Ca_(1-x)Zn_(x)In_(2)S_(4)的合成及光催化性能研究

Synthesis and Photocatalytic Activity of Ca_(1-x)Zn_(x)In_(2)S_(4)

通过水热法制备了Ca_(1-x)Zn_(x)In_(2)S_(4)系列复合光催化剂,采用X射线衍射、扫描电子显微镜、瞬态荧光光谱仪及紫外-可见光漫反射等对样品的晶体结构、显微结构及吸光特性进行了表征,并在可见光下降解甲基橙以分析其光催化性能。结果表明,相比单相ZnIn_(2)S_(4)或CaIn_(2)S_(4)光催化剂,复合相Ca_(1-x)Zn_(x)In_(2)S_(4)具有更好的可见光催化活性。当CaIn_(2)S_(4)和ZnIn_(2)S_(4)的摩尔比为3∶7时,复合相Ca_(0.3)Zn_(0.7)In_(2)S_(4)的催化活性最高,其在可见光照射40 min后,对甲基橙的降解率达95%以上。经分析发现,样品中形成的异质结有效地分离了光生电子-空穴对,从而提高了复合相Ca_(0.3)Zn_(0.7)In_(2)S_(4)体系的光催化性能。

The Ca_(1-x)Zn_(x)In_(2)S_(4)series composite photocatalysts were prepared by hydrothermal method.The crystal structure,microstructure and absorption properties of the samples were characterized by X-ray diffraction,scanning electron microscope,transient fluorescence spectrometer and ultraviolet-visible diffuse reflectance,and the photocatalytic activity of all samples were investigated by degrading methyl orange under visible light.The results showed that the photocatalytic activity of composite photocatalysts Ca_(1-x)Zn_(x)In_(2)S_(4)was better than two of single phase CaIn_(2)S_(4)and ZnIn_(2)S_(4).When the molar ratio of CaIn_(2)S_(4)to ZnIn_(2)S_(4)was 3∶7,the catalytic activity of composite sample Ca_(0.3)Zn_(0.7)In_(2)S_(4)was the highest.The degradation rate of methyl orange was over 95%after 40 min of visible light irradiation.The analysis found that the heterojunctions formed in the samples effectively separated the photogenerated electron-hole pairs,thereby improving the photocatalytic performance of the composite phase Ca_(0.3)Zn_(0.7)In_(2)S_(4)system.