Characterisation of Nanocarbons and Their Interactions: Phonon Mode-Structure Relationships

Raman spectroscopy is among the primary techniques for the characterisation of graphitic carbon materials, as it provides insights into the quality of measured materials including their structure and conductivity as well as the presence of dopants, functionalisation and interactions. Herein we re-analyse the Raman spectra of graphenes and show that traditional methods rely upon an apparent G peak (Gapp) which is in fact a superposition of the G and D’ peaks. We use this understanding to develop a new Raman characterisation method for graphenes that considers the D’ peak by using its overtone the 2D’. We demonstrate the superiority and consistency of this method for calculating the oxygen content of graphenes. We can define three regions in the oxygenation curve: A material with the proposed Raman function 25 is graphene. Non-covalent attachment of light harvesting molecules to carbon nanomaterials has the potential to open up new hybrid nanostructures. By using non-covalent methods, defects are not introduced into the graphitic carbon backbone; therefore, the conductive properties of the supporting carbon are preserved, enabling charge transfer between the molecule and the carbon support. Here we demonstrate that a simple solution mixing process can produce novel non-covalent hybrids of chlorophyll and three different nanocarbons; carbon nanotubes and graphite oxide (GrO) platelets and GO sheets, which demonstrate self-assembly and charge transfer. We show that the interaction is strong enough to form spontaneous liquid crystals, which are the likely cause of the improvement in the charge transfer properties. These interactions are studied from the perspective of the Raman spectroscopy, which gives detailed insights into the nature of the charge transfer, and the structures that are self-assembled