synthesis and characterization of mesoporous carbon...
TRANSCRIPT
Synthesis and Characterization of Mesoporous
Carbon Hybrids for Environmental Applications
University of Ioannina, Greece
M.A.Karakassides
Department of Materials Science & Engineering
Olomouc March 2011
Why mesoporous carbon?
Why hybrids?
Environmental Remediation
High surface area (up to 1700 m2g-1)
Uniform pore size
Large pore volumes
High Periodicity
mesoporous carbon
hybrids
Various properties possible
depending on precursors
and processing
Nanomaterial properties
Magnetic properties
Catalytic properties
hybrids ( mesoporous carbon
activated carbon
R. Ryoo, S. Hoon and S. Jun, J. Phys. Chem. B, 103 (1999) 7743
+ magnetic nanoparticles )
OUTLINE
Introduction to mesoporous carbons
Synthesis of hybrids, type-A (CMK-3/magnetic nanoparticles)
Synthesis of hybrids type-B (CMK-3/ZVi nanoparticles)
Study of synthesis stages and characterization of hybrids
Example of use of hybrids (sorption of hexavalent chromium)
Conclusions
M41S
MATERIALS
mesoporous
d=2-50 nm
microporous
d<2 nm
macroporous
d>50 nm
Po
re d
ime
nsio
ns
Po
re g
eo
me
try
1D
2D
3D
SBA-15 CMK-3CNTs
LDHGraphite
sheets
zeolite
Introduction to mesoporous carbons classification
foams
CMK: Mesoporous carbon materials with ordered crystalline structure
Carbon/silicon Mesoporous
carbon
Mesoporous
SBA-15 CMK-3
R. Ryoo, S. Hoon and S. Jun, J. Phys. Chem. B, 103 (1999) 7743
MCM-48
Synthesis of CMK-3
SBA-15
38oC
22 hours
95oC
24 hours
500oC
6 hours
SBA-15
Template
P123/HCl/H2O
TEOS
Si
O
O O
O
C2H5
C2H5
C2H5
C2H5
CMK-3
160oC
6 hours
SB
A-1
5
100oC
6 hours
877oC/N2
6 hours
CM
K-3
Sugar/H2O/H2SO4
1,25 / 5 / 0,14κ.β. Sugar /H2O/H2SO4
0,8 / 5 / 0,07κ.β.
Hybrids based on CMK-3
CMK-3 with nanoparticles Fe0-----CMK-3@ZVI
with nanoparticles FexOy-----CMK-3@FexOy
type-A
type-B
CMK-3
COOH
COOH
COOH
HOOC
HOOC
HOOC
CMK-3-O
Fe(NO3)3·9H2O
1:4
Vapor
CH3COOH
vapor
CH3COOH
pyrolysis
400οC/Ar
pyrolysis
400οC/Ar
CMK-3@mx
CMK-3-O@m4
FexOy
FeHO
OCH2(CH)O
OCH2(CH3)O
Fe
OCH2(CH3)O
Fe
OCH2(CH3)O
OCH2(CH3)O OCH2(CH2)O OH
OH2
OH2
H2O
H2O+
NO3-
CMK-3-O@Fe
CMK-3@Fe CMK-3@ac
CMK-3-O@ac
FexOy
Preparation of carbon hybrids (CMK-3 /FexOy)
Characterization of CMK-3
SBA-15 CMK-3
1 2 3 4 5
1,5 2,0 2,5 3,0 3,5 4,0
110200
× 10
(20
0)
(11
0)
(20
0)
(11
0)
(10
0)
Inte
nsity
2θ(ο)
CMK-3
SBA-15
(10
0)
d100 = 9.0 nm
d100 = 10.5 nm
ao =2d100/√3
ao= 12.1 nm
SBA-15
pore
CMK-3
ao= 10.4 nm
P6mm
2000 1800 1600 1400 1200 1000 800 600
Wavenumbers (cm-1)
Ab
so
rba
nce
1230
1716
1382
1580
1445
661613
1700
823
567
670
CMK-3-O@m4
1165
1350
1580
1595
661
FT-IR Spectroscopy
CMK-3
CMK-3-O
CMK-3-O@Fe
CMK-3-O@ac
CMK-3-O@m4
C=CC-H
-COOH, -COO-
NO3 -COO- Fe+
-COO-
O-C=O
Fe-OFeHO
OCH2(CH)O
OCH2(CH3)O
Fe
OCH2(CH3)O
Fe
OCH2(CH3)O
OCH2(CH3)O OCH2(CH2)O OH
OH2
OH2
H2O
H2O+
NO3-
Characterization of CMK-3@FexOy Hybrids
Raman spectra
Characterization of CMK-3@FexOy Hybrids
ID/IG=0.8-0.95
FWHF~110cm-1
CMK-3@m1
CMK-3@m2
CMK-3-O@m4
CMK-3@m10
