Nanoscale imaging and identification of a four-component carbon sample

We demonstrate the unprecedented chemical imaging of individual constituents in a four-component sample made of several carbon allotropes: single-wall carbon nanotubes, graphene oxide, C₆₀ fullerene, and an organic residue. This represents a significant advance with respect to previous works that were mainly limited to systems with one or two components having very different chemical composition. Despite the spectral and spatial overlap from different components, plasmon-based nanospectroscopy allows the discrimination of all individual carbon nanomaterials here investigated. Among other physical insights such as doping observed in carbon nanotubes, the detailed chemical imaging of graphene oxide reveals higher defect concentration at the flake edges similarly to the case of graphene. We found that the organic residue has either low adsorption or lack of resonant enhancement on GO, in contrast to graphene, suggesting a decreased van der Waals interaction. This report paves the way for routine nanoscale analysis of complex carbon systems with spatial resolution of 15 nm and below.