Synergistic Interlayer and Defect Engineering in VS₂ Nanosheets toward Efficient Electrocatalytic Hydrogen Evolution...

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• The hydrogen evolution reaction (HER) is crucial for clean energy production.
• Developing efficient and cost-effective electrocatalysts for HER remains a significant challenge.
• Transition-metal dichalcogenides (TMDs) show promise as HER catalysts, but their activity needs improvement.

Purpose of the Study:

• To synthesize defect-rich VS₂ nanosheets with expanded interlayer spacing.
• To investigate the electrocatalytic performance of these modified VS₂ nanosheets for HER.
• To understand the relationship between structural modifications and catalytic activity.

Main Methods:

• One-pot solvothermal synthesis of VS₂ nanosheets.
• Characterization of structural properties, including interlayer spacing and defects.
• Electrochemical evaluation of HER performance, including overpotential, Tafel slope, and stability.
• Density functional theory (DFT) calculations to analyze electronic structure and hydrogen adsorption.

Main Results:

• Successfully synthesized VS₂ nanosheets with a ≈74% expanded interlayer spacing (1.00 nm) and rich defects.
• Achieved superior HER kinetics: low overpotential (43 mV at 10 mA cm⁻²), small Tafel slope (36 mV dec⁻¹), and excellent long-term stability (60 h).
• Demonstrated performance comparable to commercial Pt/C, significantly outperforming pristine VS₂.
• DFT calculations revealed modified electronic structures and optimal hydrogen adsorption energy.

Conclusions:

• Interlayer and defect engineering in VS₂ nanosheets is an effective strategy to enhance HER electrocatalytic activity.
• The expanded interlayer spacing and rich defects provide more active sites and optimize electronic properties.
• This approach offers a new pathway for designing advanced TMD-based electrocatalysts for hydrogen production.