Relationship between Hydrogen Evolution and Wettability for Multiscale Hierarchical Wrinkles.

Area of Science:

• Materials Science
• Nanotechnology
• Electrochemistry

Background:

• Transition metal dichalcogenides (TMDs) are promising 2D materials for hydrogen evolution reaction (HER) catalysis.
• Current HER enhancement strategies for TMDs focus on chemical modifications like defects, doping, and phase control.

Purpose of the Study:

• To enhance HER performance in TMDs by precisely controlling wettability through hierarchical wrinkling.
• To demonstrate that wettability control alone, without altering surface chemistry, can improve catalytic efficiency.

Main Methods:

• Fabrication of hierarchical wrinkles on TMD surfaces (MoS₂ and WS₂) to tune receding contact angles.
• Characterization of the relationship between wrinkle wavelength, receding contact angle, and HER performance.
• Evaluation of gas detachment dynamics from the wrinkled catalytic surface.

Main Results:

• Hierarchical wrinkling allowed tunable receding contact angles (2-30°) by controlling wrinkle wavelength.
• Minimized receding contact angles led to reduced overpotential for HER on MoS₂ wrinkles.
• The method's effectiveness was demonstrated on both MoS₂ and WS₂, confirming the universality of wettability control.

Conclusions:

• Precise wettability control via hierarchical wrinkling is a viable strategy to enhance TMD-based HER catalysts.
• This approach offers a new pathway for catalyst optimization, independent of chemical modifications.
• The findings support broader applications of engineered TMDs in energy conversion reactions like HER, CO₂ reduction, and oxygen evolution.