Hydrogen Adsorption on Nearly Zigzag-Edged Nanoribbons: A Density Functional Theory Study

Area of Science:

• Materials Science
• Condensed Matter Physics
• Computational Chemistry

Background:

• Nitrogen-doped graphene nanoribbons (N-GNRs) offer tunable electronic properties.
• Realistic GNR structures require incorporating imperfections like zigzag edges and pyridine defects.
• Scandium functionalization is explored to modify GNR properties.

Purpose of the Study:

• To investigate the formation, energetics, stability, and electronic states of Scandium-functionalized nitrogen-doped graphene nanoribbons with nearly zigzag-edged (NZE) and pyridine (3NV) defects (Sc/NZE-3NVGNRs).
• To understand the influence of nano-shape on the magnetic properties and hydrogen storage capacity of these functionalized GNRs.

Main Methods:

• Density Functional Theory (DFT) calculations were employed to systematically study the structural and electronic properties.
• Analysis of binding energy (BE) to determine the stability of Scandium functionalization.
• Evaluation of hydrogen adsorption capabilities.

Main Results:

• The shape of NZE-3NVGNRs significantly influences magnetic order, linked to altered ribbon edge shapes.
• Scandium functionalization at 3NV and NZE sites is thermodynamically stable with strong binding energies.
• Enhanced binding energy with shorter zigzag edges or narrower ribbons suggests reduced Scandium atom clustering.
• Increasing zigzag edge length causes structural distortions.
• Sc/NZE-3NVGNRs demonstrate potential for adsorbing multiple hydrogen molecules.

Conclusions:

• Sc/NZE-3NVGNRs exhibit tunable magnetic properties influenced by structural defects and Scandium doping.
• The studied nanoribbons are stable and show potential for applications in hydrogen storage due to their adsorption capabilities.