Electronic supplementary material for
Genesis of supported carbon-coated Co nanoparticles with controlled
magnetic properties, prepared by decomposition of chelate complexes
Konstantin Tarasov,a,b Patricia Beaunier,a,b Michel Che,a,b Eric Marceau* a,b and Yanling Lib,c
a
Laboratoire de Réactivité de Surface (UMR 7197 CNRS), UPMC (Université Pierre et Marie Curie), 4 Place
Jussieu, 75252 Paris Cedex 05, France
b
CNRS, 4 Place Jussieu, 75252 Paris Cedex 05, France
c
IPCM (Institut Parisien de Chimie Moléculaire, UMR 7201 CNRS), UPMC (Université Pierre et Marie Curie),
4 Place Jussieu, 75252 Paris Cedex 05, France
e-mail : eric.marceau@upmc.fr
IR spectra, in situ UV–Visible spectra, TEM and magnetisation measurements of H2-treated
Co(EDTA)/Al2O3-400, magnetisation measurements of Co(EDTA)-900
Contents
1. Infrared transmission spectra
p.2
2. In situ UV-Visible measurements
p.3
3. TEM
p.4
4. Magnetic properties
p.4
1
1. Infrared transmission spectra
Infrared (IR) spectra recorded using KBr pellets were collected with a FT-IR M-1700 PerkinElmer spectrometer with a 4 cm-1 resolution.
Co(EDTA)/Al2O3-400
Co(EDTA)/Al2O3
3435
1621
1514
1413
Absorbance
(CH)
(OH)
2971
2927
2853
1595
 (COO )
s
1400
(CH )
-
3435
(NH)
2
1438
3210 (CH)
2973
2925
2855
1325 1104
1281
(H O)
2
0.1
 (COO )
-
as
3500
3000
2500
1800 1600 1400 1200 1000
-1
Wavenumber (cm )
Fig.1s. Infrared transmission spectra of Co(EDTA)/Al2O3 and Co(EDTA)/Al2O3-400 (recorded at room
temperature in KBr).
The IR spectrum of Co(EDTA)/Al2O3 exhibits bands which are characteristic of
[Co(EDTA)]2- (Nakamoto 1987; Tarasov, O’Hare et al. 2003): C-H vibrations in the region of
2850-3000 cm-1, C-N vibrations at ~ 1100 cm-1, and strong asymmetrical and symmetrical
COO vibrations at ~1600 and ~1400 cm-1, respectively.
Nakamoto K (1987) Infrared and Raman spectra of inorganic compounds. Wiley-Interscience, New York
Tarasov KA, O'Hare D, Isupov VP (2003) Solid-state chelation of metal ions by ethylenediaminetetraacetate
intercalated in a layered double hydroxide. Inorg Chem 42:1919-1927. doi: 10.1021/ic0203926
2
2. In situ UV-Visible measurements
UV-vis diffuse reflectance spectra were recorded in the reflectance mode with a resolution of
1 nm on a Cary 5 spectrometer (Varian) equipped with an integration sphere, a praying mantis
device and BaSO4 as reference. The spectra were collected in situ in the range 20-300°C using
a high temperature environmental cell (Spectratech).
300°C (recorded at 20°C)
300°C (recorded at 20°C)
536 565
215°C
215°C
150°C
150°C
20°C
20°C
536
571
2282
2345
1703
1740
1189
2197
2040
Absorbance (KM)
Absorbance (KM)
531
565
1189
519
1160
2182
1701
1744
2040
1114
2181
1703
1747
2040
(OH) 2043
1961
2(OH)
1391
0.2
2(NH)
1574
2(CH)
1703
0.1
500
1000
1500
Wavelength (nm)
2000
2500
2285
2339
1391
2171
381
2285
2339
1400
1600
2283
2345
(CH)
(NH)
1738
1800
2000
2200
Wavelength (nm)
2400
Fig.2s. UV-Visible-NIR spectra of Co(EDTA)/Al2O3 recorded in in situ diffuse reflectance conditions (praying
mantis and environmental cell, He flow 50 mL.min-1, temperature ramp 7.5°min-1). The minor band at 381 nm
corresponds to Co(III)-EDTA complexes resulting from the oxidation in solution of a fraction of the Co(II)
precursor. On the right – zoom of the NIR region.
The positions of the two main absorption bands observed in the UV-vis spectrum are
characteristic of Co2+ cations in octahedral coordination with EDTA: an asymmetric band
at 519 nm (4T1g(F) – 4T1g(P) transition) with a shoulder at 620 nm ( 4Т1g – 4A2g transition),
and a broad band at 1114 nm corresponding to the 4T1g – 4T2g transition (Tarasov, O’Hare
et al. 2003; Mhamdi et al. 2005). During the heating process, the sample turns violet, but
the metal cations retain their oxidation state (II) as evidenced by the two slightly shifted
absorption bands detected by in situ UV-Vis measurements. In line with thermal analysis,
bands associated with O-H vibrations in the near-infrared region disappear below 150°C,
while bands assigned to N-H vibrations disappear progressively between 150 and 300°C.
Tarasov KA, O'Hare D, Isupov VP (2003) Solid-state chelation of metal ions by ethylenediaminetetraacetate
intercalated in a layered double hydroxide. Inorg Chem 42:1919-1927. doi: 10.1021/ic0203926
Mhamdi M, Marceau E, Khaddar-Zine S, Ghorbel A, Che M, Ben Taarit Y, Villain F (2005) Preparation of
Co2+/ZSM5 catalysts by solid-state reaction: influence of the precursor on cobalt speciation. Z Phys Chem
219:963-978. doi: 10.1524/zpch.219.7.963.67087
3
3. TEM
Co(EDTA)/Al2O3 – 400 / H2
Fig. 4s. TEM image of Co(EDTA)/Al2O3-400 treated in H2 at 400°C.
4. Magnetic properties
2
1
Hc = 330 Oe
M (emu/g)
1
0
0
-1
-2000
-1000
0
1000
2000
-1
-2
-40000
-20000
0
20000
40000
H (Oe)
Fig. 5s. Magnetisation dependence M(H) recorded at 293 K of Co(EDTA)/Al2O3- 400 treated in H2 .
4
20
6
15
3
10
0
2K
-3
M (emu/g)
5
-6
0
-2 k -1 k
0
1k
2k
-5
2K
293 K
-10
-15
-20
-40000
-20000
0
20000
40000
H (Oe)
Fig. 6s. Magnetization dependences M(H) of Co(EDTA)/Al2O3-900.
5