Fabrication of BiVO4-Ni/Co3O4 photoanode for enhanced photoelectrochemical water splitting

Abstract

The low efficiency of charge separation and slow kinetics of water oxidation of BiVO4 limit its application in the PEC water splitting. Here, an effective strategy is explored with Ni-doped Co3O4 (Ni/Co3O4) decorated BiVO4 photoanode by a simple route. The photocurrent of the BiVO4-Ni/Co3O4 (2.23 mA/cm2 at 1.23 VRHE biases) has significantly increased up to 4.4 times of that of bare BiVO4, and the Vonset of BiVO4-Ni/Co3O4 shows a significant negative shift (180 mV) to 0.23 V. The IPCE value of BiVO4-Ni/Co3O4 (27%, 380 nm) is about 5 times that of the BiVO4 (5%). The ηinjection and ηseparation of BiVO4-Ni/Co3O4 at 1.23 VRHE reaches 75.82% and 37.08%. The results demonstrate that the Ni/Co3O4 could enhance the charge transfer and accelerate the kinetics of water oxidation reaction, leading to the excellent PEC water splitting performance of the photoelectrode.