On the mechanism of gas adsorption for pristine, defective and functionalized graphene

TL;DR

This study investigates how defects and functionalization in graphene influence NO2 gas adsorption, revealing that certain defects and Fe doping significantly enhance adsorption capacity, which could benefit adsorption-based applications.

Contribution

It provides a detailed density functional theory analysis of how specific defects and Fe doping improve NO2 adsorption on graphene, a novel insight for material design.

Findings

Unsaturated carbon defects increase NO2 attraction.

Fe doping enhances NO2 adsorption, especially in mono- and tetra-vacant graphene.

Adsorption energy is higher for Fe-doped mono- and tetra-vacant graphene.

Abstract

Defect is no longer deemed an adverse aspect of graphene. Contrarily, it can pave ways of extending applicability of graphene. Here, we discuss the effects of three types of defects on graphene: carbon deficiency, adatom (single Fe) dopant and introduction of functional groups (carboxyl, pyran group) on NO2 gas adsorption via density functional theory method. We have observed that the unsaturated carbon in defected graphene is highly active to attract NO2 molecules. Our study suggests that introducing Fe on graphene can enhance the NO2 adsorption process. Adsorption energy calculations suggest the enhancement in NO2 adsorption is more profound for Fe-doped mono and tetra vacant graphene than Fe doped bi- and tri-vacant graphene. This study could potentially be useful in developing adsorption-based applications of graphene.