Surface chemistry-driven CO₂ activation and conversion on V₂C MXenes.

Area of Science:

• Materials Science
• Computational Chemistry
• Electrochemistry

Background:

• MXenes, a class of two-dimensional transition metal carbides and nitrides, exhibit unique properties.
• V₂C MXene offers a higher specific surface area compared to Ti₂C MXene.
• CO₂ capture and conversion are critical for addressing climate change and developing sustainable energy solutions.

Purpose of the Study:

• To investigate the structural and electronic properties of V₂CT₂ (T= -O, -Cl, -F, -S, and -OH) using density functional theory (DFT).
• To explore the potential of V₂C MXene for CO₂ molecule activation and conversion.
• To understand the role of functionalization in enhancing MXene properties for CO₂RR applications.

Main Methods:

• Density Functional Theory (DFT) calculations were employed to study structural and electronic properties.
• Investigation of CO₂ molecule adsorption and activation on V₂C surfaces.
• Analysis of Bader charge transfer and adsorption energies.

Main Results:

• Pristine and OH-terminated V₂C exhibited high adsorption energies (-2.0 and -3.0 eV) and significant charge transfer (-1.69 and -1.81 e^-) with CO₂.
• V₂C MXene activates CO₂ via chemisorption, indicating strong interactions.
• OH-terminated V₂C MXene not only activates CO₂ but also converts it into the *COOH intermediate, crucial for CO₂ reduction reactions (CO₂RR).

Conclusions:

• Functionalization significantly enhances the properties of MXenes for CO₂ capture and conversion.
• V₂C MXene is a promising material for CO₂ capture, conversion, and related electrochemical applications.
• The study provides insights into the mechanism of CO₂ activation and conversion by functionalized MXenes.