Ag3VO4/ZnO nanocomposites with an n-n heterojunction as novel visible-light-driven photocatalysts with highly enhanced activity

The present work demonstrates the preparation of Ag3VO4/ZnO nanocomposites with an n-n heterojunction, as novel visible-light-driven photocatalysts, with different mole fractions of silver vanadate. The preparation method is facile one-pot, large-scale, and low-temperature and does not require any post preparation treatments. The microstructure, morphology, purity, and electronic properties of the as-prepared samples were studied using X-ray diffraction, scanning electron microscopy, energy dispersive analysis of X-rays, UV-vis diffuse reflectance spectroscopy, Fourier transform-infrared spectroscopy, and photoluminescence techniques. Photocatalytic activity of the nanocomposites was examined by degradation of rhodamine B under visible-light irradiation. It was found that mole fraction of silver vanadate has a considerable influence on the photocatalytic activity. The nanocomposite with 0.218 mol fraction of Ag3VO4 exhibited the superior activity relative to the other compositions. Compared with the pure ZnO and Ag3VO4, the nanocomposite exhibited 10.5 and 1.6-fold enhancement, respectively, in the degradation rate constant. In addition, influence of the refluxing time, calcination temperature, and scavengers of reactive species on the degradation activity was investigated in detail and the results were discussed. Moreover, the nanocomposite was found to be a reusable photocatalyst.