conducting polymer and reduced graphene oxide langmuir–blodgett films: a hybrid nanostructure for...
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Conducting polymer and reduced graphene oxide Langmuir–Blodgett films: a hybrid nanostructure for high performanceelectrode applications
Junfeng Wen • Yadong Jiang • Yajie Yang •
Shibin Li
Received: 18 November 2013 / Accepted: 14 December 2013 / Published online: 20 December 2013
� Springer Science+Business Media New York 2013
Abstract In this work, we prepared a reduced graphene
oxide (RGO)/poly(3,4-ethylenedioxythiophene) (PEDOT)
hybrid composite with well defined nanostructure. The
graphene oxide (GO) was first deposited on substrate
through the Langmuir–Blodgett (LB) deposition, which
provided a tunable and ordered GO arrangement on sub-
strate. Then the GO LB films were reduced to RGO by
following thermal treatment, and a ultrathin conducting
polymer (CP) PEDOT was directly coated on RGO through
a vapor phase polymerization process. The RGO/PEDOT
nanocomposite exhibits excellent electrical conductivity
about 377.2 S/cm. Electrochemical activity investigation
revealed that this nanocomposite exhibits 213 F/g high
specific capacitance at a 0.5 A/g current density and shows
better capacitance retention rate than pure PEDOT. The
detailed study also confirmed that the arrangement of RGO
shows distinct influence on the electrical and electro-
chemical properties of obtained nanocomposite. Large area
RGO/PEDOT nanocomposite with high conductivity and
electrochemical activity can be deposited on different
substrates. Such high conductivity and electrochemical
activity RGO/CP nanocomposite shows promising appli-
cation future in organic and flexible electrode materials for
sustainable energy storage.
1 Introduction
Conducting polymers (CPs) and its nanostructures have
been a subject of growing interest due to their promising
application on microelectronics, capacitor, sensor, solar
cell et al. [1–4]. It offers a high conductive and optical
transparent capability for electrode materials used on
electrochemical ultracapacitor and solar cell [5, 6]. The
optimized performance of device has been improved due to
the construction of CPs and its nanostructure for electrode
materials and modified electrode surface [7, 8]. However,
Such CPs as poly(3,4-ethylenedioxythiophene) (PEDOT) is
brittle and weak in mechanical strengths. This is one of the
drawbacks that hinders PEDOT used as organic electrodes
[9, 10]. Recently, coupling CPs with carbon nanomaterials,
such as graphene, carbon nanotube, has been demonstrated
as an effective approach to improve the mechanical
strengths and conductive performance of the CPs, and
it also shows promising future for device applications
[11–13].
However, in order to use graphene as an efficient rein-
forcing component, it is paramount to incorporate nonag-
gregated and noncrumpled graphene sheets with maximum
interfacial interactions for efficient load transfer within the
polymer matrix [14–16]. Due to the surging interest in
graphene based materials, GO has regained significant
attention as a solution-processable precursor for bulk pro-
duction of grapheme used on transparent conductors and
ultracapacitors [17, 18]. The reduced graphene oxide
(RGO) can be obtained by reducing GO through chemical
and thermal treatment [19–22]. It has been also demon-
strated RGO exhibits high mechanical strength combined
with interesting physical properties, including high per-
formance of electrical, thermal conductivity and electro-
chemical activity [23–25].
J. Wen � Y. Jiang � Y. Yang (&) � S. Li
State Key Laboratory of Electronic Thin Films and Integrated
Devices, School of Optoelectronic Information, University of
Electronic Science and Technology of China (UESTC),
Chengdu 610054, People’s Republic of China
e-mail: [email protected]
123
J Mater Sci: Mater Electron (2014) 25:1063–1071
DOI 10.1007/s10854-013-1687-z
Nanocomposites based on CPs and RGO indicate
excellent electrochemical and conductive performance
when it is used as electrode materials [26, 27]. However, it
is still a challenge to address tunable arrangement of RGO
to obtain better and effective synergistic effect in nano-
composites. The arrangement feature of carbon sheets in
nanocomposites results in performance, for instance, elec-
trical and electrochemical ability change remarkably.
