Interface engineering of heterogeneous transition metal chalcogenides for electrocatalytic hydrogen evolution

Area of Science:

• Materials Science
• Catalysis
• Computational Chemistry

Background:

• Molybdenum disulfide (MoS2) and molybdenum diselenide (MoSe2) are effective electrocatalysts for the hydrogen evolution reaction (HER).
• Current limitations in HER efficiency stem from active sites being primarily located on the material's edges.
• Activating the basal planes is crucial for improving overall catalytic performance.

Purpose of the Study:

• To investigate the potential of 2H-1T' interface structures in MoSSe and MoS2-MoSe2 heterostructures.
• To enhance the hydrogen evolution reaction (HER) activity within the basal planes of these materials.
• To provide a novel approach for improving the electrochemical performance of transition metal dichalcogenides.

Main Methods:

• Density functional theory (DFT) calculations were employed to study structural stability and electronic properties.
• Investigated various 2H-1T' interface structures within MoSSe and MoS2-MoSe2 systems.
• Evaluated HER activity using the calculation of H adsorption free energy (ΔGH).

Main Results:

• The 2H-1T' interface structures demonstrated significant HER activity in the basal planes.
• Calculated H adsorption free energy (ΔGH) values along the interface boundaries were near zero.
• Optimal active sites for HER were identified as S or Se atoms bonded to three Mo atoms in a hexagonal ring structure.

Conclusions:

• The introduction of 2H-1T' interfaces effectively activates the basal planes of MoS2 and MoSe2-based materials.
• This interface engineering strategy significantly enhances electrochemical HER performance.
• The findings offer a new pathway for designing efficient electrocatalysts for hydrogen production.