The Impact of Morphology and Crystal Orientation of the Metal Substrate on the Reactivity of Graphene with Nitrene

Effective methods for the covalent functionalization of graphene are scarce due to the low chemical reactivity of graphene. As such, reactions of graphene primarily involve reactive intermediates such as free radicals, carbenes and nitrenes. We developed the covalent chemistry of graphene using nitrenes generated from perfluorophenyl azides (PFPA). We have shown that the reactivity of graphene with the electron-deficient perfluorophenyl nitrene can be enhanced by a metal substrate, achieved through increased electron density of graphene by the electron donating metal such as Ni and Cu. In this work, we investigate the impact of morphology and crystalline lattice structure of the metal substrate on the reactivity of graphene towards PFPA. Cu was used as the model substrate, and the reactions of PFPA with graphene supported on polycrystalline Cu (pCu), electropolished pCu, Cu(111), and silicon wafers (SiO₂/Si) were carried out. Raman spectroscopy was employed to analyze the vibrational changes of graphene before and after functionalization, using the intensity ratio of D and G peaks, I_D/I_G, as the indicator for the extent of reaction. We found that graphene supported on Cu(111) exhibited the most enhanced reactivity towards PFPA. The detailed studies and results will be presented.