ZnO/Ag微米球的合成与光催化性能

用微波辅助多元醇法对预先制备的ZnO微米球进行修饰，合成了载银氧化锌微米球（ZnO/Ag）. 利用X射线衍射仪、场发射扫描电子显微镜、透射电子显微镜、X射线光电子能谱仪、紫外-可见双光束分光光度计和光致发光光谱仪等对样品的结构、形貌和光学性能进行了表征. 在紫外光照射下，通过亚甲基蓝的降解反应研究了样品的光催化活性. 结果表明，所制备的ZnO/Ag微米球是由面心立方的Ag纳米颗粒附着在纤锌矿结构的ZnO球表面形成；与ZnO相比，ZnO/Ag的紫外-可见光吸收光谱发生明显红移，在紫外和可见光范围均有较强的吸收；随着Ag含量的增加，ZnO/Ag荧光光谱强度先减弱后增强；与ZnO相比，ZnO/Ag的光催化活性明显提高，AgNO₃ 浓度为0.05 mol/L时制得的ZnO/Ag光催化活性最高.

Fabrication and Photocatalytic Property of ZnO/Ag Microspheres

ZnO/Ag microspheres were synthesized on the basis of as-prepared ZnO microspheres by microwave-assisted polyol method. The microstructures, morphologies and optical properties of the samples were characterized by X-ray diffractometer(XRD), scanning electron microscope(SEM), transmission electron microscope(TEM), UV-Visible absorption spectrometer(UV-Vis) and photoluminescence spectrometer(PL). The photocatalytic activities of the samples were tested with the photocatalytic degradation of methylene blue. Results demonstrate that the surfaces of wurtzite ZnO spheres are coated by very small face-center-cubic Ag nanoparticles; ZnO/Ag composites have strong absorption in the UV and visible light range and the absorption band shows some red-shifts compared to the ZnO microspheres. With the increase of Ag content, the photoluminescence intensity of ZnO/Ag composites decreases firstly and then increases; ZnO/Ag composites exhibit higher photocatalytic activity than ZnO particles; however, the ZnO/Ag composite prepared with AgNO₃ concentration of 0.05 mol/L has the highest photocatalytic activity.