Highly active and stable nickel–molybdenum nitride (Ni2Mo3N) electrocatalyst for hydrogen evolution

Abstract

This paper reports a highly active and stable nonprecious metal electrocatalyst based on bimetallic nanoscale nickel molybdenum nitride developed for the hydrogen evolution reaction (HER). A composite of 7 nm Ni₂Mo₃N nanoparticles grown on nickel foam (Ni₂Mo₃N/NF) was prepared through a simple and economical synthetic method involving one-step annealing of Ni foam, MoCl₅, and urea without a Ni precursor. The Ni₂Mo₃N/NF exhibits high activity with low overpotential (η₁₀ of 21.3 mV and η₁₀₀ of 123.8 mV) and excellent stability for the HER, achieving one of the best performances among state-of-the-art transition metal nitride based catalysts in alkaline media. Supporting density functional theory (DFT) calculations indicate that N sites in Ni₂Mo₃N with a N–Mo coordination number of four have a hydrogen adsorption energy close to that of Pt and hence may be responsible for the enhanced HER performance.