The adsorption properties of polycrystalline graphene: quantum-chemical simulation

This study presents the results of quantum-chemical simulation of H$_{2}$O, NH$_{3}$, PH$_{3}$, and CH$_{4}$ molecules and their fragments adsorption onto graphene nanoclusters with di erent types of grain boundaries. We describe the molecule adsorption states on graphene and estimate the absorption energy characteristics. It is shown that the presence of grain boundaries changes the geometric and electronic parameters of grapheme, and can lead to a physical adsorption and chemisorption of molecules without dissociation, unlike in orderly graphene. Dissociative chemisorption of molecules on the grain boundaries is accompanied by some signi cant changes in the geometric, electronic, and energy state of graphene. The features of the energy change di erences for the HOMO-LUMO of graphene with the chemisorbed dissociation fragments can be used to identify the gas molecules on graphene by their electronic spectra.