Moreover, tunable performance can be realized by con-
trolling the loadings of RGO in nanocomposites. So, it is
worthwhile to investigate the influence of RGO arrange-
ment characteristic in the nanocomposite, which provides a
valuable assistance to prepare excellent and tunable per-
formance RGO based nanocomposite [28–30].
In this paper, we demonstrate the preparation of a RGO/
PEDOT nanocomposite by using Langmuir–Blodgett (LB)
and vapor phase polymerization (VPP) methods. This
nanocomposite offers tunable arrangement and loading of
RGO in composite and ultrathin PEDOT coverage on
RGO. Limited work is focused on fabricating RGO based
nanocomposites through LB and VPP deposition and the
influence of defined RGO structure on composite perfor-
mance. In the first step, self-assembly of GO sheets on
substrate was performed using LB technique instead of
regular adsorption and spin-casting. Owing to its flexible
nature, folding and wrinkling of graphene oxide sheets can
be substantially minimized by using LB technique to
deposit the films. It is also a facile transfer way that the
sheets can be transferred easily to any appropriate substrate
for further integration with microelectronic devices. After
the GO LB deposition, the GO sheets is reduced into RGO
through a thermal and water vapor treatment and the
morphology of these RGO sheets can keep a LB sheet
formation with defined structure. After that, the PEDOT is
directly deposited on RGO through following VPP depo-
sition, and VPP deposition ensures close and ultrathin
package of PEDOT on RGO. This RGO/PEDOT nano-
composite combines excellent conductivity and electro-
chemical activity based on carbon RGO and CP, and it
exhibits promising applications in organic and flexible
electrode materials for sustainable energy storage.
2 Experimental
2.1 Materials
Graphite flakes used for GO preparation, 3,4-ethylenedi-
oxythiophene (EDOT) (under the respective trade name
Clevios M) and Iron(III) chloride used for PEDOT VPP
deposition were purchased from Sigma-Aldrich. GO was
synthesized from natural graphite flakes was prepared
through Hummer’s method. Stable dispersion of GO in a
solution mixture of methanol/DI water (4:1) was subjected
to ultrasonication for 30 min followed by centrifugation at
2,500 rpm, and this GO solution was used as LB film
deposition.
2.2 Preparation of RGO LB films/PEDOT
nanocomposite
Single GO sheets deposition was carried out in KSV-5000
LB system. The trough was carefully cleaned with chlo-
roform and then filled with DI water. GO solution was
dropwise spread onto the water surface using a glass syr-
inge. Surface pressure was monitored using a tensiometer
attached to a Wilhelmy plate. The film was compressed by
barriers at a speed of 1 mm/min. The GO monolayer was
transferred to substrates at various points during the com-
pression by vertically dipping the substrate into the trough
and slowly pulling it up (1 mm/min). The substrate was
first processed with a hydrophilic treatment in order to
deposit uniform single layer GO. After the GO LB depo-
sition, the single GO layer covered substrate was treated in
a water vapor oven at 190 �C for 4 h GO reduction. Then
the RGO layer covered substrate was fixed in oCVD
reactor for a PEDOT VPP deposition. The reactor pressure
was held at *10 mTorr, and the substrate temperature was
maintained at 120 �C. The EDOT was heated to 150 �C
and introduced into the reactor at a flow rate of *3 sccm
for slow reaction. Iron(III) chloride was evaporated from a
heated crucible between 130 and 150 �C. The different
thickness of PEDOT can be obtained by varying the time of
polymerization. The schematic preparation of RGO/PE-
DOT nanocomposite is shown in Fig. 1.
