Magnetic γ′-Fe4N has been considered as one of the most promising non-noble materials for the electrocatalysis of the oxygen evolution reaction (OER) due to its excellent magnetic properties, unique anti-perovskite-like structure, high chemical stability, and high intrinsic activity. Exploring environmentally friendly and efficient nitrogen sources instead of ammonia is still a huge challenge associated with obtaining pure γ′-Fe4N. In addition, it is widely acknowledged that the unique morphological and structural tuning of metal nitrides could effectively enhance their electrocatalytic capabilities. In this study, two kinds of magnetic γ′-Fe4N with different morphologies (cuboidal and rodlike) are obtained by combining facile solvent-regulated ferrous oxalate precursors with ethylenediamine-assisted thermal nitriding. The facile morphological tuning endows γ′-Fe4N with excellent soft magnetic properties while improving the activity toward OER. Specifically, the saturation magnetization of cuboidal γ′-Fe4N reaches up to 167.38 emu g–1. In addition, compared with the RuO2 benchmark for OER, cuboidal γ′-Fe4N shows more excellent OER electrocatalytic performance, showing an overpotential of 253 mV@10 mA cm–2 in 1.0 M KOH and a low Tafel slope (45 mV dec–1). This is of great significance for the non-ammonia synthesis of iron nitride and the development of non-noble-metal-based OER electrocatalysts.
Wanjia Li,Wangchang Li,Yao Ying,Jing Yu,Jingwu Zheng,Liang Qiao,Juan Li,Shenglei Che
Soft magnetic material with high saturation magnetization ( M s ) and high resistance ( ρ ) is vital to improve the power density and conversion efficient of modern electrical magnetic equipment. Yet, increasing M s is always at the expense of high resistivity, such as soft magnetic alloys substitute for the ferrite. In this work, the superior comprehensive electromagnetic properties, namely the close association of high saturation magnetization and high resistivity, are combined in a new way in a newly Fe-N based magnetic materials. A high resistance oxide interface engineering was constructed between the conducting ferromagnetic phases in the process of spark plasma sintering (SPS) to achieve superior electromagnetic properties. The ZnO composite γ' -Fe 4 N bulk has a maximum resistivity of 220 μΩ cm and a M s of up to 156.02 emu/g, while the TiO 2 composite γ' -Fe 4 N bulk has a maximum resistivity of 379 μΩ cm and a M s of 149.7 emu/g. The research findings offer valuable insights for the advancement of the next generation of soft magnetic materials, which hold significant potential for use in high-frequency, high-efficiency, and energy-saving power equipment applications.
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