Synthesis and characterization of reduced graphene oxide decorated with CeO₂-doped MnO₂ nanorods for supercapacitor applications

A novel and efficient CeO₂-doped MnO₂ nanorods decorated reduced graphene oxide (CeO₂-MnO₂/RGO) nanocomposite was successfully synthesized via hydrothermal method. The growth of the CeO₂ doped MnO₂ nanorods over GO sheets and reduction of GO were simultaneously carried out under hydrothermal treatment. The morphology and structure of as-synthesized nanocomposite were characterized by field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and Raman spectroscopy, which revealed the formation of CeO₂-MnO₂ decorated RGO nanocomposites. The electrochemical performance of as-prepared CeO₂-MnO₂/RGO nanocomposites as an active electrode material for supercapacitor was evaluated by cyclic voltammetry, charge-discharge, and electrochemical impedance spectroscopy (EIS) methods in 2 M alkaline medium. The obtained results revealed that as-synthesized CeO₂-MnO₂/RGO nanocomposite exhibited higher specific capacitance (648 F/g) as compared to other formulations (MnO₂/RGO nanocomposites: 315.13 F/g and MnO₂ nanorods: 228.5 F/g) at the scan rate of 5 mV/s. After 1000 cycles, it retained ∼90.4%, exhibiting a good stability. The high surface area, enhanced electrical conductivity, and good stability possess by the nanocomposite make this material a promising candidate to be applied as a supercapacitor electrode.