One-step synthesis of amorphous Ni–Fe–P alloy as bifunctional electrocatalyst for overall water splitting in alkaline medium

Abstract

Design of inexpensive and highly efficient bifunctional electrocatalyst is paramount for overall water splitting. In this study, amorphous Ni–Fe–P alloy was successfully synthesized by one-step direct-current electrodeposition method. The performance of Ni–Fe–P alloy as a bifunctional electrocatalyst toward both hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER) was evaluated in 30 wt% KOH solution. It was found that Ni–Fe–P alloy exhibits excellent HER and OER performances, which delivers a current density of 10 mA cm−2 at overpotential of ∼335 mV for HER and ∼309 mV for OER with Tafel slopes of 63.7 and 79.4 mV dec−1, respectively. Moreover, the electrolyzer only needs a cell voltage of ∼1.62 V to achieve 10 mA cm−2 for overall water splitting. The excellent electrocatalytic performance of Ni–Fe–P alloy is attributed to its electrochemically active constituents, amorphous structure, and the conductive Cu Foil.