Confined linear carbon chains: A route to bulk carbyne

TL;DR

This paper presents a novel method for bulk production of extremely long, stable linear carbon chains (carbyne) using double-walled carbon nanotubes, confirmed by multiple spectroscopic techniques.

Contribution

It introduces a new route for synthesizing long, stable carbyne chains in bulk, overcoming previous length limitations and stability issues.

Findings

Successfully produced chains with over 2300 carbon atoms

Confirmed bulk yield with high Raman bands and microscopy

Demonstrated stability of long chains in ambient conditions

Abstract

The extreme instability and strong chemical activity of carbyne, the infinite sp1 hybridized carbon chain, are responsible for its low possibility to survive in ambient conditions. Therefore, much less has been possible to explore about carbyne as compared to other novel carbon allotropes such as fullerenes, nanotubes and graphene. Although end-capping groups can be used to stabilize carbon chains, length limitation is still a barrier for its actual production, and even more for applications. Here, we report a novel route for bulk production of record long acetylenic linear carbon chains protected by thin double-walled carbon nanotubes. A corresponding extremely high Raman band is the first proof of a truly bulk yield formation of very long arrangements, which is unambiguously confirmed by transmission electron microscopy and near-field Raman spectroscopy. Our production establishes a way to exceptionally long stable carbon chains including more than 2300 carbon atoms, and an elegant forerunner towards the final goal of a bulk production of essentially infinite carbyne.