chemical modification of graphene tobe lab m1 kosuke hada 1
TRANSCRIPT
• Introduction• Representative previous work about
chemical modification of graphene• My work• Summary
2
Outline
Graphene
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Graphene
Graphene was isolated by using adhesive tape.
Novoselov and Geim won the Nobel Prize in 2010.
Novoselov, K. S. et al. Science 2004, 306, 666-669.
Graphene
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Zboril, R. et al. Chem. Rev. 2012, 112, 6156−6214.
Properties of Graphene ・ Strength
・ Zero band gap
・ Ultrahigh carrier mobility
New MaterialTouch screensSensorSolar cell
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Chemical Modification ( 化学修飾 ) of Graphene
sp2 carbon : conductivesp3 carbon : non-conductive
Changing of sp2 Carbons to sp3 Carbons by Addition of Organic Molecules
Graphene
or R = moleculeCC CC
RCC
RH
R
• Controlling conductivity of graphene• Functionalizing property of graphene
Representative Previous Work onChemical Modification of Graphene
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Covalent chemistry for graphene electronics
Niyogi, S.; Bekyarova, E.; Hong, J.; Khizroev, S.; Berger, C.; Heer, W.; Haddon, R. C. J. Phys. Chem. Lett. 2011, 2, 2487–2498.
Nitrophenyl Radical
Representative Previous Work onChemical Modification of Graphene
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Nitrophenyl Radical
Epitaxial Graphene (EG)
SicSiC
Sic
Graphene1100 ℃Si
CSi
CSi
CSi
CSi
CSi
CSi
CSi
CSi
CSi
CSi
SiC
SiC
SiC
SiC
SiC
Si
C
SiC
SiC
SiC
SiC
SiC
Si
SiC
SiC
SiC
SiC
SiC
Si
C
SiC
SiC
SiC
SiC
SiC
Si
Si
CSi
CSi
C
Si
CSi
CSi
SiC
SiC
SiC
SiC
SiC
SiC
Si
CC
C
CC
CC
CC
CC
CC
CC
CC
CC
CC
CC
CC
CC
CC
CC
C
C
C
CC
CC
CC
CC
CC
C
CC
CC
CC
CC
CC
C
C
C
CC
CC
CC
CC
CC
C
C
CC
CC
C
C
CC
C
CC
CC
CC
CC
CC
CC
CC
C
C
Method of Chemical Modification
Raman Spectrum
vibration of lattice of graphene
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vibration of defects
Functionalized by NitrophenylEpitaxial Graphene
One or Two Layered Graphene
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STM
Nitrophenyl Functionalized Epitaxial Graphene
removing graphene latticehigher-order filteredEpitaxial Graphene
STM
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superimpose( 重ね合わせ )
superimpose( 重ね合わせ )
Epitaxial Graphene
Nitrophenyl Functionalized Epitaxial Graphene
Resistance
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0.4 kΩ at r.t. 3.2 kΩ at r.t.
