ZnO/WO3 nanostructure as an efficient visible light catalyst

Highly photosensitive ZnO/WO3 photocatalysts were fabricated by wet impregnation of zinc oxide (ZnO) in different contents. Tungsten trioxide (WO3) was synthesized by hydrothermal route. The presence of ZnO inhibited the crystallization of WO3 and caused agglomeration of WO3 nanoparticles surface. The formation of ZnO-W linkage was studied by X-ray photoelectron emission (XPS) and Fourier transforms Infra-red spectra (FTIR). These linkages were responsible for red shift of absorption peak of composites as compared to individual ZnO and WO3. The band gap was decreased due to incorporation of ZnO in WO3 which promoted the separation of photo-generated carriers. As a result, ZnO/WO3 composite showed extremely high efficiency for MO degradation in comparison with Degussa P25, pure ZnO and WO3. 2.0% ZnO/WO3 composite displayed the highest activity in photocatalytic decomposition of methyl orange (MO) dye.