Two-Dimensional Topological Platinum Telluride Superstructures with Periodic Tellurium Vacancies for Efficient and...

Area of Science:

• Materials Science
• Catalysis
• Condensed Matter Physics

Background:

• Defect engineering in transition metal dichalcogenides (TMDs) aims to enhance catalytic activity by creating single-atom sites.
• Achieving ordered superstructures with single-atom spacing for uniform high-density sites on TMDs is challenging.
• Existing TMD catalysts often fall short of the performance seen in carbon-supported single-atom catalysts (SACs).

Purpose of the Study:

• To develop an efficient TMD-based topological catalyst for the hydrogen evolution reaction (HER).
• To create a catalyst with high-density, uniformly distributed single-atom reactive centers.
• To investigate the catalytic performance and stability of a novel (7 × 7)-PtTe_2- superstructure.

Main Methods:

• Synthesis of a few-layer (7 × 7)-PtTe_2- superstructure.
• Electrocatalytic testing for hydrogen evolution reaction (HER) performance and stability.
• First-principles calculations to analyze active sites, hydrogen adsorption, and material topology.

Main Results:

• The (7 × 7)-PtTe_2- superstructure exhibited superior HER performance compared to pristine Pt(111), PtTe₂, and (2 × 2)-PtTe_2-.
• The enhanced performance is attributed to a higher density of undercoordinated Pt sites and favorable hydrogen adsorption energies.
• The catalyst demonstrated exceptional stability at high current densities and possesses nontrivial band topologies with robust edge states.

Conclusions:

• The developed (7 × 7)-PtTe_2- topological catalyst offers a promising platform for efficient and stable hydrogen evolution.
• The findings advance the field of TMD-based catalysts and highlight the potential of topological materials in catalysis.
• This work provides a pathway for creating high-density single-atom sites on inert basal planes of TMDs.