Novel cobalt doped hafnium oxide/reduced graphene oxide nanosphere composite materials exhibit superior supercapacitor performance and long cyclic stability

Abstract

This paper describes a unique synthesized nanosphere using6% Cobalt doped hafnium oxide/reduced graphene oxide nanocomposite (6% Co doped HfO2/rGO) for its feasibility as electrode materialin supercapacitor applications utilizing a simple one-step hydrothermal technique. The structural behavior, binding energies, and quality of the synthesized 6% Co doped HfO2/rGO nanocomposite were exhibited by XRD, FTIR, XPS, and Raman analyses. The 6% Co doped HfO2 nanospheres in the 6% Co doped HfO2/rGO nanocomposite were coated across the exterior of the rGO sheet, according to HR-SEM and HR-TEM imaging. The 6% Co doped HfO2/rGO nanocomposite revealed enhanced specific capacitance (1015 F/g at 1A/g), which was compared to 6% Co doped HfO2 (396 F/g at 1A/g) electrode in the redox active 1 M H2SO4 electrolyte (0.0 to 0.7 V). After 4000 continuous cycles, the electrode material maintained 97 % of its capability and exceptional long-term cyclic stability. The superior super-capacitive performance established the 6% Co doped HfO2/rGO nanocomposite as a promising electrode for supercapacitor applications.