2.3 Characterization
The surface pressure–area (p–A) isotherm recorded by
computer and the morphology analysis of GO sheets at air–
water interface was characterized by the Brewster Angle
Microscopy (BAM 300). Surface morphology of LB film
was investigated by atomic force microscopy (AFM,
Model SP 3800, SII, Japan) with a tapping mode. Mor-
phological properties were investigated with scanning
electron microscopy (SEM), using a Hitachi made (SEM)
scanning electron microscopy (Model S-2400). Elemental
composition analysis was carried out by X-ray photoelec-
tron spectrum (XPS) with a Scienta ESCA200 spectrometer
at the pressure of 3 9 10-10 mbar and monochromatized
Al Ka radiation (hm = 1,486 eV). FT-IR spectrum was
characterized with a WGH-30 analysis instrument (Tianjin,
China).
The current–voltage (I–V) curves of RGO and RGO/
PEDOT was obtained by using a keithley semiconducting
testing system with model 4200. Electrochemical
1064 J Mater Sci: Mater Electron (2014) 25:1063–1071
123
performance was characterized by using a CHI600 elec-
trochemistry workstation. Cyclic voltammetry (CV), gal-
vanostatic charge–discharge were performed with 1 mol/L
H2SO4 aqueous electrolyte using a platinum sheet as
counter electrode, and Ag/AgCl as the reference electrode.
To investigate the conductive performance, A GO, RGO
and RGO/PEDOT-FET device was fabricated with source
and drain electrodes on Si/SiO2 substrate with gold back
gate. The length and width of the channel of the FET
device are 60 and 50 lm respectively. The electrodes
(source and drain) were made by thermally coated gold of
20 nm thickness. All the measurements were performed at
ambient temperature.
3 Results and discussion
Figure 2 shows surface pressure–area (p–A) isothermal of
GO at air–water interface. Due to the geometrically simi-
larity of GO with air–water interface, GO can float on a
water surface without surfactants or stabilizing, which
makes it ideally accommodate the flat sheets. It can be seen
from the Fig. 2 that GO sheets arrange compactly at air–
water interface with continuous compression. This compact
arrangement of GO sheets can be constructed on different
substrate through vertical or horizontal deposition. By
controlling the surface pressure, surface coverage of the
graphene oxide sheets was manipulated to realize a uniform
deposition with compact and incompact arrangement.
Moreover, large area LB deposition can also be realized on
GO sheets with tunable arrangement on different substrates.
To keep the original morphology of GO, we choose
thermal treatment at a water vapor environment as
efficiently reduction process to obtain RGO. Figure 3
shows AFM images of single layer GO and RGO sheets
deposited on Si substrate. The thermal treatment does not
lead to distinct morphology change of as-prepared GO, and
the obtained RGO sheets can keep ordered and compact
formation from GO LB films. Figure 3b (indicated by
black arrow) shows high surface pressure results in occa-
sional wrinkles and overlaps. It also can be seen that, due to
assemble from abundant GO sheets, large numbers of
interspace exists in RGO LB sheets although deposited at
very high surface pressure, and this hampers formation of
complete single GO layer with large area. However, as a
nanocomposites preparation method, this discontinuous
RGO sheets affords convenient template for CP inserting
and covering on RGO and this RGO/CP nanocomposite
Fig. 1 Schematic RGO/PEDOT preparation based on LB and VPP deposition, and digital camera images of RGO LB films and RGO LB films/
PEDOT deposited on Si substrate
Fig. 2 Surface pressure–area (p–A) isothermal of GO at air–water
interface with continuous compress, and arrangement evolution
images of GO monitored by BAM
J Mater Sci: Mater Electron (2014) 25:1063–1071 1065
123
would represent excellent synergistic effect for improving
electrical and electrochemical performance. As above-
mentioned in this paper, we investigate the influence of this
tunable RGO sheets arrangement on obtained nanocom-
posites performance and prepare the RGO/CP nanocom-
posites with tunable performance.
