Mo-H interaction modification and heterostructure engineering of Mo2C for striking water splitting electrocatalyst

Abstract

Facing the inherent sluggish hydrogen evolution reaction/oxygen evolution reaction (HER/OER) kinetics of Mo₂C catalyst, a straightforward and scalable approach is proposed to synthesize flower-like heterojunction catalysts TM-Mo₂C/NC, consisting of carbon nanosheets doped with nitrogen and Mo₂C nanoparticles doped with transition metals (Fe, Co, Ni). Benefiting from the layered hollow sphere framework that provides numerous active sites, the Ni-Mo₂C/NC catalyst demonstrates outstanding HER activity, achieving an overpotential of 111 mV at 10 mA cm⁻². Co-Mo₂C/NC has the lowest Tafel slope of 54.9 mV dec⁻¹ during the OER process, indicating the highest inherent catalytic activity. The synergistic effect of Mo-H interaction regulation and heterostructure construction can be achieved by the TM dopant, which significantly improves the HER/OER activity. This work offers an effective strategy for devising high efficiency Mo₂C-based catalysts for energy conversion.