Chemically Activating Tungsten Disulfide via Structural and Electronic Engineering Strategy for Upgrading the...

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Layered metal dichalcogenides require improved intrinsic activity and basal plane site activation for enhanced electrocatalysis.
• Efficient electrocatalysts are crucial for energy storage and conversion technologies.

Purpose of the Study:

• To develop palladium (Pd)-doped tungsten disulfide (WS2) epitaxially sheathed around tungsten oxide (W3O) for the hydrogen evolution reaction (HER).
• To investigate the effect of Pd doping on the electronic structure and catalytic activity of WS2 basal sites.
• To evaluate the electrocatalytic performance and stability of the novel Pd-WS2/W3O catalyst.

Main Methods:

• Synthesis of Pd-doped WS2 epitaxially sheathed around W3O core-shell nanostructures.
• Characterization of the material's structure and composition.
• Electrochemical evaluation of the hydrogen evolution reaction (HER) in an acidic electrolyte.
• Theoretical calculations to understand the mechanism of Pd doping and catalytic activity.

Main Results:

• Pd doping successfully tuned the electronic structure of WS2, activating basal plane sites.
• The core-shell structure facilitated efficient charge transfer.
• The Pd-WS2/W3O catalyst (5.65 wt % Pd) demonstrated a low overpotential (54 mV at -10 mA cm-2) and superior stability.
• Performance surpassed the 5 wt % Pt/C benchmark and was unprecedented for WS2-based catalysts.
• Theoretical studies confirmed the stability of Pd substitution and identified new catalytic active sites.

Conclusions:

• The study presents a novel multiscale structural and electronic engineering strategy for transition-metal dichalcogenides.
• Pd-doped WS2 represents a highly promising electrocatalyst for the hydrogen evolution reaction.
• This approach offers a pathway to significantly improve catalytic performance in energy conversion applications.