Ligand Modulation of Active Sites to Promote Cobalt-Doped 1T-MoS2 Electrocatalytic Hydrogen Evolution in Alkaline Media

Highly efficient hydrogen evolution reaction (HER) electrocatalyst will determine the mass distributions of hydrogen-powered clean technologies, while still faces grand challenges. In this work, a synergistic ligand modulation plus Co doping strategy is applied to 1T?MoS₂ catalyst via CoMo-metal-organic frameworks precursors, boosting the HER catalytic activity and durability of 1T?MoS₂. Confirmed by Cs corrected transmission electron microscope and X-ray absorption spectroscopy, the polydentate 1,2-bis(4-pyridyl)ethane ligand can stably link with two-dimensional 1T?MoS₂ layers through cobalt sites to expand interlayer spacing of MoS₂ (Co?1T?MoS₂-bpe), which promotes active site exposure, accelerates water dissociation, and optimizes the adsorption and desorption of H in alkaline HER processes. Theoretical calculations indicate the promotions in the electronic structure of 1T?MoS₂ originate in the formation of three-dimensional metal-organic constructs by linking π-conjugated ligand, which weakens the hybridization between Mo-3d and S-2p orbitals, and in turn makes S-2p orbital more suitable for hybridization with H-1s orbital. Therefore, Co?1T?MoS₂-bpe exhibits excellent stability and exceedingly low overpotential for alkaline HER (118 mV at 10 mA cm^?2). In addition, integrated into an anion-exchange membrane water electrolyzer, Co?1T?MoS₂-bpe is much superior to the Pt/C catalyst at the large current densities. This study provides a feasible ligand modulation strategy for designs of two-dimensional catalysts.