CoS2 Nanoparticles-Decorated MoS2/rGO Nanosheets as An Efficient Electrocatalyst for Ultrafast Hydrogen Evolution

Water electro-reduction for sustainable hydrogen production is a critical factor of water-splitting devices. However, designing and engineering cheap and highly-efficient alternative electrocatalysts to replace currently used platinum-based electrocatalysts is still prerequisite for commercialization of hydrogen production. Herein, a robust and highly active catalyst of CoS2 nanoparticle-decorated MoS2/reduced graphene oxide (CoS2@MoS2/rGO(-)(w)) nanosheets is fabricated by hydrothermal reaction for hydrogen evolution reaction (HER). The optimized CoS2@MoS2/rGO(-0.05) nanocomposite exhibits outstanding HER performance with a low onset overpotential of 15 mV, overpotentials of 66 mV at current density 10 mA cm(-2), a small Tafel slope of 33.9 mV dec(-1), and high electrochemical durability in 0.5 m H2SO4 solution. The high HER of CoS2@MoS2/rGO(-0.05) can be mostly ascribed to synergistic effect between CoS2 and MoS2. This work offers a novel strategy for design and engineering efficient electrocatalysts for the HER based on earth-abundant materials.