Transforming carbon nanotubes by silylation: An ab initio study

TL;DR

This study uses ab initio calculations to explore how silyl radicals covalently functionalize carbon nanotubes and graphene, transforming their electronic properties and providing vibrational signatures for successful silylation.

Contribution

It demonstrates that silyl radicals can covalently bond with nanotubes and graphene, converting all nanotubes into semiconductors regardless of chirality, and identifies vibrational signatures of silylation.

Findings

Silyl radicals form strong covalent bonds with carbon nanostructures.

Silylation converts all nanotubes into semiconductors.

Vibrational spectra can indicate successful silylation.

Abstract

We use ab initio density functional calculations to study the chemical functionalization of single-wall carbon nanotubes and graphene monolayers by silyl (SiH3) radicals and hydrogen. We find that silyl radicals form strong covalent bonds with graphene and nanotube walls, causing local structural relaxations that enhance the sp3 character of these graphitic nanostructures. Silylation transforms all carbon nanotubes into semiconductors, independent of their chirality. Calculated vibrational spectra suggest that specific frequency shifts can be used as a signature of successful silylation.