About graphene ribbons development in laser synthesized nanocarbon

The work presents preliminary studies with the goal to extend the share of long graphene ribbons in laser-synthesized carbon black. Investigations revealed the existence, as a major constituent, of graphene ribbons composed of up to 10-15 graphene layers, spaced at ∼0.35-0.37 nm and of tens of nanometres in length. The samples used to study the development of this specific structure were obtained from sensitized acetylene-based mixtures and the experiments were performed following the variation of both the experimental parameters and gas composition.

Research highlights▶ Laser-induced pyrolysis is capitalizing very particular characteristics of laser radiation, presents tempting technological features and proves its ability for producing carbon nanopowders with controlled size and morphology. ▶ Laser-induced pyrolysis of a C2H2/SF6 gas mixture leads to structural changes of the synthesized carbon nanopowders, from an altered turbostratic structure, with puckered graphene layers, up to well developed graphene bands, when C/F atomic ratio ≥3. ▶ The work is proposing to investigate the possibilities of changing, through laser-induced pyrolysis, the morphology of this last type of nanocarbon in order to have an ultimate material with a higher content of graphene ribbons with foreseen structure. ▶ Preliminary experimental data obtained by X-ray diffraction, Raman spectroscopy, high-resolution electron microscopy and its associated techniques (e.g. electron energy loss spectroscopy) from C2H2/SF6 samples with C/F atomic ratio ≥3, proved the possibility to achieve these goals in situ by changing both gas composition and experimental parameters.