Carbon nitride/polypyrrole composite supercapacitor: Boosting performance and stability

In this work, one-step electrochemical synthesis of a supercapacitor with high performance and stability based on carbon nitride and polypyrrole is described. The new composite was easily obtained through the electrodeposition of polypyrrole on the surface of carbon nitride using an aqueous suspension. This material was fully characterized using both theoretical studies and experimental techniques. The sample showed a capacitance value of 810 F g−1 (at 0.2 A g−1), retaining 92% of its initial value after 6000 charge-discharge cycles at 6.0 A g−1. Furthermore, the composite material has a capacitance value of 610 F g−1 at 9.0 A g−1. To explain these results, it was used impedance spectroscopy and DFT calculations. The computational calculations showed the formation of hydrogen bonds between the NH of the polypyrrole and the π-system of the carbon nitride which stabilized the structures. Besides, a planarization effect could also be observed over the polypyrrole chains. Both results are supported by the experimental data collected from the impedance experiments.