Bi2WO6 nano- and microstructures:: Shape control and associated visible-light-driven photocatalytic activities

The shape-controlled synthesis of nano- and microstructured materials has opened up new possibilities to improve their physical and chemical properties. In this work, new types of Bi2WO6 with complex morphologies, namely, flowerlike, tyre- and helixlike, and platelike shapes, have been controllably synthesized by a facile hydrothermal process. The benefits of the present work also stem fr,om the first report on the transformation of Bi2WO6 from three-dimensional (3D) flowerlike superstructures to 2D platelike structures, and on the formation of tyre- and helixlike B'2WO6 superstructures. UV/Vis absorption spectra show that the optical properties of Bi2WO6 samples are relevant to their size and shape. More importantly, the photocatalytic activities of Bi2WO6 nano-and microstructures are strongly dependent on their shape, size, and structure for the degradation of Rhodamine B (RhB) under visible-light irradiation. The reasons for the differences in the photocatalytic activities of these Bi2WO6 nano- and microstructures are further investigated.