Nanostructured Amorphous Ni-Co-Fe Phosphide as a Versatile Electrocatalyst Towards Seawater Splitting and Aqueous Zinc-Air Batteries

Electrocatalysis provides a desirable approach for moving toward a sustainable energy future. Herein, a rapid and facile potential pulse method was implemented for a one-pot electrosynthesis of the amorphous Ni-Co-Fe-P (NCFP) electrocatalyst. The 2 mg cm-2 loaded electrode displayed excellent trifunctional electrocatalytic activities toward the hydrogen evolution reaction (η HER j=10 = 102 mV), oxygen evolution reaction (η OER j=10 = 250 mV), and oxygen reduction reaction (E ORR 1/2 = 0.73 V) in alkaline solutions. Interestingly, even a lower overpotential of η HER j=10 = 86 mV was obtained at a super-high mass loading of 18.7 mg cm-2, demonstrating its feasibility for industrial-level applications. The NCFP electrocatalyst also offered superior catalytic activity in alkaline seawater electrolysis at industrially required current rates (500 mA cm-2). When implemented as an air cathode catalyst of an aqueous and quasi-solid state zinc-air battery, both devices delivered excellent performance. This study provides insights into a transformative technology towards a sustainable energy future.