Synthesis and Electrochemical Characterization of Reduced Graphene Oxide-Manganese Oxide Nanocomposites

Lee, Yu-Ri; Song, Min-Sun; Lee, Kyung-Min; Kim, In-Young; Hwang, Seong-Ju

doi:2011.2.1.1

J. Electrochem. Sci. Technol > Volume 2(1); 2011 > Article

Article

Journal of Electrochemical Science and Technology 2011;2(1):1-7.
DOI: https://doi.org/10.5229/JECST.2011.2.1.001

Synthesis and Electrochemical Characterization of Reduced Graphene Oxide-Manganese Oxide Nanocomposites

Yu-Ri Lee, Min-Sun Song, Kyung-Min Lee, In-Young Kim, Seong-Ju Hwang

Center for Intelligent Nano-Bio Materials (CINBM), Department of Chemistry and Nano Sciences, Ewha Womans University;Center for Intelligent Nano-Bio Materials (CINBM), Department of Chemistry and Nano Sciences, Ewha Womans University;Center for Intelligent Nano-Bio Materials (CINBM), Department of Chemistry and Nano Sciences, Ewha Womans University;Center for Intelligent Nano-Bio Materials (CINBM), Department of Chemistry and Nano Sciences, Ewha Womans University;Center for Intelligent Nano-Bio Materials (CINBM), Department of Chemistry and Nano Sciences, Ewha Womans University;

Abstract

Nanocomposites of reduced graphene oxide and manganese (II,III) oxide can be synthesized by the freeze-drying process of the mixed colloidal suspension of graphene oxide and manganese oxide, and the subsequent heat-treatment. The calcined reduced graphene oxide-manganese (II,III) oxide nanocomposites are X-ray amorphous, suggesting the formation of homogeneous and disordered mixture without any phase separation. The reduction of graphene oxide to reduced graphene oxide upon the heat-treatment is evidenced by Fourier-transformed infrared spectroscopy. Field emission-scanning electronic microscopy and energy dispersive spectrometry clearly demonstrate the formation of porous structure by the house-of-cards type stacking of reduced graphene oxide nanosheets and the homogeneous distribution of manganese ions in the nanocomposites. According to Mn K-edge X-ray absorption spectroscopy, manganese ions in the calcined nanocomposites are stabilized in octahedral symmetry with mixed Mn oxidation state of Mn(II)/Mn(III). The present reduced graphene oxide-manganese oxide nanocomposites show characteristic pseudocapacitance behavior superior to the pristine manganese oxide, suggesting their applicability as electrode material for supercapacitors.

Keywords: Reduced graphene oxide, nanocomposite, manganese oxide, pseudocapacitance, porous structure