Activating interfacial S sites of MoS2 boosts hydrogen evolution electrocatalysis

The hydrogen evolution reaction (HER) of molybdenum disulfide (MoS2) 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 MoS2 nanosheets. The density functional theory (DFT) calculation and experimental results show that the interfacial S electronic structure was modulated. And the results of ΔGH* demonstrate that the adsorption of H on the MoS2 was also optimized. With the advantage of interfacial S sites activation, the Ru-MoS2 needs only overpotential of 110 and 98 mV to achieve 10 mA·cm−2 in both 0.5 M H2SO4 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.