Liquid NaK‐Enabled Strategy for the Facile and Scalable Synthesis of Porous Fe/Co/Ni‐Based Materials for Magnetically Enhanced OER Catalysis

The advancement of water electrolysis is hindered by the scarcity of electrocatalysts that integrate high activity, rapid mass transport, and energy-efficient operation modes. We address this challenge via a versatile room-temperature synthesis using a liquid NaK alloy as a dual-function reagent to fabricate porous, multiphase Fe/Co/Ni-based magnetic electrocatalysts. This method eliminates high-temperature calcination and toxic etchants, enabling facile scaling with yields > 80% and efficient solvent recovery. The resulting amorphous materials feature mesoporosity (up to 101 m²/g) and a synergistic mix of metallic and oxide phases. They demonstrate exceptional oxygen evolution reaction (OER) performance, with the Fe-Co-based catalyst achieving a low overpotential of 243 mV at 10 mA/cm² with a Tafel slope of 57 mV/dec and a high current density of 20 mA/cm²·mg under an external magnetic field (250 mT). Crucially, the amorphous structure outperforms its crystalline counterpart, and the performance enhancement under a magnetic field is primarily driven by magnetohydrodynamic effects amplified by the material's porous architecture. This work establishes a sustainable platform for designing next-generation electrocatalysts where structural complexity is engineered to overcome intrinsic limitations in energy conversion.