Lithium stabilizes square-two-dimensional metal sheets: a computational exploration.

Area of Science:

• Materials Science: Design and characterization of novel two-dimensional (2D) materials.
• Computational Chemistry: Theoretical exploration of material properties and reaction mechanisms.
• Catalysis: Investigation of electrocatalytic activity for carbon dioxide reduction.

Background:

• Exploration of two-dimensional (2D) materials beyond graphene and transition metal dichalcogenides.
• Need for stable and functional materials for mechanical applications and catalysis.
• Potential of binary metal compounds for unique electronic and mechanical properties.

Purpose of the Study:

• To computationally design and investigate novel two-dimensional (2D) M2Li sheets.
• To assess the stability, mechanical properties, and auxetic behavior of these 2D materials.
• To explore the potential of these materials, particularly Ag2Li-I, in CO2 electrocatalysis.

Main Methods:

• First-principles calculations and molecular dynamics simulations to determine material stability.
• Particle Swarm Optimization (PSO) to identify global minima structures.
• Density Functional Theory (DFT) to study CO2 activation and reduction pathways.

Main Results:

• Stable 2D M2Li-I monolayers (M = Sb, Bi, Ag, Au) were designed and confirmed.
• Three M2Li-I monolayers (M = Sb, Bi, Ag) exhibited half-auxetic behavior.
• Ag2Li-I demonstrated efficient CO2 activation and conversion to HCOOH, with a low limiting potential for electrocatalysis.

Conclusions:

• Lithium incorporation stabilizes square metal monolayers, creating novel 2D binary metal sheets.
• These stable sheets possess diverse mechanical and electrochemical properties.
• The findings suggest potential applications in mechanics and electrochemical catalysis, particularly for CO2 reduction.