Full metadata record
DC Field | Value | Language |
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dc.contributor.author | 최진호 | - |
dc.contributor.author | 황성주 | - |
dc.date.accessioned | 2016-08-28T12:08:37Z | - |
dc.date.available | 2016-08-28T12:08:37Z | - |
dc.date.issued | 2009 | - |
dc.identifier.issn | 1932-7447 | - |
dc.identifier.other | OAK-6128 | - |
dc.identifier.uri | https://dspace.ewha.ac.kr/handle/2015.oak/220409 | - |
dc.description.abstract | 1D nanorods/nanowires of manganese oxides with different crystal structures and morphologies were prepared and characterized to understand the influence of the Mn valence in the solid-state precursor on the electrochemical activity of these nanomaterials and to elucidate the mechanism responsible for the excellent activity of β-MnO2 nanorods as well. According to powder X-ray diffraction analyses, treating manganese oxide precursors that have an oxidation state of ≤+3 with persulfate ions under hydrothermal conditions yields manganese oxides with the β-MnO2 structure. In contrast, the use of a LiMn2O4 precursor with a higher Mn valence leads to the formation of the α-MnO2-structured manganese oxide. Electron microscopic studies clearly show a 1D nanorod-type morphology for the β-MnO2 material, whereas a 1D nanowire-type morphology with a higher aspect ratio is observed for the α-MnO2 material. The diameter of the β-MnO2 nanorods decreases as the Mn valence in the precursors becomes smaller. According to electrochemical measurements, the formation of nanorods dramatically improves the electrode performance of the β-MnO2 phase. This compares with a relatively weak performance enhancement for the α- and δ-MnO2 phases upon the nanowire formation. The optimum electrode property results from the smaller β-MnO2 nanorods prepared with the MnO precursor. 7Li magic angle spinning nuclear magnetic resonance spectroscopy clearly demonstrates that Li+ ions in the lithiated β-MnO2 phase are adsorbed mainly on the sample surface. On the basis of this finding, we attribute the improved electrode performance of the β-MnO2 nanorods to their expanded surface area. © 2009 American Chemical Society. | - |
dc.language | English | - |
dc.title | Origin of improved electrochemical activity of β-MnO2 nanorods: Effect of the Mn valence in the precursor on the crystal structure and electrode activity of manganates | - |
dc.type | Article | - |
dc.relation.issue | 51 | - |
dc.relation.volume | 113 | - |
dc.relation.index | SCIE | - |
dc.relation.index | SCOPUS | - |
dc.relation.startpage | 21274 | - |
dc.relation.lastpage | 21282 | - |
dc.relation.journaltitle | Journal of Physical Chemistry C | - |
dc.identifier.doi | 10.1021/jp908556h | - |
dc.identifier.wosid | WOS:000272712700003 | - |
dc.identifier.scopusid | 2-s2.0-73849091700 | - |
dc.author.google | Kim I.Y. | - |
dc.author.google | Ha H.-W. | - |
dc.author.google | Kim T.W. | - |
dc.author.google | Paik Y. | - |
dc.author.google | Choy J.-H. | - |
dc.author.google | Hwang S.-J. | - |
dc.contributor.scopusid | 최진호(8044393000) | - |
dc.contributor.scopusid | 황성주(7404626171) | - |
dc.date.modifydate | 20190901081003 | - |