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Single precursor approach to AB2O4 nanorods using MCM as a
template
Chang G. Kim*, Kiwhan Sung, Taek-Mo Chung, and Yunsoo Kim
Advanced Materials Division, Korea Research Institute of Chemical Technology,
Yusong P. O. Box 107, Daejon 305-600, Korea
The rational approach to prepare AB2O4 nanorods is described. The heterometallic
single precursors were designed and synthesized to contain the AB2O4 moieties with
reactive ligands of methyl and isopropoxide groups, resulting in the chemical formula
[A{(-OiPr)2B(Me)2}2] 1. The precursors have been reacted in dry THF with surface
silanol groups inside the pores of MCM. Then the intermediate was washed with water
and dried to produce reactive hydroxyl groups. The incorporation of the precursors onto
the inner walls of the template MCM resulted in the decrease of the pore sizes and
surface areas of the AB2O4-containing MCM, compared to those of the support by the
analyses of N2 adsorption.
i
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H
O
B
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O
iS
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Si-MCM-41
H3C
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H3C
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iO
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iO
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H2O
repeat several times
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HF or NaOH
iO
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iO
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AB2 O4 -MCM-41
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2 O4
Scheme 1. Molecular layer growth of AB2O4 inside MCM template to produce AB2O4 nanorods
This process, “Molecular Layer Growth” has been done several times to fill the pores
with AB2O4. The products AB2O4 nanorods were obtained by calcining AB2O4-MCMs
followed by dissolving SiO2 with HF or NaOH. The physical properties of
AB2O4-MCMs and AB2O4 nanorods were characterized by XRD, TEM, and other
analytical techniques. Molecular layer growth technique using single precursor could
be used for the preparation of nanopipes, nanocomposites and alternative inorganic
nanolayers.
Acknowledgment. The authors are grateful to the Ministry of Science and Technology
of Korea for financial support.
References.
1. (a) Koh, W.; Ku, S.-J.; Kim,Y. Chem. Vap. Deposition 1998, 4, 192. (b) Kim, C. G.;
Koh, W.; Ku, S.-J.; Nah, E. J.; Yu, K.-S.; Kim, Y. J. Phys. IV France 1999, Pr8-853. (c)
Ku, S.-J. Ph.D. Thesis, Kyungpook National University, 1998.