Highly efficient and durable Ce-CoPWO composite catalyst on nickel foam for water splitting via one-step electrodeposition

A Ce-CoPWO catalyst supported on a nickel foam substrate was successfully synthesized via a simple one-step electrodeposition method. The catalyst exhibited remarkable electrocatalytic performance in both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). For HER, it achieved an overpotential of only 44 mV at a current density of 10 mA·cm⁻², while for OER, the overpotential was 224 mV. In the overall water-splitting reaction, the catalyst delivered a current density of 10 mA·cm⁻² at a cell voltage of 1.491 V, demonstrating high catalytic efficiency. The outstanding performance is attributed to the synergistic effects of its unique composite structure, which includes a nanospherical cluster morphology that provides a high electrochemically active surface area and the combination of the Keggin structure of PW₁₂ nanocrystals with amorphous cerium-doped cobalt oxide. This structure enhances the exposure of active sites, optimizes reactant adsorption, and accelerates charge transfer, thereby improving catalytic activity. Additionally, the catalyst showed excellent stability during prolonged high-current tests, highlighting its reliability and durability for water-splitting applications.