CeO_(2)/ZnO复合光催化剂制备及其可见光催化性能

Preparation and visible light catalytic performance of CeO/ZnO composite photocatalyst

采用微波超声法,以ZnO为基体原位生长CeO_(2)晶体,得到CeO_(2)/ZnO复合光催化剂。利用XRD、SEM、TEM、PL、UV-Vis DRS等方法对制备的材料进行表征,并通过可见光降解AF对样品的光催化性能进行评价。结果表明,ZnO为纳米片互相穿插形成的花形球状结构,其表面附着有纳米CeO_(2)颗粒,分散性较好。ZnO和CeO_(2)的摩尔比为20∶1的CeO_(2)/ZnO复合光催化剂在可见光下表现出良好的光催化活性,光照90 min后对AF的光降解率达到96.44%,较纯相ZnO和CeO_(2)有显著提高。CeO_(2)/ZnO的稳定性较好,6次使用后对AF的光降解率仍达到93.53%。机制研究发现,·O_(2)-是光催化降解AF过程中的主要活性物种。

CeO_(2)/ZnO composite photocatalysts were prepared via in-situ precipitation of CeO_(2)nanoparticles on ZnO substrate by ultrasonic microwave method and were characterized by XRD,SEM,TEM,PL,UV-Vis DRS and other techniques.The photocatalytic properties of the samples were investigated by degrading acid fuchsin(AF).The results show that ZnO has flower-shaped spherical structure assembled by ZnO nanoflskes,and its surfaces are evenly attached with CeO_(2)nanoparticles.CeO_(2)/ZnO composite photocatalyst showed good photocatalytic activity with visible light irradiation.When the molar ratio of ZnO and CeO_(2)was 20∶1,the photodegradation rate of AF reached 96.44%after 90 min of illumination,which was significantly higher than those of pure phase ZnO and CeO_(2).CeO_(2)/ZnO indicated high stability,as the degradation rate retained 93.53%after repeated use of the same photocatalyst for 6 times.The photdegradation mechanism study shows that superoxide radical(·O_(2)-)was the main active substance in photdegrading AF.