Ruthenium-modified oxygen-deficient NiCoP catalysts for efficient electrocatalytic water splitting†

Ruthenium-doped nickel cobalt compounds are promising catalysts for the hydrogen evolution reaction. We report a synergistic strategy of “defect engineering + noble metal modification” to develop Ru-modified oxygen-deficient NiCoP catalysts (Ru-NiCoP-O_v). By precisely controlling the synthesis conditions, we systematically investigated the impact of Ru modification and oxygen vacancies on the electrocatalytic performance of NiCoP catalysts. The prepared Ru-NiCoP-O_v catalyst exhibits excellent hydrogen evolution catalytic performance in conventional alkaline electrolyte (1 M KOH): it requires only a low overpotential of 51.5 mV at a current density of −10 mA cm⁻² for the hydrogen evolution reaction (HER). More importantly, the catalyst also performs excellently in simulated seawater electrolysis environments (1 M KOH seawater solution), with an HER overpotential of 68.1 mV at −10 mA cm⁻² current density. This outstanding performance fully demonstrates the importance of the synergistic effect of Ru modification and oxygen vacancies in enhancing catalytic activity, providing new design strategies and experimental evidence for developing efficient seawater electrolysis catalysts, and offering a feasible approach to achieving efficient and low-cost hydrogen energy production.