Synergistic effect of S vacancies and P dopants in MoS2/Mo2C to promote electrocatalytic hydrogen evolution

Abstract

Herein, a new strategy is proposed for constructing hierarchical heterojunctions of P-MoS₂/Mo₂C. Owing to the exposed coordination-unsaturated Mo atoms of S vacancies, P-MoS₂/Mo₂C offered active sites for water adsorption and activation, which accelerated the water dissociation steps. Additionally, P-doping can stabilize the S vacancies. This ensured that the as-prepared P-MoS₂/Mo₂C exhibited high stability and excellent HER activity with an ultra-low overpotential of 66 mV at a current density of 10 mA cm⁻² and a Tafel slope of 67 mV dec⁻¹ in 1 M KOH.