Tuning the properties of graphene oxide by chemical functionalization

Graphene oxide (GO) has attracted rising interest since the discovery of the wet chemical route to graphene. GO is a non-stoichiometric, bi-dimensional carbon nanomaterial composed of a graphitic sheet decorated with various oxygen functional groups (OFGs). It is easily produced in large quantities and of good quality by wet-chemical oxidation and exfoliation of bulk graphite. Amongst the most, Hummers’ method is the most widely employed synthetic approach. The GO produced by these means is rich in OFGs such as islands of epoxides and hydroxyls in the basal plane and carbonyls, phenols, and carboxyl-groups on the edges and in the defects1. The coexistence of these groups makes GO prone to chemical functionalization through a plethora of synthetic pathways and to a wide range of electrostatic interactions. Furthermore, the presence of graphitic domains enables non-covalent functionalization through dispersive interactions such as π- π stacking. Additionally, GO and GO-based materials can be reduced by both electrochemical and chemical means to restore the π-delocalized network obtaining a reduced graphene oxide (rGO) with similar properties to pristine graphene. Therefore, due to its quivering chemistry, graphene oxide can be regarded as a perfect starting point for the design of graphene-based functional materials2. This work aims to obtain graphene-based materials e.g. carboxyl-rich GO (GO-COOH) and reduced graphene oxide through different reaction approaches on previously synthesized GO. Respectively, these functionalized materials are obtained by exploiting O-acylation with succinic anhydride and reduction reaction with ascorbic acid and sodium ascorbate3. Furthermore, it will be explored the electrochemical reduction and concurrent deposition of GO and GO-based nanomaterials on different substrates. The materials obtained are characterized, step-by-step, by spectroscopy means e.g. XPS, Raman, and UV-Vis spectroscopies. References (1) Halbig C. A., Mukherjee B., Eigler S., Garaj S. J. Am. Chem. Soc., 2024, 146, 7431-7437. (2) Guo S., Garaj S., Bianco A., Ménard-Moyon C. Nat. Rev. Phys., 2022, 4, 247-262. (3) Amato F., Motta A., Giaccari L., Di Pasquale R., Scaramuzzo F. A., Zanoni R., Marrani A. G. Nanoscale Adv., 2023, 5, 893-906.