CdS/TiO2复合半导体薄膜的制备及其光催化性能

以微弧氧化法制备出锐钛矿型TiO₂，进而以化学水浴法沉积CdS，通过调控时间，制备CdS/TiO₂复合半导体薄膜. X射线检测表明，微弧氧化所制备的TiO₂为锐钛矿结构， 化学水浴法制备的CdS主要以离子离子的方式沉积在TiO₂薄膜上. SEM及可见光催化降解亚甲基蓝的试验表明，沉积时间为15 min的复合半导体薄膜上的CdS粒子呈圆球形、单层孤立、均匀地分散在TiO₂表面，绝大多数粒子的粒径在nm级别，分布比较均匀，对亚甲基蓝有着较好的光催化性能，与TiO₂薄膜相比，复合半导体薄膜的光催化性能有很大的提高. 结合光催化评价结果，对复合半导体薄膜的光催化剂机制进行了讨论. 

Preparation and Photocatalytic Study of Coupled Semiconductor CdS/TiO2 Films

Anatase TiO_2 films were prepared by micro-arc oxidation,and CdS particles were deposited onto the prepared TiO_2 films by chemical bath deposition(CBD)with various deposition times.X-ray diffraction showed that the phase of TiO_2 prepared by micro-arc oxidation was anatase,and CdS prepared by CBD method was grown dominantly by the ion-by-ion process on the TiO_2 films.The results of scanning electron microscopy(SEM)and photocatalytic degradation of methylene blue under visible light indicated that the best CdS/TiO_2 couple with fine CdS particles dispersed equally on TiO_2 film was obtained after 15 min deposition of CdS,and the diameter of the vast majority particles was nano scale.The coupled semiconductor had good catalytic activity in decomposition of methylene blue.As compared with TiO_2,the photocatalytic activity of the couple increased significantly under visible light illumination.Combined with the results of the photocatalytic evaluation,the photosensitization mechanism of the coupled semiconductor was also discussed.