Vapor phase polymerization process is able to form
chemically well defined and ultrathin polymeric films
directly on the well-defined surface or template, which
results in the formation of a well defined nanofilm struc-
ture. As shown in Fig. 3b, after the VPP depositon of
PEDOT, a dinstinct change of film morphology and
thickness is observed in RGO LB films. The RGO LB
sheets is covered with lots of protuberances PEDOT layers,
and these protuberances become more obvious in RGO/
PEDOT nanocomposites obtained from lower surface
pressure. The thickness of PEDOT layer deposited on RGO
can be adjusted by controlling the VPP deposition time and
a ultrathin PEDOT layer can be obtained in a short depo-
sition time. The thickness of PEDOT films in Fig. 3b is
about 40–50 nm. As shown in Fig. 1, a color change of
RGO films is observed after VPP deposition of PEDOT and
RGO/PEDOT films shows deep blue color due to the doped
state of PEDOT.
The FT-IR spectra of GO LB films, RGO LB films, and
PEDOT/RGO is shown in Fig. 4. The featureless FT-IR
spectrum of RGO indicates that the thermal reduction of
GO at the water vapor environment is relatively complete
with few oxygen-containing groups. From the FT-IR
spectrum of RGO/PEDOT, the vibrational bands at about
1,519 and 1,342 cm-1 are attributed to the C=C and C–C
stretching vibrations of the quininoid structure of the thi-
ophene ring, respectively. The bands at 1,200, 1,142, and
1,088 cm-1 are ascribed to the C–O–C bond stretching in
the ethylene dioxy (alkylenedioxy) group. Additionally, the
C–S bond in the thiophene ring is evidenced by the
Fig. 3 a AFM images of GO
LB films and after thermal
treatment, b RGO LB films
deposited at different surface
pressure and SEM images after
VPP deposition of PEDOT
1066 J Mater Sci: Mater Electron (2014) 25:1063–1071
123
presence of bands at about 981 and 836 cm-1. The series
of bands suggests that the PEDOT is deposited on RGO
through a chemical VPP deposition. Figure 5 shows the
presence of sulfur spin-split doublet of RGO/PEDOT at
around 164.4 eV (S 2p3/2) and 167.5 eV (S 2p1/2).The
higher binding energy doublet at around 174.2 and
175.5 eV is ascribed to sulfur spin-split coupling from
PEDOT/Cl- due to the incorporation of counterion Cl-
into PEDOT. As shown in Fig. 1, the result is accordance
with the color change after the VPP deposition of PEDOT,
indicating the formation of doped PEDOT.
As shown in Fig 6a, current versus voltage (I–V) char-
acteristics of GO LB films deposited at different surface
pressure is studied. The linear I–V curves of all GO LB
films confirm the good ohmic contact between GO LB film
and electrodes. It has been proven that the electrical per-
formance of GO LB films dependences weakly on depo-
sition surface pressure, which is ascribed to the poor
conductivity of GO sheets.
