Highly active and stable electrocatalytic hydrogen evolution catalyzed by nickel, iron doped cobalt disulfide@reduced graphene oxide nanohybrid electrocatalysts

The development of highly active and earth-abundant electrocatalysts for the hydrogen evolution reaction (HER) from water holds great promise for clean energy storage and conversion technologies. Pyrite phase transition metal disulfides based electrocatalysts have attracted much attention because of their activity and earth-abundance. In this work we report on the synthesis of in-situ growing quaternary Co_0.8Ni_0.1Fe_0.1S₂ nanoparticles decorating on the reduced graphene oxide (CNFS@rGO) as hybrid Pt-free HER catalyst with high-activity as well as durability. Specifically, the additional active sites can attribute to the incorporation of the Ni and Fe, moreover, the enhancement of anti-aggregation and electron transporter efficiently from rGO which is visually verified by the result of electrochemically active area. As a result, the nanohybrid electrocatalysts possess high HER properties with the need of overpotential of only 138 mV to drive 10 mA cm⁻², an small Tafel slope of 49 mV dec⁻¹, and superior long-term continuous durability in 0.5 M H₂SO₄ (over 33 h). This study offers us a pathway to design and fabrication of multicomponent low-cost metal disulfides based electrocatalysts.