Fabrication of fluorographene nanosheets with high yield and good quality based on supercritical fluid-phase exfoliation

This article presents a novel and simple method of supercritical fluid-phase exfoliation to fabricate fluorographene (FG) nanosheets with high yield and good quality. After soaking with supercritical CO2 and glycol at 10 MPa and 50 °C for 24 h, fluoride graphite powder was exfoliated by the intercalated CO2 and glycol molecules during an abrupt depressurization step. Here, supercritical CO2 acted as a penetrant and glycol acted as a “molecular wedge” to exfoliate fluoride graphite very well. The properties of FG nanosheets were detected by TEM, AFM, UV spectra, FTIR, XPS, Raman spectra, and XRD, which show the possibility of producing thickness-controlled FG nanosheets by varying numbers of supercritical CO2 process and the high yield of pure FG nanosheets of 32 wt%, four times higher than that of the sample treated only by the traditional method of sonication. Its simplicity, high productivity, low cost, and short processing time make this technique suitable for large-scale manufacturing of FG nanosheets.