After the thermal treatment, the reduced GO resembles
graphene but with some residual oxygen and structural
defects presents a conductivity that is comparable to that of
doped conductive polymers25. The tunable electrical per-
formance of RGO is also an useful property for the
application in organic electronics. To evaluate the electri-
cal performance of RGO LB films, the GO LB films are
Fig. 4 FT-IR spectrum of GO LB films, RGO LB films, and PEDOT/
RGO nanocomposites
Fig. 5 XPS core-level spectra of RGO-PEDOT
Fig. 6 Current–voltage (I–V) curves of a GO LB films, b RGO LB
films and c variation of RGO/PEDOT constructed from GO films
deposited at 15 mN/m
J Mater Sci: Mater Electron (2014) 25:1063–1071 1067
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reduced into RGO by a thermal treatment, and the I–V
curves of this RGO LB films is shown in Fig. 6b. A dra-
matically enhancement of conductivity, more than 2 orders
of magnitude, is observed after the thermal treatment of
GO. This result indicates the successful thermal reduction
of GO to RGO in LB films and it is also confirmed by FT-
IR analysis. Whereas, unlike GO, the deposition surface
pressure shows relative strong influence on electrical per-
formance of RGO LB films, and the RGO obtained from
high deposition surface exhibits better conductive perfor-
mance. It is well known that RGO LB films obtained from
higher surface pressure addresses more compact and con-
tinuous arrangement of RGO sheets, resulting in uniform
and compact conducting channel for effective carries
transfer. Moreover, due to the functional group is removed,
the individual RGO sheet exhibits better conductivity than
GO. The slight change in conducting channel caused by
deposition surface pressure results in remarkable change of
conducting performance in RGO LB films. Figure 6c
shows the change of conductive performance after VPP
deposition of PEDOT on RGO LB films. The coverage of
PEDOT on RGO and insertion in interspace of adjacent
RGO sheets lead to complete coverage of nanocomposites
on substrate. It can be seen that, in our experiment, the
RGO LB films exhibits slight lower conductivity than pure
PEDOT obtained through VPP deposition and the obtained
GO/PEDOT exhibits slight decrease in conductivity.
Table 1 shows electrical conductivity of PEDOT, RGO
and PEDOT/RGO. A 20 layers RGO LB films exhibits
electrical conductivity about 326.7 S/cm, and PEDOT
deposited from VPP process with same thickness has a
conductivity about 382.5 S/cm. It can be seen that the RGO
shows comparable conductive performance to that of
doped CP due to some residual oxygen and structural
defects in carbon sheets. This alike conductive perfor-
mance ensure lower contact resistance and better syner-
gistic effect between PEDOT and RGO in nanocomposites.
After VPP deposition of PEDOT on RGO, a slight elec-
trical conductivity decrease of PEDOT/RGO is presented,
and this conductive performance mostly comes from CP
due to the latter formed continuous PEDOT layer. It can be
seen that, compared with pure PEDOT and RGO LB films,
a expected synergistic effect obtained in RGO/PEDOT
nanocomposites, and this nanocomposites exhibits high
conductivity about 377.2 S/cm.
As a electrochemical capacitor electrode applications,
the brittle and weak mechanical strength of PEDOT hin-
ders it is used as organic electrodes, for instance, electro-
chemical electrode for supercapacitors. The direct
Table 1 Electrical conductivity of PEDOT, RGO LB films and PE-
DOT/RGO
Conductivity(S/cm) PEDOT RGO (20 layers) RGO/PEDOT
382.5 326.7 377.2
Fig. 7 Cycle voltammetry curves of a RGO/PEDOT, GO/PEDOT
and VPP PEDOT at a 60 mv/s scanning voltage speed, b RGO/
PEDOT at different scanning voltage speed and c GO/PEDOT at
different scanning voltage speed
1068 J Mater Sci: Mater Electron (2014) 25:1063–1071
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deposition of ultrathin PEDOT layer onto RGO LB films
produces nanocomposites with good mechanical strength
as well as an enhancement of specific surface area.
Moreover, RGO/PEDOT nanocomposits can present
hybrid capacitance performance based on carbon and CP,
and high conductive performance of RGO/PEDOT can also
make sure device with low equivalent series resistance
(ESR) for fast charge/discharge. Therefore, the electro-
chemical capacitive properties of the RGO/PEDOT mate-
rials are investigated by using cycle voltammetry, charge/
discharge techniques and electrochemical impedance
spectra (EIS).
Figure 7a shows the cyclic voltammograms (CVs) of
RGO/PEDOT, GO/PEDOT and VPP PEDOT electrode at a
constant scanning voltage speed. RGO/PEDOT curve
shows almost rectangular shape, suggesting the good
capacitive properties of RGO/PEDOT. This good capaci-
tive behavior is contributed to the successive redox reac-
tions of PEDOT along with the transport of counterions
into and out of the polymer. However, a distorted rectan-
gular CV is obtained from the VPP PEDOT electrode,
indicating an uncompensated resistance in the system.
