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Probing the Thermal Deoxygenation of Graphene Oxide Using High-Resolution In Situ X-ray-Based Spectroscopies

Biomedical Sciences Research Institute Computer Science Research Institute Environmental Sciences Research Institute Nanotechnology & Advanced Materials Research Institute

Ganguly, A, Sharma, S, Papakonstantinou, P and Hamilton, JWJ (2011) Probing the Thermal Deoxygenation of Graphene Oxide Using High-Resolution In Situ X-ray-Based Spectroscopies. The Journal of Physical Chemistry C, 115 . pp. 17009-17019. [Journal article]

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URL: http://pubs.acs.org/doi/abs/10.1021/jp203741y

DOI: 10.1021/jp203741y

Abstract

Despite the recent developments in graphene oxide due toits importance as a host precursor of graphene, the detailed electronicstructure and its evolution during the thermal reduction remain largelyunknown, hindering its potential applications. We show that a combina-tion of high-resolution in situ X-ray photoemission and X-ray absorptionspectroscopies offer a powerful approach to monitor the deoxygenationprocess and comprehensively evaluate the electronic structure of gra-phene oxide thin films at different stages of the thermal reduction process.It is established that the edge plane carboxyl groups are highly unstable,whereas carbonyl groups are more difficult to remove. The resultsconsistently support the formation of phenol groups through reaction of basalplane epoxide groups with adjacent hydroxyl groups at moderate degrees ofthermal activation (∼400 C). The phenol groups are predominant overcarbonyl groups and survive even at a temperature of 1000 C. For the first time, a drastic increase in the density of states (DOS) near theFermi level at 600 C is observed, suggesting a progressive restoration of aromatic structure in the thermally reduced graphene oxide.

Item Type:Journal article
Faculties and Schools:Faculty of Computing & Engineering
Faculty of Computing & Engineering > School of Engineering
Research Institutes and Groups:Engineering Research Institute
Engineering Research Institute > Nanotechnology & Integrated BioEngineering Centre (NIBEC)
ID Code:19602
Deposited By:Professor Pagona Papakonstantinou
Deposited On:06 Sep 2011 14:51
Last Modified:06 Sep 2011 14:51

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