Constructing Reactive Micro-Environment in Basal Plane of MoS₂ for pH-Universal Hydrogen Evolution Catalysis

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Molybdenum disulfide (MoS₂) is a promising catalyst for the hydrogen evolution reaction (HER).
• Current MoS₂ catalysts exhibit inefficient, pH-dependent activity, hindering practical water splitting applications.
• Optimizing water dissociation and hydrogen desorption kinetics is key for universal pH HER catalysts.

Purpose of the Study:

• To enhance the pH-universal catalytic activity of MoS₂ for the hydrogen evolution reaction (HER).
• To investigate the effect of cobalt single-atom doping on MoS₂'s electronic structure and catalytic performance.
• To provide a facile strategy for developing high-performance HER catalysts.

Main Methods:

• Experimental synthesis of cobalt-doped MoS₂.
• Electrochemical characterization of HER performance across various pH conditions (alkaline, acidic, neutral).
• Theoretical calculations (e.g., DFT) to confirm the formation of a reactive micro-environment and analyze electronic properties.

Main Results:

• Cobalt single-atom doping successfully created a reactive Co-Mo-S micro-environment on the MoS₂ basal plane.
• The doped catalyst exhibited superior HER performance in alkaline conditions (36 mV overpotential at 10 mA cm^-2, 33 mV dec^-1 Tafel slope).
• The catalyst also demonstrated significant activity in acidic (97 mV) and neutral (117 mV) environments, showcasing pH-universal efficacy.

Conclusions:

• Single-atom cobalt doping effectively modifies the electronic properties of MoS₂, boosting HER catalysis.
• The engineered Co-Mo-S micro-environment facilitates both water dissociation and hydrogen desorption.
• This study presents a viable approach for designing advanced MoS₂-based electrocatalysts for widespread HER applications.