AgBr/ZnO复合材料光催化剂及其光催化性能

通过一步水热法制备了AgBr/ZnO复合光催化剂,并采用扫描电子显微镜、透射电子显微镜、X射线衍射仪、X射线光电子能谱仪、紫外–可见光漫反射光谱仪和光致发光光谱仪对样品进行表征,分析了AgBr/ZnO体系的合成对材料光催化性能的影响。以罗丹明B溶液为目标污染物,研究复合催化剂的光催化活性。结果表明:在制备的复合样品中,Ag Br与ZnO摩尔比为1:5时(AgBr/ZnO-2)光催化活性最好,在可见光照射下,60 min对罗丹明B的降解率可达98.98%,相比于ZnO光催化活性明显提升,降解速率常数提升了11.08倍;与商用TiO2(P25)相比,降解速率常数提升了10.14倍,这主要归因于Ag Br/ZnO拥有比ZnO更低的电子空穴复合概率,且复合催化剂的光学吸收带边发生红移,从而增强了对可见光的吸收。

AgBr/ZnO Composite Photocatalyst ant Its Photocatalytic Performance

Ag Br/ZnO composite photocatalyst was prepared by a simple one-step hydrothermal method. The composites were characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, ultraviolet-visible spectroscopy and photoluminescence spectroscopy. The effect of AgBr/ZnO system synthesis on the photocatalytic properties of the materials was analyzed. The photocatalytic activity of the composite catalyst was investigated with rhodamine B solution as a target pollutant. The results show that an optimum AgBr/ZnO-2 composite with a molar ratio of AgBr to ZnO of 1:5 has a degradation rate of rhodamine B of 98.98% for 60 min under visible light irradiation. Compared to ZnO, the photocatalytic activity is improved and the degradation rate constant is increased by 11.08 times. Compared to commercial TiO2(P25), the degradation rate constant is increased by 10.14 times. That is mainly since AgBr/ZnO has a lower electron–hole recombination ratio than ZnO, and the optical absorption band edge of the composite catalyst is red-shifted, thereby enhancing the absorption of visible light.