Structural Changes in Reduced Graphene Oxide upon MnO2 Deposition by the Redox Reaction between Carbon and Permanganate Ions
journal contributionposted on 06.02.2014, 00:00 by Suk-Woo Lee, Seong-Min Bak, Chang-Wook Lee, Cherno Jaye, Daniel A. Fischer, Bae-Kyun Kim, Xiao-Qing Yang, Kyung-Wan Nam, Kwang-Bum Kim
We explore structural changes of the carbon in MnO2/reduced graphene oxide (RGO) hybrid materials prepared by the direct redox reaction between carbon and permanganate ions (MnO4–) to reach better understanding for the effects of carbon corrosion on carbon loss and its bonding nature during the hybrid material synthesis. In particular, we carried out near-edge X-ray absorption fine structure spectroscopy at the C K-edge (284.2 eV) to show the changes in the electronic structure of RGO. Significantly, the redox reaction between carbon and MnO4– causes both quantitative carbon loss and electronic structural changes upon MnO2 deposition. Such disruptions of carbon bonding have a detrimental effect on the initial electrical properties of the RGO and thus lead to a significant decrease in electrical conductivity. Electrochemical measurements of the MnO2/reduced graphene oxide hybrid materials using a cavity microelectrode revealed unfavorable electrochemical properties that were mainly due to the poor electrical conductivity of the hybrid materials. The results of this study should serve as a useful guide to rationally approaching the syntheses of metal/RGO and metal oxide/RGO hybrid materials.