Facile preparation of Cu2O nanoparticles/Bi2WO6/rGO hybrid with enhanced photoelectrochemical performance

Bi2WO6 (BWO) has recently received extensive interest for water splitting application due to its attractive properties of non-toxicity, high stability and narrow band gap (similar to 2.7 eV). However, the photoelectrochemical (PEC) performance of pure BWO is limited by the inefficiency visible light absorption, and the low electron transport efficiency. Herein we prepared a novel Cu2O nanoparticles/BWO/reduced graphene oxide (Cu2O NPs/BWO/rGO) hybrid by a facile solvothermal synthesis followed by a chemical reduction. The Cu2O NPs and rGO decorate homogeneously on the surface of hydrangea-like BWO. This novel hybrid exhibits a significantly enhanced PEC performance with a similar to 14 times high photocurrent density than that of pure BWO under simulated sunlight irradiation. This enhancement of the PEC performance is attributed to the significant improvement of coupling Cu2O NPs and rGO, which proves a direct Z-scheme as the main mechanism in Cu2O NPs/BWO, and rGO as a pivotal charge transmission bridge for the efficient photogenerated charge separation, and the increased visible light absorption. The results have provided a new way for the practical water splitting application of BWO.