Fabrication of cobalt oxide@cellulose/nitrogen doped carbon nanotubes decorated metal organic frameworks composite for symmetric supercapacitor applications

Abstract

The two main issues facing the world's population now are energy storage needs and environmental protection. A lot of work has gone into creating electrochemical energy storage using chemical processes and a variety of possible electrode active materials. Supercapacitors, which are energy storage devices with a unique structure and morphology of cellulose materials for green energy resource. In this regard, solid state hydrothermal process is used to fabricate Co3O4@Cellulose (CE), Co3O4@CE/N-MWCNT, and Co3O4@CE/N-MWCNT/ZIF-67 composite materials. XRD, XPS, BET, and HR-TEM analyses verified the structural, surface, and morphological analysis. The electrochemical studies by a three- and two-electrode fabrication in presence of 1M KOH electrolyte for supercapacitor applications. When 1M KOH electrolyte is present, the fabricated Co3O4@CE/N-MWCNT/ZIF-67composite electrode displayed exceptional cyclic stability and a specific capacitance of ∼835 F g−1 at 1 A/g. The constructed composite electrodes of Co3O4, Co3O4@CE, and Co3O4@CE/N-MWCNT have specific capacitances of 263, 406, and 576 F g−1 at 1 A/g, respectively, which improves electrochemical properties using a three-electrode design. The Co3O4@CE-N-MWCNT/ZIF-67//1MKOH/SSC composite is produced using two electrode configurations. The final material showed a capacitance of 258 F g−1 at 1 A/g, a capacitance retention of 84.95 % across 8000 cycles, and an energy density of 30.99 W h kg−1 at a power density of 5409 W kg−1. Hence, the composite electrodes that have been produced have the potential to be used in electrochemical systems. © 2025 Elsevier B.V.