Interactions between the Aryldiazonium Cations and Graphene Oxide: A DFT Study

Abstract

Understanding the grafting behavior of the aryldiazonium cations is of fundamental and also of practical importance for the vast number of applications that involve the use of modified graphene oxide (from simple adsorption process to electronic and photovoltaic applications). In this work, the mechanism of the adsorption and grafting of diazonium cations on the graphene oxide surface was investigated by the use of density functional theory. Two types of aryldiazonium cations, one bearing only phenyl ring and the other nitrophenyl, were selected as adsorbates/grafted moiety. By evaluating the adsorption energies at 7 different positions onto the graphene oxide both in the gaseous and solvent phase (using COSMO approach), the most probable adsorption sites were found. Moreover, the most stable adsorption sites were used to calculate and plot NCI (noncovalent interactions). The obtained results are important as they not only give molecular insights regarding the nature of the interaction and its dependence on the adsorption site of the graphene oxide surface but also on the activation energy for such a grafting reaction to take place, providing a mechanistic aspect to understand these grafting reactions.

The influence of the grafted aryl groups on the solvation properties of the graphyne and graphdiyne - a MD study

“…This value is much higher than the values obtained for the gold surface (up to -38 kcal/mol) reflecting much stronger interface stability. The BDE has similar value as in the case of grafted graphene oxide surface (when the phenyl moiety is attached directly on aromatic carbon), even though in comparison to this surface, the adsorption energy for the graphyne and graphdiyne is smaller [40].…”

A theoretical and experimental study of the adsorptive removal of hexavalent chromium ions using graphene oxide as an adsorbent

“…Ab initio calculations were carried out with the DFT using the Dmol3 software. A previously employed GO model served for the adsorption study consisted of a 5 × 5 graphene layer (with epoxy, carboxy, and hydroxyl functional groups on its surface) [18]. The calculations were based on the triple-numeric quality with the polarization functions (TNP) basis set [19].…”

“…The calculations were based on the triple-numeric quality with the polarization functions (TNP) basis set [19]. The exchange-correlation energy is described by the Perdew-Burke-Ernzerhof (PBE) functional within the generalized gradient approximation (GGA) [18,20]. The van der Waals interaction on the calculations was accounted for using the Tkatchenko-Scheffler method [21].…”

“…All energy minima were characterized by performing a vibrational analysis to ensure the lack of imaginary frequencies [22,23]. The adsorption energy [14,18,23] was calculated as follows:…”

“…The electron density difference (EDD) was calculated using Cambridge Sequential Total Energy Package software [26]. The geometry optimization is performed by using the GGA-PBE [18,20]. A norm-conserving pseudopotential was used for the calculations.…”