Nickel–Iron Nitride–Nickel Sulfide Composites for Oxygen Evolution Electrocatalysis

Abstract

Advance applications like water splitting system and rechargeable metal-air battery are highly dependent on efficient electrocatalyst for the oxygen evolution reaction (OER). Heterostructured materials, with a high active surface area and electron effect, accomplish enhanced catalytic performance. Here, a nitride-sulfide composite (FeNi₃N-Ni₃S₂) has been prepared by a simple hydrothermal process coupled with nitridation. The prepared composite electrocatalyst FeNi₃N-Ni₃S₂ possesses lower electron densities compared to those of FeNi₃N and Ni₃S₂, lessening the activation energy (<i>E</i>_a) toward the OER. Consequently, the prepared FeNi₃N-Ni₃S₂ exhibits excellent OER performance with a low overpotential (230 mV) and a small Tafel slope (38 mV dec^-1). Highly stable FeNi₃N-Ni₃S₂ composite delivers lower charging voltage and extended lifetime in rechargeable Zn-air battery, compared with IrO₂.