Design, preparation and enhanced photocatalytic activity of porous BiOCl/BiVO4 microspheres via a coprecipitation-hydrothermal method

Novel three-dimensional BiOCl/BiVal hierarchical microspheres featured with p-n heterojunction and a porous structure have been successfully synthesized via a coprecipitation process followed by hydro thermal treatment. Our investigation focuses on the design of a heterojunction structure to overcome limitations of single-component semiconductors, such as poor light response and short carrier lifetime. With elongated heat treatment, the morphology of the BiOCl/BiVO4 composite evolves from porous micro/nanosheets to microspheres with a hierarchical structure, while the monoclinic BiVO4 powders grow in the form of dendritic crystal. Transmission electron microscopy (TEM) analyses demonstrate that the BiOCl and BiVO4 phases distribute uniformly throughout the composite microspheres. Photo degradation rate of rhodamine B (RhB) deposited over the surface of the porous BiOCl/BiVO4 composite is much higher than that of the BiVO4 particles, indicating that hybridization of BiOCl and BiVO4 is an effective way to separate the photogenerated carriers in the composite and the p-n heterojunction improves the photocatalytic activity. (C) 2017 Published by Elsevier B.V.