Facile synthesis and spectroscopic characterization of fluorinated graphene with tunable C/F ratio via Zn reduction

摘要

A facile approach has been developed to synthesize fluorinated graphene (FG) nanosheets with tunable C/F ratio through liquid-phase exfoliation of fluorinated graphite (FGi) in N-methyl-2-pyrrolidone (NMP) and subsequent reduction with Zn powder. The evolution of surface composition and electronic structure of FG is investigated by X-ray photoelectron spectroscopy (XPS), X-ray absorption near-edge structure (XANES) spectroscopy and Raman spectroscopy. It is shown that the C/F atomic ratio of FG can be easily varied by Zn reduction with different reaction time and addition of diluted HCl solution. Both XPS and XANES results indicate the effective removal of covalent C-F bonds and progressive restoration of sp(2) -hybridized structure upon the treatment of FG with Zn. Raman measurements further reveal that Zn reduction can effectively restore the pi-electron conjugated electronic structure and reduce the optical gap of FG. This study provides a simple and effective route to tailor the surface composition and electronic structure of FG for potential applications. (C) 2016 Elsevier B.V. All rights reserved.