Synthesis and Catalytic Abilities
97
Electron Microscope. Magnetization measurements were
performed at room temperature using Lake Shore 7410
vibration sample magnetometer (VSM). UV–visible spec-
tra were recorded on a Shimadzu UV-240 spectropho-
tometer. IR spectra (KBr pellets) were recorded on a
Thermo Nicolet NEXUS-670 Fourier transformation infra-
red spectrometer. The concentration of the iron ion in
nanoparticles was determined with a Perkin–Elmer AA700
atomic absorption spectrophotometer (AAS). The oxida-
tion products were confirmed by Shimadzu QP-2010
GC-MS and authentic samples, and were analyzed by a
Shimadzu GC-2010 gas chromatograph (GC) equipped
with a PEG-20 M column (25 m 9 0.25 mm 9 0.25 lm)
and a flame ionization detector. The carrier gas was
nitrogen. Injector and detector temperatures were both set
at 200 °C and the oven temperature was set at 120 °C.
Three metalloporphyrin carboxylic acids, Manganese
(III) 5-(p-carboxyphenyl)-10,15,20-triphenylporphyrin chlor-
idize (MnCPTPPCl), Iron (III) 5-(p-carboxyphenyl)-10,15,
20-triphenylporphyrinchloridize(FeCPTPPCl), Cobalt (II)5-
(p-carboxyphenyl)-10,15,20-triphenylporphyrin (CoCPTPP),
were synthesized, purified and characterized according to the
methodology in the literature [9]. Water used in all experi-
mental procedures was deionized and doubly distilled prior to
use. PhIO was synthesized following the method of Sharefkin
and Saltzmann [10, 11] by hydrolysis of iodophenyldiacetate,
stored in a freezer and titrated before use. All the other
reagents and solvents were obtained from commercialsources
and used without further purification.
were placed in a round bottom flask and the solution was
mechanically stirred. Once the mixture was homogeneous
system, the magnetic Fe3O4 fluid (5 mL) was placed into
the flask. The suspension was continuous stirred 1 h,
ammonium (4 mL) and tetraethyl orthosilicate (4 mL,
TEOS) was then added in the flask. After the mixture was
stirred at room temperature for 24 h, the reaction solution
was easily decanted with the aid of the magnet. The
obtained nanoparticles were redispersed in water (200 mL)
by sonicating for 5 min, and separated magnetically. The
nanoparticles were washed thoroughly with water and
twice with ethanol as above. After third washing, the
nanoparticles were dried under vacuum at 80 °C overnight
and stored in a desiccator. When the different magnetic
Fe3O4 fluids F(1), F(2), F(3), F(4), F(5) were used, cor-
responding silica-coated Fe3O4 nanoparticles S(1), S(2),
S(3), S(4), S(5) were obtained.
2.3 Preparation of Nano-SiO2 Particles
The nano-SiO2 particles were prepared by the similar
preparation procedure of silica-coated Fe3O4 nanoparticles.
The difference is that an equal volume of water instead of
the magnetic Fe3O4 fluid was added to the mixture of
cyclohexane, 1-hexanol and Triton X-100. In addition, the
obtained nano-SiO2 particles were separated by centrifu-
gation from the reaction solution. These nanoparticles were
also washed thoroughly with water and twice with ethanol.
After third washing, the nano-SiO2 particles S(0) were dried
under vacuum at 80 °C overnight and stored in a desiccator.
2.2 Preparation of Silica-coated Fe3O4 Nanoparticles
with Different Saturation Magnetization
2.4 Preparation of Nanoparticle Bonded
Metalloporphyrins
The magnetic Fe3O4 fluid was prepared by chemical
coprecipitation. Ferrous chloride and ferric chloride with a
mole ratio of 1:2 were added to water in a three-neck round
bottom flask, and the solution was mechanically stirred.
Then the ammonia was added into the solution. After stirring
for 30 min, a magnet was held next to the flask, in dozens of
seconds, the Fe3O4 nanoparticles were deposited on the wall
of the reaction flask and the reaction mixture became
transparent. Then, the reaction solution was decanted with
the aid of a magnet. The Fe3O4 nanoparticles were redi-
spersed in 10 mL water by sonicating for 5 min and
recovered magnetically. After this process was repeated
twice more, a series of magnetic Fe3O4 fluids F(1), F(2), F(3),
F(4), F(5) were obtained by dispersing the Fe3O4 nanoparti-
cles in different amount of water and the amount of Fe3O4 in
these magnetic Fe3O4 fluids is 1.5 mg/mL, 3.1 mg/mL,
4.6 mg/mL, 6.2 mg/mL, 7.7 mg/mL, respectively.
A solution of thionyl chloride (3 mL) and metalloporphyrin
carboxylic acid (50 lmol) in chloroform (15 mL) were
placed in a round bottom flask and the solution was refluxed
for 3 h. Then, chloroform and excess thionyl chloride were
distilled off under reduced pressure from the flask. After the
obtained solid mixture was redissolved in 15 mL fresh
chloroform, a solution of APTES (60 lmol) and triethyl-
amine (0.25 mL) in chloroform (30 mL) was slowly added
and the resultant reaction mixture was stirred for 1 h. After
then, nanoparticles (340 mg, silica-coated Fe3O4 nanopar-
ticles S(1), S(2), S(3), S(4), S(5) or nano-SiO2 particles
S(0)) were added and the volatiles were immediately
evaporated via vacua. The obtained solid mixture was dried
under vacuum at 110 °C. 3 h later, it was redispersed in
20 mL fresh chloroform by sonicating for 5 mixtures. The
solid substance could be recovered by magnetic separation
or centrifugation. This process was repeated twice more.
After the third washing, the final products were dried under
Silica-coated Fe3O4 nanoparticles were synthesized
by water-in-oil microemulsion approach. Cyclohexane
(120 mL), 1-hexanol (30 mL) and Triton X-100 (30 mL)
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Liu, Chang-Xiang
