Proceedings of the IConSSE FSM SWCU 2015, pp. BC.64–70 ISBN: 978-602-1047-21-7
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Modulated synthesis and characterization of Ni-UiO66
Dini Iflakhah and Ratna Ediati
Department of Chemistry ITS, Kampus ITS Keputih Sukolilo, Surabaya 60111, Indonesia
Abstract
Modulated synthesis of Ni-UiO66 is reported via direct conventional solvothermal method. Zirconium tetrachloride ZrCl
4
, 1,4-benzen dicarbocarboxylic acid H
2
BDC, and nickel II nitrate NiNO
3 2
.6H
2
O were dissolved in mixture of N-N -dimethyl formamide DMF and variant concentrations of acetic acid CH
3
COOH. Acetic acid was used as modulator in which variants concentrations were 5eq, 10eq, and 20eq. All mixtures were
heated at 140 °C for 6h. The structures of Ni-UiO66 obtained from modulated synthesis were confirmed to be isostructural to UiO-66 by powder X-Ray diffraction PXRD. The
data present a unique crystalline phase, which is in good agreement with the UiO-66 pattern by Cavka. The characterization PXRD pattern of Ni-UiO66 has main peak with a
high intensity at 2 of 7.3°, as well as other characteristic peaks with lower intensity at 2 of 8.6, 10.3, 20.6 and 30.5°. The crystallinity of Ni-UiO66 can be enhanced by adding
modulator to the reaction mixture. Ni-UiO66 with variant modulator is 20eq has the highest crystalline. The IR spectra of UiO-66 and Ni-UiO66 are almost the same, further
confirming the isostructural to UiO-66. SEM images of UiO-66 and Ni-UiO66 show the modulator leads to the morphology of intergrown particles decreasing.
Keywords UiO-66, bimetallic MOF, modulated synthesis
1. Introduction
Metal Organic Framework MOF is coordination polymer consist of metal ion or polynuclear unit and organic compound as linker Zhou et al., 2013. Thus, the combination
of such unbelievable levels of porosity, surface area, pore size and wide chemical inorganic organic composition has recently brought these materials to the attention of many
researchers both in academia and industry, with over 1000 publications on metal organic frameworks Czaja et al., 2009. MOF was applied as hidrogen storage Kuppler et al., 2009,
gas separation applications Lee, 2012 and heterogeneous catalysis Burrows et al., 2013, Vermoortele et al., 2013. The most representative MOFs is UiO-66 with thermal stability up
to 500
o
C. UiO-66 or Zr-MOF is one of member group MOF consist of zirconium Zr and 1,4 benzene dicarboxylic acid BDC as organic linker. The 3D structure of UiO-66 was built by an
inner Zr
6
O
4
OH
4
core in which the triangular faces of the Zr
6
-octahedron are alternatively capped by 3-O and 3-OH groups Cavka et al., 2008.
Solvotermal method is a commonly method used for the synthesis of UiO-66. Solvotermal method is very easy to apply, but have weaknesses, its product formed micro-
sized aggregates of nanocrystal or intergrown crystal Cavka et al., 2008, Abid et al., 2012 and Ren et al., 2014. Recently, some researchers reported how the use of modulators can
produce highly crystalline with high porosity comparable to that of bulk crystals synthesized by the conventional solvothermal method Tsuruoka et al., 2009, Horieke and Kitagawa,
2011. Vermoortele 2013 reported that the addition of modulator can minimize the formation of intergrown, leveling pore size distribution and reproduce the active side.
Generally, modulators used are carboxylic acids such as acetic acid, formic acid, benzoic acid,
D. Iflakhah, R. Ediati
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BC.65
pivalik acid, trichloroacetic acid and acid trifluoroasetik. Ren 2014 have reported also modulation UiO-66 using formic acid to produce crystals of crystalline and reduced
agglomeration by increasing the concentration of formic acid is added. Bimetallic Ni-MOF5 was reported by Li and co-workers in 2012. The results
demonstrated that the Ni-MOF5 not only exhibit larger specific surface areas and larger pores than the MOF-5, but also significantly enhance water resistance of the framework. Herein,
we report the modulated synthesis of bimetallic Ni-UiO66 with solvothermal method.
2. Materials and methods 2.1
