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Supporting Information
High-rate Capacitive Performance of Graphene Aerogel with a Superhigh C/O Molar
Ratio
Xiaozhong Wu, Jin Zhou, Wei Xing,* Guiqiang Wang, Hongyou Cui, Shuping Zhuo,*
Qingzhong Xue, Zifeng Yan, Shi Zhang Qiao*
Mr. X. Wu, Prof. W. Xing, Prof. Q. Xue, Prof. Z. Yan
School of Science
State Key Laboratory of Heavy Oil Processing
China University of Petroleum, 66, Changjiang West Road
Qingdao 266580 (P. R. China)
Email: [email protected]
Mr. X. Wu, Dr. J. Zhou, Prof. W. Xing, Prof. G. Wang, Prof. H. Cui, Prof. S. Zhuo.
School of Chemical Engineering, Shandong University of Technology
Zibo 255049 (P. R. China)
E-mails: [email protected]
Prof. S. Z. Qiao
School of Chemical Engineering
The University of Adelaide, SA5005 (Australia)
Email: [email protected]
Electronic Supplementary Material (ESI) for Journal of Materials ChemistryThis journal is © The Royal Society of Chemistry 2012
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Content
Figure S1 Optical images of GO suspension in deionized water (left) and graphene oxide
hydrogel after self-assembly process (right)
Figure S2 SAED patterns for (a) GOA and (b) GA
Figure S3 UV-Vis absorption spectra of GO, GOA and GA
Figure S4 Optical images of samples dispersed in deionized water and ethanol (solution
concentration: 0.1 mg mL-1)
Figure S5 TG and differential thermogravimetry (DTG) curves of GOA
Figure S6 FT-IR spectra of GO, GOH-D (vacuum dried graphene oxide hydrogel) and GOA
Figure S7 (a) Specific capacitance and capacitance retention ratio at different potential scan
rates; (b) a plot of specific capacitance vs. Frequency; (c) imaginary part of
capacitance vs. frequency for GOA and GA
Figure S8 The specific capacitance and its retention ratio vs. current densities of GA in
organic and ionic liquid electrolytes
Figure S9 Galvanostatic charge-discharge curves of GA at different current densities in
organic electrolyte
Electronic Supplementary Material (ESI) for Journal of Materials ChemistryThis journal is © The Royal Society of Chemistry 2012
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Figure S1 Optical images of GO suspension in deionized water (left) and graphene oxide
hydrogel after self-assembly process (right)
Figure S2 SAED patterns for (a) GOA and (b) GA
(a) (b)
Electronic Supplementary Material (ESI) for Journal of Materials ChemistryThis journal is © The Royal Society of Chemistry 2012
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200 300 400 500 600 700 800
GOA
GA
249 nm
269 nmAb
so
rba
nc
e
Wavelength / nm
230 nm
GO
Figure S3 UV-Vis absorption spectra of GO, GOA and GA
Figure S4 Optical images of samples dispersed in deionized water and ethanol (solution
concentration: 0.1 mg mL-1)
Electronic Supplementary Material (ESI) for Journal of Materials ChemistryThis journal is © The Royal Society of Chemistry 2012
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0 200 400 600 800 10000
20
40
60
80
100
Wei
gh
t re
ma
inin
g /
%
Temperature / oC
40%
dW
/dT
-15%
-19%
Figure S5 TG and differential thermogravimetry (DTG) curves of GOA
The weight change of GOA during thermal treatment process under H2 atmosphere is
recorded by TG analysis. There are two obvious weight losses within the temperature ranges
of 20-150 oC and 150-300 oC, corresponding to the release of adsorbed water and
decomposition of oxygen-containing groups such as carboxylic and lactone groups, [1,2]
respectively. Other oxygen-containing groups (carbonyl, phenol, quinine and hydroxyl
groups) are decomposed at temperatures ranging from 400 to 1000 oC. [2] There is no obvious
weight change above 1000 oC, which indicates that most oxygen-containing groups are
eliminated completely at 1000 oC. The remaining weight is about 40 % when the temperature
reaches up to 1100 oC.
Electronic Supplementary Material (ESI) for Journal of Materials ChemistryThis journal is © The Royal Society of Chemistry 2012
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4000 3000 2000 1000
3398.0
GOH-D
C=Ocarboxyl
C=C
alkoxyl C-O
GOA
epoxyl C-O
carboxyl O-H
carbonyl
Tra
ns
mit
tan
ce
Wave number / cm-1
hydroxyl
GO3383.8
1732.8
1716.9
Figure S6 FT-IR spectra of GO, GOH-D (vacuum dried graphene oxide hydrogel) and GOA
Graphene oxide hydrogel was further vacuum dried at 50 oC to obtain GOH-D. Compared
with GOH-D, there is an obvious decrease of hydroxyl groups in the spectrum of GOA, which
is probably due to the dynamic operation at high pressure (20 MPa) during supercritical CO2
drying.
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Figure S7 (a) Specific capacitance and capacitance retention ratio at different potential scan
rates in ; (b) a plot of specific capacitance vs. Frequency; (c) imaginary part of capacitance vs.
frequency for GOA and GA
0 20 40 60 80 1000
20406080
100 GOA
GA
Rat
io /
%
Potential scan rate / (mV s-1)
0
40
80
120 GOA GA
Cs
/ (F
g-1)
(a)
0.01 0.1 1 10 100 10000
20
40
60
80
100
0.5 Hz GOA GA
Cap
acit
ance
/ (
F g
-1)
Frequency / Hz
0.05 Hz
(b)
0.01 0.1 1 10 100 10000
5
10
15
20
25
30 GOA GA
0.3 s
C"
/ (
F g
-1)
Frequency / Hz
4.2 s
(C)
Electronic Supplementary Material (ESI) for Journal of Materials ChemistryThis journal is © The Royal Society of Chemistry 2012
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0 400 800 1200 1600 20000
20406080
100
organic ionic liquid
Ra
tio
/ %
Current density / (mA g-1)
0306090
120150
organic ionic liquid
Cs
/ (
F g
-1)
Figure S8 The specific capacitance and its retention ratio vs. current densities of GA in both
organic and ionic liquid electrolytes
0 100 200 300 400 500 600 7000.0
-0.5
-1.0
-1.5
-2.0 0.5 A g-1
1 A g-1
2 A g-1
Po
ten
tial
/ V
Time / s
Figure S9 Galvanostatic charge-discharge curves of GA at different current densities in
organic electrolyte
References in supporting information
[1] S. Stankovich, D. A. Dikin, R. D. Piner, K. A. Kohlhaas, A. Kleinhammes, Y. Jia, Y. Wu,
S. T. Nguyen and R. S. Ruoff, Carbon, 2007, 45, 1558.
[2] X. Li, H. Wang, J. T. Robinson, H. Sanchez, G. Diankov and H. Dai, J. Am. Chem. Soc.,
2009, 131, 15939.
Electronic Supplementary Material (ESI) for Journal of Materials ChemistryThis journal is © The Royal Society of Chemistry 2012