Balanced adsorbate interactions in CeVO4 nanosheets: A highly efficient and stable electrocatalyst for water splitting

This study focusses on the synthesis of cerium vanadate (CeVO4) nanosheets on nickel foam (NF) via a single-step hydrothermal method and their bifunctional performance as electrocatalysts for overall water splitting under alkaline conditions. The CeVO4/NF catalyst exhibited excellent oxygen evolution reaction (OER) activity with a low overpotential of 255 mV at 10 mA cm−2 and outstanding long-term durability, retaining 94.3% of its activity after 75 hours. It also showed competitive performance for the hydrogen evolution reaction (HER), achieving an overpotential of 184 mV. Density functional theory (DFT) calculations revealed that vanadium serves as the primary active site, offering balanced adsorbate interactions, strong enough to promote adsorption of key intermediates while still allowing efficient desorption. This balance explains the favorable energy profile and the rate-determining step (OOH* desorption), contributing to enhanced OER efficiency. When coupled with Pt/C as the cathode in a two-electrode alkaline electrolyser, CeVO4/NF delivered a low cell voltage of 1.58 V and maintained excellent performance for over 120 hours, outperforming the IrO2||Pt/C benchmark. These findings underscore the potential of CeVO4/NF as a highly efficient and durable electrocatalyst for sustainable water splitting.