ZnO/CdS/Ag复合光催化剂的制备及其催化和抗菌性能

先用水热反应合成六方晶相CdS多层级花状微球并在其表面生长ZnO纳米棒形成均匀的ZnO/CdS复合结构，然后用光还原法将Ag纳米颗粒负载于ZnO纳米棒制备出ZnO/CdS/Ag三元半导体光催化剂，对其进行扫描电镜和透射电镜观察、光电性能测试、活性基团捕获实验以及光催化降解和抗菌性能测试，研究其对亚甲基蓝(MB)的降解和抗菌性能。结果表明：ZnO纳米棒均匀生长在CdS微球表面，CdS晶体没有明显裸露，Ag纳米粒子负载在ZnO纳米棒的表面；ZnO/CdS/Ag三元复合光催化剂有良好的可见光响应、较低的阻抗和较高的光电流密度；ZnO/CdS/Ag复合光催化剂能同时产生羟基和超氧自由基等活性氧基团；ZnO/CdS/Ag三元复合光催化剂对亚甲基蓝(MB)的30 min降解率高于90%;0.25 mg/mL的ZnO/CdS/Ag对革兰氏阴性菌(大肠杆菌)的灭菌率高于96%，对革兰氏阳性菌(金黄色葡萄球菌)能完全灭除。

Construction of ZnO/CdS/Ag Composite Photocatalyst and Its Catalytic and Antibacterial Performance

Firstly, hexagonal crystalline CdS multilayer flower-like microspheres were synthesized by hydrothermal reaction, next on the surface of which ZnO nanorods were grown on to form uniform ZnO/CdS composite, and thirdly ZnO/CdS/Ag ternary semiconductor photocatalyst was prepared by depositing Ag nanoparticles onto ZnO nanorods by photoreduction method. The prepared ZnO/CdS/Ag photocatalyst was characterized by scanning electron microscope and transmission electron microscope, while its photoelectric property, active group capture characteristics, photocatalytic degradability for methylene blue (MB) and antibacterial property were also examined. The results show that ZnO nanorods uniformly grow on the surface of CdS microspheres, and Ag nanoparticles were deposited on the surface of ZnO nanorods. ZnO/CdS/Ag ternary photocatalyst has good visible light response, low impedance and high photocurrent density. ZnO/CdS/Ag composite photocatalyst can simultaneously produce hydroxyl and superoxide radicals and other reactive oxygen groups. The degradation rate of methylene blue (MB) on ZnO/CdS/Ag ternary photocatalyst in 30 min is higher than 90%. The sterilization rate of 0.25 mg/mL ZnO/CdS/Ag to Gram-negative bacteria (Escherichia coli) is higher than 96%, and gram-positive bacteria (Staphylococcus aureus) can be completely destroyed.