Adsorption of molecular oxygen on doped graphene: atomic, electronic and magnetic properties

TL;DR

This study uses density functional theory to analyze how molecular oxygen interacts with various doped graphene materials, revealing potential for electronic and spintronic applications through chemisorption-induced property changes.

Contribution

It provides a detailed theoretical analysis of oxygen adsorption on doped graphene, highlighting the effects on electronic structure and magnetism, especially the role of chemisorption and local curvature.

Findings

O2 physisorbs on B- and N-doped graphene with weak interactions.

Chemisorption occurs on Al-, Si-, P-, Cr-, and Mn-doped graphene, affecting electronic and magnetic properties.

Chemisorption on Cr-doped graphene shows antiferromagnetic behavior.

Abstract

Adsorption of molecular oxygen on B-, N-, Al-, Si-, P-, Cr- and Mn-doped graphene is theoretically studied using density functional theory in order to clarify if O2 can change the possibility of using doped graphene for gas sensors, electronic and spintronic devices. O2 is physisorbed on B-, and Ndoped graphene with small adsorption energy and long distance from the graphene plane, indicating the oxidation will not happen; chemisorption is observed on Al-, Si-, P-, Cr- and Mn-doped graphene. The local curvature caused by the large bond length of X-C (X represents the dopants) relative to CC bond plays a very important role in this chemisorption. The chemisorption of O2 induces dramatic changes of electronic structures and localized spin polarization of doped graphene, and in particular, chemisorption of O2 on Cr-doped graphene is antiferromagnetic. The analysis of electronic density of states shows the contribution of the hybridization between O and dopants is mainly from the p or d orbitals. Furthermore, spin density shows that the magnetization locates mainly around the doped atoms, which may be responsible for the Kondo effect. These special properties supply a good choice to control the electronic properties and spin polarization in the field of graphene engineering.