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      https://www.ias.ac.in/article/fulltext/boms/044/0062

    • Keywords

       

      Nanographite; a-MnO2; graphite electrochemical exfoliation; hydrothermal process; supercapacitor.

    • Abstract

       

      Design and production of $\alpha$-MnO$_2$ structures over carbonaceous material is considered as potential strategy for improving electrochemical performance of supercapacitors. This study describes the development of a simple methodfor hydrothermal synthesis of a composite material with directly anchoring $\alpha$-MnO$_2$ over a nanographite matrix. The nanographite matrix was obtained by electrochemical exfoliation of graphite rods (from depleted Leclanché batteries) and characterized by X-ray diffraction (XRD), Raman spectroscopy and field emission gun-scanning electron microscopy (FEG-SEM). The obtained results indicated that nanographite produced presented low levels of defects with a mildoxidized surface. This nanographite was used as anchoring base for producing MnO$_2$ particles, using the developed hydrothermal procedure. For paralleling, pure MnO$_2$ particles were also produced in same conditions. The preparedmaterials were characterized by XRD, Raman spectroscopy and FEG-SEM. XRD patterns proved formation of $\alpha$-MnO2 for pure and composite materials. Morphological characterization indicated the formation of nanoneedles in both situations; however, in the composite the $\alpha$-MnO$_2$ was produced as smaller nanoneedles homogeneously spread over the nanographite surface. Raman spectra showed that the desired composition was achieved. Electrochemical characterization showed that the adopted strategy was successful in producing materials with improved pseudocapacitive performance, high reversibility, presenting specific capacitance of 279.8 F g$^{-1}$ and coulombic efficiency of 99.7%.

    • Author Affiliations

       

      GUSTAVO MARCINIUK1 RODOLFO T FERREIRA1 ALEX V PEDROSO1 ARIANE S RIBAS1 RENAN A P RIBEIRO1 SÉRGIO R DE ÁZARO1 EDER C F DE SOUZA1 LUIS F Q MARCHESI2 JAREM R GARCIA1

      1. Department of Chemistry, State University of Ponta Grossa, Ponta Grossa 84030-900, Brazil
      2. Federal University of Technology, Ponta Grossa 84016-210, Brazil
    • Dates

       
  • Bulletin of Materials Science | News

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