3D 1T-MoS₂ /CoS₂ Heterostructure via Interface Engineering for Ultrafast Hydrogen Evolution Reaction.

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Metallic phase molybdenum disulfide (1T MoS₂) is a promising material for the hydrogen evolution reaction (HER).
• Achieving a high percentage of the 1T phase and maintaining its stability are key challenges.

Purpose of the Study:

• To develop a novel interface-induced strategy for synthesizing stable, high-percentage 1T MoS₂.
• To investigate the catalytic activity of the resulting 1T-MoS₂/CoS₂ heterostructure for the hydrogen evolution reaction.

Main Methods:

• In situ growth of interlinked 1T-MoS₂ and CoS₂ nanosheets from a molybdate cobalt oxide nanorod precursor under moderate conditions.
• Characterization of the heterostructure's phase composition, morphology, and electrochemical properties.

Main Results:

• A high percentage of metallic phase (1T) MoS₂ (76.6%) was achieved due to strong MoS₂-CoS₂ interaction.
• The 1T-MoS₂/CoS₂ heterostructure exhibited enhanced electroconductivity, abundant active sites, and a large exposed surface area.
• Near-zero free energy for hydrogen adsorption at the heterointerface was observed, indicating fast kinetics and excellent catalytic activity.

Conclusions:

• The interface-induced strategy successfully produced a stable 1T-MoS₂/CoS₂ heterostructure with a high percentage of the metallic phase.
• The heterostructure demonstrated superior performance in the hydrogen evolution reaction, with low overpotentials and Tafel slopes in both alkaline and acidic media.