Raman microspectroscopy study of calcined electrically conductive nanocomposite polypyrrole/ghassoul

Abstract

Moroccan clay ghassoul (GHA) was used in preparation process of electrically conductive nanocomposite contained polypyrrole (PPy/GHA). Based on our previous studies on electrically conductive nanocomposites, the calcination may lead to formation of graphite and few-layer graphene. Prepared PPy/GHA nanocomposite was compressed to the square tablets which were calcined in an inert atmosphere at 1300 °C. XRD measurements confirmed presence of graphite in the PPy/GHA sample. However, this method does not provide information about distribution of the graphitic and the few-layer graphene phases. Therefore, Raman microspectroscopy, which has an ability to distinguish the carbonaceous forms and allows showing their distribution on Raman spectral maps, was used as a major tool for the study of PPy/GHA. Several maps were created and studied. Spectral maps proved that the calcination leads to the formation of few-layer graphene on the surface of the tablet. Distribution of the graphitic phases was observed at the edge and on the surface of the tablet. Moreover, spectral maps were used to evaluate if and how the selected regions in one side correspond to each other.