Interfacial synthesis: amphiphilic monomers assisted ultrarefining of mesoporous manganese oxide nanoparticles and the electrochemical implications.
Interfacial synthesis: amphiphilic monomers assisted ultrarefining of mesoporous manganese oxide nanoparticles and the electrochemical implications.
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DOI：
10.1021/am200625p
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发表时间：
2011-08
影响因子：
9.5
通讯作者：
Wei Xiao;Di Hu;C. Peng;G. Chen
中科院分区：
文献类型：
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作者：
Wei Xiao;Di Hu;C. Peng;G. Chen
利用两亲性单体吡咯和苯胺在二氯甲烷/水界面还原高锰酸盐离子(MnO(4)(-))，制备超细氧化锰（MnO(x), x≤2）纳米颗粒（NPs）。这些单体在被MnO(4)（-）氧化后没有发生聚合，但在有机水界面上通过还原MnO(4)（-）产生的MnO(x) NPs具有超细化的有趣效果。这是由于单体能够从有机相和水相进入界面反应位点，从而延缓了生成的MnO(x)核在界面上的聚集。所得产物是三维互连且均匀的伪球形MnO(x) NPs （<20 nm）的介孔基质。相反，使用更疏水的单体，即邻氨基酚，来还原MnO(4)(-)，可以产生嵌入微米大小的MnO(x)块中的聚（邻氨基酚）纳米带的复合材料。苯胺或吡咯制备的超细MnO(x) NPs在水溶液Na(2)SO(4)中表现出高电容性，有望用于超级电容器。同时发现，吡咯辅助合成的MnO(x) NPs比电容高于苯胺辅助合成的MnO(x) NPs，尽管苯胺辅助合成的MnO(x) NPs比表面积更高。这两种样品的晶体学性质和含水量的差异进行了讨论。
Amphiphilic monomers, namely pyrrole and aniline, were used to reduce permanganate ion (MnO(4)(-)) at the dichloromethane/water interface for the preparation of ultrafine manganese oxide (MnO(x), x ≤ 2) nanoparticles (NPs). These monomers did not undergo polymerization upon oxidation by MnO(4)(-), but exerted an interesting effect of ultrarefining the produced MnO(x) NPs from reducing MnO(4)(-) at the organoaqueous interface. This was attributed to the ability of the monomer to access the interfacial reaction sites from both organic and aqueous phases, and hence retard the as-produced MnO(x) nuclei from aggregation at the interface. Such obtained products were mesoporous matrixes of three-dimensionally interconnected and uniform pseudospherical MnO(x) NPs (<20 nm). On the contrary, using a more hydrophobic monomer, i.e., o-aminophenol, to reduce MnO(4)(-) produced a composite of nanobelts of poly(o-aminophenol) embedded in micrometer-sized MnO(x) blocks. The ultrafine MnO(x) NPs prepared from using aniline or pyrrole exhibited highly capacitive behavior in aqueous Na(2)SO(4), promising their use in supercapacitors. It was also found that the MnO(x) NPs prepared from pyrrole-assisted synthesis possessed higher specific capacitance than that from aniline-assisted synthesis, despite the latter having a higher specific surface area. This difference is discussed in terms of crystallographic properties and water contents of these two samples.