Fabrication and Photocatalytic Performance of GaN/ZnO Composites

Abstract

GaN powder was firstly synthesized by the Sol-Gel method using polyvinylpyrrolidone (PVP) and gal- lium nitrate (Ga(NO3)3) as surfactant and gallium source, respectively. Then, GaN/ZnO composites were prepared by solid phase method through mechanical mixing GaN powder and ZnO powder with different proportions. The composites were characterized by using X-Ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive spectrometer (EDS), high-resolution X-ray electron microscope (HRTEM) and photoluminescence (PL) spectra. The photocatalytic performance of GaN/ZnO composites as catalyst was tested by degradation of methyl- ene blue in aqueous solution under white light irradiation. The results show that the photocatalytic property of GaN/ZnO composites is obviously improved comparing with that of pure GaN and ZnO powders. The photocata- lytic activity is analyzed by pseudo-first-order kinetics equation, showing that the best photodegradation rate con- stant k is 0.11 min -1 for the GaN/ZnO composites with GaN and ZnO mixing ratio of 1: 2.