太阳光照射下CdS/TiO_2复合纳米粉体的光催化性能  

Photocatalytic Activity of CdS/TiO_2 Composite Nano-powder under Sunlight Irradiation

作　　者：赵文霞[1,2] 白志鹏[1] 任爱玲[2] 郭斌[2] 王鑫杰[2] 

机构地区：[1]南开大学环境科学与工程学院,天津300071 [2]河北科技大学环境科学与工程学院,河北石家庄050018

出　　处：《精细化工》2009年第12期1226-1229,1234,共5页Fine Chemicals

基　　金：天津市科技发展计划攻关培育项目(06YFGPSHO4200);2009年度河北科技大学大学生科技创新基金项目~~

摘　　要：分别采用溶胶-凝胶法和化学沉积法两种方法将CdS修饰在Degussa P25TiO2上,制备得到CdS/TiO2复合纳米粉体,借助XRD、UV-vis漫反射、EDS等手段对其进行表征分析,选择亚甲基蓝(MB)为模型反应物,考察了太阳光照射条件下CdS/TiO2的光催化性能。结果表明,亚甲基蓝溶液初始质量浓度为20mg/L,光催化剂投加量为2g/L时,持续光照60min后,CdS/TiO2对MB的降解率较P25TiO2提高11%～15%;光照120min后,MB降解率最高,达90%以上。阳光照射下CdS/TiO2对MB的光降解反应遵从Langmuir-Hinshelwood模型,动力学结果符合假一级动力学方程,对应的表观反应速率常数是P25TiO2的1.1～1.4倍。用化学沉积法制备的CdS/TiO复合体的光催化活性优于溶胶-凝胶法,与XRD、UV-vis漫反射、EDS等表征结果一致。CdS/TiO2 composite nano-powder was prepared by cadmium sulfide（CdS） modified Degussa P25 TiO2 using the two methods of sol-gel method and chemical precipitation method. Their properties were characterized by X-ray diffraction（ XRD）, UV -vis diffuse reflection absorption spectras and the energy dispersive analysis system of X-ray （EDS）. Methylene blue （MB） was selected as the model reactant. The photocatalytic activities of CdS/TiO2 under sunlight irradiation were also investigated. The results showed that under the condition of initial concentration of MB 20 mg/L, the added amount of photocatalysts 2 g/L and sunlight irradiating 60 min, the photodegradation rate of MB with CdS/TiO2 composites increased 11% -15% ,higher than that with P25 TiO2 ;irradiated 120 min, the degradation rate of MB with CdS/TiO2 composites reached the maximum, more than 90%. The photodegradation reaction of MB with CdS/TiO2 composites under sunlight,fitted with the Langmuir-Hinshelwood model, the kinetic results followed the pseudo-first-order equation and the apparent reaction rate constant was 1.1 - 1.4 times as large as that with P25 TiO2. The photodegradation activities of CdS/TiO2 composites prepared by chemical precipitation method slightly better than that by the sol-gel method. It was consistent with the characterized results of XRD, UV - vis and EDS.

关 键 词：太阳光 CDS 纳米TIO2 光催化活性 亚甲基蓝 水处理技术与环境保护 

分 类 号：TQ314.242[化学工程—高聚物工业]