A Re‐evaluation of How Functional Groups Modify the Electronic Structure of Graphene Oxide

Abstract

The first 4 eV of the conduction band in graphene oxide is dominated by states from carbon sites that are in close proximity, but not directly bonded, to oxidizing functional groups. The carbon sites that are bonded directly to these groups, such as epoxide and hydroxyl groups, are much higher in energy.

Tuning the electronic structure of graphene through nitrogen doping: experiment and theory

“…2) can be seen. 51 As it is shown in our calculations, for the N-doped graphene samples, this feature is assigned to the graphitic conguration of C-N bonding. 55 The feature at 291.8 eV in the C 1s spectra is attributed to the long range order in the electronic structure of graphene.…”

“…41,51,52 We note that the absence of feature E and the strong F peak in the N 1s XAS spectrum of sample 4 show that this is the sample with the highest graphitic N-sites amongst the other N-doped graphene samples. Although there are differences in the spectra of our N-doped samples, the good match between two distinct features, peaks F (at 401.8 eV) and G (at 408.2 eV) in the N 1s XAS and peak B as the main feature in the N Ka XES of all the measured and calculated spectra, validates the graphitic nitrogen defect as the dominant nitrogen conguration.…”

Pronounced, Reversible, and in Situ Modification of the Electronic Structure of Graphene Oxide via Buckling below 160 K

“…As we have shown previously, residual π-conjugated networks can still be found even on strongly oxidized graphene. (30) Strain-induced TB-epoxide makes the functionalization of the graphene lattice much more complete, thus destroying any residual π-conjugated pathways. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 1,3,5 carbon sites, is responsible for this change in the electronic structure.…”

“…(30) When attempting to quantify the effect that amorphous solid water may have upon the graphene DOS, we simulated many different structures with water/graphene or water/oxidized graphene. The two that we chose to display in 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 does not change even with light oxidation; any changes to the C pDOS of the graphene sheets is entirely due to the functional group.…”

Theoretical X-ray absorption spectroscopy database analysis for oxidised 2D carbon nanomaterials

“…Some representatives of these resource-sustainable and environmentally-friendly materials can either be directly used as photocatalysts for water-splitting with tunable bandgaps, 1 or can serve as precursor materials for the production of reduced graphene oxide 2,3 as well as biocompatible diagnostics or drug-carrying nanoparticles. 4,5 For all of these applications, the extent and type of surface functionalisation is of major importance since it determines not only the electronic structure of the 2D material 6 but also other important properties like colloidal stability and surface charge. 7 Although its first discovery dates back over 150 years, 8 the atomic structure of GO however remains highly debated.…”