Utilising graphene to enhance PEC sensing performance

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3. STRONGER
It is the most resistant &
impermeable membrane ever.
It is 200x stronger than steel. 1
3

4. LIGHTER
It is 6x lighter than steel,
extremely thin, transparent &
bendable. 1
4

5. FASTER
Electron mobility is 70x faster
than silicon and better
conductance. 1
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6. ENERGY
COMPUTING
ENGINEERING
HEALTH
6

7. ENERGY
COMPUTING
ENGINEERING
HEALTH
ENERGY
7

8. SKAM 2015
Photoelectrochemical Performance of
Reduced Graphene Oxide/Cadmium Sulfide
Modified Carbon Cloth in Copper(II) Detection
FOO CHUAN YI
Material Science Chemist
Chemistry Department
Faculty of Science
UPM
8

9. INTRODUCTION
Solar
energy
Electro-
chemical
energy
Photovoltaic
devices
Photoelectrochemical (PEC)
measurement is implemented in
developing techniques for sensing
platforms because of its
Low processing cost 2
Simple instrumentation 2
Accurate miniaturization method 3
PHOTOELECTROCHEMISTRY
9

10. Narrow
Band gap
(2.39eV) 4
SEMICONDUCTING MATERIALS
Traditional synthesis method of
cadmium sulfide (CdS) involve
CdS
Effective
Light
harvesting
media 5
Excellent
Charge separation
properties 6
INTRODUCTION
DC sputtering 7
Sonochemical treatment 7
Chemical bath deposition 7
Aerosol-assisted
Chemical vapor deposition
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11. SYNTHESIS OF CdS NANOPARTICLES
METHODOLOGY
Cadmium acetate (0.05M)
Thiourea (0.1M)
Methanol
Atomizer
450oC for
60 min.
Reaction Chamber
Argon gas
11
CdS/CC

12. RESULTS
FESEM IMAGES ON CARBON CLOTH
Carbon cloth
fiber
CdS
nanoparticles
EDX analysis
CdS
nanoparticles
12

13. RESULTS
PHOTOCURRENT INTENSITIES
CdS
nanoparticles
-50
0
50
100
150
200
250
Photocurrent(A)
Elapse times (s)
CdS/CC
83 A
Light off
Light on
13

14. SYNTHESIS OF CdS/rGO/CC
METHODOLOGY
Graphite Oxide
(0.8 mg/mL)
CdS/CC
Reduced
Graphene
Oxide (rGO)
Thermal
annealing
at 200oC
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15. SYNTHESIS OF CdS/rGO/CC
METHODOLOGY
Graphite Oxide
(0.8 mg/mL)
CdS/CC
Reduced
Graphene
Oxide (rGO)
Thermal
annealing
at 200oC
CdS
nanoparticles
EDX analysis
15

16. PHOTOCURRENT INTENSITIES
RESULTS
Reduced
Graphene
Oxide (rGO)
CdS
nanoparticles
0
30
60
90
120
150
180
210
Photocurrent(A)
Elapse times (s)
CdS/CC
CdS/rGO/CC
Light on Light off
206 A
240%
16
Sufficient interfacial
contact
Max. electron
conductivity

17. RAMAN SPECTRA OF GO and rGO
RESULTS
Reduction of GO to rGO using thermal
method shows that
2D peak of rGO is higher than GO
Intensity ratio of D and G band (ID/IG) of
GO and rGO were 1.00 and 1.12,
respectively.
Thermal treatment cause drastically
structural defects which attribute to the
evolution of COx (x=1,2). 8
Removing the O lead to better connectivity
through the formation of new sp2 cluster. 8
17

18. SCHEMATIC ILLUSTRATION
RESULTS
The enhance efficiency of the CdS/rGO/CC
could be due to
Intimate integration with carbon cloth
Facilitate charge separation and
transport
Bridging effect
18

19. LINEAR SCAN VOLTAMOGRAM
RESULTS
0
50
100
150
200
250
300
-0.05 0.04 0.13 0.22 0.31 0.40
Photocurrent(A)
Potential (V)
ON-OFF OFF ON
0
50
100
150
200
250
300
-0.20 -0.11 -0.02 0.07 0.16 0.25 0.34 0.43
Photocurrent(A)
Potential (V)
ON-OFF OFF ON
CdS/CC CdS/rGO/CC
19

20. ELECTRON IMPEDANCE SPECTRA
RESULTS
0
50
100
150
200
250
300
-0.05 0.04 0.13 0.22 0.31 0.40
Photocurrent(A)
Potential (V)
CdS/CC CdS/rGO/CC
62%
Recombinant resistance of CdS/rGO/CC was
significantly lower than CdS/CC
Smaller diffusion resistance
Intimate integration of rGO with CdS
20

21. APPLICATION
Photoelectrochemical
Sensor for Copper (II) ion Detection
21

22. APPLICATION
PHOTOELECTROCHEMICAL SENSING
-50
0
50
100
150
200
Photocurrent(A)
Elapse times (s)
Light
on
Light
off 0.0 M 1.0 M
22

23. RESULTS
SCHEMATIC ILLUSTRATION OF Cu DETECTION
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24. RESULTS
LINEAR DETECTION RANGE AND LIMITS
No. Detection method LDR* LOD** Ref.
1 Photoluminesence 0.0–10.0 M 0.50 M 9
0.001–3.0 M 0.50 nM 10
2 Electrochemiluminesence 0.1–10.0 M 20.0 nM 11
3 Fluoresence 0.1–5.0 M 0.02 M 12
0.01–20.0 M 0.10 M 13
7.5 nM–314.0 M 0.10 M 14
4 Photoelectrochemical 1.0–38.0 M 0.55 M 15
0.1–1.0 M 0.04 M This work
Comparison of proposed work with some
typical detection methods
for Cu 2+ using CdS materials.
* Linear Range of Detection
** Limit of Detection
PEC approach in copper ion detection has
rarely been reported.
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25. CONCLUSION
CdS/rGO/CC synthesized using AACVD method could produce significantly high
photocurrent at a relative low applied potential. By utilizing the phenomenon of metal
sulfide formation, a sensitive and selective PEC sensor was designed to detect trace
amount of copper (II) ions.
This proposed method has several advantages which shows propitious application for
other photovoltaic application
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26. REFERENCES
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1. Abergel, D. S. L., Apalkov, V., Berashevich, J., Ziegler, K., & Chakarborty, T. (2010). Properties of Graphene: A Theoretical
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THANK YOU

28. RESULTS
PHOTOELECTROCHEMICAL SELECTIVITY TEST
0.00227
0.01683
0.08688
0.00635
0
0.01
0.02
0.03
0.04
0.05
0.06
0.07
0.08
0.09
0.1
K
Na+
Mg2+
Ba2+
Zn2+
Mn2+
Al3+
Cu2+
Fe3+
Ni2+
Co2+
Intensity
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