1. synthesized by CBD using pyrrole and KMnO4
National conference on
ADVANCES IN BIODIVERSITY, SCIENCE, ENGINEERING AND THE ENVIRONMENT
ncabsee2016
Cyclic Voltammetric study of K2S4O6 doped PPy : Mn(OH)2 composite thin films
synthesized by CBD using pyrrole and KMnO4
V. Thakur, B. J. Lokhande*
Solapur University , Solapur

2. Table of contents Supercapacitors (Idea, types and applications)
Materials
Why PPy
Ppy composites
3. Methods of thin film deposition
CBD advantages
parameters
4. Materials and sample codes
5. Film Formation mechanism
6. XRD analysis
7. FTIR analysis
8. CV
CV of different samples with Molar variations
CV of optimized samples for various scan rates
9. Results and conclusions

4. The metal oxides have been being used as electrode materials
The metal oxides have been being used as electrode materials. They store the power electrochemically by means of the fast Faradaic reactions occuring at the electrode surface.
Eg. CuO, Co3O4 , RuO2, NiO2, Fe2O3, etc.
Generally all the metal oxides show pseudocapacitive nature.
The conducting polymers are also being used as the electrode materials
They have
1. high conductivity ,
2. charge storage throughout the bulk,
3. porosity etc.
eg. Polyaniline (PAN), Polyethylene-dioxy-thiophene (PEDOT), Polypyrrole(PPy), Polythiophene (PTh) etc
The composites of Metal oxides and polymers gives more specific power and more energy.
The enhanced performance of the thin film can be obtained by using the techniques of hybridization in the preparation of supercapacitive electrodes and devices.
By preparing the composites we can combine and enhance the desirable features like capacitance, energy density, conductivity, adherence to the substrate etc.

5. Why Polypyrrole (PPy)
Ease of production,
Conductivity S/cm2 by means of the shifting of electrons in conjugate pair,
Solubility of monomer in aqueous as well as non aqueous media,
Low oxidation potential
Charge storage throughout the bulk volume
But PPy films have following ambiguities
Less adherence to the substrate,
Poor electrochemical stability,
Less elasticity of shape hence could not regain their shape once expanded by doping.
Further
The polymerizaros are affecting the composition by implantaing the species formed during the chemical reactions during the PPy synthesis hence pure PPy is tough to get

6. The oxidative polyerizer should be such chosen that the metal oxide/hydroxide, chalcogenides etc formed and goes in the PPy matrix must improve the supercapacitive performance , adherence and electrochemical stability.
There are different oxidizers viz. FeCl3, K2Cr2O7, H2O2 etc.
Potassium dichrmate is the strongest oxidizer in the acidic media
whereas the KMnO4 acts as a strong oxidizor in basic medium.
In the present study we tried and achieved the thin films of oxidative polymerization of PPy using acidic KMnO4
The present study equal volumes of,
0.1M Pyrrole (anionic precursor) and
different molar variations (20mM to 40mM) of KMnO4 cationic precursor
were taken as the initial sources as the precursor feed for the Chemical Bath Deposition.

8. Advantages of Chemical Bath Deposition over
the other methods of thin film deposition
No need of highly sophisticated mechatronic arrangements
Can work at any temperature (even room temperature)
No constraints on the size and shape of substrate
It maintains the stoichiometry of the material in the thin film
Thin films of different thickness can be deposited
No evolution of toxic gases hence eco friendly
Set up is easy to build and cost effective

9. Chemical Bath Deposition Volume of precursor feed
Molarity of precursor
Volume of precursor feed
Substrate material
RPM of the solution
Deposition time
Temperature
Chemical Bath Deposition Schematics
Table 1 Sample codes for CBD samples with Molar variations in the anionic source
Sample
Codes
Cationic source
Anionic source
RPM
Deposition time
Bath temperature
Deposition hrs M1
0.1M Pyrrole
0.02 M KMnO4
200
45 min (2700 sec)
315K
2hrs
(7200 sec) M2
0.03M KMnO4
45min (2700 sec) M3
0.04M KMnO4

10. Reaction mechanism

11. Schematics of Xray diffractometer

12. X-Ray diffraction pattern of the sample with optimum parameters
Peak details and calculated parameters for K2 S4O6
as per JCPDS card
Peak details and calculated parameters for Mn(OH)2
as per JCPDS card
Obs 2θ
Std 2θ
Obs. d
Std. d
hkl
18.11
18.081
4.8943
4.902
2 2 2
23.57
23.44
3.7715
3.7816
5 1 0/ 5 1 1
27.36
27.37
3.257
2.6528
6 0 2
28.69
28.717
3.109
3.1005
1 1 3
32.77
32.74
2.7306
2.733
7 1 2
33.96
33.84
2.6376
2.6465
1 3 0
Obs 2θ
Std 2θ
Obs. d
Std. d
hkl
36.25
36.63
2.4761
2.453
1 0 1
49.78
49.97
1.8302
1.825
1 0 2

13. FTIR spectrograph of the sample M1
C-C, C=C bonds and streching vibrations, N-H streching and vibrations C-H strechings and ring vibrations confirm the formation of PPy

14. Schematics of Cyclic voltammetry set up
Actual set up of Cyclic Voltammetry
Schematics of Cyclic voltammetry set up
Electrode conncetions

15. Cyclic voltammogram of samples M1, M2 and M3 at 5mV/S
Cyclic Voltammograms of samples with different molarity at the scan rate 2mVSec-1
Specific capacitances of different samples at the scan rate 2mVSec-1
Samples
Specific capacitance
SC (F/g) M1 M2 M3

16. Cyclic voltammograms of M1 at different scan rates.
Cyclic voltammograms for sample M1 at different scan rate
Variation of C, SC and IFC for sample M1 with scan rate
Scan rate
(mVSec-1)
Capacitance
C (F)
Specific capacitance
SC (Fg-1)
Interfacial capacitance
IFC (Fcm-2) 2
271.45
5.4289 5
8.7254
218.13
4.3626 10
9.0021
225.05
4.5009 20
9.7044
242.61
4.8521 25
5.4643
136.60
2.7321 50
7.1727
179.31
3.5863
100
5.5364
143.41
2.8680

17. Plausible cell reactions during the Cyclic Voltammetric study
The reaction during anodic positive sweep is responsible for the reduction S from (+5 state to +4 state) corresponding to reduction peak.
During the anodic negative sweep, the recombination of SO2 and O2 to give S4O6– is not possible
The only possible reactions are
Dedoping of PPy and
Oxidation of Mn(OH)2 to MnO2
Neither the de-doping nor the oxidation of Mn hydroxide to oxide is responsible for the pseudocapacitance hence no peaks are observed on the oxidation sweep.

18. Tetrathionate ion

19. Result and conclusion
Potassium tetrathionate doped PPy : Mn(OH) thin flims were deposited on the SS
substrate using Chemical Bath deposition method.
2. The optimized sample shows irreversible behavior.
3. Though the area under curve on CV plot goes on increasing with increase in scan
rate , the capacitance, specific capacitance and interfacial capacitance goes on
decreasing as the number of intercalations- deintercalations do not increase in
the same proportion.