Bimetallic MOF-derived oxides modified BiVO4 for enhanced photoelectrochemical water oxidation performance

In this work, bimetallic NiCo-MOF was fabricated on BiVO 4 by method of electrostatic attraction and then calcined to prepare Ni x Co 1−x O/BiVO 4 composite photoanode. The obtained Ni x Co 1−x O with high porosity and surface area showed excellent oxygen evolution performance. It is found that Ni x Co 1−x O acting as a strong hole extraction increases the rate of surface water oxidation by promoting charge separation efficiency. As a result, this composite photoanode can provide a photocurrent of 3.2 mA/cm 2 at 1.23 V vs RHE (0.5 M Na 2 SO 4 , AM 1.5 G illumination), far larger than that of pure BiVO 4 photoanode. The enhanced performance can be ascribed to synergistic effect between Ni and Co, which plays an important role for boosting water oxidation.