Solvothermal synthesis of nanostructured BiVO4 with highly exposed (010) facets and enhanced sunlight-driven photocatalytic properties

Nanostructured monoclinic BiVO4 (m-BiVO4) sheets with highly exposed (0 1 0) facets was synthesized by a surfactant-free solvothermal route, during which glycerol aqueous solution was first used as solvent. The effects of volume fraction of glycerol aqueous solution and pH value in the solvothermal process have been studied by means of the XRD, SEM, TEM, HRTEM, EDS, BET, FTIR, and UV-vis techniques. The adoption of glycerol is shown to influence preferential crystal growth of BiVO4 along its (0 1 0) facets to further act as the directing agent, as well as the morphology and crystalline structure. Moreover, the pH value also has significant influence on the crystal growth direction and morphology of the products. The sheet-like m-BiVO4 sample with highly exposed (0 1 0) facets could be obtained by using 15% glycerol aqueous solution as solvent at pH 6, and exhibited the best sunlight-driven photocatalytic performance for methylene blue degradation. It is concluded that the excellent photocatalytic activity on m-BiVO4 can be attributed to the preferentially exposed surfaces of the (0 1 0) facets which increases the separation efficiency of photogenerated electron-hole pairs and improves the surface active sites. (C) 2015 Elsevier B.V. All rights reserved.