Molecular theory of graphene oxide

Abstract

Applied to graphene oxide, the molecular theory of graphene considers its oxide as a final product in the succession of polyderivatives related to a series of oxidation reactions involving different oxidants. The graphene oxide structure is created in the course of a stepwise computational synthesis of polyoxides of the (5,5) nanographene molecule governed by an algorithm that takes into account the molecule's natural radicalization due to the correlation of its odd electrons, the extremely strong influence of the structure on properties, and a sharp response of the molecule behavior on small actions of external factors. Taking these together, the theory has allowed for a clear, transparent and understandable explanation of the hot points of graphene oxide chemistry and suggesting reliable models of both chemically produced and chemically reduced graphene oxides.

Neutron scattering from graphene oxide paper and thermally exfoliated reduced graphene oxide

“…7a) is based on the parent (5, 5) graphene molecule (a rectangular fragment with five benzenoid units along armchair and zigzag edges). As has been shown, a molecule of this size is large enough to reliably reveal the main idiosyncrasies of graphene's chemistry [5,23]. It is currently widely accepted that the atomic oxygens and hydroxyls (mainly) and carboxyls (in minority) take part in the graphene oxygenation, resulting in the formation of epoxy and hydroxy groups on the molecule basal planes, while carbonyls, hydroxyls, and carboxyls are spread over the circumferences (see a detailed analysis in [5]).…”

“…As has been shown, a molecule of this size is large enough to reliably reveal the main idiosyncrasies of graphene's chemistry [5,23]. It is currently widely accepted that the atomic oxygens and hydroxyls (mainly) and carboxyls (in minority) take part in the graphene oxygenation, resulting in the formation of epoxy and hydroxy groups on the molecule basal planes, while carbonyls, hydroxyls, and carboxyls are spread over the circumferences (see a detailed analysis in [5]). The distribution of these OCGs over the carbon core is not standard and may vary widely, depending on the chemical protocol in use as well as on external conditions of the oxygenation.…”

“…Assuming that the thickness of a GO layer is ∼ 0.6 nm [16], the ppGO stacks may consist of 4 -6 layers.…”

“…The former exhibits the fact that both basal plane and the circumference area of the parent graphene molecules are involved in the oxidation while the latter points to the prepotency of epoxy units among the GO oxygen-containing groups (OCGs). A common feature of rGO is related to the interlayer distance of ∼ 3.5Å that points to the recovered planarity of the rGO carbon skeleton, on one hand, and to the location of residual OCGs in the circumference area [2,5], on the other. Individual differences within the two communities are caused by the difference in size and shape of carbon skeletons of the parent graphene molecules and, consequently, by different numbers of attached OCGs, as well as by evidently individual combinations of these groups in each case.…”

Graphite oxide catalyzed synthesis of $\beta $-amino alcohols by ring-opening of epoxides

“…The graphite oxide surface comprises various oxygen-containing groups such as hydroxyl and carbonyl groups, which confer an acidic character to the material. 52 This property has recently been exploited for the conversion of oxiranes into thiiranes, 39 esterification of organic acids, 40 and preparation of 1,4-dihydropyridines.…”