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Atomic Plane-Vacancy Engineering of Transition-Metal Dichalcogenides with Enhanced Hydrogen Evolution Capability
Cong Wei1, Wenzhuo Wu1, Hao Li1
1College of Materials Science and Engineering , Zhengzhou University , Zhengzhou 450001 , China.
ACS Applied Materials & Interfaces
|July 3, 2019
Summary
Creating sulfur vacancies in transition-metal dichalcogenides (TMDs) using solid-phase reduction enhances their catalytic activity for hydrogen production. This method also aids in efficient exfoliation of TMD nanosheets.
Area of Science:
- Materials Science
- Catalysis
- Nanotechnology
Background:
- Two-dimensional transition-metal dichalcogenides (TMDs) show promise for catalysis.
- Anion vacancies are known to enhance catalytic activity in TMDs.
- Efficient methods for creating vacancies and exfoliating TMDs are needed.
Purpose of the Study:
- To develop a solid-phase reduction (SPR) strategy for simultaneous exfoliation and controlled generation of chalcogen vacancies in TMDs.
- To investigate the impact of sulfur vacancies on the catalytic activity of molybdenum disulfide (MoS2) and tungsten disulfide (WS2) nanosheets for hydrogen evolution.
- To establish a general platform for developing advanced TMD-based electrocatalysts.
Main Methods:
- Solid-phase reduction (SPR) strategy applied to bulk MoS2 and WS2.
- Controlled generation of consecutive sulfur vacancies on the basal plane.
- Characterization of exfoliated nanosheets and their interlamellar distances.
- Electrocatalytic testing for hydrogen-evolution reaction (HER).
Main Results:
- SPR successfully created sulfur vacancies and expanded interlamellar distances (approx. 16%) in MoS2 and WS2.
- Expanded interlamellar distances facilitated easy exfoliation of TMD nanosheets.
- MoS2 and WS2 nanosheets with sulfur vacancies exhibited significantly enhanced HER activity.
- Achieved overpotentials of -238 mV for MoS2 and -241 mV for WS2 at 10 mA cm-2.
Conclusions:
- The SPR strategy is effective for simultaneous exfoliation and vacancy engineering in TMDs.
- Sulfur vacancies critically enhance the electrocatalytic performance of MoS2 and WS2 for hydrogen evolution.
- This approach offers a versatile platform for designing high-performance TMD electrocatalysts for water splitting and hydrogen production.
Keywords:
hydrogen-evolution reactionscalable exfoliationsolid-phase reductiontransition-metal dichalcogenidesvacancy engineeringMore Related Videos
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