Trapping molecules in a covalent graphene-nanotube hybrid

TL;DR

This paper uses molecular dynamics simulations to demonstrate that hydrocarbon molecules can passively diffuse and be securely trapped within a covalent graphene-nanotube hybrid, offering potential for gas storage and separation.

Contribution

It reveals a novel passive trapping mechanism in a graphene-nanotube hybrid, highlighting the role of binding energy variations and the gate effect at room temperature.

Findings

Molecules undergo self-diffusion into nanotubes without external forces.

Trapped molecules remain secure at room temperature due to the gate effect.

The mechanism has implications for gas storage and separation technologies.

Abstract

This study employs molecular dynamics simulations to examine the physisorption behavior of hydrocarbon molecules on a covalent graphene-nanotube hybrid nanostructure. The results indicate that the adsorbed molecules undergo self-diffusion into the nanotubes without the need for external driving forces, primarily driven by significant variations in binding energy throughout different regions. Notably, these molecules remain securely trapped within the tubes even at room temperature, thanks to a ``gate'' effect observed at the neck region, despite the presence of a concentration gradient that would typically hinder such trapping. This mechanism of passive mass transport and retention holds implications for the storage and separation of gas molecules.