摘要

The selective conversion of alcohol into aldehyde in water was achieved over Bi2WO6-reduced graphene oxide (RGO) photocatalysts. The Bi2WO6-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 Bi2WO6-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, Bi2WO6-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 Bi2WO6 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 Bi2WO6-RGO were proposed.