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タイトルElectrochemical synthesis of layered manganese oxides intercalated with tetraalkylammonium ions
作成者Nakayama, Masaharu
Konishi, Sayaka
Tagashira, Hiroki
Ogura, Kotaro
作成者ヨミナカヤマ, マサハル
コニシ, サヤカ
タガシラ, ヒロキ
オグラ, コウタロウ
作成者別表記中山, 雅晴
作成者所属山口大学大学院理工学研究科(工学)
内容記述(抄録等)Thin films of birnessite-type layered manganese oxides with various interlayer spacings have been prepared on a platinum electrode by a one-step electrochemical procedure. The process involves a potentiostatic oxidation of aqueous Mn^<2+> ions at around +1.0V (Ag/AgCl) in the presence of tetraalkylammonium cations with different alkyl chain lengths. X-ray diffraction indicates that the films deposited with tetrabutylammonium (TBA), tetrapropylammonium (TPA), and tetraethylammonium (TEA) ions are composed of a single phase where unhydrated tetraalkylammonium ions are accommodated as a monolayer between manganese oxide layers. The interlayer spacing of the products increases in an order of TEA < TPA < TBA. The film deposited with tetramethylammonium (TMA) is a mixture of two phases relating to hydrated and unhydrated guest cations, the former being predominant probably as a result of less hydrophobic property of TMA compared to that of other tetraalkylammonium ions. The TBA^+-intercalated Mn oxide film-coated electrode exhibits a good charge/discharge property in a KCl solution between 0 and +0.8 V. In this case, TBA^+ ions between the Mn oxide layers are rapidly replaced with K^+ in solution by ion exchange, accompanying a shrinkage of the interlayer. The incorporated K^+ ions as well as protons play an important role in the electrochemical conversion between Mn^<4+> and Mn^<3+> in the oxide layer. In the TBACl solution, the interlayer TBA^+ ions can be excluded electrochemically during the positive-going scan, concomitant with the oxidation of Mn^<3+> sites. This causes an anodic current and the accompanying shrinkage of the interlayer. On the reverse scan, however, the compressed interlayer does not allow the incorporation of bulky TBA^+ ions from the electrolyte, with virtually no cathodic current observed. Such an obvious difference in electrochemical behavior between the two electrolytes can be recognized by considering that most of the Mn oxide surface is present inside the layered structure, not on the external surface. This indicates that the layered structure is formed over the entire film.
本文言語eng
資料タイプtext
出版者American Chemical Society
NII資料タイプ学術雑誌論文
査読の有無査読あり
ISSN0743-7463
NCIDAA10461730
掲載誌名Langmuir : the ACS journal of surfaces and colloids
21
1
開始ページ354
終了ページ359
発行日2005-01
DOIinfo:doi/10.1021/la048173f
関連情報URL(IsPartOf)http://pubs.acs.org/journals/langd5/index.html
著者版/出版社版その他
リポジトリID2008010088
地域区分山口大学
URIhttp://www.lib.yamaguchi-u.ac.jp/yunoca/handle/2008010088