Co, Ni-Doped MoS₂ Nanosheet Composites for Electrocatalytic Hydrogen Evolution

Developing low-cost, highly active, and stable electrocatalysts is crucial for large-scale hydrogen production. Here, we utilized Anderson-type polyoxometalate (NH 4 ) 4 [NiMo 6 O 24 H 6 ]·5H 2 O (NiMo 6 ) as the precursor, [Co(NH 3 ) 6 ]Cl 3 as the cobalt source, and thiourea as the sulfur source to synthesize MoS 2 -based nanomaterials doped with Co and Ni, forming MoS 2 –Co 4 S 3 –NiS 2 . 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.