Structure, Stability, and Property Modulations of Stoichiometric Graphene Oxide

The recent success in synthesizing graphene monoxide (GMO) with rigorous stoichiometric ratio C:O = 1:1 has highlighted the need to determine its ground state geometry and to explore its physical properties. Using density functional theory and molecular dynamics simulation, we have found a new ether-type configuration of the GMO that is not only lower in energy than any other structures reported thus far, but is also stable up to 2000 K at which previous reported structures dissociate into CO molecules. The dynamic stability of the structure is further confirmed by calculating its phonon spectra. Furthermore, this ether-type structure exhibits anisotropies in mechanical stiffness and in electronic transport. Band gap, carrier concentration, and effective mass can be sensitively modulated by strain or higher oxidation level with C:O = 1:2. This study provides new theoretical insights into geometry, stability, and properties of the hotly pursued graphene oxide with unprecedented applications.