Dissociative adsorption of atmospheric molecules at vacancies on the graphite (0 0 0 1) surface of samples exposed to plasma

The quantum Density Functional Theory (DFT) model of a single atom vacancy on the basal graphite surface is first validated through comparison of the theoretical vibrational spectra of the fully hydrogenated defect with the corresponding High Resolution Energy Loss Spectroscopy (HREELS) spectra. We then proceed to investigate atmospheric molecules adsorption on vacancy defects on the (0 0 0 1) graphite surface. Carbon dioxide and nitrogen have no interaction with the defect whereas carbon monoxide is incorporated into the vacancy with an activation energy of 1.5 eV. Water dissociates with a barrier of 1.6 eV, forming an adsorbed hydroxyl radical. Molecular oxygen dissociates with a very low barrier (0.2 eV).