Chemical bonding and stability of multilayer graphene oxide layers

Cheng Gong , Suenne Kim (1) , Si Zhou (2) , Yike Hu (3) , Muge Acik (4) , Walt A de Heer (5) , Claire Berger (6) , Angelo Bongiorno (2) , Elisa Riedo (1) , Yves J Chabal (7)

1 School of Physics
2 GATECH - College of Computing
3 School of Physics [Atlanta]
4 Department of Materials Science and Engineering (Dallas, USA)
5 Georgia Institute of Technology [Atlanta]
6 NEEL - QuantECA - Circuits électroniques quantiques Alpes
7 UT Dallas - University of Texas at Dallas [Richardson]

The chemistry of graphene oxide (GO) and its response to external stimuli such as temperature and light are not well understood and only approximately controlled. This understanding is however crucial to enable future applications of the material that typically are subject to environmental conditions. The nature of the initial GO is also highly dependent on the preparation and the form of the initial carbon material. Here, we consider both standard GO made from oxidizing graphite and layered GO made from oxidizing epitaxial graphene on SiC, and examine their evolution under different stimuli. The effect of the solvent on the thermal evolution of standard GO in vacuum is first investigated. In situ infrared absorption measurements clearly show that the nature of the last solvent in contact with GO prior to deposition on a substrate for vacuum annealing studies substantially affect the chemical evolution of the material as GO is reduced. Second, the stability of GO derived from epitaxial graphene (on SiC) is examined as a function of time. We show that hydrogen, in the form of CH, is present after the Hummers process, and that hydrogen favors the reduction of epoxide groups and the formation of water molecules. Importantly, this transformation can take place at room temperature, albeit slowly (~ one month). Finally, the chemical interaction (e.g. bonding) between GO layers in multilayer samples is examined with diffraction (XRD) methods, spectroscopic (IR, XPS, Raman) techniques, imaging (APF) and first principles modeling.

Mots clés: chemical stability and evolution; infrared spectroscopy; graphene oxide; first principles calculations

Domaines: Systèmes mésoscopiques et effet Hall quantique [cond-mat.mes-hall]

Cheng Gong, Suenne Kim, Si Zhou, Yike Hu, Muge Acik, et al.. Chemical bonding and stability of multilayer graphene oxide layers. Proceedings of SPIE, the International Society for Optical Engineering, 2014, Oxide-based Materials and Devices V, 8987, pp.89872C. ⟨10.1117/12.2045554⟩. ⟨hal-01784085⟩