Heterostructured Zr-Ni4Mo/Mo2N nanorod with lattice expansion induced by Zr doping for efficient and durable hydrogen evolution reaction

Abstract

Non-precious metal electrocatalysts with high activity for hydrogen evolution reaction (HER) is important for decreasing the energy consumption of hydrogen production and the cost of water electrolysis devices. However, the existing highly active electrocatalysts generally suffer from oxidation and deactivation under harsh conditions of industrial water splitting. Herein, a heterostructured Zr-Ni₄Mo/Mo₂N nanorod material with lattice expansion induced by Zr doping is fabricated as an efficient and durable electrocatalyst for HER. The prepared Zr-Ni₄Mo/Mo₂N exhibits ultra-low overpotential of only 8 mV at 10 mA cm⁻² in 1 M KOH. Particularly, the electrolytic cell equipped with Zr-Ni₄Mo/Mo₂N cathode consumes a low voltage of only 1.585 V under industrial alkaline water electrolysis conditions (3000 A m⁻², 80 °C, 30 wt% KOH). The exceptionally high catalytic activity of Zr-Ni₄Mo/Mo₂N is proved by the low activation energy (E_a^η=0) of 18.19 kJ mol⁻¹. The lattice expansion and heterointerfaces generate abundant catalytic active sites. Moreover, Zr doping not only regulates electronic structure of Zr-Ni₄Mo/Mo₂N and reduces the kinetic energy barrier of HER, but also prevents the oxidation of active sites, which endows the Zr-Ni₄Mo/Mo₂N with excellent activity and strong durability. This work provides a new avenue for the design of non-precious metal electrocatalysts, which exhibit a promising prospect in industrial water splitting.