Core-shell CoS2@MoS2 nanoparticles as an efficient electrocatalyst for hydrogen evolution reaction

Structure and morphology play a crucial role in improving the performance of catalysts. In this work, we prepared core-shell structured CoS2@MoS2 nanoparticles by a two-step hydrothermal method. The unique electrochemical properties of the core-shell CoS2@MoS2 nanoparticles with a narrow size distribution centered at 20–30 nm were demonstrated. An excitation-dependent photoluminescence emission was observed for the core-shell CoS2@MoS2 nanoparticles. These core-shell CoS2@MoS2 nanoparticles showed an excellent catalytic activity towards hydrogen evolution reaction (HER), indicated by the onset potential of 190 mV (vs. RHE), the overpotential of 276 mV at a current density of 10 mA cm−2 and the Tafel slope of 60 mV·dec−1. Therefore, the developed core-shell CoS2@MoS2 nanoparticles can be applied for HER for their excellent catalytic activities.