Synthesis and magnetism of single-phase γ′-Fe4N by non-ammonia route and applied in oxygen evolution reaction electrocatalysis

Abstract

It is significant to develop a facile and environmentally-friendly method for the synthesis of single-phase γ′-Fe4N with excellent magnetic properties. Single-phase γ′-Fe4N was synthesized through non-ammonia nitridation, using ethylenediamine as nitrogen source, and high-temperature nitridation treatment of α-Fe2O3 precursor prepared by solvothermal method under the protection of nitrogen. The as-prepared γ′-Fe4N possesses good soft magnetic properties that with low coercivity and retentivity and the saturation magnetization can reach 163 emu g−1 at room temperature under the optimal conditions. Moreover, benefiting from the inherent almost metallic properties with good electrical conductivity of transition-metal nitrides, γ′-Fe4N materials exhibit small Tafel slope (40 mV dec−1) and low overpotential (337 mV) to achieve a current density of 10 mA cm−2 in the process of electrochemical catalysis of oxygen evolution reaction (OER) in alkaline solution, making it a promising electrocatalyst for oxygen evolution reaction.