Research scope of Yoon’s Lab

量子理工学概論IV
講義1

 Synthesis and applications of functional materials
 Energy and environmental engineering- Outline and Interrelation of Research Topics

Environmental Preservation

Advanced Catalytic Reaction

Adsorptive Reaction：DeSOｘ、DeNOｘ
Selective Ads.：VOC、CO2、Black carbon,
Sick house gas, Nano-particles
Gas storage and separation：CH4, H2

Coal and Petroleum - Selective Reactions
Hydrogenation・C1, C4 Chemistry、Highly-purified Fuel

Catalyst Preparation

ナノカーボンの調製とエネルギー・環境デバイスへの応用

Metal, Oxide, Complex, Oxygen, Microorganism

Liquefaction・gasification
refining and reforming

CalcinationGraphitization

Refined Precursors
Gas Oils

Meso-fication
Carbonization

尹 聖昊
九州大学先導物質化学研究所

Coal and Petroleum
Oil Shell
Taryoon@cm.kyushu-u.ac.jp
http://carbon.cm.kyushu-u.ac.jp/

Functional Carbons

Functional Composites

Activated Carbons and Fibers (AC, ACF)
Carbon Fibers (CF)Needle Cokes
Green Cokes and Calcined Cokes
Binder Pitch
Mesophase Pitch
Carbon Nanofibers （CNF)
Fullerene and its Derivatives

Hydrocarbons
Organic Materials
Biomass

Fundamentals of Carbon Engineering
Carbon Structure Fundamentals：modeling and functional prediction of
structural units of CF, ACF, and CNF
Control and Uses of Surface and Pore Structure
Thermal and Electrochemical Characterization of Carbons

Composite
ArtifactCarbonization
CVDMixing

CF-Composites
AC, ACF Adsorption
ElectrodeCokes, Binders
CNF-Composites
Nano-particle Composites
Inorganic Nanofibers

Chemical, Electrochemical Modification
Composite and Functionalizing

EnergyAdvanced Materials

High Functional Li-ion secondary battery
Supercapacitor Materials
Desalination：fresh water making
Fuel Cell Catalysts, Separators

Field Emission Display
Transparent Conductive Films
EMI Shield、Sensors
ER Fluid, Nano-fluid

Flow chart of CNF studies in Yoon Lab

Short introduction of carbon
nanofiber study in Yoon Lab- Carbon nanofiber general- Preparation and structural analysis ofcarbon nanofibers

341

CNF (Small & Middle Diameters)

Standard CNFs

5

Structural variety of CNFs

7

Surfaces of PCNF

8

J PHYS CHEM B 108 (5): 1533-1536 FEB 5 2004

2

Control of Graphitic Properties of TCNFs

9Highly graphitic CNFs

Carbon, 42, 1279-1283, 2004

10

N-doped CNFs

123

Preparation (Fixed Bed Method)

13

Catalysts for CNF Preparation

14

Mono-metal- Fe, Co, Ni- Fe, Co, Ni / Supports
Support: Alumina, Silica >>> MgO
Bimetallic Catalyst- Fe, Co, Ni / Fe, Ni, Mn, Cu, …/Supports
Trimetallic Catalyst- Fe, Co, Ni / Fe, Ni, Cu, Mn / Cr, Al,…/Supports

Functions of Second or Third Metals ?
CARBON 42 (3): 591-597 2004

Main Catalyst

2nd Catalyst
Cr
Fe:Cr:Mg=6.4:1.6:2
収率 : 4.6倍
倍
繊径 : 40nm
TubularMn

Fe
Fe:Mg=8:2
収率:
収率 1.2倍倍

Fe:Mn:Mg=6:2:2
収率 : 1.1倍倍

Cu
Fe:Cu:Mg=6:2:2
収率 : 2.0倍
倍Ni

3rd Catalyst

JOURNAL OF PHYSICAL CHEMISTRY C, 112, 10050-10060, 2008

Mass Production of CNFs

Mo
Fe:Cr:Mo:Mg=6:1:1:2
収率 : 27.8倍
倍
繊径 : 20nm
TubularCoFe:Mn:Co:Mg=4:2:2:2
収率 : 11.6倍
倍
繊径 : 50nm
不均一 CNF

