Growth of single wall carbon nanotubes from $^{13}$C isotope labelled organic solvents inside single wall carbon nanotube hosts

TL;DR

This study demonstrates catalyst-free growth of single wall carbon nanotubes from isotope-labeled organic solvents inside host nanotubes, revealing new insights into inner tube formation and enabling in-tube chemistry research.

Contribution

It introduces a novel method for growing inner SWCNTs from organic solvents inside host nanotubes using isotope labeling, challenging existing growth models.

Findings

Inner tubes originate from the encapsulated solvent

Growth occurs at 1270°C under vacuum

Provides a new approach for in-tube chemistry

Abstract

Exploring the synthesis of novel molecular nanostructures has been in the forefront of material research in the last decade. One of the most interesting nanostructures are single wall carbon nanotubes (SWCNTs). Their catalyst free growth, however, remains an elusive goal. Here, we present the growth of single wall carbon nanotubes from organic solvents such as benzene and toluene in a confined environment, inside a host SWCNT. The solvents encapsulated in SWCNTs are transformed to an inner tube when subject to a heat treatment under dynamic vacuum at 1270 $^{\circ}$C. We used isotope labeling of the different carbon sources to prove that the source of the inner tubes is indeed the solvent. Our results put constraints on the models explaining the inner tube growth and provides a simple alternative for the fullerene based inner tube growth. It also provides the possibility to study a completely new field of in-the-tube chemistry.