Edge engineering on layered WS₂ toward the electrocatalytic reduction of CO₂: a first principles study

Area of Science:

• Materials Science
• Electrochemistry
• Computational Chemistry

Background:

• Transition-metal dichalcogenides (TMDCs) show promise for CO₂ reduction reaction (CO₂RR).
• Limited research exists on edge-modified WS₂ for CO₂RR.
• Understanding edge structure is crucial for optimizing TMDC electrocatalysts.

Purpose of the Study:

• To investigate the electrocatalytic CO₂RR performance of edge-modified WS₂.
• To explore the effects of transition metal doping (Zn, Fe, Co, Ni) on WS₂ edge structure and activity.
• To identify optimal doping strategies for enhanced CO₂RR.

Main Methods:

• Density functional theory (DFT) calculations were employed.
• Models of WS₂ doped with transition metals (WS₂-xTM-y) were constructed.
• Effects of dopant species, concentration, and adsorption sites were analyzed.

Main Results:

• Tungsten (W) atoms at the edge are the active sites for CO₂RR.
• Doping with transition metals alters W-S bond strength and improves electrical conductivity.
• The WS₂-2Zn-1 model exhibited the highest catalytic activity, with a limiting potential of -0.51 V for CO production.

Conclusions:

• Edge doping of WS₂ with transition metals is an effective strategy to enhance CO₂RR.
• The WS₂-2Zn-1 catalyst demonstrates superior performance and stability across various pH values.
• This work provides a theoretical foundation for designing advanced WS₂-based electrocatalysts for CO₂ conversion.