Figure 7b, c show cycle voltammetry curves of GO/PE-
DOT and RGO/PEDOT at different scanning voltage
speed. It can be observed the redox current of RGO-PE-
DOT increases with the increase of scan rate, indicating a
good rate capability. In the present study, due to the
comparable conductivity of RGO and PEDOT, the RGO/
PEDOT composite may represent good conductive syner-
gistic effect and low contact resistance, leading to the
observed good capacitive behavior. Compared with RGO-
PEDOT, the increase of redox current is relative slight in
GO-PEDOT electrode (in Fig. 7c), which may ascribe to
the poor conductive performance of this nanocomposite.
Figure 8 shows the charge/discharge curves of RGO/
PEDOT and GO/PEDOT respectively. The curves of RGO/
PEDOT almost exhibit equilateral triangle shape because
the potential of charge/discharge is a linear response to
time, indicating a good reversibility during the charge/
discharge processes (Fig. 8a). As expected from the CV
results, the GO/PEDOT nanocomposite performed rela-
tively poor charge/discharge performance. The charging
and discharging cycle deviates markedly from the ideal
triangular shape of a capacitor, and the discharge time is
short and unstable (Fig. 8c). The inset nyquist plot in
Fig. 8a, c demonstrate the EIS performance of PEDOT/
RGO and PEDOT/GO electrodes. It can be seen that the
PEDOT/RGO presents distinct semicircle performance in
low frequency and exhibits better capacitance performance
than PEDOT/GO. This indicates that a low resistance
interface is formed between the PEDOT and RGO and this
interface is also suitable for solution ions fast adsorption
and desorption. Moreover, compared with PEDOT/GO, the
PEDOT/RGO electrode also presents lower equivalent
resistance during the charge/discharge process due to the
high conductive nature. In addition, as shown in Fig. 8b, d,
Fig. 8 Charge/discharge curves
of a RGO/PEDOT electrode at
different scanning current
b RGO/PEDOT obtained from
different deposition surface
pressure at a 1.0 A/g scanning
current, c GO/PEDOT electrode
at different scanning current,
d GO/PEDOT obtained from
different deposition surface
pressure at a 1.0 A/g scanning
current, and the insets in (a) and
(c) shows nyquist plot of
different electrode
J Mater Sci: Mater Electron (2014) 25:1063–1071 1069
123
PEDOT/RGO nanocomposites obtained from GO LB films
deposited at higher surface pressure shows larger specific
capacitance. We conclude that, with the increase of film
deposition pressure, more GO sheets are deposited on
substrate, which leads to more RGO is formed in RGO/
PEDOT nanocomposites successively. Therefor, larger
specific surface area afforded by RGO is presented to
solution ion and directly results in the enhancement of
specific capacitance of electrode materials.
The specific capacitances obtained from these data are
tabulated in Table 2, it can be seen that both RGO/PEDOT
and GO/PEDOT containing carbon sheets exhibit larger
specific capacitance than pure PEDOT. The surface pres-
sure of the deposition of GO LB film influences obviously
on specific capacitance of nanocomposites. The RGO/PE-
DOT deposited at a surface pressure about 20 mN/m shows
high specific capacitance about 213 F/g at a current density
of 0.5 A/g.
