Insights on graphene oxide reactivity via XPS, raman and UV-Vis spectroscopy

Graphene is one of the most interesting materials of XXI Century thanks to its outstanding properties. Besides its advantages there are two main drawbacks: it is hard to produce in scalable quantities and it is poorly dispersible in water [1]. One convenient pathway to produce graphene is through the chemical oxidation of graphite. Such reaction inserts a series of oxygenated functional groups (OFGs) on the sheets of graphite. These moieties lead to an increased interlayer spacing, which permits a simpler exfoliation of the graphite oxide to graphene oxide (GO). A subsequent reduction process leads to a product called reduced graphene oxide (rGO), a nanomaterial with similar properties to graphene but with still some residual functional groups and structural defects [2]. Graphene oxide should not be seen only as a mean to obtain graphene or its similar species, rGO, but also as a stand-alone nanomaterial. The presence of various OFGs expands the chemistry of graphene oxide to a series of functionalization reactions, which pave the way to its application in many fields [3]. The aim of this study is to understand the structural modification of graphene oxide towards a carboxylation reaction via the XPS, Raman and UV-Vis techniques, with the aim to obtain both scalable and water-dispersible rGO. [1] C. Anichini, P. Samorì, Small, 2021, 17, 2100514. [2] D. C. Marcano, D. V. Kosynkin, J. M. Berlin, A. Sinitskii, Z. Sun, A. Slesarev, L. B. Alemany, W. Lu, J. M. Tour, ACS NANO, 2010, 4, 8. [3] S. Guo, S. Garaj, A. Bianco, C. Ménard-Moyon, Nature Reviews Physics, 2022, 4, 247-262