Regulating the Bonding Nature and Location of C-F Bonds in Fluorinated Graphene by Doping Nitrogen Atoms

Chemical regulation of fluorinated graphene (FG) is of great importance for promoting its practical application but is still challenging due to the complexity of its chemical structure. Here, we demonstrate that the introduction of nitrogen (N) into graphene sheets is a feasible method to regulate the bonding nature and location of C-F bonds in the corresponding FG product. The fluorination reactivity of graphene materials is improved by doping N atoms into graphene sheets, which can even be increased by 2.7 times. Under the same F/C ratio, more covalent C-F bonds existed in fluorinated N-doped graphene than in fluorinated reduced graphene without doped N atoms. Results of DFT calculations, polarized ATR-FTIR, and WAXD confirmed that doped N atoms could significantly enhance the fluorination reactivity of their surrounding C atoms and thus localized C-F bonds around them. The local enrichment of C-F bonds certainly improved the covalent bonding nature; even the F/C ratio is not high enough. Meanwhile, this work provides a method for preparing N, F bifunctional graphene in large quantities, and an ultrahigh-bifunctional graphene with N/C ratio of 0.24 and F/C ratio of 0.56 has been obtained here, which has potential contributions to the industrialization of the preparation of ultrahigh-functional graphene.