The electrocatalytic HER activity of MoS2 decorated with adjustable-size ruthenium nanoparticles

MoS2 is a potential electrocatalytic material for its excellent durability and stability. Here, we investigate the electrocatalytic hydrogen evolution reaction performance of MoS2 nanosheets decorated with size-controlled Ru nanoparticles. The MoS2 compounded with 2.46 nm-Ru exhibits the good electrocatalytic performance with overpotential of 53 mV at 10 mA/cm2 in 0.5 M H2SO4 condition. The enhanced electrocatalytic activity of Ru@MoS2 results from accelerated charge migration between the Ru metal and MoS2 semiconductor, as well as the addition of Ru increases the number of active sites on the surface of MoS2. Furthermore, the first-principles calculations demonstrated the ΔGH* of Ru@MoS2 (−0.05 eV) is lower than P–MoS2 (2.04 eV) and the narrowed bandgap facilitates more efficient electron migration. And the theoretical calculations further reveal that the Ru nanoparticles with suitable size at the interface own the ideal ΔGH* by manipulating the D-band center of the Ru.