Hierarchically nanostructured Ni2Fe2N as an efficient electrocatalyst for hydrazine oxidation reaction

Abstract

A Ni foam-supported, hierarchically nanostructured Ni 2 Fe 2 N nanoflowers (Ni 2 Fe 2 N/NF) exhibits high activity and good operation stability towards hydrazine electrooxidation. • Hierarchically nanostructured Ni 2 Fe 2 N was anchored on Ni foam by a two-step procedure. • Ni 2 Fe 2 N/NF exhibits higher HzOR activity than the top-notch electrocatalysts hitherto reported. • Ni 2 Fe 2 N/NF shows high reaction selectivity toward faradic decomposition of hydrazine. The application of direct hydrazine fuel cells (DHFCs) as portable or vehicular power sources calls for the development of cheap and efficient catalysts for the anodic hydrazine oxidation reaction (HzOR). Herein, we report the facile fabrication of a Ni-foam-supported, hierarchically nanostructured Ni 2 Fe 2 N (Ni 2 Fe 2 N/NF) as a high-performance HzOR catalyst. The Ni 2 Fe 2 N/NF catalyst was fabricated by a simple hydrothermal method and a subsequent nitridation treatment. The thus-prepared Ni 2 Fe 2 N possesses high intrinsic activity towards HzOR, good electronic conductivity as well as a hierarchical architecture, which endows the catalyst with abundant active sites and improved mass transfer properties. Benefiting from these attributes, Ni 2 Fe 2 N/NF demonstrates highly efficient HzOR performance with a high current density of 1017 mA cm −2 at 0.3 V versus RHE, excellent stability and a nearly 100% selectivity for the faradaic hydrazine decomposition following 4-electron pathway, surpassing most previously reported top-notch HzOR electrocatalysts.