Mechanical and Thermal Stability of Graphyne and Graphdiyne Nanoscrolls

TL;DR

This study uses atomistic simulations to explore the formation and thermal stability of graphyne and graphdiyne nanoscrolls, revealing their stability conditions and comparing them to graphene nanoscrolls.

Contribution

It provides the first detailed analysis of the formation dynamics and thermal stability of various graphyne nanoscrolls, highlighting their structural stability limits.

Findings

Stable nanoscrolls can be formed for all studied graphyne types.

Stability depends on the width-to-height ratio of the sheets.

Graphyne nanoscrolls are less stable than graphene ones due to higher porosity.

Abstract

Graphynes and graphdiynes are carbon 2D allotrope structures presenting both sp2 and sp hybridized atoms. These materials have been theoretically predicted but due to intrinsic difficulties in their synthesis, only recently some of these structures have been experimentally realized. Graphyne nanoscrolls are structures obtained by rolling up graphyne sheets into papyrus-like structures. In this work we have investigated, through fully atomistic reactive molecular dynamics simulations, the dynamics of nanoscroll formation for a series of graphyne ({\alpha}, \b{eta}, and {\delta} types) structures. We have also investigated their thermal stability for a temperature range of 200-1000K. Our results show that stable nanoscrolls can be formed for all structures considered here. Their stability depends on a critical value of the ratio between width and height of the graphyne sheets. Our findings also show that these structures are structurally less stable then graphene-based nanoscrolls. This can be explained by the graphyne higher structural porosity which results in a decreased pi-pi stacking interactions