Identifying Metallic Transition-Metal Dichalcogenides for Hydrogen Evolution through Multilevel High-Throughput...

Area of Science:

• Materials Science
• Computational Chemistry
• Electrochemistry

Background:

• High-performance electrocatalysts require high activity, thermodynamic stability, and electronic conductivity.
• Metallic 1T-phase MoS2 and WS2 show promise for hydrogen evolution reaction (HER), but designing new materials is challenging.
• A deeper understanding of electronic and compositional attributes linked to catalytic activity in transition-metal dichalcogenides (TMDs) is needed.

Purpose of the Study:

• To systematically screen all possible two-dimensional (2D) TMD materials for high-performance HER electrocatalysts.
• To identify novel 2D-TMDs with catalytic activity comparable to platinum (Pt).
• To understand the electronic structure and defect-induced activity in metallic 2D-TMDs.

Main Methods:

• High-throughput computational screening of all known 2D-TMD materials.
• Application of criteria including zero band gap, high thermodynamic stability, low vacancy formation energy, and near-zero hydrogen adsorption energy.
• Electronic structure analysis and machine learning methods to correlate properties with HER activity.

Main Results:

• Identified several promising 2D-TMD materials: perfect monolayers VS2 and NiS2, transition-metal ion vacancy (TM-vacancy) ZrTe2 and PdTe2, and chalcogenide ion vacancy (X-vacancy) MnS2, CrSe2, TiTe2, and VSe2.
• These materials exhibit catalytic activity comparable to Pt(111) for HER.
• Electronic analysis revealed that defect-induced active electrons are delocalized, not confined to single-atom sites.

Conclusions:

• Defect engineering in metallic 2D-TMDs is a viable strategy for discovering highly active HER electrocatalysts.
• The HER catalytic activity can be quantitatively predicted using local electronegativity and valence electron number descriptors.
• This work expands the library of potential 2D-TMD electrocatalysts beyond MoS2 and WS2.