Mace-like hierarchical MoS₂/NiCo₂S₄ composites supported by carbon fiber paper: An efficient electrocatalyst for the hydrogen evolution reaction

The rational design and preparation of earth-abundant, stable and efficient electrocatalysts for hydrogen production is currently the subject in extensive scientific and technological researches toward the future of a clean-energy society. Herein, a mace-like MoS₂/NiCo₂S₄ hierarchical structure is designed and synthesized on carbon fiber paper via a facile hydrothermal method, and evaluated as electrocatalyst for hydrogen evolution reaction. In the MoS₂/NiCo₂S₄/carbon fiber paper hierarchical structures, MoS₂ nanosheets are dispersively distributed on the surface of NiCo₂S₄ nanowires, which provides an enlarged surface area, abundant interfaces and catalytic active sites. As for hydrogen evolution reaction, such MoS₂/NiCo₂S₄/carbon fiber paper heterostructures give rise to a hydrogen evolution reaction catalytic current density of 10 mA cm⁻² with a lower overpotential of 139 mV and a smaller Tafel slope of 37 mV·dec⁻¹ than those of MoS₂/carbon fiber paper and NiCo₂S₄/carbon fiber paper counterparts, exhibiting a prominent electrocatalytic performance. Moreover, the electrocatalytic properties change little after 5000 CV cycles and continual electrolysis for 12 h without obvious decay, respectively, demonstrating high durability and stability. The excellent hydrogen evolution reaction performances endow the hierarchical configuration MoS₂/NiCo₂S₄/carbon fiber paper with promising alternative in HER and other related renewable energy fields.