Nickel mesh-based catalysts with crystalline-amorphous synergistic catalytic effect for enhanced efficiency and stability in alkaline water electrolysis at ampere-level current densities

Abstract

Amid the pressing need for sustainable hydrogen production, developing high-performance electrocatalysts for alkaline electrolysis using nickel-based materials has become increasingly important, which are widely used in industry due to their robustness and cost-effectiveness. In this study, we report the electrochemical deposition-fabricated P-Co(OH)₂/NM and P-NiFe catalysts, which shows excellent performance in the hydrogen evolution reaction and oxygen evolution reaction, respectively. Specifically, P-Co(OH)₂/NM achieved overpotentials of 41 mV at 10 mA cm⁻² and 240 mV at 1000 mA cm⁻², while P-NiFe compound exhibited overpotentials of 278 mV and 403 mV at these currents, respectively. These improvements are attributed to the synergistic effects of crystalline and amorphous phases and the unique porous structure formed via the dynamic hydrogen bubble template method. The assembled electrolyzer demonstrated superior overall water splitting (OWS) performance, requiring only 1.57 V at 10 mA cm⁻² and 1.81 V at 1000 mA cm⁻², with remarkable stability exceeding 1000 h. When the OWS temperature is increased to 60 °C, the performance was further enhanced, achieving 1000 mA cm⁻² at just 1.72 V. With their simple synthesis and unique structure, these catalysts hold great promise for industrial applications.