First-principles study of Ni adatom migration on graphene with vacancies

Area of Science:

• Materials Science
• Condensed Matter Physics
• Computational Chemistry

Background:

• Graphene's unique electronic and structural properties make it a promising material for various applications.
• Understanding metal atom interactions on graphene is crucial for developing novel electronic and catalytic devices.
• The presence of defects, such as vacancies, can significantly alter graphene's properties and reactivity.

Purpose of the Study:

• To investigate the interaction and diffusion mechanisms of nickel (Ni) atoms on pristine graphene and graphene with a single vacancy.
• To analyze the structural and electronic effects of Ni adsorption on graphene.
• To determine the influence of vacancies and structural distortions on Ni diffusion pathways and energy barriers.

Main Methods:

• First-principles calculations were employed to model Ni-graphene interactions.
• The climbing image nudged elastic band (CI-NEB) methodology was used for energy barrier calculations.
• Analysis included electron localization function and charge density to understand bonding and structural changes.

Main Results:

• Adsorption of Ni atoms on pristine graphene causes structural changes and modifies the electronic structure.
• Ni atom adsorption induces distortions in graphene with a vacancy, dependent on proximity to the defect.
• Vacancy and structural distortions significantly affect the minimum energy paths and saddle points for Ni diffusion.

Conclusions:

• The study provides a detailed understanding of Ni atom behavior on defective graphene.
• The findings are essential for designing graphene-based materials with controlled Ni atom diffusion for applications in electronics and catalysis.
• First-principles calculations offer a robust approach to predict and control atom-surface interactions on 2D materials.