金属离子掺杂的TiO_2薄膜的制备及其光催化降解甲苯的性能

Preparation of Metallic Ion-Doped TiO_2 Thin Films and Their Photocatalytic Performance for Toluene Degradation

采用溶胶-凝胶法制备了负载于铝板上掺杂金属离子的TiO2薄膜光催化剂,并通过空气中甲苯光催化降解实验评价了其光催化活性.结果表明,Pt和Fe的掺杂对TiO2薄膜的光催化活性起促进作用,甲苯降解率分别提高了17%和6%;Ag的掺杂引起催化剂失活;Mn的掺杂未对TiO2薄膜的光催化活性起明显促进作用.XRD结果表明,掺杂金属离子前后TiO2均为锐钛矿相;TEM观察到薄膜催化剂微观结构为球形颗粒,粒径分布均匀,平均粒径为19nm;紫外漫反射光谱表明,Pt-TiO2薄膜催化剂的反射率几乎为0,表明其对光的吸收能力很强,因而Pt掺杂的TiO2薄膜光催化降解甲苯的活性最高.

The metal-doped TiO2 thin films were prepared by the sol-gel technique, and their photocatalytic activity was evaluated by the photocatalytic degradation of toluene. The results indicated that the doping of Pt and Fe greatly improved the photocatalytic activity of TiO2 thin films, and the degradation rate of toluene were 76% and 65%, respectively, which were higher than that of pure TiO2 (59%). The doping of Ag caused the catalyst deactivation, and the surface of the TiO2 thin film turned brown, which was due to the adsorption of the involatile organic compounds. The doping of Mn did not enhance the photocatalytic activity of TiO2 thin films. XRD results showed that both pure and metal-doped TiO2 thin films were of anatase type, and no doping metal oxide crystal was detected. TEM results showed that the particle size of both TiO2 and Pt-TiO2 powders was uniform with an average particle diameter of 19 nm. The UV diffuse reflectance spectra showed that the reflection rate of Pt-TiO2 thin films was nearly zero, and its strong absorption capacity for UV light was responsible for the high photocatalytic activity.