Ab initio studies of the electronic structure induced by the CO and N2 adsorptions on graphene and on graphite slab

In this paper, we present an Ab initio study on the electronic properties of graphene and graphite slabs, using band structure and density of states calculations. The calculations are based on the use of GPAW (Grid-based Projector-Augmented Wave) and ASE (Atomistic Simulation Environment) methods. Our study also focuses on the adsorption mechanism of CO and N-2 molecules, deposited on adsorbents such as graphene and graphite slabs. The main results of our work are the optimization of the energies of CO (optimal energy equals -14.67 eV) and N-2 (optimal energy equals -15.80 eV) molecules, as well as the calculation of the optimal adsorption distance of these molecules on the adsorbents namely d(C0-gra phene) = 4.69 angstrom, d(N-2-graphene) = 6.03 angstrom, d(C0-graphite) = 4.69 angstrom and d(N-2-graphite) = 5.36 angstrom. The calculated changes in adsorption energies and density of state of the adsorbent could be exploited as an application for gas sensors. Simulated surface/gas tunneling microscopy (STM) observations are also reported. They allow to highlight the change of electronic structure of the surface when the gas is absorbed. All results contribute to the optimization of the potential realization of a gas sensor. Our paper provides interesting information for the theoretical and experimental communities working on this research area. It contributes to the debate on the adsorption of CO and N-2 molecules on graphene and on a graphite slab. Copyright (C) 2022 Elsevier Ltd. All rights reserved.