CMK-3
Characterization of CMK-3@FexOy Hybrids
1.0 1.5 2.0 2.5 3.0
(20
0)
(11
0)
CMK-3@m10
CMK-3@m2
CMK-3
CMK-3@m1
Inte
nsity
2θ(ο)
(10
0)
1.0 1.5 2.0 2.5 3.0
(10
0)
CMK-3
CMK-3-O
Inte
nsity
2θ(ο)
CMK-3-O@m4
(20
0)
(11
0)
X-ray Diffraction (XRD)
X-ray Diffraction (XRD)
Β
Cu
BD
cos*
*9,0Scherrer:
Characterization of CMK-3@FexOy Hybrids
28 32 36 40 44
CMK-3@m1
CMK-3@m2
CMK-3-O@m4
CMK-3
(400)(220)
(311)
Fe3O4
Inte
nsity
2θ (degrees)
γ-Fe2O3
CMK-3@m10
20nm
Average size FexOy
13nm
8nm
100 200 300 400 500 600 700 800
CMK-3
CMK-3-O@m4
Temperature(oC)
400
356
DT
Aexo
endo
100 200 300 400 500 600 700 800
0
10
20
30
40
50
60
70
80
90
100
CMK-3-O@m4
CMK-3
Temperature(oC)
%T
G
12,6%
Characterization of CMK-3@FexOy Hybrids
Thermal Analysis
27.3 wt%
11.5 wt%
iron oxide content
(Fe2O3) of hybrids
SURFACE AREA MEASUREMENTS
CMK-3@FexOy HybridsCharacterization of
0.0 0.2 0.4 0.6 0.8 1.0
200
400
600
800
1000
1200
CMK-3@m4
CMK-3-O
Vad
s (
cm
3/g
)
p/p0
CMK-3
CMK-3@m1
Isotherms
0.0 0.4 0.8 1.2 1.6 2.0
0.0
0.4
0.8
1.2
1.6
2.0
CMK-3-O
CMK-3@m1
Vliq
(cm
3/g
)
t/nm
CMK-3
2
1
CMK-3-O@m4
V-t plots
r~1.7nm
1.2 1.5 1.8 2.1 2.4 2.7 3.0
dV
/dr
r(nm)
Mössbauer spectroscopy
Characterization of CMK-3@FexOy Hybrids
Μössbauer parameters resulting from least square
fits of the spectra
γ-Fe2O3
CMK-3@m1
Magnetic measurements
T
(K)
Mmax+ (7 T)
(emu/g)
HC
(Oe)
MR
(emu/g)
CMK-3@m1 5 2.1205 500 0,5811
Characterization of CMK-3@FexOy Hybrids
CMK-3@m1
300K
ao=9 nm
d=3 nm
Characterization of CMK-3@FexOy Hybrids
CMK-3@m1Transmission Electron Microscopy (ΤΕΜ)
CMK-3@m1
25 30 35 40 45 50 55 60
CMK-3@ZVI-12:1
Inte
nsity
2θ(ο)
CMK-3@ZVI-4:1
Fe0
CMK-3
ZVI
Β
Cu
BD
cos*
*9,0Scherrer:
~2,7nm
~11,2nm
<2,7nm
44,9o
35,5o
Characterization of CMK-3/Fe0 Hybrids
0.0 0.2 0.4 0.6 0.8 1.0
0
100
200
300
400
500
600
700
800
CMK-3@ZVI-12
Vads (
cm
3/g
)
p/p0
CMK-3
0.0 0.2 0.4 0.6 0.8 1.0
0
200
400
600
800
1000
CMK-3@ZVI-4
Va
ds (
cm
3/g
)
p/p0
CMK-3
Characterization of CMK-3/Fe0 Hybrids
SBET (m2/g)
1284
708
SBET (m2/g)
993
696
Vpore (cm3/g)
0,65
0,39
Vpore (cm3/g)
0,54
0,41
400 450 500 550 600 650 700
0,00
0,25
0,50
0,75
1,00
Ab
so
rba
nce
Wavelength (nm)
0,2 mg/L
0,4 mg/L
0,6 mg/L
0,8 mg/L
1 mg/L
542nm
Cr6+ +
0,0 0,2 0,4 0,6 0,8 1,0 1,2
0,00
0,15
0,30
0,45
0,60
0,75
0,90
A=0,85186*C-0,00836
Absorb
ance
Συγκέντρωση Cr(VI) mg/L
Environmental remediation
( aqueous solution Cr6+)
1,5-diphenylcarbohydrazide
400 450 500 550 600 650 700
0,0
0,1
0,2
0,3
0,4
0,5
0,6
Ab
so
rba
nce
Wavelength (nm)
0h
0,5h
1h
2h
6h
9h
pH=5,5
CMK-3
542
400 450 500 550 600 650 700
0.0
0.1
0.2
0.3
0.4
0.5
0.6
A
bso
rba
nce
Wavelength (nm)
0h
0.5h
1h
2h
3h
6h
9h
24h
pH=5,5
542
CMK-3@ZVI-12
0,4686
0,3774
400 450 500 550 600 650 700
0,0
0,1
0,2
0,3
0,4
0,5
0,6CMK-3
Ab
so
rba
nce
Wavelength (nm)
pH=3
0h
0,5h
1h
2h
3h
6h
9h
24h
542
0,0375
0,4702
400 450 500 550 600 650 700
0.0
0.1
0.2
0.3
0.4
0.5
0.6
CMK-3@ZVI-12
0h
0.5h
1h
2h
3h
6h
9h
24h
Ab
so
rba
nce
Wavelength (nm)
pH=3
542
