Graphene material prepared by thermal reduction of the electrochemically synthesized graphite oxide

Abstract

In the present work we demonstrate a simple and effective way to produce bulk quantities of graphene material. For the first time, graphite oxide (GO), synthesized by electrochemical treatment of natural graphite in HClO 4 aqueous solution, was used to obtain thermally exfoliated-reduced graphite oxide (TRGO). Herein, GO was thermally exfoliated and reduced at 500 C in air, giving the final product of TRGO. Due to shock treatment, the volume of the synthesized TRGO drastically increased compared to the starting GO. Furthermore, the exfoliation process resulted in a significant decrease in the concentration of oxygen functionalities. The choice of GO exfoliation temperature was preceded by thermogravimetric analysis (TGA). TRGO was characterized using X-ray diffraction (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and atomic force microscopy (AFM) analysis. Fig. 6 Topography of a graphene-like sheet (a) and its height profile (b), micrograph of a 50 Â 50 mm area of a silicon substrate supporting graphene material flakes (c), flake equivalent radius distribution of 876 graphene material flakes (d) and its thickness distribution (e). 63062 | RSC Adv., 2016, 6, 63058-63063 This journal is

Graphene material preparation through thermal treatment of graphite oxide electrochemically synthesized in aqueous sulfuric acid

“…[2][3][4][5] A variety of methods have been employed to produce graphene materials, however exfoliation by mechanical (ball milling, micromechanical cleavage, sonication) 5 as well as electrochemical treatment [6][7][8] appear to be most oen used. Graphene materials can also be synthesized by other methods, such as chemical or electrochemical reduction of graphene oxide, 2,7 thermal exfoliation of graphite/graphene oxide, [9][10][11] unzipping of carbon nanotubes, 12 chemical vapour deposition, 13 or plasma assisted method. 14 Properties of graphene materials being strongly related to the method used as well as conditions applied, determine its practical application, i.e.…”

“…Owing to thus method large quantities of graphene material can be synthesized. 11,17 Thermal treatment of GO reduces the concentration of oxygen functional groups, in parallel the volume of formed TRGO drastically increases comparing to the starting GO. 9 GO being the precursor for thermal reduction process is commonly synthesized by chemical methods.…”

“…9,10,17 However GO prepared by electrochemical overoxidation of graphite can be also used. 11,18 GO can be thermally reduced by shock treatment at the temperatures higher than 1000 C in air or argon atmosphere [19][20][21][22] or by gradual heating under the inert gas ow (nitrogen or argon). 9,23 To remove all oxygen functionalities from the graphitic structure, thermal treatment of GO should be carried out in the presence of hydrogen.…”

Scalable Production of Nanographene and Doping via Nondestructive Covalent Functionalization

“…Modified versions of Hummers' method can produce nanographene oxide at gram‐scale, but these reactions require large quantities of harsh chemicals that create sp 3 defects, disrupting the π‐conjugated system of the materials. This in turn diminishes favorable electrical and optical properties as compared with pristine graphene . Nanographene can also be grown directly by carbon vapor deposition (CVD) and similar techniques .…”

Cross-plane thermal transport in graphene-based structures

“…This can be explained as the loss of carbon atoms from the graphene lattice which results in formation of defects such as vacancies and distortions, where the integrated sp 2 domains are further separated into smaller ones [59]. Further reduction is likely to induce the decrease of the ID/IG, due to the recovery of the sp 2 -hybridized C-C bonds [55,143,144]. This recovery is apparent in the highly reduced GP structure studied in Chapter 3.…”