Graphene oxide as a hole extraction layer loaded on BiVO4 photoanode for highly efficient photoelectrochemical water splitting

The tailor-made oxygen evolution catalysts (OECs) paired with photoanodes offer a path to promote water oxidation kinetics; however, the unsatisfied interface between OECs and photoanode sets a barrier for efficient charge transfer. Herein, a graphene oxide (GO) layer to promote the charge transfer from BiVO4 (BVO) to NiOOH OEC is reported. It is found that GO layer inserted between BVO and NiOOH can not only serve as hole extraction layer due to its hole storage capability, but also improve the stability. Finally, the rationally designed NiOOH/GO/BVO photoanode achieves a photocurrent density of 3.81 mA center dot cm(-2) at 1.23 V (vs. reversible hydrogen electrode (RHE)), which is 3.85 times as high as that of bare BVO. This work opens up low-cost auxiliary materials for enhancing photoelectrochemical water splitting.