Co
Fe:Cu:Co:Mg=6:1:1:2
収率 : 60.2倍
倍
繊径 : 180nm
Herringbone CNF

Co

Fe:Ni:Co:Mg=7:0.5:0.5:2
収率 : 60.2倍
倍
繊径 : 120nm
Tubular15164

Primary Structures of Various CNFs

Recent new finding by us :Platelet and herringbone CNFs are constructed by two typesof structural units, a nano-rod type and a nano-plate type.

b.an@aist.go.jp

Structural Models for CNFs
by STM

by TEM
NanoRodaxis

axis

axis

axis

Platelet CNF

Units
Herringbone CNF
axis

axis

axis

Nano
PlateTubular CNF

S-H. Yoon et al., Carbon 42 (2004),3087.
Carbon 43 (2005),1828.

18

Schematic model of nucleation and growth process of CNTs

Separation of structural units
from CNFs- From PCNF to Nano-graphene

Small 6 (22), pp. 2526-2529 (2010) 19

20
205

Separation of structural unit (Nano-rod)

Separation of structural unit (Nano-platelet)

2122

23

24

CNF preparation using waste
industrial gases
 Effect of poison gases: H2S, COS
 Effect of oxidative gases：： CO2, H2O
 Effect of different reactive gases(a) C2H4(b) CO(c) CH4Carbon 2011 (Shanghai)

6

2526

Conjectured reaction mechanism
1. Ethylene+H2+CO2→ CO+CH4+…
2. CO spillovers to Fe

1. CO+H2 to Fe surface→ Growth of CNF
Disproportionation reaction

CNFs for Battery Study
C2H4
H2

CO2

H2H2OCOFe particle
2728

7

Preparation and Analysis of SiO-CNF Composites

Concept of CNF composites

29Comparison bet. Composite and Mixture

Electrochimica Acta, 55, 5519-5522 (2010)

30
30Cycle performances of PCSi-CNF composite

400

Volume expansion (%)

Electrolyte penetration only (2days)
After charging to 0V
301%

300
248%

200
153%
112%

124%

126%

100Composite (Fe cat.)

Mixture (CNF)

Mixture (KB)

31

CARBON, 48, 3381-3391, 2009.

328

800
700
600
500
400
300

20Si/PyC/CNF-30%20Si/PyC/CNF-20%20Si/PyC/CNF-10%MAG

200
10000510152025

Dischage capacity(mAh/g)Dischage capacity(mAh/g)Si-CNF composite / Graphite Hybridization700600

CNF for Capacitor Study

500
400
300

50Si/PyC/CNF-30%
50Si/PyC/CNF-20%
50Si/PyC/CNF-10%MAG

200100030051015202530Cycle

Cycle

Carbon 2011 (Shanghai)

33

Surface-modified PCNF series

34

Functional Groups vs. capacitance
Polarized anodic HCNF by binderless polarization condition in 30 wt% H2SO4
Cyclic voltammogram of GPCNF series

GPCNF

30

Polarized HCNF under binderless condition in 30 wt% H2SO4

Capacitance (F/g)

20

10Anode (＋＋ electrode)

0Dome-likebasal plane

Graphitic edge-30
-0.4

0.08

PCNFGPCNF
GPCNF-NAGPCNF-EC
-0.2

0.0

0.2

0.4

0.6

GPCNF-EC

Elemental analysis (wt%)

Recoveredgraphitic edge

Recoveredgraphitic edge

0.06

0.04

0.8

Elemental analysis of GPCNF series

Samples

0.08

0.06

E / V (vs. Ag/AgCl)

GPCNF-NA

0.10-10-20

5 nm

Cathode (－－ electrode)

0.10

H

C

N

O
(diff.)

