Co, Ni-Doped MoS₂ Nanosheet Compositesfor Electrocatalytic Hydrogen Evolution

Abstract

Developing low-cost, highly active, and stable electrocatalysts is crucial for large-scale hydrogen production. Here, we utilized Anderson-type polyoxometalate (NH₄)₄[NiMo₆O₂₄H₆]·5H₂O (NiMo₆) as the precursor, [Co­(NH₃)₆]­Cl₃ as the cobalt source, and thiourea as the sulfur source to synthesize MoS₂-based nanomaterials doped with Co and Ni, forming MoS₂–Co₄S₃–NiS₂. The catalyst exhibited a low overpotential of only 32 mV at 10 mA cm^–2 with a Tafel slope of 33.46 mV dec^–1 for hydrogen evolution. Moreover, they demonstrated excellent long-term stability in alkaline solutions. This controlled synthesis approach not only achieved superior hydrogen evolution reaction (HER) properties but also extended the application of polyoxometalates (POMs) in electrocatalysis.