Highly Active Catalyst of Two-Dimensional CoS2/Graphene Nanocomposites for Hydrogen Evolution Reaction

Hydrogen evolution reaction (HER) by electrochemical water splitting using new promising non-precious metal catalysts shows great potential for clean energy technology. The design and fabrication of a high-performance electrode material based on cobalt disulfide/reduced graphene oxide (CoS2/RGO) nanocomposites is reported by a one-step hydrothermal method. Benefiting from its structural advantages, namely, large amount of exposed surface, fast charge transfer, and synergistic effect between CoS2 and RGO, the as-prepared nanocomposites are exploited as a catalyst for the HER. The results indicate that CoS2/RGO-5 % exhibits the best performance of hydrogen evolution and the smallest overpotential of 159 mV to achieve a 15 mA cm(-2) current density, possessing the easiest releasing of hydrogen gas and the highest charge transfer rate, as well as remarkable stability.