Confined synthesis of MoS2 with rich co-doped edges for enhanced hydrogen evolution performance

Abstract

Activating MoS2 with atomic metal doping is promising to harvest desirable Pt-matched hydrogen evolution reaction (HER) catalytic performance. Herein, we developed an efficient method to access edge-rich lattice-distorted MoS2 for highly efficient HER via in-situ sulphuration of atomic Co/Mo species that were well-dispersed in a formamide-derived N-doped carbonaceous (f-NC) substrate. Apart from others, pre-embedding Co/Mo species in f-NC controls the release of metal sources upon annealing in S vapor, grafting the as-made MoS2 with merits of short-range crystallinity, distorted lattices, rich defects, and more edges exposed. The content of atomic Co species embedded in MoS2 reaches up to 2.85 at.%, and its atomic dispersion has been systematically confirmed by using XRD, HRTEM, XPS, and XAS characterizations. The Co-doped MoS2 sample exhibits excellent HER activity, achieving overpotentials of 67 and 155 mV at j = 10 mA cm−2 in 1.0 M KOH and 0.5 M H2SO4, respectively. Density functional theory simulations suggest that, compared with free-doping MoS2, the edged Co doping is responsible for the significantly improved HER activity. Our method, in addition to providing reliable Pt-matched HER catalysts, may also inspire the general synthesis of edge-rich metal-doped metal chalcogenide for a wide range of energy conversion applications.