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

• Published in: Angewandte Chemie International Edition Vol. 62; no. 48; pp. e202313845 - n/a
• Main Authors: Liu, Hai‐Jun, Zhang, Shuo, Chai, Yong‐Ming, Dong, Bin
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 27-11-2023
• Edition: International ed. in English
• Subjects: Absorption spectroscopy; Anion exchanging; Catalysts; Catalytic activity; Clean technology; Cobalt; Cobalt Doping; Durability; Electrocatalysts; Electronic structure; Enlarged Interlayer Space; Ethane; Hybridization; Hydrogen; Hydrogen Evolution Reaction; Hydrogen evolution reactions; Interlayers; Ligand Modulation; Ligands; Modulation; Molybdenum disulfide; Molybdenum Sulfide
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.202313845

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.
A synergistic ligand modulation plus cobalt doping strategy is applied to modulate the orbital hybridization of 1T‐MoS2 catalyst via CoMo‐MOF precursors. The polydentate 1,2‐bis(4‐pyridyl)ethane (bpe) ligand can stably link with 1T‐MoS2 layers to achieve expanded interlayer spacing, which promotes the joint participation of highly efficient active sites in the basal plane and the interlayer in alkaline HER processes.