Interaction of chlorine with Stone-Wales de- fects in graphene and carbon nanotubes, and thermodynamical prospects of chlorine-induced nanotube unzipping

TL;DR

This study investigates how chlorine interacts with defects in graphene and carbon nanotubes, revealing conditions under which chlorine can facilitate nanotube unzipping into graphene nanoribbons, with implications for controlled nanostructure fabrication.

Contribution

It provides a thermodynamic analysis of chlorine-induced nanotube unzipping and identifies defect sites as potential nucleation points for this process.

Findings

Chlorine-rich environments can thermodynamically favor nanotube unzipping.

Defects increase chlorine binding energies, acting as nucleation sites.

Limited chlorine binding at graphene defects under ambient conditions.

Abstract

We study the binding of chlorine atoms to carbon nanotubes and graphene at a Stone-Wales defect and to the sidewalls of pristine nanotubes. We show using ab initio thermodynamics that if the environment is chlorine-rich enough, the unzipping of carbon nanotubes into graphene nanoribbons with chlorinated edges may be thermodynamically feasible. By controlling the Cl chemical potential through temperature and pressure, opening selectively tubes below a threshold diameter might be possible. Additionally, we find increased binding energies for chlorine atoms bound to Stone-Wales defects as compared to defect-free graphene and nanotubes, indicating that defects might act as nucleation sites for tube unzipping. On graphene, no more than a single Cl atom may be bound to the defect in ambient conditions, limiting possible Cl-induced changes in the resulting nanoribbons.