Enhanced electrocatalytic hydrogen evolution from nitrogen plasma-tailored MoS2 nanostructures

Abstract

Two-dimensional (2D) layered transition metal dichalcogenides such as MoS₂ have been viewed as the most favorable candidates for replacing noble metals in catalyzing the hydrogen evolution reaction in water splitting owing to their earth abundance, superb chemical stability, and appropriate Gibbs free energy. However, due to its low number of catalytic sites and basal catalytic inertia, the pristine MoS₂ displayed intrinsically unsatisfactory HER catalytic activity. Here, the hydrogen evolution catalytic activities of nanostructured MoS₂ powder before and after plasma modification with nitrogen doping were experimentally compared, and the influence of treatment parameters on the hydrogen evolution catalytic performance of MoS₂ has been studied. The feasibility of regulating hydrogen evolution catalytic activity by nitrogen doping of MoS₂ was verified based on density functional theory calculations. Our work demonstrates a more convenient and faster way to develop cheap and efficient MoS₂-based catalysts for electrochemical hydrogen evolution reactions. Additionally, theoretical studies reveal that N-doped MoS₂ exhibits strong hybridization between Mo-d and N-p states, causing magnetism to evolve, as confirmed by experiments.