Functionalization of graphene oxide by fluorination and its characteristics

• Graphene oxide was fluorinated under different ratio of fluorine to nitrogen.
• Oxygen functional groups on graphene oxide were controlled by fluorination.
• Crystallite size and interplanar distance of fluorinated-graphene oxide changed depending on fluorine concentration.
• Fluorination is enable for graphene oxide to be applied to many application, such as composites, capacitors, and sensors.

We report on the gas fluorination of graphene oxide (GO) to control functionality. GO is fluorinated at room temperature using fluorine–nitrogen mixed gas in different ratios. X-ray photoelectron spectroscopy (XPS) and Fourier-transform infrared (FT-IR) are used to characterize the surface functional groups on the fluorinated GO. The oxygen functional groups in GO are getting decreased according to an increase of fluorine gas ratio. The proportion of semi-covalent CF bond is increased with increasing the fluorine gas ratio. The structural properties of the fluorinated GO are investigated by X-ray diffraction (XRD) and Raman spectroscopy. The d-spacing and crystallite size of fluorinated GO are decreased to 0.771 and 2.125 nm, respectively. The thermal and morphological characteristics are also investigated. The results suggest that gas fluorination of GO enables to control the functionality and crystallite size of GO.

Figure optionsDownload as PowerPoint slideBy varying the gas ratio of fluorine to nitrogen, it was possible to control oxygen functional groups on graphene oxide surface and crystallite size of graphene oxide.