Bismuth tungstate nano/microstructures: Controllable morphologies, growth mechanism and photocatalytic properties

A facile hydrothermal process was utilized to synthesize bismuth tungstate (Bi2WO6) hierarchical nano/microstructures, by which various morphologies could be achieved, including caddice clew-like, nest-like, flower-like and plate-like nanostructures. From the scanning electron microscopy (SEM) and X-ray diffraction (XRD) analysis, the morphologies and phases of the as-synthesized Bi2WO6 exhibited a strong dependence on the pH value of the precursor solutions. Moreover, the formation mechanisms of the controllable assembly of these Bi2WO6 nano/microstructures under different pH values were investigated. The photocatalytic performances of Bi2WO6 with different morphologies were also discussed, and the nest-like Bi2WO6 displayed the best photocatalytic activity due to the effective visible absorption and the large surface areas.