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

Abstract 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.