观察了Ag在TiO2表面的分布与形貌,以漫反射紫外-可见光谱(DRS)分析了不同Ag担载量的光催化剂的光谱特征. 结果表明,适宜担载量的Ag可显著提高TiO2的光催化活性. TEM观察显示,Ag在TiO2表面形成纳米级团簇结构,随Ag担载量的增加,团簇尺寸增大. DRS分析表明,Ag的担载对TiO2紫外区域的光谱特征没有影响. 根据Ag团簇的能级随其几何尺寸的变化分析了Ag担载量的变化对TiO2光催化活性的影响机理.

Effect of Silver Deposition on Photocatalytic Activity of TiO2

The Ag/TiO 2 photocatalyst with varying Ag loadings was prepared by the photodeposition method and its photocatalytic activity was tested using phenol degradation as the model reaction. Transmission electron microscopy and diffuse reflectance spectroscopy (DRS) were used to observe the distribution and size of silver clusters on the TiO 2 surface and to determine the optical characteristics of Ag/TiO 2, respectively. The results showed that a suitable Ag loading could greatly enhance the TiO 2 photocatalytic activity. Ag clusters were formed on the TiO 2 surface and the size of Ag clusters increased with the increase in Ag loading. The DRS results indicated that silver deposition had no effect on the optical characteristics of the catalyst in the UV region. The relationship between the Ag loading and the photocatalytic activity of Ag/TiO 2 was discussed.