高效光催化活性g-C3N4/ZnxCd1-xS复合材料的性能分析

Performance Analysis of Highly EfficientPhotocatalytic Activity of g-C3N4/ZnxCd1-xS Com Posites

采用原位生长技术,利用共沉淀-水热法制备g-C3N4/ZnxCd1-xS光催化剂。通过XRD、SEM、TEM、EDS、UV-Vis DRS等手段对光催化剂的结构组成和光化学性质进行测试和表征。通过亚甲基蓝(MB)在可见光照射下的降解评价g-C3N4/ZnxCd1-xS的光催化活性;并通过捕获剂测试研究光催化降解机制。结果表明:g-C3N4与ZnxCd1-xS形成了结晶良好的异质结结构,g-C3N4的加入增大了复合材料的光吸收范围,且随着x值的增大,材料光吸收范围逐渐减小。其中g-C3N4/Zn0.5Cd0.5S光催化性能最佳,可见光照射210 min后,MB的降解率达到了99%。且经过4次重复性试验后,光催化活性没有出现明显降低;通过捕获剂实验发现,参与降解的主要活性物质为h+和O-2·。

In this paper,in-situ growth technique was used,and g-C3N4/ZnxCd1-xS heterojunction photocatalyst was prepared by coprecipitation-hydrothermal method.The structure and photochemical properties of the photocatalyst were characterized by XRD,SEM,TEM,EDS and UV-Vis DRS.Photocatalytic activity of g-C3N4/ZnxCd1-xS was evaluated by degradation of methylene blue(MB)under visible light irradiation.The mechanism of photocatalytic degradation was studied by capture agent test.The results show that g-C3N4 and ZnxCd1-xS form a well-crystallized heterojunction structure,and as the value of x increases,the light absorption range of the heterojunction gradually decreases.Among them,g-C3N4/Zn0.5Cd0.5S have the best photocatalytic performance.After 210 minutes of visible light irradiation,the degradation rate to MB reached 99%.After 4 reproducibility tests,there was no significant decrease in photocatalytic activity.Through the capture agent experiments,the main active substances involved in degradation are h+and O-2·.