The search for cleaner energy sources is required to shift focus to the generation of energy from electrochemical systems, batteries and fuel cells, solar cells, and super capacitors, among others. We report a simple one-step approach for microwave-assisted synthesis of manganese oxide nanoparticles deposited on the graphene (MnO₂/GR) or carbon (MnO₂/C) supports. The MnO₂/GR and MnO₂/C nanocomposites have been synthesized with different morphologies. The MnO₂ nanoparticles were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), Transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). Electrochemical performance of the MnO₂/GR and MnO₂/C nanocomposites was evaluated using cyclic voltammetry (CV) and galvanostatic charge-discharge.

It was found that the graphene supported MnO₂ nanoparticles has significant influence on the electrochemical performance of composites electrodes compared with that of the carbon supported MnO₂ nanoparticles. The maximum specific capacitance of 108 F g^-1 was achieved at the MnO₂/GR electrode in the 1 M Na₂SO₄ aqueous solution at the scan rate of 10 mV s^-1.

Acknowledgement

This research is funded by the European Social Fund under the No. 09.3.3-LMT-K-712-02-0142 “Development of Competences of Scientists, other Researchers and Students through Practical Research Activities” measure.