Fabrication and Photocatalytic Property of ZnO/Ag Microspheres

ZnO/Ag microspheres were synthesized on the basis of as-prepared ZnO microspheres by micro. wave-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.