Constructing Ni/MoN heterostructure nanorod arrays anchored on Ni foam for efficient hydrogen evolution reaction under alkaline conditions

Abstract

The alkaline hydrogen evolution reaction (HER) is a half-reaction in the industrial water-alkali and chlor-alkali electrolytic technology. Nevertheless, most of the electrocatalysts exhibit inferior HER performance under alkaline conditions due to their sluggish kinetics involving high activation energy. Herein, we report a bimetallic Ni/MoN heterostructure nanorod electrocatalyst anchored on Ni foam (Ni–MoN@NF) via synchronous reduction and nitrogenization using dicyandiamide. The nitrided nanorod arrays have abundant active sites and good electron transfer ability, making their HER activity much higher than that of the corresponding Ni foam. The prepared Ni–MoN@NF electrocatalyst featured excellent hydrogen evolution performances with low overpotentials of 37.36 mV at 10 mA cm⁻² and 110.83 mV at 100 mA cm⁻², respectively, in alkaline media. Simultaneously, the resulting materials exhibited a significantly enhanced long-term durability over 100 h almost without any degradation. Particularly, the Ni–MoN@NF heterostructure nanorod still maintains excellent activity at high current density (the overpotential is only 283.83 mV at 1000 mA cm⁻²). This work will provide a positive strategy for the preparation and application of metal nitride-based electrocatalysts in the field of renewable energy.