Tailoring the Mo-N/Mo-O configuration in MoO₂/Mo₂N heterostructure for ampere-level current density hydrogen production

Mo-based electrocatalysts have garnered significant attention for their promising hydrogen evolution reaction (HER) efficiency, however, the strong adsorption of hydrogen poses a challenge to speedy gaseous hydrogen release. In this respect, regulating the coordination of Mo atoms is an efficient strategy to optimize the electronic configuration and accelerate the HER kinetics. Herein, MoO₂/Mo₂N heterostructures are prepared by a programmed in situ nitridation process. The precisely controlled Mo-N/Mo-O configuration in MoO₂/Mo₂N heterostructure weakens hydrogen adsorption on the Mo sites leading to HER with an ampere-level current density. The electrocatalyst delivers 1 A cm⁻² at an overpotential of 335 mV in 0.5 M H₂SO₄. Furthermore, the electrocatalyst has excellent stability by maintaining a current density of 1 A cm⁻² for 180 hours with a remarkable Faradaic efficiency of 99.8%. The results reveal a novel strategy to precisely modulate the electronic configurations of low-cost transition metal-based electrocatalysts boding well for industrial-scale hydrogen production. © 2023 Elsevier B.V.