Abstract:

A series of ZnO nano-materials was prepared by sedimentation method under different microwave power(100, 150, 200, 250 and 300 W) irradiation. The crystal structures, morphologies and surface physicochemical properties of the as-prepared samples were characterized by X-ray diffraction(XRD), UV-Vis diffuse reflectance spectrum(UV-Vis/DRS), scanning electron microscopy(SEM) and N₂ adsorption/desorption determination. The results indicate that the crystalline phase of ZnO sample with different microwave power irradiation is hexagonal wurtzite, moreover, compared with the ZnO prepared by conventional sedimentation, there are blue shift or red shift in the absorption spectra, and the specific surface area is increased more or less. The morphology of each ZnO sample is much distinctive because of the different microwave power, which shows many kinds of shape including nano-grain, oval nano-clusters, nano-plane, spherical nano-clusters and so on. Photocatalytic properties of the ZnO nano-materials were tested by the UV irradiation and microwave-assisted photodegradation of Rhodamine B(RhB). The results show that the photocatalytic activities of ZnO prepared under different microwave power irradiation are enhanced in different degrees, which are much higher than that of P25 and ZnO sample without microwave irradiation.

Key words: Microwave, ZnO nano-material, Photocatalysis, Rhodamine B