Vol.:(0123456789) 1 3
J Mater Sci: Mater Electron
DOI 10.1007/s10854-017-8074-0
C
10
H
8
N
2
-PPy hybrid flexible electrodes: SILAR synthesis
and electrochemical study
A. V. Thakur
1
· B. J. Lokhande
1
Received: 18 July 2017 / Accepted: 15 October 2017
© Springer Science+Business Media, LLC 2017
1 Introduction
Organic materials, organo-metallic composites and co-pol-
ymers have been used in different applications in order to
improve the qualities of materials as per the desired applica-
tions like thermally stable composites, electromagnetic wave
absorption, microwave absorption medicinal use (antioxi-
dants), batteries and supercapacitors [1–6]. Electrochemical
charge storage devices include batteries and supercapacitors.
Among different electrically conducting polymers (ECPs),
polypyrrole (PPy) is considered as good electrode material
for supercapacitors because of its good electrical conductiv-
ity, water soluble monomer, easy production, low oxidation
potential, and high charge storage ability [7, 8]. Conjugated
electrons are responsible for the electrical conductivity of
PPy [9, 10]. Literature shows variety of the aqueous route
synthesis of PPy by oxidative polymerization of pyrrole (Py)
[11–14]. Several research works found in literature indicate
the chemical synthesis of PPy using different oxidizers viz.
FeCl
3
, (NH
4
)
2
S
4
O
8
and K
2
C
r2
O
7
[15] with the H
2
SO
4
to
acidify the solutions. Ppy suffers from poor electrochemi-
cal cycling stability when used as electrochemical charge
storage device. Hence researchers have been trying to pre-
pare different composites and hybrids of PPy with inorganic
materials like oxides/hydroxides of transition metals viz.
MnO
2
[16], Cu(OH)
2
[17, 18], Co
3
O
4
[19–21] as well as
organic materials viz. PAni [22], PVC, PMMA [23], carbon
nano tubes [24], graphene [25] PEG etc.
2,2′-Bipyridine is widely used bidentate ligands for coor-
dination of various metal cations [26] as well as protons [27]
The electronic states of the conjugation system, are greatly
affected by the co-ordination forcing the redox potential and
chromic variations [28]. Thus, incorporation of 2,2′-bipyri-
dine into any conjugated system provides a new system in
which the conductance is function of cationic conjugation.
Abstract 2,2′-bipyridine has been significantly focused
by researchers because of its electrical conductivity, chelat-
ing properties and ability to affect the color and electro-
chemical properties of the materials. In present work,
2,2′-bipyridine:polypyrrole (C
10
H
8
N
2
:PPy) hybrid flexible
electrodes (HFE) have been fabricated by successive ionic
layer adsorption and reaction technique using 0.1 M solu-
tion of pyrrole (Py) acidified with 0.1 M HClO
4
and 30 wt%
H
2
O
2
at 366.15 K. XRD pattern of the HFE exhibits char-
acteristic broad peak at 2θ angles 22.35° and 23.09° as well
as at 27
ο
are indicating the formation of bipyridine as well
as PPy respectively. The characteristic peak at 1559 cm
−1
in
the FTIR spectrum is due to pyrrole ring vibrations confirms
the formation of PPy. The SEM image of HFE with 30 s
dipping time each in pyrrole and H
2
O
2
, depicts flesh like
morphology with interconnected globules. The contact angle
~ 10° indicate hydrophilic nature of HFE. Cyclic voltammet-
ric (CV) analysis and galvanostatic charge discharge (GCD)
have been carried out in 0.5 M H
2
SO
4
. The CV curves rep-
resent the symmetric and reversible nature at lower scan rate
which becomes quasi irreversible and asymmetric at higher
scan rates. The observed maximum specific capacitance was
281.49 F/g at 5 mV/s which is nearly same as given by GCD
which was 209 F/g at 1 mA/cm
2
. These HFE are useful for
high energy supercapacitors and battery applications.
* B. J. Lokhande
bjlokhande@yahoo.com
1
Lab of Electrochemical Studies, School of Physical Sciences,
Solapur University, Solapur, Maharashtra 413255, India