Adsorption of H2O, NH3, CO, NO2, and NO on graphene: A first-principles study

TL;DR

This study uses first-principles calculations to analyze how various gas molecules adsorb onto graphene, revealing their preferred binding sites, energies, charge transfer characteristics, and magnetic effects relevant for sensor applications.

Contribution

It provides detailed insights into the adsorption behaviors, energies, and doping effects of H2O, NH3, CO, NO2, and NO molecules on graphene, advancing understanding for sensor design.

Findings

Determined optimal adsorption positions and orientations.

Calculated adsorption energies for each molecule.

Analyzed charge transfer and magnetic effects.

Abstract

Motivated by the recent realization of graphene sensors to detect individual gas molecules, we investigate the adsorption of H2O, NH3, CO, NO2, and NO on a graphene substrate using first-principles calculations. The optimal adsorption position and orientation of these molecules on the graphene surface is determined and the adsorption energies are calculated. Molecular doping, i.e. charge transfer between the molecules and the graphene surface, is discussed in light of the density of states and the molecular orbitals of the adsorbates. The efficiency of doping of the different molecules is determined and the influence of their magnetic moment is discussed.