【摘要】 采用浸渍法制备了CdS/TiO2复合半导体光催化剂.使用XPS和UV Vis扩散—反射谱对样品的表面组成及光吸收特性进行了分析.结果表明,样品中的硫主要以CdS形式存在,其外层包裹了一层CdSO4;由于在TiO2表面修饰了CdS,使样品的吸收带边由400nm(3.1eV)红移至530nm(2.3eV).采用粉末电导装置对CdS/TiO2薄膜的表面态能级进行了测试,并以活性艳红X 3B水溶液的光催化脱色为指标反应,对CdS/TiO2的活性进行了评价.与单一TiO2相比,CdS/TiO2的表面态更靠近TiO2的导带,有利于电子在表面的捕获,从而提高了样品中自由电荷的浓度,加速了活性艳红X 3B水溶液的光催化脱色反应.更多还原

【Abstract】 The compound semiconductor photocatalyst CdS / TiO₂ was prepared by dipping method. XPS and UV-Vis diffusing-reflecting spectra were applied to analyze the surface composite and the optical properties of as-prepared CdS / TiO₂ respectively. The results indicated that sulfur in the samples existed in the form of CdS covered with a layer of CdSO₄, and that the threshold of the samples shifted from 400 nm （3.2 eV） to 530 nm （2.3 eV） because of the modification of CdS on the surface of TiO₂. Powder conductivity method was applied to measure the surface state of the samples, and the activities of CdS / TiO₂ were evaluated with the photocatalytic decoloration of Reactive Brilliant Red X-3B aqueous solution as model. Compared with pure TiO₂, the surface state energy levels of CdS / TiO₂ were closer to the conduction band energy level of TiO₂, which means that more excited electrons were trapped at the surface of the sample, and finally resulted in the promotion of the photocatalytic decoloring rate of Reactive Brilliant Red X-3B aqueous solution.更多还原