A remarkably simple characterization of glassy carbon-supported films of graphite, graphene oxide, and chemically converted graphene using Fe(CN)3−6/Fe(CN)4−6 and O2 as redox probes

Abstract

A remarkably simple characterization of glassy carbonsupported films of graphite, graphene oxide, and chemically converted graphene using Fe(CN) 3{ 6 / Fe(CN) 4{ 6 and O 2 as redox probes3

An Oxygen Reduction Study of Graphene-Based Nanomaterials of Different Origin

“…0.3 and 0.2 in case of GO and rGO samples, respectively. This is also consistent with the literature data [52,58]. Based on these observations, we may conclude that the hydrazine treatment results in a limited reduction of GO, since oxygen-containing functionalities still exist in the final product and it is clear that the rGO material synthesised in this work is only partially reduced graphene oxide.…”

“…In more specific, the nitrogen content of 2 at.% was estimated by XPS, suggesting that some amount of nitrogen may be present due to the hydrazine treatment [28]. This feature is in good agreement with the literature [52], where a similar synthesis procedure was used to obtain rGO. Figure 4 shows Raman spectra of graphene nanopowder (from Graphene Supermarket), graphene nanoplatelet aggregates (from Strem Chemicals), GO and rGO.…”

“…Based on these observations, we may conclude that the hydrazine treatment results in a limited reduction of GO, since oxygen-containing functionalities still exist in the final product and it is clear that the rGO material synthesised in this work is only partially reduced graphene oxide. However, according to the literature this result is rather expected [15,51,52,59]. Additionally, the XPS survey spectra of rGO revealed a small N 1s peak (see Figure 3).…”

“…The main difference between GO and rGO is that GO is with higher oxygen content than rGO [54,55]. Even though the reduction of GO should supposedly remove the oxygen-containing species from the rGO surface in order to restore some unique properties of pristine graphene [15], it has been shown that some amount of oxygen still remains in the sample of rGO [24,28,38,52,56,57]. In this study, according to the XPS survey spectra of rGO (see Figure 3c), the O 1s peak of rGO have been declined compared with the XPS spectra of GO (data not shown), revealing that part of the C-O functionalities on the surface of GO have been reduced.…”

“…284.5 eV and it is well-known that this corresponds to the sp 2 carbon. Additionally, the XPS spectra of GO (data not displayed) and rGO (see Figure 3c) revealed another peak around 286.4 eV presumably attributed to the C-O species (e.g., hydroxyl and epoxy groups) [37,47,51,52]. According to the literature, GO should also consist carboxylic and carbonyl groups, which decorate the edge sites, whereas hydroxyl and epoxy groups are present on the basal plane of a GO sheet [15,30].…”