Self-limited conversion of MoO2 into ultramicro MoS2 nanosheets on graphene/CNTs matrix for hydrogen evolution with excellent stability

Abstract

Current research on MoS₂/graphene hybrids for the hydrogen evolution reaction (HER) reveals that there is still a huge challenge due to restacking and the scarcity of active sites. In this work, ultramicro MoS₂ nanosheets with good dispersion and rich active sites are vertically grown on graphene via a self-limited growth strategy (S–MoS₂). Moreover, carbon nanotube (CNT) scaffolds can effectively limit the restacking of graphene and MoS₂, accelerating the transport of electrons and electrolytes. The synergism among the multi-function structures and composition control can improve the electrochemical HER activity. The obtained S–MoS₂/rGO/CNTs exhibits a low overpotential of 159 mV (vs. RHE) at 10 mA cm⁻² and a small Tafel slope of 85 mV dec⁻¹ in 0.5 M H₂SO₄. Moreover, the S–MoS₂/rGO/CNTs shows excellent electrochemical durability at 10 mA cm⁻² for 18 h. This work supplies a fresh strategy to design high-performance and cost-effective MoS₂-based catalysts for the HER.