Hydrothermal soft chemical process for synthesis of manganese oxides with tunnel structures
Hydrothermal soft chemical process for synthesis of manganese oxides with tunnel structures
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DOI：
10.1023/a:1009657724306
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发表时间：
1998-05-01
影响因子：
2.6
通讯作者：
Yamasaki, N
中科院分区：
文献类型：
--
作者：
Feng, Q;Yanagisawa, K;Yamasaki, N
采用软化学方法合成了具有隧道结构的锰氧化物。该方法包括两个步骤：第一步是通过软化学反应制备具有层状结构的前体并将模板（结构导向剂）插入其层间空间[1]，第二步是通过水热处理将模板插入的前体转化为隧道结构。通过从具有层状结构的水钠锰矿型锰氧化物合成六种隧道锰氧化物，证明了该过程的有用性。用X射线衍射、差热-热重分析、化学分析和红外光谱等方法研究了层状结构向隧道结构的转化反应。分别以Li+、K+、Ba 2+和Mg 2+离子为模板剂，可以得到具有（1 × 3）、（2 × 2）、（2 × 3）和（3 × 3）隧道结构的尖晶石型、硬锰矿型、锰锰矿型和钙锰矿型锰氧化物。在酸性溶液中可以得到具有（1 × 1）和（1 × 2）隧道结构的软锰矿型和斜方锰矿型锰氧化物。所得到的隧道的位置对应于模板的大小。
A soft chemical process is used for the synthesis of manganese oxides with tunnel structures. This process comprises two steps: the first step is the preparation of a precursor with layered structure and insertion of templates (structure-directing agents) into its interlayer space by a soft chemical reaction [1], and the second step is the transformation of the template-inserted precursor into a tunnel structure by hydrothermal treatment. The usefulness of this process was demonstrated by synthesizing six kinds of tunnel manganese oxides from a birnessite-type manganese oxide with layered structure. The transformation reactions from layered structure to tunnel structures were investigated by X-ray, DTA-TG, and chemical analyses, and IR spectroscopy. Spinel-, hollandite-, romanechite-, and todorokite-type manganese oxides, which have (1 x 3), (2 x 2), (2 x 3), and (3 x 3) tunnel structures, can be obtained by using Li+, K+, Ba2+, and Mg2+ ions as the templates, respectively. Pyrolusite- and ramsdellite-type manganese oxides with (I x 1) and(l x 2) tunnel structures can be obtained in acidic solutions. The site of the resulting tunnels correspond to the size of the templates.