Shape controlled synthesis of rod-like Co3O4 nanostructures as high-performance electrodes for supercapacitor applications

Abstract

Hydrothermal synthesis of Co3O4 nanorod electro-active material has been reported. The obtained Co3O4 material displays the cubic structure with 1D rod-like architecture. FT-IR and Raman spectral analyses have been carried out to confirm the functional groups and phase formation of Co3O4 electro-active material. Thermal stability of the as-prepared electro-active material has been studied by TG/DTA analysis. The electrochemical properties of the modified Co3O4 electrode have been analyzed by CV, CP and EIS using three electrode systems. The modified Co3O4 electrode exhibits the higher specific capacitance of 655 F g−1 at a current density of 0.5 A g−1 in 1 M KOH electrolyte. The high capacitance performance of the modified Co3O4 electrode was attributed to the highly crystalline rod-like structure. The Co3O4 electrode exhibits the excellent supercapacitive behaviour with better cyclic stability and high rate capacitive retention. The modified electrode reveals the Faradic behaviour, which is attributed to the redox contribution of Co(OH)/CoOOH (or) Co2+ ↔ Co3+ ↔ Co4+ in alkaline medium that makes this material as a potential electrode for charge storage applications in supercapacitors.