PCNF

0.33

98.15

0.05

1.47

GPCNF

0.10

99.90

00

GPCNF-NA

0.15

99.12

0.06

0.67

GPCNF-EC

0.13

98.50

01.37

0.04

Current (mA)axis

Current (mA)

PCNF

0.02
0.00
-0.02
-0.04

0.00
-0.02
-0.04

Reduced HCNF
Polarized HCNF at 1.0 V
Polarized HCNF at 1.5 V
Polarized HCNF at 2.0 V
Polarized HCNF at 2.5 V

-0.06
-0.08
-0.10
-0.4

0.02

-0.2

0.0

0.2

0.4

0.6

0.8

-0.08
-0.10
-0.4

Potential (V)Langmuir, 22 (22), 9086 -9088, 2006
35

Reduced HCNF
Polarized HCNF at 1.0 V
Polarized HCNF at 1.5 V
Polarized HCNF at 2.0 V
Polarized HCNF at 2.5 V-0.06* According to increase of the potential,

-0.2

0.0

0.2

0.40.60.8

Potential (V)in anode, EDLC and psudocapacitane increased.
in cathode, capacitance decreased slightly.

Carbon 49 (1), pp. 96-105 (2011)

36

9CNF coated MgO (CNF-MgO)
CNF
Catalyst

Ceramic applications

MgO

Model of CNF-MgO
CNF- Increasing the strength of refractorythrough the small amount addition of CNFMgO composites

MgO

100nm

CNF’s diameter : 10 ~ 20nm
100nm

UNITECR2011, Best Oral Award

Stress – strain curves

37

Scanning electron microscopy
F (CNF : 0.40%)

Specimen A (CNF : 0%)Stress / MPa

5432.2 times

2

CNF content / %A 0
B 0.03
C 0.07
D 0.13
E 0.27
F 0.40

MgO

MgO

MgO
MgO
10µm

CNF
CNF
10µm

100123Strain

456CNF( × 10 -3 )
100nm

100nm

10

Mechanism of strengthening – Ⅱ( Detail : crack arresting)

Tip of the crack
CNF-MgO
MgO

CNFs for Nanofluid
MgO

Crack

Crack
MgO

(a)

MgO

(b)

42

CNF AS A Novel Nanofiller for Nanofluid Applications

CNFs for Green Organic Chemistry
 CHEMISTRY-AN ASIAN JOURNAL 2 (12): 1524-1533 2007
 JOURNAL OF SYNTHETIC ORGANIC CHEMISTRYJAPAN, 67, 7, 724-734, JUL 2009
 Organic Letters, 11, 5042-5045 (2009)a) Photograph of CNF-10-water suspensions. Left:pristine CNFs (0.5 vol %); middle: TCNFs fromplasma oxidation for 30 min (0.5 vol %); right: TCNFwater suspension diluted 20 times. b) TC
enhancement of nanofluid containing various
contents of CNFs. The dot-dashed line indicates thetheoretical prediction for TC enhancement based on
the Hamilton-Crosser (H-C) equation

SEM images of a) pristine CNFs andb) TCNFs (CNF-10).
Insets: higher-magnification SEM images

Small, 3, Issue 7, Date: July 2, 2007, Pages: 1209-1213

4411

Reduction Catalyst

Applications of Modified CNFs

Organic Letters, 11, 5042-5045 (2009)

Application for green catalyst supports

Structure control
Hybridization

CNF

CNF / Si46

CNF / SiO
CNF / TiSi

CNF: surface control

PCNF

CNF / Graphite

TCNF-NG/Li

Commercial catalyst

Metal oxide dispersion

High dispersion
Size control
Problems of activity
and selectivity

GPCNF
CNF-T

CNF-H

CNF-P

Mesofication
Isolation＋“Nano on nanoapproachLnM

カルボニル錯体)
CO (カLnM(オオレフィン錯体)

