Hydrophilic Graphene Preparation from Gallic Acid Modified Graphene Oxide in Magnesium Self-Propagating High Temperature Synthesis Process

Abstract

Hydrophilic graphene sheets were synthesized from a mixture of magnesium and gallic acid (GA) modified graphene oxide (GO) in a self-propagating high-temperature synthesis (SHS) process, and hydrophilic graphene sheets displayed the higher C/O ratio (16.36), outstanding conductivity (~88900 S/m) and excellent water-solubility. GO sheets were connected together by GA, and GA was captured to darn GO structure defects through the formation of hydrogen bonds and ester bonds. In SHS process, the most oxygen ions of GO reacted with magnesium to prevent the escape of carbon dioxide and carbon monoxide to from the structure defects associated with vacancies, and GA could take place the high-temperature carbonization, during which a large-area graphene sheets formed with a part of the structure defects being repaired. When only GO was reduced by magnesium in SHS process, and the reduced GO (rGO) exhibited the smaller sheets, the lower C/O ratio (15.26), the weaker conductivity (4200 S/m) and the poor water-solubility because rGO inevitably left behind carbon vacancies and topological defects. Therefore, the larger sheet, less edge defects and free structure defects associated with vacancies play a key role for graphene sheets good dispersion in water.

Sustainable synthesis of graphene-based adsorbent using date syrup

“…These results reveal that D-GSH has largely sp 2 frame graphene-like carbon material obtained by the conversion of sucrose and fructose molecules present in the date syrup. The intensity ratio, I D /I G of 0.94 indicates that D-GSH has a structural disorder same as that of graphene oxide 34 . On the other hand, the I 2D /I G ratio was found to be 0.43, attributed to the presence of multilayer graphene on D-GSH 35 .…”

Multifunctional Platforms Based on Graphene Oxide and Natural Products

“…The 2D band appears in the 2800 cm −1 and 3200 cm −1 range. Raman spectra did not show important differences in the D and G band between GO and GO loaded with bioactive compounds spectra, [43,72,73] thereby the graphene structure has not been altered, the bioactive compounds being adsorbed on the surface and no additional disorder was induced. The intensity ratio (I D /I G ) for GO (0.97) is slightly larger than GO loaded with bioactive substances starting from 0.87 (GO-limonene) to 0.92 (GO-gallic acid) which suggests that the active compounds can repair the defects of graphene during functionalization [73].…”

Reduced Graphene Oxide–Epoxy Grafted Poly(Styrene-Co-Acrylate) Composites for Corrosion Protection of Mild Steel

“…The Raman spectra of rGO, GESA1, GESA2, GESA3, GESA4, and GESA5 are shown in Figure 3, and two characteristic D and G peaks were observed for all samples. The D band arose from the defects and disorder of carbon in graphene platelets and moreover, the G band originated from the first-order scattering of the E 2g vibration mode and the in-plane vibration of ordered sp 2 -bonding carbon atoms [27]. The peak intensity ratio of the D band to the G band (I D /I G ) was investigated to examine the degree of defects and disorder.…”