Environmental remediation
( aqueous solution Cr6+)
Cr6+=6ppm
CMK-3=180ppm
Cr6+=6ppm
CMK-3@ZVI=180ppm
CMK-3@ZVI - Hybrid
0 2 4 6 8 10 12 14 16 18 20 22 24
0,0
0,1
0,2
0,3
0,4
0,5
0,6
0,7
0,8
0,9
1,0
time (hours)
[Cr6
+] t /
[C
r6+] 0
CMK-3@ZVI-12:1 (pH=3)
CMK-3 (pH=3)
CMK-3@ZVI-12:1 (pH=5,5)
CMK-3 (pH=5,5)
0 2 4 6 8 10 12 14 16 18 20 22 24 26
0
1
2
3
4
5
1/[C
r(V
I)] t
time (hours)
CMK-3
CM
K-3
@Z
VI-
12:1 second order
6 5 4 3 2 1 0
0
2
4
6
8
10
12
14
16
18
r (m
g*L
-1*h
-1)
[Cr(VI)] (mg*L
-1)
CMK-3@ZVI-12:1
CMK-3
2,1
14,4 pH=3
0
2)]([
1
)]([
1
VICrtk
VICr t
Second order equation
K2 (L·mg-1·h-1) R2 t1/2 (h)
CMK-3 0,066 0,989 2,7
CMK-3@ZVI-12:1 0,417 0,986 0,4
2
2 ))](([ tVICrkr
Evaluation of hybrids
CMK-3@ZVI - Hybrid
0
2)]([
1
)]([
1
VICrtk
VICr t
22 ))](([ tVICrkr
0 2 4 6 8 10 12 14 16 18 20 22 24
0
1
2
3
4
5
time (hours)
1/[
Cr(
VI)
] t
second order
CMK-3
CM
K-3
@m
2
Second order reaction
k2(L·mg-1·h-1) R2 t1/2(h)
CMK-3@m2 0,434 0,983 0,4
CMK-3 0,082 0,989 2,1
0 2 4 6 8 10 12 14 16 18 20 22 24
0,0
0,2
0,4
0,6
0,8
1,0
CMK-3@m2 (pH=5,5)
CMK-3@m2 (pH=3)
CMK-3 (pH=5,5)
[C
r6+] t /
[C
r6+] 0
time (hours)
CMK-3 (pH=3)
6 5 4 3 2 1 0
0
2
4
6
8
10
12
14
16
pH=3
r (m
g*L
-1*h
-1)
[Cr(VI)] (mg*L
-1)
CMK-3
CMK-3@m214,5
2,7
Evaluation of hybrids
CMK-3@FexOy - Hybrid
Hybrids for environmental applications were prepared:
a) via interaction of acetic acid vapors with iron cations dispersed on the surface of a CMK-3
mesoporous carbon. (CMK-3@FexOy)
b) using a CMK-3 carbon as a matrix for wet impregnation of FeCl3, followed by reduction of iron
species by means of NaBH4 and drying of the sample in vacuum. (CMK-3@Fe0)
The XRD, FT-IR, TEM, DTA/TG and surface area measurements revealed the well defined
carbon mesoporous structure and the successfully preparation of hybrids.
Magnetic experiments suggested the ultrafine character of the iron oxide nanoparticles which
exhibit a superparamagnetic behaviour.
Mössbauer measurements showed:
a) γ-Fe2O3 as the major magnetic iron oxide phase in CMK-3@FexOy hybrids
b) the well known iron core-shell structure for the ZVI nanoparticles in CMK-3@Fe0
c) almost zero recoil-free nanoparticles at temperatures above 77K in hybrids.
CMK-3@Fe0 and CMK-3@FexOy hybrids showed very rapid uptake kinetics in the removal of
aqueous Cr6+ ions and total remediation of aqueous solution of Cr6+ at conditions- pH: 3,
concentration: 6ppm, treatment time: 24hours .
Both type of hybrids showed significant improvement of sorption and/or reduction capability of
Cr6+ ions/g of specific sorbent in comparison with pristine CMK-3 or unsupported ZVI
nanoparticles.
Conclusions
Dr. M.Baikousi
Dr. D.Dimos
Mrs. E.Petala, M.Sc.
Assist. Prof. A.Bourlinos
Assist. Prof . A.Douvalis
Professor T.Bakas
Professor R.Zboril
Dr. Jiří Tuček
Dr.Klára Šafářová
Dr. Jan Filip
Acknowledgements
Department of Materials
Science &Engineering
University of Ioannina
Greece
Department of Physics
University of Ioannina
Greece