Supporting Information
Challenges and Rewards of the Electrosynthesis of Macroscopic Aligned Carbon
Nanotube Array / Conducting Polymer Hybrid Assemblies
B. Endrődi, G. F. Samu, D. Fejes, Z. Németh, E. Horváth, A. Pisoni, P. Matus, K. Hernádi, C.
Visy, L. Forró, C. Janáky*
B. Endrődi, G. F. Samu, Prof. C. Visy, Prof. C. Janáky
Department of Physical Chemistry and Materials Science, University of Szeged, Rerrich B.
Sq. 1., H-6720 Szeged, Hungary
E-mail: janaky@chem.u-szeged.hu (Csaba Janáky)
B. Endrődi, G. F. Samu, Prof. C. Janáky
MTA-SZTE „Lendület” Photoelectrochemistry Research Group, Rerrich B. Sq. 1.
H-6720 Szeged, Hungary
E-mail: janaky@chem.u-szeged.hu (Csaba Janáky)
D. Fejes, Z. Németh, E, Prof. K. Hernádi
Department of Applied and Environmental Chemistry, University of Szeged, Rerrich B. Sq.
1., H-6720 Szeged, Hungary
D. Fejes, E. Horváth, A. Pisoni, P. Matus, L. Forró
Laboratory of Physics of Complex Matter, École Polytechnique Fédérale de Lausanne, CH1015 Lausanne, Switzerland
Keywords: MWCNT array, polyaniline, thermoelectrics, supercapacitor, thermal management
1. Thermoelectric measurements
FIGURE S1 Schematic illustration of the home-built, custom designed device used for
thermoelectric measurements.
For thermoelectric measurements, the samples were placed on the lower (Peltier-heated) copper
block (Figure S1). The upper, mobile copper block was put on the top of the sample.
Temperature gradient was formed by applying constant heating power, and was registered by
two thermistors, embedded in the contact surface of the copper blocks. The resulting thermovoltage was measured between the two copper blocks.
2. Electrochemical synthesis of MWCNTA/PEDOT-PSS composites
Electrochemical synthesis of the MWCNTA/PEDOT-PSS hybrids was realized in the same setup as the other MWCNTA based composites, from aqueous solution of 0.01 M EDOT and 0.1
M Sodium p-toluenesulfonate (NaPSS). Electrochemical synthesis of MWCNTA/PEDOT-PSS
composites was carried out by both potentiostatic and potentiodynamic methods (Figure S2).
In both cases, continuous growth of the polymer was experienced during the polymerization.
To achieve high filling ratio – analogously to the MWCNTA/P3HT system – the potentiostatic
method was chosen for further studies.
3.0
1000
(a)
2.0
800
1.0
600
I (A)
I (mA)
(b)
0.0
400
-1.0
200
-2.0
0
-0.75 -0.50 -0.25 0.00 0.25 0.50 0.75 1.00
E (V)
0
10000
20000
30000
40000
50000
t (s)
FIGURE S2 Synthesis of MWCNTA/PEDOT-PSS composite from 0.01 M EDOT and 0.1 M
NaPSS containing aqueous solution by (A) potentiodynamic method (ν=50 mV s-1) (B)
potentiostatic method (E=800 mV).
FIGURE S3 SEM image of (a, c) Bare MWCNTA (b,d) potentiostatically prepared
(t=50000s) MWCNTA/PEDOT-PSS composite
1.5
I (mA)
35
P3HT on MWCNTA
P3HT on Pt
2.0
30
25
1.40 V
1.0
20
0.5
15
0.0
10
-0.5
5
-1.0
I (mA)
2.5
0
1.46 V
-1.5
-5
0.0
0.5
1.0
1.5
2.0
E vs. Ag/AgCl (V)
FIGURE S4 First cycles recorded during the potentiodynamic polymerization of 3hexylthiophene on Pt and the MWCNTA electrodes (v=50 mV s-1, in acetonitrile solution,
containing 0.1 M Bu4NClO4 and 0.1 M 3-hexylthiophene).
As seen in Figure S3, by applying long polymerization time (thus large transferred charge), the
voids among the individual nanotubes are completely filled with PEDOT, and a compact hybrid
structure was formed. As discussed in the main text, the CNTs have also a catalytic effect in
the polymerization, as seen in Fig. S4, from the less positive onset potential.
3. Electrochemical synthesis of MWCNTA/PANI composites
Normalized intensity
MWCNTA/PANI
PANI
MWCNTA
400
800
1200
1600
2000
Raman shift (cm-1)
FIGURE S5 Raman spectra of a PANI film on Au, a MWCNTA, and a MWCNTA/PANI
FIGURE S6 SEM image of (a, d) bare MWCNTA (b, e) potentiodynamically prepared
MWCNTA/PANI composite (200 polymerization cycles) (c, f) potentiodynamically prepared
MWCNTA/PANI composite (500 polymerization cycles).
TABLE S1 Selected examples of CP/nanocarbon composites for thermoelectric application
CP
Carbon
σ (S cm-1)
S (µV K-1) κ / W m-1 K-1 P (µW m-1 K-2)
ZT
Ref.
PEDOT/PSS Graphene
32
59
0.14
11.09
0.021 [28]
PEDOT/PSS SWCNT
400
27
0.4
26
0.02
[29]
PEDOT/PSS SWCNT
4000
20
0.4-0.7
140
0.06
[30]
P3HT
MWCNT
0.11
11.3
N.A.
0.0014
N.A.
[31]
P3HT
Graphene
1.2
35
N.A.
0.16
N.A.
[32]
P3HT
SWCNT
1000
29
0.5
96
0.015 [33]
PANI
SWCNT
769
65
0.43
176
0.12
PANI
MWCNT
60
28
0.4-0.5
5
0.003 [35]
PANI
SWCNT
125
40
1.5
20
0.004 [36]
PANI
MWCNT
17
10
N.A.
0.18
PANI
Graphene
59
33
13
6
0.0001 [38]
40.35
27
0.02
18.2
0.0022 [39]
PANI
MWCNT
network
N.A.
[34]
[37]