Synthesis and comparison of photocatalytic properties for Bi2WO6 nanofibers and hierarchical microspheres

Bi2WO6 nanofibers and hierarchical microspheres were synthesized by an electrospinning process and a hydrothermal method. The phase, microstructure and photocatalytic performance of the obtained Bi2WO6 photocatalysts were investigated. The X-ray powder diffraction and Fourier transform infrared spectroscopy suggest that Bi2WO6 nanofibers and hierarchical microspheres have the single orthorhombic phase. The scanning electron microscope and transmission electron microscope images show that Bi2WO6 nanofibers are composed of nanoparticles and Bi2WO6 hierarchical microspheres consist of a large number of nanosheets. The Barrett-Emmett-Teller results, X-ray photoelectron spectroscopy, ultravioletevisible diffuse reflectance spectra, emission spectra, photocurrent and electrochemical impedance spectroscopy reveal that Bi2WO6 hierarchical microspheres have a higher photocatalytic activity than that of Bi2WO6 nanofibers. This is confirmed by the photo decomposition of Rhodamine B under light irradiation. The Bi2WO6 hierarchical microspheres show a faster and higher efficiency decomposition of Rhodamine B under light irradiation. The higher photocatalytic activity of Bi2WO6 hierarchical microspheres results from the larger specific surface area. The large specific surface area provides more surface active sits and makes an easier charge carrier transport. (C) 2016 Elsevier B.V. All rights reserved.