Ce-accelerated spontaneous redox synthesis of NiFe-based electrocatalysts for efficient oxygen evolution reaction

Abstract

Sluggish reaction kinetics in the oxygen evolution reaction (OER) hinder the efficiency of water electrolysis systems. Herein, an ultrafast and cost-effective strategy for fabricating high-performance NiFe-based electrocatalysts is presented, utilizing a Ce⁴⁺-assisted spontaneous redox reaction at room temperature. By employing ammonium cerium nitrate as a potent sacrificial oxidant (E° = +1.72 V vs. SHE), the surface reconstruction of nickel foam was accelerated, yielding a dense and porous NiFe-based hydroxide layer within only 15 minutes. The optimized FeCe40/NF catalyst achieved a low overpotential of 349 mV at 50 mA cm⁻², outperforming pristine Fe-only/NF and commercial IrO₂/NF. Analytical results confirmed that Ce⁴⁺ acts as a kinetic promoter. This kinetically driven redox engineering offers a highly scalable methodology for the mass production of high-efficiency, binder-free electrodes.