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

Abstract Bi 2 WO 6 nanofibers and hierarchical microspheres were synthesized by an electrospinning process and a hydrothermal method. The phase, microstructure and photocatalytic performance of the obtained Bi 2 WO 6 photocatalysts were investigated. The X-ray powder diffraction and Fourier transform infrared spectroscopy suggest that Bi 2 WO 6 nanofibers and hierarchical microspheres have the single orthorhombic phase. The scanning electron microscope and transmission electron microscope images show that Bi 2 WO 6 nanofibers are composed of nanoparticles and Bi 2 WO 6 hierarchical microspheres consist of a large number of nanosheets. The Barrett−Emmett−Teller results, X-ray photoelectron spectroscopy, ultraviolet–visible diffuse reflectance spectra, emission spectra, photocurrent and electrochemical impedance spectroscopy reveal that Bi 2 WO 6 hierarchical microspheres have a higher photocatalytic activity than that of Bi 2 WO 6 nanofibers. This is confirmed by the photo decomposition of Rhodamine B under light irradiation. The Bi 2 WO 6 hierarchical microspheres show a faster and higher efficiency decomposition of Rhodamine B under light irradiation. The higher photocatalytic activity of Bi 2 WO 6 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.