One-step growth of nitrogen-decorated iron–nickel sulfide nanosheets for the oxygen evolution reaction

Abstract

The large overpotential loss of the oxygen evolution reaction (OER) is a major obstacle restricting the wide commercial application of water-splitting devices. Herein, we report one-step growth of nitrogen-decorated iron–nickel sulfide nanosheet arrays on a conductive Ni–Fe alloy foam (N–(Ni,Fe)₃S₂/NIF). It is noteworthy that N–(Ni,Fe)₃S₂/NIF has an ultra-low overpotential of 167 mV at 10 mA cm⁻² and exhibits the best OER performance among the non-precious electrocatalysts reported so far. Furthermore, N–(Ni,Fe)₃S₂/NIF shows nearly no degradation after a long-term OER test for 50 h at a constant current density of 10 mA cm⁻². The superior catalytic activity and stability for the OER is due to the application of simultaneous regulation of specific morphologies, incorporation of Fe, and surface nitrogen-anion decoration on Ni₃S₂ materials. In addition, N–(Ni,Fe)₃S₂/NIF prepared by another method also shows excellent OER activity. This work will pave a new way to develop advanced electrocatalysts with a lower OER overpotential.