A simple mechanical technique to obtain carbon nanoscrolls from graphite nanoplatelets

Abstract

A simple approach for the bulk production of carbon nanoscrolls (CNSs) is described. This method is based on the application of shear-friction forces to convert graphite nanoplatelets into carbon nanoscrolls using a bi-axially oriented polypropylene (BOPP) surface. The combined action of shear and friction forces causes the exfoliation of graphite nanoplatelets and the simultaneous roll-up of graphite layers. Evidence of the CNS formation is given by optical microscopy, scanning electron microscopy, and transmission electron microscopy. These investigations reveal that the CNSs have a long tube-like and fusiform structure with a hollow core surrounded by few layers of graphene. Micro-Raman spectroscopy shows that the produced structures are not defect free, and optical spectroscopy reveals distinctive features due to the presence of two weak absorption bands at 224 and 324 nm.

Hydrothermal synthesis of spherical carbon nanoparticles (CNPs) for supercapacitor electrodes uses

“…The spectrum exhibits a peak in the UV region at about 264 nm. This peak is due to the collective π-π* electronic transition of the condensed aromatic rings in the graphene sheet [32]. This single absorption peak in the UV region is observed due to the linear dispersion of Dirac electrons in nano-graphitic carbon [32].…”

Synthesis and Characterization of Highly Intercalated Graphite Bisulfate

“…5 b . The observed shift of the 2D mode position to lower wavenumber values with respect to pristine graphite is a signature of presence of graphene sheets, indicating the formation of low stage GICs [ 19 ]. A large intercalation configuration in the NaIO 4 and NaClO 3 systems is inferred because the Raman signal results generated by almost monolayers of graphene (low stage number).…”

Vortex fluidic mediated transformation of graphite into highly conducting graphene scrolls

“…This suggests the presence of disorder in the scroll structures, which can be attributed to the scrolled edges where the translation symmetry is broken. [39][40][41] The G band originates from the activation of the doubly degenerate zone centre E 2g phonon mode and thus the shape and position of the band are strongly dependent on the phonon dispersion. We observed a prominent red shi ($20.8 cm À1 ) and broadening of the full width at half maximum (FWHM) of the G band which was expected for the graphene scrolls, and in this case, it was within a range of 40 cm À1 to 90 cm À1 compared to that of pristine graphite akes which was approximately 20 cm À1 .…”