Graphene Oxide Synthesis, Properties and Characterization Techniques: A Comprehensive Review

Abstract

The unique properties of graphene oxide (GO) have attracted the attention of the research community and cost-effective routes for its production are studied. The type and percentage of the oxygen groups that decorate a GO sheet are dependent on the synthesis path, and this path specifies the carbon content of the sheet. The chemical reduction of GO results in reduced graphene oxide (rGO) while the removal of the oxygen groups is also achievable with thermal processes (tpGO). This review article introduces the reader to the carbon allotropes, provides information about graphene which is the backbone of GO and focuses on GO synthesis and properties. The last part covers some characterization techniques of GO (XRD, FTIR, AFM, SEM-EDS, N2 porosimetry and UV-Vis) with a view to the fundamental principles of each technique. Some critical aspects arise for GO synthesized and characterized from our group.

Polarized ATR-IR spectroscopy for the identification of material structure: The case of graphene oxide

“…The band cluster centered at 1635 cm -1 corresponds to the stretching of the C=C bonds composing the graphitic network [11], hence the 1602 cm -1 band is in agreement with its assignment to a C=C bond stretching mostly oriented along the xy plane [12]. The signal found on A z around 1793 cm -1 can be associated to the C=O bond stretching of carboxylic acid groups [12][13][14] since they are perpendicular to the sheet plane [15] and as 1732 and 1713 cm -1 bands are assigned to carbonyls C=O groups [15]. Figure 1b) suggests that this band originates from a low amount of COOH groups in the film instead of a packing defect.…”

“…According to molecular simulations [15], the shoulder at 1644 cm -1 may be assigned to stretching modes of more complex carbonyl-containing groups such as benzoquinone or pyrone. For the signal at ca 1625 cm -1 , several assignments were made in literature [12,13,16]. Based on orientation, the 1625 cm -1 signal might come from the C=O stretch near a vacancy of the graphitic sheet [17].…”

Facile preparation of a MXene–graphene oxide membrane and its voltage-gated ion transport behavior

“…In addition, the interfacial charge transfer resistance (R ct ) of MGO-7 is significantly lower than those of other membranes with different modulation ratios and pure MXene films (ESI, † Table S1), indicating that the ionic conductivity of MGOm is improved with the addition of a small amount of GO. However, when the amount of GO exceeds a range (up to 60 wt% of GO), GO behaves as an insulator with sheet resistance R s of B10 12 O sq À1 owing to the defect and the isolation of the SP2 region by oxygen groups, 44 which makes the electrical conductivity of the film decrease instead of increasing. In addition, the MGO-7 film has a low diffusion resistance; therefore, the graphical slope for the MGO-7 film is obviously larger than that of the pure MXene film.…”

Flake Graphene as an Efficient Agent Governing Cellular Fate and Antimicrobial Properties of Fibrous Tissue Engineering Scaffolds—A Review

“…Due to presence of those oxygen functional groups, GO has different properties compared to rGO or G [ 46 ]. Pristine graphene is a highly thermally and electrically conducting material with high electron mobility [ 47 , 48 , 49 ] due to the zero-overlap semimetal with electron and holes as charge carriers [ 50 ]. It was reported in the literature that graphene addition to other materials can improve their thermal and electrical conductivity [ 51 , 52 ].…”