Marigold flower like Co3O4 nanoparticles as high performance electrodes for supercapacitors

Abstract

Transition metal oxides promised as electrode materials for supercapacitors have received much interest, especially cobalt oxide (Co3O4) nanoparticles. However, the low intrinsic electrical conductivity and aggregation of Co3O4 nanoparticles limit their electrochemical performance and impede the commercialization of these electrode materials. The present study describes a simple, and cost-effective solution combustion approach for producing marigold Co3O4 at 300 °C. Further, the effect of vacuum annealing on the microstructural and electrochemical properties is studied to explore the nanostructured samples of Co3O4 as potential electrode material. The electrochemical nature of prepared marigold Co3O4 nanoparticles in 3 M KOH aqueous electrolyte has the highest specific capacitance of 603 Fg−1 at a scan rate of 1 mVs−1 with greater electrochemical stability even after 5000 cycles. The possible reasons for a decrease in specific capacitance on annealing of as prepared Co3O4 at 300 °C are explored in this paper and some significant reasons are highlighted.