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 CoS 2 nanoparticle‐decorated MoS 2 /reduced graphene oxide (CoS 2 @MoS 2 /rGO − w ) nanosheets is fabricated by hydrothermal reaction for hydrogen evolution reaction (HER). The optimized CoS 2 @MoS 2 /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 H 2 SO 4 solution. The high HER of CoS 2 @MoS 2 /rGO −0.05 can be mostly ascribed to synergistic effect between CoS 2 and MoS 2 . This work offers a novel strategy for design and engineering efficient electrocatalysts for the HER based on earth‐abundant materials.