复合Ag/ZnO分级结构微球的制备及其光催化性能研究

采用化学沉淀法制备ZnO微球，利用柠檬酸三钠（TCD）避光还原硝酸银在ZnO表面沉积银粒子制备Ag/ZnO复合材料.利用XRD、SEM、TEM、EDS、FTIR、UV-vis DRS、PL、BET等对Ag/ZnO的结构、组分、形貌及光谱性质进行了表征，通过紫外及可见光照降解甲基橙溶液评价样品的光催化性能.结果表明：ZnO纳米微球是由ZnO纳米片相互交错构筑而成的具有丰富孔道的分级结构，Ag纳米粒子均匀沉积在ZnO纳米片上.Ag的沉积显著增加了ZnO的可见光吸收，猝灭了ZnO荧光，提高了ZnO催化活性.

Preparation of Hierarchical Ag/ZnO Microsphere Composites and Their Photocatalytic Properties

Hierarchical ZnO microspheres were prepared by a chemical precipitation method. Ag nanoparticles were deposited on the surface of ZnO by reducing silver nitrate with trisodium citrate dihydrate (TCD) in the absence of light in order to obtain Ag/ZnO nanocomposites. XRD, SEM, TEM, EDS, FTIR, UV-vis-DRS, PL and BET were used to characterize the structure, composition, morphology, photoluminescence and absorption properties of Ag/ZnO. The photocatalytic activity of Ag/ZnO was investigated by the photocatalytic degradation of methyl orange (MO) aqueous solution using mercury or xenon lamp as light source. The results show that the ZnO microspheres are composed of lots of interlaced ZnO nanosheets and exhibit abundant pore channels. Ag nanoparticles are uniformly deposited on the surface of ZnO nanosheets to form Ag/ZnO composites. The Ag particle deposition on the surface of ZnO expanded obviously the visible absorption range, quenched the PL emission, as well as enhanced the photocatalytic activity of ZnO.