Interface construction of P-Substituted MoS2 as efficient and robust electrocatalyst for alkaline hydrogen evolution reaction

Molybdenum disulfide is known as a promising candidate for Pt-based catalysts in the hydrogen evolution reaction (HER), while the lack of the active-edge-site in-plane dominantly limits their intrinsic activity. Herein, a new strategy is reported to synthesize interface construction between MoS2 and MoP, derived from the partial phosphidation of MoS2 by incorporating P source (MoS2–MoP/NC). As a novel interface engineering electrode, MoS2–MoP/NC exhibits not only Pt-like catalytic activity but robust durability in alkaline electrolyte. Experiments and density functional theory (DFT) calculations certify that the formation of S vacancies on MoS2 basal plane are facilitated by interlayer-interface construction between MoS2 and MoP. Due to the delocalized electron inside S vacancies, the exposed coordination-unsaturated Mo atoms of S-defected MoS2 offer active sites for water adsorption and activation, which accelerates the water dissociation steps. On the other hand, MoP provides active sites for hydrogen formation and desorption, which could weaken the adsorption strength of atomic hydrogen through van der Waals force of interlayer-interface. Our results show that the origin of the enhanced alkaline HER catalytic performance of MoS2–MoP/NC comes from the introduction of new active sites by interface construction, which provides an insight into the development of interlayer-interface engineering on MoS2. It is expected that this interface construction strategy can be extended to other 2D metal sulfides for enhancing their electrocatalytic activity.