Comparative study of different scalable routes to synthesize graphene oxide and reduced graphene oxide

Abstract

Graphene is considered the world's strongest and thinnest material, in addition to be a very good heat and electricity conductor. Traditional methods to produce graphene include mechanical exfoliation, Chemical Vapor Deposition or thermal expansion but none of them are attractive from the commercial point of view due to its low yield or the poor quality of the retrieved product [1]. Graphite and graphene oxide are the most important graphene allotropes. Graphite oxide is obtained by generation of oxygenated functional groups on the surface and edges of graphite which, after its layer expansion, provides graphene oxide. Nowadays, graphene oxide reduction (via chemical or thermal routes) seems to be the best method to synthesize graphene at industrial scale [2] although, as a consequence of the experimental procedure followed, some defects remain in the final structure of the product. Graphite oxide can be synthesized by either Brodie, Staudenmaier, or Hummers method and its variations, namely Modified Hummers Method or Improved Hummers Method [3]. Among them, Improved Hummers Method is characterized by its both lower toxicity and several advantages in terms of the resulting products. Even so, the oxidation protocol associated to the Improved Hummed Method clearly depends on the abundant use of strong acids (leading to subsequent environmental issues), high treatment times and tedious purification processes, which results in high manufacture costs [4]. These reasons among others make the industrial commercialization of graphite oxide and its derivative products to be limited. In previously papers, optimization of the Improved Hummers Method (as reported in Literature [3]) which use graphite as the raw material and KMnO 4 and H 2 SO 4 as chemical reagents to produce the oxidation of graphite was reported. Chen et al. [5] proposed in 2013 the elimination of NaNO 3 for the reaction and H 3 PO 4 for graphite oxide washing and demonstrated the disposal of waste water. Lavin-Lopez et al. [6] showed that the oxidation time could be

E‐Waste Based V2O5/RGO/Pt Nanocomposite for Photocatalytic Degradation of Oxytetracycline

“…Figure 1b shows the structural characterization of the RGOV, RGO, and RGOV-20/Pt(1%) nanocomposites. A sharp diffraction peak at 2θ = 10.2 originated from RGO, is in good agreement with a previous study [21]. The x-ray diffraction spectroscopy (XRD) spectrum of V 2 O 5 indicates that the synthesized photocatalyst is crystalline in nature.…”

Surface modification of reduced graphene oxide‐polyaniline nanotubes nanocomposites for improved supercapacitor electrodes

“…The most prominent bands observed in the μ ‐Raman spectra are the D and G bands. The G band appears due to in‐plane vibration of sp 2 carbon atoms and the D band arises from a ring‐breathing mode of sp 2 atoms, which is activated only in the presence of structural imperfections and defects in a carbon material . The ratio of intensities of the D and G bands ( I D / I G ), termed as the disorder parameter, provides information about defects density in a carbon nanostructure and can determine the ion irradiation induced damage in both RGO and PAniNTs .…”

Recent Developments in Graphene Oxide/Epoxy Carbon Fiber-Reinforced Composites

“…The most common method for producing graphene derived materials for research in to polymer and materials science is the wet-chemical synthesis of graphite oxide from a graphite feedstock (Romero et al, 2018). This technique is the loosely termed "modified Hummers" method which involves the aggressive oxidation of graphite in a concentrated solution of sulphuric acid (H 2 SO 4 ) and potassium permanganate (KMnO 4 ).…”

“…GO is a precursor for graphene material and can be further processed to make rGO; the most popular methods are wet-chemical and thermally annealing (Tang et al, 2012;Abdolhosseinzadeh et al, 2015;Romero et al, 2018). Hydrazine hydrate (N 2 H 4 • H 2 O) reducing agent is a popular treatment to remove oxygen functionalities from the basal plane of GO and produces nitrogen gas and water.…”