Effects of pH on hydrothermal synthesis and characterization of visible-light-driven BiVO4 photocatalyst

BiVO4 powders were hydrothermally synthesized at different pHs and characterized by XRD, SEM, DRS, nitrogen adsorption and Raman techniques. It revealed that the pH Values of the precursors can influence significantly on the morphologies and structures of the products. The photocatalytic activities of the catalyst obtained were evaluated by the decolorization of methyl orange in aqueous solution undervisible light irradiation. It was found that monoclinic BiVO4 showed better photocatalytic activities than those shown by the tetragonal phase under visible light, which are attributed to its wider bandgap. The results also revealed that the dispersive particles with larger surface area represented higher activities than the coagulate ones when considering their photocatalysis. (C) 2009 Elsevier B.V. All rights reserved.