Controlling Morphologies and Visible Light Photocatalytic Activity of Microstructured BiVO_4 in a Microwave Hydrothermal Process

摘要

A CTAB-assisted microwave hydrothermal method was used to synthesize BiVO_4 photocatalysts with different shapes. The obtained products were characterized by powder X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), UV-vis diffuse reflectance spectroscopy (DRS). The results showed that the monoclinic phase BiVO_4 polyhedron was formed via a tetragonal zircon-type BiVO_4 precursor. UV-vis diffuse reflectance spectra showed a great shift to longer wavelengths in the visible region for the monoclinic phase BiVO_4 samples compared to the BiVO_4 precursor. The photocatalytic activity of the sample was investigated for the liquid phase photocatalytic degradation of RhB under visible light irradiation (λ>420nm). The effects of different reaction times on the photocatalytic activity of BiVO_4 had also been investigated, and the highest efficiency was observed when the sample was prepared at 140 °C for 30min.