All-water-based solution-processed Ni–Fe–P self-supported electrode for efficient oxygen evolution reaction in anion exchange membrane water electrolyzers

초록

Hydrogen production via water electrolysis is a promising approach for sustainable and carbon-neutral energy conversion. However, large-scale applications remain challenging owing to the complexity of electrocatalyst fabrication. Enhancing the kinetics of the oxygen evolution reaction (OER) in alkaline media is crucial for reducing the energy consumption of industrial electrolyzers. In this study, a self-supported nickel–iron phosphide electrocatalyst (NiP-FN/NF) was synthesized on nickel foam (NF) using a facile low-temperature solution-phase strategy combining electrodeposition and corrosion engineering. The electrodeposition parameters and concentration of the Fe(NO3)3 solution were optimized to control the morphology and composition. Electrochemical evaluation in 1.0 M KOH revealed improved OER performance, with NiP-FN/NF achieving a low overpotential of 275 mV at 10 mA cm−2 and a low Tafel slope of 32.0 mV dec−1. Additionally, NiP-FN/NF exhibited minimal charge-transfer resistance and a significantly increased electrochemical active surface area (ECSA). When integrated into an anion exchange membrane water electrolyzer (AEMWE), NiP-FN/NF enabled efficient hydrogen production, delivering a cell voltage of 1.71 V at a current density of 1.0 A cm−2. This study developed a simple, green, and scalable strategy for fabricating high-performance Ni-Fe-P electrocatalysts, which holds significant promise for use in industrial water splitting and sustainable hydrogen generation.

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