Metal oxide
dispersion
Capacitor
RuO2
Co2O3NiO
Polypyrrole

Mesoporous
CNF

Metal chelation：： Thermal decomposition

Fe/CNF-P
dav = 5.0 nm

Ru/CNF-P
dav = 2.5 nm

Rｈ
ｈ/CNF-P
dav = 7.6 nm

Pd/CNF-P
dav = 4.2 nm

Pｔｔ/CNF-P
dav = 1.4 nm

Outline1 Preparation of graphene discs

Nano-graphene

Battery
Li4Ti5O12Si

Nano-graphene/ TCNF

Fuel Cell
Pt
Pt/Ru
WxC

Activated Carbons

Graphites

Nanofluid
Nano-shuttle
Catalyst

Fuel Cell:
DMFC,PEMFC

Capacitor
electrodematerials

Li-batteryelectrodematerials

1. Preparation of graphene discs47

2 Preparation of mesoporous CNFs

Oxidation

graphitexxxxxxxxxx
graphite oxide

4 Electrochemical applications
References

Long, D.; Hong, J.Y.; Li, W.; Miyawaki, J.; Ling, L.; Mochida, I.; Yoon, S.H.; Jang, J. ACS Nano 2011,
2011 5(8), 6254-6261.
Long, D.; Li, W.; Qiao, W.; Miyawaki, J.; Yoon, S.-H.; Mochida, I.; Ling, L.
Chem. Commun. 2011,2011 47(33), 9429-9431.
Long, D.; Li, W.; Qiao, W.; Miyawaki, J.; Yoon, S.-H.; Mochida, I.; Ling, L.
Nanoscale 2011,2011 3(9) 3652-3656.
Long, D.; Li, W.; Miyawaki, J.; Qiao, W.; Ling, L.; Mochida, I.; Yoon, S.-H.
Chem. Mater. 2011,
2011 23(18), 4141-4148.

48

Chemically derived graphene via exfoliation and reduction(1) Isolation into graphene oxide

3 Preparation of partially unzipped CNF

MixingSonication

xxxxxxxxxx

isolated graphene oxides

The chemical reduction method is a suitable approachto producing graphene sheets in bulk quantity at relatively low cost.

(2) Reduction to graphene

However, preparation of graphene with defined shapeis still a challenging work.

graphene oxideReductiongraphene121. Preparation of graphene discs

1. Preparation of graphene discs

49

Preparation of uniform graphene discOxidation, exfoliation and reduction of GPCNF

Step-by-step cutting of graphenes of platelet carbon nanofiber (PCNF)
PCNF consists of nano-sized platelet structuralunits stacked perpendicular to fiber axis.
The plate unit has the thickness of 2-3 nm
consisted of 6-10 graphene layers.

Graphitized PCNF
(GPCNF)xxx
Sonication xxxxxxxxx
x

Oxidation

x Reductionxx
Isolated
GPCNF oxides(Graphene oxides)

GPCNF
oxide

Graphene
PCNF

50

Graphene layers(Graphene discs)(1) Oxidation of GPCNF to PCNF oxide by the Hummer’s method
Dispersion of 1g GPCNF in 100 mL of 98% H2SO4
Addition of 1～7 g KMnO4
Stirring at 0oC for 30 min and then 40oC for 30 min

Structural unit

Yoon SH et al. Carbon 43,
43 1828 (2005).

(2) Washing with assistant of centrifuge
Washing with water and H2O2
Centrifugation at 4800 rpm
Washing with HCl and acetone(3) Exfoliation through strong sonication(4) Reduction
Chemical reduction or Mechanical reduction

Cutting to structural unit, and then graphene

1. Preparation of graphene discs

1. Preparation of graphene discs

51

Structure of graphitized PCNFs

52

TEM images of exfoliated GPCNFs
xxx

GPCNF (2800oC)

xxxxxxxxx K/GP = KMnO4/GPCNF ratio

SBET = 50 m2/g
d002 = 0.3476 nm

K/GP = 0

K/GP = 1

K/GP = 2

K/GP = 3

K/GP = 4

K/GP = 5

K/GP = 6

K/GP = 7131. Preparation of graphene discs

1. Preparation of graphene discs

5354

XRD patterns and 13C-NMR spectra of oxidized GPCNFs

SEM and AFM images of exfoliated GPCNFs
K/GP = 1xxx

Intensity (a.u.)

