Bismuth Tungstate-Reduced Graphene Oxide Self-Assembled Nanocomposites for the Selective Photocatalytic Oxidation of Alcohols in Water

The selective conversion of alcohol into aldehyde in water was achieved over Bi 2 WO 6 -reduced graphene oxide (RGO) photocatalysts. The Bi 2 WO 6 -RGO-H catalysts were synthesized by an electrostatic self-assembly method followed by hydrothermal reduction. It was found the valence band and conduction band edges of Bi 2 WO 6 -RGO-H underwent a continuous increase in energy with the increasing weight ratio of graphene oxide, which resulted in a high selectivity to aldehydes. Furthermore, Bi 2 WO 6 -RGO samples with different degrees of reduction of RGO were prepared, and the conversion of alcohol was influenced greatly by the RGO reduction degree. Based on the results of photo-electrochemistry and photoluminescence spectroscopy, the clear enhancement in alcohol conversion can be ascribed to the efficient separation of photogenerated charge carriers, which results from the fast migration of photoelectrons between excited Bi 2 WO 6 and highly reduced RGO. Additionally, based on the results of radical-trapping and ESR spectroscopy, the primary reactive species and a plausible pathway for alcohol oxidation over Bi 2 WO 6 -RGO were proposed. Graphical Green synthesis : Highly selective and efficient conversions of alcohols into aldehydes can be achieved in aqueous suspensions of Bi 2 WO 6 -reduced graphene oxide (RGO) under artificial solar light irradiation. The selectivity to the product aldehydes can be tuned with the weight ratios of graphene oxide, and the conversion of reactant alcohols can be controlled by the reduction degree of RGO.