Rate performance of electrode films is a vital factor for
the practical application in electrochemical capacitor. As
shown in Fig. 9, the rate performance of RGO/PEDOT and
PEDOT is evaluated by charging/discharging at different
current densities. For RGO/PEDOT, the specific capaci-
tance maintained 87 % capacitance after 2,000 cycles at
scan current density 0.5 A/g. The results indicate a good
cycling ability of the composite materials. The RGO LB
sheets provided a robust support for the CPs. Therefore, the
mechanical strength of the composites is enhanced, and the
swelling and shrinking of ultrathin CPs during the long-
term cycling is avoided. Compared with pure PEDOT, the
composite RGO/PEDOT is more stable and suitable for
high performance electrochemical electrode materials. The
GO/PEDOT electrode also presents good capacitance
retention performance, and it can keep more than 80 % of
initial capacitance after 2,000 cycles (the data is not
shown). However, the higher equivalent resistance in this
composite restricts it as high performance electrochemical
electrode materials due to the higher ESR and worse EIS
performance during fast charge/discharge process.
Moreover, it also can be seen that the surface pressure
for GO LB film deposition is crucial to rate performance of
RGO/PEDOT nanocomposites. Nanocomposites obtained
from GO LB films deposited at higher surface pressure
shows better capacitance retention performance. It is well
known that more GO sheets deposit on substrates at higher
surface pressure and loading analysis in nanocomposites
confirm that RGO loadings increase from 5 to 12 % with
the increase of surface pressure from 5 to 20 mN/m. More
RGO loading formed in nanocomposites realizes a distinct
increase of specific area. In addition, the good conductive
performance of RGO/PEDOT also produces good capaci-
tive performance. With the decrease of surface pressure,
less RGO is formed in RGO/PEDOT nanocomposite. The
RGO/PEDOT constructed on GO LB films deposited at
5 mN/m exhibits poor capacitive retention characteristic
like pure PEDOT, and it can only maintained 78 %
capacitance after 500 cycles. So, It is crucial to address the
uniform and high density arrangement of RGO LB sheets
in PEDOT/RGO nanocomposites, which could ensure the
optimized large specific capacitance and prevent PEDOT
from aggregating and swelling simultaneously. With the
controlling of RGO loadings in PEDOT/RGO, this nano-
composite exhibits tunable electrical and electrochemical
performance for high performance electrode materials.
4 Conclusions
LB deposition provides facile way to deposit large area GO
LB films on different substrate with tunable arrangement.
The direct coating of ultrathin CP layer on RGO sheets is
achieved by using a VPP method. The combination of LB
and VPP methods provides a simple and efficient way to
prepare RGO-PEDOT nanocomposites. The electrical
properties reveals a good electrical synergistic effect
achiever after the VPP deposition of PEDOT on RGO. The
Table 2 Specific capacitances of GO/PEDOT, RGO/PEDOT
obtained from different deposition pressure and VPP PEDOT at a
0.5 A/g current density
Samples Specific capacitance (F/g)
5 mN/
m
10 mN/
m
15 mN/
m
18 mN/
m
22 mN/
m
GO/PEDOT 83 92 117 133 136
RGO/PEDOT 105 122 147 213 209
PEDOT (VPP
deposition)
76 9 9 9 9
Fig. 9 Capacitance retention performance RGO-PEDOT and PE-
DOT (at 0.5 A/g scan current density)
1070 J Mater Sci: Mater Electron (2014) 25:1063–1071
123
electrical properties of subsequent RGO depend on the
surface pressure of the deposition of GO LB film. The
superior capacitive performance of the RGO-PEDOT com-
posites is demonstrated by the test of electrochemical
properties. The specific capacitance of sample RGO/PEDOT
is as high as 213 F/g at a current density of 0.5 A/g. The
capacitive retention of RGO/PEDOT electrode was 87 %
after 2,000 cycles, which is much better than that of pure
PEDOT. Tunable arrangement of RGO in nanocomposites
obtained by LB deposition resulted in good and variable
capacitive performance of the RGO/CP composites.
Acknowledgments The work was supported by the National Sci-
ence Foundation of China (NSFC) (No.61101029 and No.61204098),
A Plan for Supporting the New Century Talents (No. NCET-12-
0091).
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