0.763 nmK/GP = 2

0.339 nmxxxxxxxxx

GPCNF oxide
GPCNF
PCNF
204060-COOH

80

C-O-C

K/GP=7

K/GP = 5

Intensity (a.u.)

K/GP = 3

Single-layer graphite oxide discs

Intensity (a.u.)2θ (ο)

K/GP=7
K/GP=6
K/GP=5

K/GP=5C-OH
C=C

K/GP=2
K/GP=1

K/GP=3K/GP=2K/GP=1204060

K/GP=3300

250200150

100500-50-100

Chemical shift (ppm)80

13C solid-state NMR spectra2θ(°)

XRD patterns

1. Preparation of graphene discs

1. Preparation of graphene discs

55

StepStep-byby-step cutting model ofGPCNF into graphene discs

Hydrothermal reduction using NaBH4 at 130oC for 5 hOxidation

K/GP= 5Intensity (a.u.)

56

Chemical reduction of GPCNF oxidexxxx Sonication xxxxxxReductionxx

K/GP= 3

K/G= 2294 291 288 285 282

540537534531528Binding energy (eV)XPS spectra

K/GP = 1

K/GP = 3

K/GP = 5

K/GP = 614

1. Preparation of graphene discs
Chemical reduction of GPCNF oxide

Mechanical reduction of GPCNF oxide

Hydrothermal reduction using NaBH4 at 130oC for 5 h

Wet milling method using nano-dispersion machine

Intensity (a.u.)

K/GP=5K/GP=3K/GP=5K/GP=3
K/GP=2K/GP=1

K/GP=2
K/GP=140

60

T.K.FILMICS 56, PRIMIX Sample(18400 rpm, 100oC)

Oxidized802θ (°)

ReducedIntensity (a.u.)

Intensity (a.u.)

K/GP=7
K/GP=620

XRD patterns

4060GPCNF

300

250200150100500-50-100

Chemical shift (ppm)

13C solid-state NMR spectra

Absorbance (a.u.)

Intensity (a.u.)

Intensity (a.u.)

288286284

300

400500K/GP = 6600

700800296 294 292 290 288 286 284 282 280

Binding energy (eV)XPS spectra

Binding energy (eV)Wavelength (nm)UVvis absorption spectra

1. Preparation of graphene discs
Mechanical reduction of GPCNF oxide

59

Reduction time

200

290

K/GP = 3

K/GP=5214 nm K/GP=3292

150

GPCNF oxide (K/GP = 6)
7.4 × 10-4XRD patterns
FT-IR spectra
Graphene discs
14256 nmK/GP = 3294

Electrical conductivity (S/cm)

802θ (°）

Hydrothermalreduction

296

58

K/GP = 3

K/GP=620

1. Preparation of graphene discs

57

UVvis absorption spectra

Nitrogen-Doped Graphenes by a Combined Chemical andHydrothermal Reduction

Influence of solvent during mechanical reduction

K/GP = 6

Concentration > 2.0 g/L

15

2. Preparation of mesoporous CNFs

2. Preparation of mesoporous CNFs

61

62

Preparation of mesoporous PCNFs from asas-prepared PCNFs

Thermal expansion of CNF oxide

Rapidheat treatment
in N2, 300oC, 30oC/min

CNF oxide(without sonication)

