Ternary structured magnesium cobalt oxide/graphene/polycarbazole nanohybrids for high performance electrochemical supercapacitors

Abstract

In the present work, polycarbazole (PCz)/magnesium cobalt oxide (MgCo₂O₄)/reduced graphene oxide (RGO) based ternary nanocomposite was prepared through in-situ polymerization, and utilized it as an active electrodes for electrochemical energy storage supercapacitor applications. The electrochemical behaviour of PCz and its nanocomposites were investigated by measuring specific capacitance using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and Galvanostatic charge–discharge (GCD) analysis. The PCz/MgCo₂O₄/RGO hybrids exhibited higher capacitance (548.54 F/g) than that of PCz (117.65 F/g) and PCz/MgCo₂O₄ (482.92 F/g) at the scan rate of 50 mV/s, as determined by CV method. The enhanced supercapacitance indicates high power and energy storage capabilities of the ternary metal oxide-graphene based polycarbazole nanocomposites. Electrochemical impedance spectroscopy confirmed low solution resistance of PCz/MgCo₂O₄/RGO. Thermogravimetric analysis affirmed the increased thermal stability of PCz/MgCo₂O₄/RGO composite compared to that of pure polycarbazole and PCz/MgCo₂O₄ nanocomposite. The scanning electron micrographs of nanocomposite confirmed the successful incorporation of nanofillers into the PCz matrix. On the basis of the research findings, PCz/MgCo₂O₄/RGO can be expected to be a promising electrode active material for high performance energy storage supercapacitors.