Synthesis and Characterization of Mesoporous Carbon...

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

P. Selvam, S. K. Bhatia and C. S. Sonwane, Ind. Eng. Chem. Res., 40 (2001) 3237

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


ID/IG=0.8-0.95

FWHF~110cm-1

CMK-3@m1

CMK-3@m2

CMK-3-O@m4

CMK-3@m10

CMK-3


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:


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%


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


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


CMK-3@m1

300K

Transmission Electron Microscopy (ΤΕΜ)


CMK-3-O@m4

ao=9 nm

d=3 nm


CMK-3@m1Transmission Electron Microscopy (ΤΕΜ)

CMK-3@m1

FeCl3·6H2O

1:2

CMK-3 CMK-3@ZVI

NaBH4

Synthesis of CMK-3/Fe0 Hybrids

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

Thank you

Synthesis and Characterization of Mesoporous Carbon...

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