Synthesis and formation mechanism of nanoneedles and nanorods of manganese oxide octahedral molecular sieve using an ionic liquid.
Single-crystalline cryptomelane-type manganese oxide octahedral molecular sieve (OMS-2) nanoneedles and nanorods were prepared by a solution-phase approach in the presence of an ionic liquid 1-n-butyl-3-methylimidazolium tetrafluoroborate ([BMIM]BF4). [BMIM]BF4 can act as a cosolvent, structure-directing agent, and reducing reagent in the reaction system. Based on the redox reaction of MnCl2 and KMnO4 in the mixed solvents of water and [BMIM]BF4, the formation of OMS-2 nanoneedles followed the rolling mechanism with lamellae as an intermediate. However, the direct reaction of KMnO4 with [BMIM]BF4 resulted in the formation of OMS-2 nanorods with diameters as small as 3-6 nm. The formation mechanism of OMS-2 nanostructures was discussed.
State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, People's Republic of China.
Li-Xia
LX
Yang
Ying-Jie
YJ
Zhu
Wei-Wei
WW
Wang
Hua
H
Tong
Mei-Ling
ML
Ruan