Towards controllable inner chirality in double-walled carbon nanotubes

Abstract

Double-walled carbon nanotubes have many advantages over their singled-walled counterparts such as higher mechanical strength and thermal stability. They can be synthesized by well-established methods like arc-discharge, chemical vapor deposition, and the annealing of molecules and nanocompounds encapsulated in single-walled carbon nanotubes. However, the material grown with these methods does not necessarily have a homogeneous morphology across an entire sample. Aiming at a controllable structure, we have decomposed molecules encapsulated in the hollow core of known diameter nanotubes via in situ laser annealing while simultaneously monitoring the Raman spectral response of the material. Our results show that thin inner tubes can be synthesized inside their single-walled hosts. We have also observed that monitoring the laser wavelength and power and choosing the host's diameter, the chirality of the inner tubes can be tailored in a controlled manner. Interestingly, linear carbon chains, as a one-dimensional allotrope of carbon, were formed as well. The dynamic of the chains annealed at higher power indicates the decomposition of the longer into shorter ones.