Hexagon Preserving Carbon Nanofoams

TL;DR

This study investigates hypothetical hexagon-preserving carbon nanofoams using DFTB methods, revealing their stability, electronic properties, and potential as new stable carbon allotropes with hybridized bonds.

Contribution

It introduces a computational analysis of porous carbon foams, highlighting their stability and electronic characteristics, which are novel compared to known carbon allotropes.

Findings

High structural stability at low density

Electronic properties similar to carbon nanotubes

Bulk moduli between graphite and diamond

Abstract

Carbon foams are hypothetical carbon allotropes that contain graphite-like (sp$^2$ carbon) segments, connected by sp$^3$ carbon atoms, resulting in porous structures. In this work the DFTB (Density Functional based Tight-Binding) method with periodic boundary conditions (PBC) was employed to study energetics, the stability and electronic properties of this unusual class of carbon systems. Concerning the most stable phases of carbon (graphite and diamond), foams show high structural stability at very low mass density. The electronic band structure and electronic DOS (density of states) of foams indicate a similar size dependence as carbon nanotubes. The calculated bulk moduli are in the range between that of graphite (5.5 GPa) and diamond (514 GPa). These structures may represent novel stable carbon modifications with sp$^2$+sp$^3$ hybridization.