Low-cost and multi-level structured NiFeMn alloy@NiFeMn oxyhydroxide electrocatalysts for highly efficient overall water splitting

Abstract

Fabricating energy-saving, inexpensive and high-activity electrocatalysts for overall water splitting has always been a significant challenge. Electrochemical deposition is considered as a promising method for large-scale industrial applications, but it is prone to generating dense compounds, which reduces the effective catalytic activity area of electrodes. Herein, a low-cost and high-performance bifunctional NiFeMn alloy@NiFeMn oxyhydroxide electrocatalyst was deposited by several minute electrodeposition. Due to the doping of manganese, this method effectively engineers a multi-level dendritic NiFeMn alloy and oxyhydroxide layer, and significantly reduces the energy barrier for the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER), which has been proved by the density functional theory calculations. Specifically, the as-prepared catalyst shows excellent electrocatalytic performance for OER (219 mV) and HER (19 mV) at a current density of 10 mA cm⁻². Experimentally and theoretically, the catalyst demonstrated extraordinary performance for overall water splitting and provides a new possibility for industrialization in the future.