title: Room-temperature metastability of multilayer graphene oxide films.
abstract: Graphene oxide potentially has multiple applications. The chemistry of graphene oxide and its response to external stimuli such as temperature and light are not well understood and only approximately controlled. This understanding is crucial to enable future applications of this material. Here, a combined experimental and density functional theory study shows that multilayer graphene oxide produced by oxidizing epitaxial graphene through the Hummers method is a metastable material whose structure and chemistry evolve at room temperature with a characteristic relaxation time of about one month. At the quasi-equilibrium, graphene oxide reaches a nearly stable reduced O/C ratio, and exhibits a structure deprived of epoxide groups and enriched in hydroxyl groups. Our calculations show that the structural and chemical changes are driven by the availability of hydrogen in the oxidized graphitic sheets, which favours the reduction of epoxide groups and the formation of water molecules.
authors.affiliation: School of Physics, Georgia Institute of Technology, Atlanta, Georgia 30332-0430, USA.
authors.forename: Suenne
authors.initials: S
authors.lastname: Kim
authors.forename: Si
authors.initials: S
authors.lastname: Zhou
authors.forename: Yike
authors.initials: Y
authors.lastname: Hu
authors.forename: Muge
authors.initials: M
authors.lastname: Acik
authors.forename: Yves J
authors.initials: YJ
authors.lastname: Chabal
authors.forename: Claire
authors.initials: C
authors.lastname: Berger
authors.forename: Walt
authors.initials: W
authors.lastname: de Heer
authors.forename: Angelo
authors.initials: A
authors.lastname: Bongiorno
authors.forename: Elisa
authors.initials: E
authors.lastname: Riedo