The morphology of the carbonaceous residue was analysed
by SEM and TEM. The representative SEM images of
different morphological geometries were displayed in Figs.
4(a)–4(d) with sequential higher magnification scale bar
from 50 to 5 μm. These images show the compact nature of
graphite sheet along with bundle of long carbon rods in different
regions. The surface of carbon rod is not absolutely
free from the graphitic particles. The selective adherences of
particles on the surface of graphitic materials indicate the
defect in graphitization where space/void remained for particle
depositions and/or functionalized carbon which has
strong interaction with other materials. The functionalized
carbons on these structures were found through XPS analysis
which is discussed later.16)