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Chemical Modification of Graphene Oxide by Nitrogenation: An X-ray Absorption and EmissionSpectroscopy Study

Chuang, CH, Ray, SC, Mazumder, D, Sharma, S, Ganguly, A, Papakonstantinou, Pagona, Chiou, JW, Tsai, HM, Shiu, HW, Chen, CH, Lin, HJ, Guo, J and Pong, WF (2017) Chemical Modification of Graphene Oxide by Nitrogenation: An X-ray Absorption and EmissionSpectroscopy Study. Scientific Reports, 7 . p. 42235. [Journal article]

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URL: http://www.nature.com/articles/srep42235

DOI: 10.1038/srep42235

Abstract

Nitrogen-doped graphene oxides (GO:Nx) were synthesized by a partial reduction of graphene oxide (GO) using urea [CO(NH2)2]. Their electronic/bonding structures were investigated using X-ray absorption near-edge structure (XANES), valence-band photoemission spectroscopy (VB-PES), X-ray emission spectroscopy (XES) and resonant inelastic X-ray scattering (RIXS). During GO:Nx synthesis, different nitrogen-bonding species, such as pyrrolic/graphitic-nitrogen, were formed by replacing of oxygen-containing functional groups. At lower N-content (2.7 at%), pyrrolic-N, owing to surface and subsurface diffusion of C, N and NH is deduced from various X-ray spectroscopies. In contrast, at higher N-content (5.0 at%) graphitic nitrogen was formed in which each N-atom trigonally bonds to three distinct sp2-hybridized carbons with substitution of the N-atoms for C atoms in the graphite layer. Upon nitrogen substitution, the total density of state close to Fermi level is increased to raise the valence-band maximum, as revealed by VB-PES spectra, indicating an electron donation from nitrogen, molecular bonding C/N/O coordination or/and lattice structure reorganization in GO:Nx. The well-ordered chemical environments induced by nitrogen dopant are revealed by XANES and RIXS measurements.

Item Type:Journal article
Keywords:nitrogen doped reduced graphene oxide, X-ray Absorption spectroscopy (XANES), X ray emission spectroscopy, valence-band photoemission spectroscopy (VB-PES), resonant inelastic X-ray scattering (RIXS).
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:36932
Deposited By: Professor Pagona Papakonstantinou
Deposited On:15 Feb 2017 13:52
Last Modified:17 Oct 2017 16:27

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