Epitaxial Graphene Nitrophenyl Functionalized Epitaxial Graphene
• Raman Spector• STM• Resistance
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Summary of the Work
・ Chemical modification change the conductivity of graphene・ Reaction positions and rate weren’t controlled
My purpose is to control reaction positions and rate
= molecules
= substrate
= photoresist
= substrate
light
Top-down approach (photolithography)
Bottom-up approach (molecular self-assembly)
Self-assembly
About 100 nm scale 1~10 nm scale19
Construction of Nano Structure on Surfaces
STM Image of DBA on Graphite
Honeycomb Structure of Dehydrobenzo[12]annulene (DBA) at the Liquid/Graphite Interface
O O
O
OO
O
=
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DBA
Self-Assembly at the Liquid/Solid Interface
Characters of DBA
R
R R
R
DBAOC10: R = OC10H21DBAOC12: R = OC12H25DBAOC14: R = OC24H29DBAOC16: R = OC16H33DBAOC18: R = OC18H37DBAOC20: R = OC20H41
R
R
DBA
=
You can change the size of DBA and holes
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Purpose of My Work
• Chemical stability of diazirine• Precursor of carbene• Photo-reaction under long wavelength
Diazirine
C14H29O OR
OC14H29
ORC14H29O
RO
R = (CH2)10OCF3
NN
DBA 1
C14H29O OR
OC14H29
ORC14H29O
RO
R = (CH2)10OCF3
DBA 1
hv
350 nmDiazirine Carbene
R R'
Y H
R''
R R'
R R'
Y H
R''
• High reactivity• Adding to graphene
Carbene
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Purpose of My Work
=
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Diazirine
Graphene
Self-Assembly
C14H29O OR
OC14H29
ORC14H29O
RO
R = (CH2)10OCF3
NN
DBA 1
Purpose of My Work
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C12H25O OR
OC12H25
ORC12H25O
RO
R = (CH2)8OCF3
NNC14H25O OR
OC14H25
ORC14H25O
RO
R = (CH2)10OCF3
NNC10H21O OR
OC10H21
ORC10H21O
RO
R = (CH2)6OCF3
NN
14 carbons 12 carbons 10 carbons
Graphene and DBA before chemical modification
Purpose of My Work
28Graphene after chemical modification
C12H25O OR
OC12H25
ORC12H25O
RO
R = (CH2)8OCF3
NNC14H25O OR
OC14H25
ORC14H25O
RO
R = (CH2)10OCF3
NNC10H21O OR
OC10H21
ORC10H21O
RO
R = (CH2)6OCF3
NN
28 units 36 units 46 units
14 carbons 12 carbons 10 carbons
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Purpose of My Work
TBSO OMOM
OTBS
OMOMTBSO
MOMO
C14H29O OMOM
OC14H29
OMOMC14H29O
MOMO
CsF, C14H29Br
DMF
10
CBr4
iPrOH
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81% 84%
C14H29O OH
OC14H29
OHC14H29O
HO
K2CO3, 9
acetone
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19%
OC14H29 OR
OC14H29
OROC14H29
RO
R = (CH2)10OCF3
NN
DBA 1
BrMeO MeOCF3
O
THF
MeOCF3
NOHNH2OH・HCl
EtOH
MeOCF3
NHHN
MeOCF3
NOTs
TsCl, NEt3DMAP
liquid NH3 BBr3
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6
7 8
Ag2O
Et2O3 4
acetone
CH2Cl2
CH2Cl2 CH2Cl2
BrC10H20Br, K2CO3
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2 79% 89% 94%
93%
84%
67% 46%
N(CH2CH3)2COCF3
n-BuLi
CF3
NN
MeO CF3
NN
HO CF3
NN
BrC10H20O
Protection from Light
STM Image of DBA at the 1,2,4-trichlorobenzene/Graphite Interface
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Cl
Cl
Cl
2.9 × 10-6 mol/LSTM Image of DBA 1
on Graphite
Solvent1,2,4-trichlorobenzene
C14H29O OR
OC14H29
ORC14H29O
RO
R = (CH2)10OCF3
NN
DBA 1
STM Image of DBA at the 1,2,4-trichlorobenzene/Graphene Interface
Cl
Cl
Cl
2.9 × 10-6 mol/L
Solvent1,2,4-trichlorobenzene
C14H29O OR
OC14H29
ORC14H29O
RO
R = (CH2)10OCF3
NN
DBA 1
STM Image of DBA 1 on Graphene
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UV Spector after Photo Irradiation
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0s
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C4H9O OC4H9
OC4H9
OC4H9C4H9O
C4H9O
H3COCF3
NN
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50000
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150000
200000
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300s
60s
30s
10s
0s
OC14H29 OR
OC14H29
OROC14H29
RO
R = (CH2)10OCF3
NN
DBA 1
photo irradiation of 350~400 nm
stable under photo irradiation photo irradiation generated carbene
photo irradiation generated carbene