It has been reported in the literature that groups such as P-C, C-P-O, C-P=O exist in the Pdoped carbon. Among the various functionalities, P-O groups are assumed to enhance the supercapacitive performance of P-doped carbon. For instance, the capacitive behaviour of Pdoped graphene obtained using phytic acid is higher compared to other two precursors such as potassium dihydrogen phosphate and orthophosphoric acid . This is because of the fact that P-O content of P-doped RGO obtained by phytic acid is 69.4% which is appreciably greater compared to P-doped RGO synthesized by the other two precursors such as potassium dihydrogen phosphate (47%) and orthophosphoric acid (41.7%). When the content of P-O is high then the carbon atom has been distorted from the planar structure and end up with lattice distortions of the graphene which suggesting that the faradaic response from the P-doped RGO is significant if the content of P-O is greater. Additionally, the phosphorus-oxygen based functionalities is distributed between the sheets of graphene, thereby giving rise to the low aggregation and leads to the increased specific surface area and specific capacitance. In another literature, the activation of GO with H3PO4 accompanied by passivation in an inert atmosphere lead to a relatively greater proportion of C3-P=O and C-P=O bonding links, while the content of C3-P and C-O-P bonds reduces in the final structure . It has been suggested that groups such as C3-P=O and C-P=O enhance the wettability of the electrode and facilitate the effective diffusion of ions of the electrolyte into the surface of the electrode. Hence the influence of oxygen functionalities on the capacitive performance of any heteroatom doped carbon-based materials could not be avoided.