Carbon supported manganese(IV)–cobalt(II/III) oxides nanoparticles for high-performance electrochemical supercapacitors

Abstract

The carbon supported manganese(IV)-cobalt (II/III) oxides nanoparticles labelled as MnO 2 -Co 3 O 4 /C nanocomposites have been prepared by a simple one-step microwave-assisted heating method using different precursor materials. Scanning electron microscopy (SEM), transmission electron microscopy (TEM) and inductively coupled plasma optical emission spectroscopy (ICP-OES) have been used for the characterization of morphology, structure and composition of the synthesized nanocomposites, whereas the electrochemical performance of the prepared nanocomposites has been evaluated by using cyclic voltammetry (CV).It was determined that the use of different precursor materials for the synthesis of the carbon supported MnO 2 and Co 3 O 4 nanocomposites results in a different morphology of the prepared substances. A high specific capacitance (C s ) of 658.8 F g −1 at a scan rate of 10 mV s −1 in a 1 M Na 2 SO 4 solution has been obtained for the MnO 2 -Co 3 O 4 /C-2 nanocomposite that has a spherical shape of nanoparticles. Moreover, it significantly outperforms the MnO 2 -Co 3 O 4 /C-1 nanocomposite that has a lamellar shape of nanoparticles.