Comparison of thermally and chemically reduced graphene oxides by thermal analysis and Raman spectroscopy

Abstract

Graphene oxide (GO) is not only an intermediate in top-down graphene preparation, but it is also acknowledged for its convenient application when the hydrophobicity of graphene is a drawback. Its preparation through the wet exfoliation of graphite inevitably leads to a product lacking several of the outstanding features of graphene. The destroyed graphene structure can be at least partially reconstructed by thermal and/or wet chemical reduction. Thermally reduced graphene oxide (TRGO) was obtained by mild heat treatment (300 °C) in argon, while chemically reduced graphene oxide (CRGO) was prepared by using a green reagent, ascorbic acid (AA). The parent GO and the two GO derivatives were compared by thermogravimetric analysis coupled with mass spectroscopy and Raman spectroscopy. Both reductive treatments resulted in enhanced thermal stability and higher C/O ratio. Although the chemical reduction with AA was more efficient in the elimination of the O functionalities, it also resulted in significant fragmentation of the graphene-like platelets.

Ecotoxicity Assessment of Graphene Oxide by Daphnia magna through a Multimarker Approach from the Molecular to the Physiological Level including Behavioral Changes

“…For the ecotoxicity tests, a 100 mg/L GO stock suspension was prepared with distilled water. The concentration of this stock suspension was checked with UV-Vis spectroscopy [ 15 ].…”

“…The Daphnia magna acute lethality and immobilization tests were performed based on the OECD 202 [ 15 ] test protocol.…”

Graphene Oxide Protected Copper Benzene-1,3,5-Tricarboxylate for Clean Energy Gas Adsorption

“…GO loses the physically adsorbed water prior to 150 °C, and above 200 °C, the oxygen-containing functional groups decompose. Around 550 °C, the GO starts to burn [ 75 ]. The thermogravimetric curves of HKUST-1 and HKUST-1@GO-2 are very similar.…”

“…The C/O atomic ratio from the XPS measurement was 2.6 [ 74 ]. Further characteristics are reported in [ 72 , 75 ].…”

In situ control of graphene oxide dispersions with a small impedance sensor

“…The ratio of the intensity of D/G Bands was also calculated and it is acan be considered as a measure of defects in the structure [38]. Likewise, Farah et al [39] used the same ratio to study the reduction phenomena. As shown in the graph, the ratio of the intensity of those peaks lowers decreases as ultrasonication energy increases, thus showing consistency with the FT-IR results.…”