Graphene oxide nanoplatelets of different crystallinity synthesized from helical-ribbon carbon nanofibers and multiwall carbon nanotubes

Graphene oxide nanoplatelets (GONPs) were obtained by unraveling helical-ribbon carbon nanofibers (HR-CNF) using a modified Hummers and Offeman method in conjunction with ultrasonication. In this account, we carry out a complete evaluation of the effect of different oxidative agent concentrations on the resulting platelet materials. Transmission electron microscopy, atomic force microscopy, Fourier transform infrared, x-ray diffraction, x-ray photoelectron spectroscopy, and thermogravimetric analysis were performed to carefully characterize GONPs resulting from the oxidative process. Comparative experiments using multiwall carbon nanotubes (MWCNTs) and graphite were also carried out. Our studies suggest that the oxidation treatment is more effective in HR-CNFs than in MWCNTs. Furthermore, the unraveling of HR-CNFs results in GONPs consisting of less stacked layers when compared to other starting materials such as graphite. Therefore, HR-CNFs appear to be excellent precursors to produce few-layered GONPs.