NiCo3-LDH catalysts decorated with p-n heterojunction CuCoO2/BiVO4 photoanodes for enhanced photoelectrochemical water oxidation

Due to the suitable bandgap and valence band for photoelectrochemical (PEC) water oxidation, BiVO4 has been regarded as a promising photoanode material. However, poor charge-separation and-transport behavior as well as sluggish surface oxygen evolution reaction (OER) kinetics caused the BiVO4 photoanode for water splitting to be significantly lower than its theoretical value. In this study, the synergistic effect of constructing an n-BiVO4/p-CuCoO2 heterojunction and NiCo3-LDH as an OER cocatalyst was designed to enhance the PEC performance of BiVO4 photoanode. The resultant BiVO4/CuCoO2/NiCo3-LDH demonstrates a maximum photocurrent density of 6.95 mA/cm2 at 1.8 V vs. RHE, which is approximately 24.8 times that of BiVO4 (0.28 mA/cm2) and 5.5 times that of BiVO4/CuCoO2 (1.27 mA/cm2) with good stability (70 % remained after 2 h of operation). This work broadens the construction strategy of photoanode heterojunctions to enhance PEC performance.

Automated summary

By constructing an n-BiVO4/p-CuCoO2 heterojunction and utilizing NiCo3-LDH as an OER cocatalyst, the PEC performance of BiVO4 photoanode has been significantly enhanced, leading to higher photocurrent density and improved stability.