MesoporousCNF

distortion
AsAs-prepared PCNF
SBET = 56 m2/g

2. Preparation of mesoporous CNFs

Mesoporous PCNF (MG(MG-PCNF)
SBET = 355 m2/g

2. Preparation of mesoporous CNFs

63

64

Preparation of mesoporous HCNF and TCNF

Characterization of mesoporous PCNFs

From asas-prepared HCNF and TCNF
Herringbone
CNF (HCNF)

XRD patterns

XPS spectra

SBET = 247 m2/g
Tubular
CNF (TCNF)
SBET = 355 m2/g

SBET = 69 m2/g

13C solid-state NMR spectra

N2 adsorption isotherms at 77 K

SBET = 168 m2/g

16

2. Preparation of mesoporous CNFs

3. Preparation of partially unzipped CNF 66

65

Preparation of mesoporous HCNF and TCNF
From graphitized HCNF and TCNF (GHCNF and GTCNF)
GPCNF
SBET = 307 m2/g

TCNF
GHCNF

TCNF oxide(o(o-TCNF)

PUPU-TCNF

SBET = 215 m2/g

GTCNF
SBET = 168 m2/g

3. Preparation of partially unzipped CNF 67
Characterization of partially unzipped TCNF

4. Electrochemical applications
TCNF

TCNF oxide(o-TCNF)

PU-TCNF68Pt@PU-TCNF

TCNF
PU-TCNF

PU-TCNF

o-TCNFo-TCNF

TCNF

TCNF

40 wt% Pt loadingo-TCNFXRD patterns

TCNF

PU-TCNF

Pt@TCNF

Raman spectra

Pt@TCNF
Pt@PU-TCNF

TCNF
o-TCNF
PU-TCNF

SBET = 168 m2/g

o-TCNF

PU-TCNF

SBET = 72 m2/g

Pt@
PU-TCNF

XRD patterns
XPS spectra

N2 adsorption isotherms at 77 Kd(avg.) = 3.2 nm

17

4. Electrochemical applications69

 Improved electrocatalytic performance Good durability
Pt@PU-TCNF
Pt@TCNF
Pt@Vulcan (XC-72)

Pt@
PU-TCNF

Pt@TCNF

1. Special properties of CNFs are still promising for theircommercial applications through the innovation of theperformances of conventional carbons.
2. Very homogeneous nano-graphene and special fibrousmesoporous carbon can be obtained using CNFs as aneffective precursor
3. We have to solve the problems of CNFs for the effective
applications to the real market.
• From science to engineering• Full understanding of the performances and costsof the conventional functional carbons

Pt@PU-TCNF
Pt@Vulcan
Pt@TCNF

Cyclic voltammograms
in 0.5 M H2SO4

Pt@Vulcan

Durability tests
SampleElectrochemically active
surface area, ESA (m2/g)

Pt@PU-TCNF

129

38

Pt@TCNF

64

11

Pt@Vulcan

71

65

70

Conclusion

Decay rateof ESA (%)

Proton exchange membrane
fuel cell (PEMFC) single-cell
profilesLab members

Acknowledgements

 Seong-Ho Yoon: Professor
 Isao Mochida: Professor of special appointment
 Jin Miyawaki: Assistant Professor
 1 Guest Professor
 2 Post-doctorates
 2 Researcher for Analyses
Members for Nano-studies
 9 Doctor course students• Faculties
 5 Mater course students• 1 Post-doctorate
 3 Secretary• 3 Doctor course students•This work was done within the category of CREST
program of JST. We are sincerely appreciated to thefinancial support of JST.
•This work is supported by a grant from the Global-Centerof Excellence (GCOE) in Novel Carbon Resource
Sciences, Kyushu University. And, the authors are gratefulfor financial assistance provided by the Global-Centre ofExcellence in Novel Carbon Resource Sciences, Kyushu
University.

Email:
yoon@cm.kyushu-u.ac.jp•The authors are very grateful to Dr. An Bai and Dr. Jang
Sang-Min, Mr. Matsuo Yasunori, and Dr. Long Donghui for
their contributions on this work.
72

71

Thank you for attentions!

18