可见光响应催化剂Sm_2InNbO_7的制备及其光催化性能研究

采用高温固相法制备了可见光响应的光催化剂Sm2InNbO7,并通过XRD和UV-vis DRS手段对其进行了表征。测试结果表明,Sm2InNbO7属于烧绿石型结构,能带宽度为2.75 eV。以亚甲基蓝的降解率为指标,考察了催化剂用量、溶液pH值、H2O2添加量对Sm2InNbO7的光催化性能的影响。结果表明,随溶液pH值的增加,亚甲基蓝的光催化降解率增大;添加H2O2使亚甲基蓝完全降解的时间缩短;当Sm2InNbO7的用量为0.1 g/50 mL、pH为11.5、H2O2添加量为0.5 mL时,可见光照射下1.5 h,即可将亚甲基蓝溶液完全降解。另外,也讨论了Sm2InNbO7的光催化性质与晶体结构及电子结构的关系。

Preparation and photocatalytic activity of visible-light-driven photocatalyst Sm_2InNbO_7

A visible-light-driven photocatalyst Sm2InNbO7 was prepared by a conventional solid-state reaction method.Its crystal structure and photophysical properties were characterized by XRD and UV-vis DRS,respectively.The results indicated that the Sm2InNbO7 compound had the pyrochlore-type structure and its band gap was about 2.75 eV.Effect of catalyst concentration,H2O2 dosage and pH value of the solution on the photocatalytic activity of Sm2InNbO7 were investigated with degradation rate of methylene blue（MB） as target.It was found that the degradation rate increased with increasing pH value,and the addition of H2O2 enhanced markedly the degradation rate.When photocatalyst amount was 0.1 g/50 mL,pH was 11.5,H2O2 dosage was 0.5 mL,the MB was thoroughly decomposed in 1.5 h under visible light illumination.In addition,the photocatalytic activity was also discussed in connection with crystal and electronic structure.