Synthesis and characterization of polypyrrole/graphitic carbon nitride/niobium pentoxide nanocomposite for high-performance energy storage applications

Graphitic carbon nitride (GCN) has been employed as a supercapacitor electrode because of its high carbon-to-nitrogen ratio and flexible structure. However, its low surface area and poor conductivity continue to be obstacles for practical usage. GCN's electrochemical characteristics are enhanced by the hybrid structure it forms with polypyrrole and Nb2O5. The synthesized polypyrrole (Ppy)/GCN/niobium pentoxide (Nb2O5) (Ppy/GCN/Nb2O5) nanocomposite electrode was tested for supercapacitance by cyclic voltammetry (CV) and Alternating current impedance techniques in 6 M Potassium hydroxide(KOH) electrolyte. The Ppy/GCN/Nb2O5 is linked to a network of agglomerated GCN and Nb2O5 nanoparticles with additional spherical shapes. The specific capacitance of Ppy/GCN/Nb2O5 was determined to be 1177 Fg(-1) at a current density of 5 Ag-1. The Ppy/GCN/Nb2O5 electrode in KOH has average specific energy and specific power densities of 33 Wh kg(-1) and 2991 W kg(-1), respectively. The electrode showed excellent capacitance-retention ability of 97% after 10,000 cycles. The results demonstrate the high stability and efficient performance of the Ppy/GCN/Nb2O5 electrode employed in supercapacitors. The performance of the Ppy/GCN/Nb2O5 electrode was found to be superior to those reported for other carbon-based materials.