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

This study focusses on the synthesis of cerium vanadate (CeVO 4 ) 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 CeVO 4 /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 h. 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, CeVO 4 /NF delivered a low cell voltage of 1.58 V and maintained excellent performance for over 120 h, outperforming the IrO 2 ||Pt/C benchmark. These findings underscore the potential of CeVO 4 /NF as a highly efficient and durable electrocatalyst for sustainable water splitting. • Single-step hydrothermal synthesis fabricated CeVO 4 nanosheets on nickel foam, achieving bifunctionality in water splitting. • CeVO 4 /NF demonstrated a low OER overpotential of 255 mV at 10 mA cm −2 with 94.3% activity retention after 75 hours. • DFT analysis identified vanadium as the active site, balancing adsorption and desorption of intermediates and lowering OER energy barriers. • CeVO 4 /NF||Pt/C exhibited excellent durability, sustaining water splitting for 120 hours with a cell voltage of 1.58 V, outperforming the IrO 2 ||Pt/C benchmark system.