Activating interfacial S sites of MoS2 boosts hydrogen evolution electrocatalysis

The hydrogen evolution reaction (HER) of molybdenum disulfide (MoS 2 ) is limited in alkaline and acid solution because the active sites are on the finite edge with extended basal plane remaining inert. Herein, we activated the interfacial S sites by coupling with Ru nanoparticles on the inert basal plane of MoS 2 nanosheets. The density functional theory (DFT) calculation and experimental results show that the interfacial S electronic structure was modulated. And the results of Δ G H* demonstrate that the adsorption of H on the MoS 2 was also optimized. With the advantage of interfacial S sites activation, the Ru-MoS 2 needs only overpotential of 110 and 98 mV to achieve 10 mA·cm −2 in both 0.5 M H 2 SO 4 and 1 M KOH solution, respectively. This strategy paves a new way for activating the basal plane of other transition metal sulfide electrocatalysts for improving the HER performance.