Nanostructured amorphous Ni–Co–Fe phosphide as a versatile electrocatalyst towards seawater splitting and aqueous zinc–air batteries

Abstract

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 (<i>η</i> ^HER _<i>j</i>=10 = 102 mV), oxygen evolution reaction (<i>η</i> ^OER _<i>j</i>=10 = 250 mV), and oxygen reduction reaction (<i>E</i> ^ORR _1/2 = 0.73 V) in alkaline solutions. Interestingly, even a lower overpotential of <i>η</i> ^HER _<i>j</i>=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.