Theoretical Investigation of the Functionalized MOene V₂O: A Density Functional Approach.

Area of Science:

• Materials Science
• Condensed Matter Physics
• Computational Chemistry

Background:

• Two-dimensional (2D) materials beyond graphene, such as transition metal oxides, are gaining attention.
• Vanadium oxide (V2O)-based materials offer unique electronic and structural properties.
• Understanding the stability and properties of functionalized V2O-based materials is crucial for their application.

Purpose of the Study:

• To investigate the structural, thermodynamic, dynamical, and electronic properties of pristine and functionalized V2O-based MOenes.
• To explore the effects of different functional groups (Br, Cl, F, N, OH) on the 1T and 2H polymorphs.
• To assess the potential of these materials for energy storage and nanoelectronic applications.

Main Methods:

• Density Functional Theory (DFT) calculations were employed.
• Analysis of structural, thermodynamic, and dynamical stability (phonon dispersion).
• Investigation of electronic properties and adsorption energies (e.g., lithium adsorption).

Main Results:

• Pristine 1T and 2H V2O MOene phases are dynamically and thermodynamically stable.
• The HV site is favored for 1T functionalization, while the H site is favored for 2H.
• F- and OH- functionalization are stable in both polymorphs; Br-functionalization is stable only in 2H.
• Br functionalization induces a metal-to-semiconductor transition (indirect band gap of 0.64 eV).
• 2H phases exhibit favorable lithium adsorption energies (~ -1.8 to -1.5 eV) with minimal lattice deformation.

Conclusions:

• V2O-based MOenes are stable 2D materials with tunable electronic properties.
• The 2H phase is generally more stable and suitable for functionalization.
• These materials show significant potential for applications in energy storage (e.g., batteries) and nanoelectronics.