Methylbenzenes on graphene

TL;DR

This study uses density functional theory to analyze how methylbenzenes and benzene adsorb onto graphene, revealing a linear increase in binding energy with methyl group addition, relevant for sensor and filter applications.

Contribution

It provides a detailed theoretical analysis of methylbenzene adsorption on graphene, highlighting the linear relationship between methyl groups and binding energy using vdW-DF functionals.

Findings

Binding energy increases linearly with methyl groups (0.09 eV per group)

vdW-DF1 and vdW-DF-cx functionals produce consistent results

Insights applicable to sensor and filter material design

Abstract

We present a theory study of the physisorption of the series of methylbenzenes (toluene, xylene and mesitylene), as well as benzene, on graphene. This is relevant for the basic understanding of graphene used as a material for sensors and as an idealized model for the carbon in active carbon filters. The molecules are studied in a number of positions and orientations relative graphene, using density functional theory with the van der Waals functional vdW-DF. We focus on the vdW-DF1 and vdW-DF-cx functionals, and find that the binding energy of the molecules on graphene grows linearly with the number of methyl groups, at the rate of 0.09 eV per added methyl group.