Fabrication of a BiVO4/CuCo2O4 Heterojunction Photoanode for Photoelectrochemical Water Splitting

Abstract

Bismuth vanadate (BiVO₄) is highly studied for its potential in photoelectrochemical (PEC) water splitting, but its effectiveness is reduced by the rapid recombination of photogenerated carriers on the surface. This study presents a straightforward approach to integrating CuCo₂O₄ with BiVO₄ to form a p–n junction, substantially enhancing the separation of electron-hole pairs on electrode surfaces. The photoelectrode BiVO₄/CuCo₂O₄, which was prepared with an optimal CuCo₂O₄ loading, achieved a significant photocurrent density of 1.26 mA/cm² at a potential of 1.23 V relative to the reversible hydrogen electrode (RHE). Experimental investigations confirmed that the presence of CuCo₂O₄ enhances the mobility and separation of photogenerated electron-hole pairs. The outstanding performance in PEC water splitting demonstrated by the CuCo₂O₄/BiVO₄ composite electrode suggests its excellent suitability for applications involving solar-assisted water splitting.