Self-assembled three-dimensional hierarchical Bi2WO6 microspheres by sol–gel–hydrothermal route

Abstract

Self-assembled three-dimensional (3D) hierarchical Bi2WO6 microspheres built from 2D nanoplates alignment were successfully prepared by the sol–gel–hydrothermal route. Based on X-ray diffraction and scanning electron microscopy observation of the products at different reaction time periods, the formation mechanism of 3D hierarchical Bi2WO6 microspheres was proposed. UV–vis diffuse reflectance spectra indicated that the obtained 3D hierarchical Bi2WO6 microspheres had enhanced absorption in both UV and visible light regions. The photocatalytic activities of the as-prepared products were evaluated by monitoring the degradation of methylene blue solution under visible light irradiation. Due to the structural feature and good optical quality, Bi2WO6 prepared by the sol–gel–hydrothermal route possessed the highest photocatalytic activity than those of Bi2WO6 samples prepared by hydrothermal and sol–gel routes.