Structural and vibrational study of graphene oxide via coronene based models: theoretical and experimental results

We use the Coronene (C24H12), a simple and finite molecule, to make a model to study the spectroscopic and structural alterations generated by oxygenated groups in graphene oxide (GO). Based on the Lerf-Klinowski model, we chose the hydroxyl [OH-], the carboxyl [COOH-] and the epoxy [the ring C2O inside the molecule] as our radicals of interest and study their collective and isolated effects. We perform geometry optimization, vibrational IR (via AM1 and DFT-B3LYP) and Raman spectra (via DFT-B3LYP) of a series of functionalized coronene molecules. As results, we obtain some useful data for the analysis of IR and Raman spectra of GO, which facilitate the understanding and identification of the peaks found in the experiment. Finally, we suggest a new model to study GO, producing an accurate signature when compared to our experimental data. Such molecule shows in more details of the structural effects caused by functionalization when compared to experimental data.