Preparation and characterizations of BiVO₄/reduced graphene oxide nanocomposites with higher visible light reduction activities.

Bismuth vanadate/reduced graphene oxide (BiVO4/RGO) composites were synthesized by one-step hydrothermal method with graphite oxide, Bi(NO3)3 and NH4VO3 as precursors. The as-synthesized nanocomposites were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, UV-Vis spectroscopy (UV), fluorescence spectroscopy (FL) and electrochemical impedance spectroscopy (EIS). The reduced graphene oxide sheets were decorated by butterfly-like BiVO4 lamellas. Such combination not only alleviated the agglomeration of BiVO4 particles but also restrained the restacking of reduced graphene oxide. A preliminary study on the photo-reductions of Cr (VI) and CO2 under the illumination of simulated sunlight with as-synthesized BiVO4/RGO nanocomposites as catalyst was carried out. The nanocomposites showed better photo-catalytic activity than the conventional BiVO4 particles. The photo-reduction efficiency of BiVO4/RGO nanocomposites increased about 50.1% and the ethanol yield improved about 15.4 μmol/g-cat comparing with pure BiVO4. The enhancements of the photo-catalytic activities were attributed to the effective charge transfer of photo-generated electron from BiVO4 to RGO and improved absorption performance.