Preparation and modification of hierarchical nanostructured Bi2WO6 with high visible light-induced photocatalytic activity.

Hierarchical nanostructured Bi(2)WO(6) micro-clews were synthesized by a solvothermal process with mixed solvents and formaldehyde. The hierarchical Bi(2)WO(6) micro-clews, with an average diameter of ca. 1.0 µm, consisted of nano-sheets assembled in a special fashion and the formation process mainly went through an Ostwald ripening-anisotropic growth and self-assembling process. The Bi(2)WO(6) micro-clews were further modified by Bi(2)O(3) to fabricate heterojunction photocatalysts, where Bi(2)O(3) nanoparticles were uniformly assembled on the surface of Bi(2)WO(6) nano-sheets. Compared with pure Bi(2)WO(6) and Bi(2)O(3), the composite photocatalyst exhibits higher photocatalytic activity for the degradation of rhodamine B under visible light. On the basis of characterization by x-ray diffraction, photoluminescence and UV-vis diffuse reflectance spectroscopies, a mechanism was proposed to account for the enhanced photocatalytic activity of the Bi(2)O(3)/Bi(2)WO(6) heterojunction.