1

2

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

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LIGHTERIt is 6x lighter than steel, extremely thin, transparent &bendable. 1

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FASTERElectron mobility is 70x fasterthan silicon and betterconductance. 1

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ENERGYCOMPUTINGENGINEERINGHEALTH

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ENERGYCOMPUTINGENGINEERINGHEALTH

ENERGY

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SKAM 2015Photoelectrochemical Performance of

Reduced Graphene Oxide/Cadmium SulfideModified Carbon Cloth in Copper(II) Detection

FOO CHUAN YIMaterial Science Chemist

Chemistry DepartmentFaculty of Science

UPM

9

INTRODUCTION

Solar energy

Electro-chemicalenergy

Photovoltaicdevices

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

10

Narrow Band gap (2.39eV) 4

SEMICONDUCTING MATERIALSTraditional synthesis method of cadmium sulfide (CdS) involve

CdS

EffectiveLight

harvestingmedia 5

Excellent Charge separation

properties 6

INTRODUCTION

DC sputtering 7

Sonochemical treatment 7

Chemical bath deposition 7

Aerosol-assisted Chemical vapor deposition

11

SYNTHESIS OF CdS NANOPARTICLESMETHODOLOGY

Cadmium acetate (0.05M)Thiourea (0.1M)Methanol

Atomizer

450oC for 60 min.

Reaction Chamber

Argon gasCdS/CC

RESULTSFESEM IMAGES ON CARBON CLOTH

Carbon cloth fiber

CdSnanoparticl

es EDX analysis

CdSnanoparticl

es

12

RESULTSPHOTOCURRENT INTENSITIES

CdSnanoparticl

es

-50

0

50

100

150

200

250 CdS/CC

Elapse times (s)

Phot

ocur

rent

(A)

83 ALight

offLight on

13

SYNTHESIS OF CdS/rGO/CCMETHODOLOGY

Graphite Oxide(0.8 mg/mL)

CdS/CC

ReducedGraphene

Oxide (rGO)

Thermal annealingat 200oC

14

SYNTHESIS OF CdS/rGO/CCMETHODOLOGY

Graphite Oxide(0.8 mg/mL)

CdS/CC

ReducedGraphene

Oxide (rGO)Thermal annealingat 200oC

CdSnanoparticl

es

EDX analysis

15

PHOTOCURRENT INTENSITIESRESULTS

ReducedGraphene

Oxide (rGO)

CdSnanoparticl

es

0

30

60

90

120

150

180

210

CdS/CCCdS/rGO/CC

Elapse times (s)

Phot

ocur

rent

(A)

Light on

Light off206 A

240%

16

Sufficient interfacial contact

Max. electron conductivity

17

RAMAN SPECTRA OF GO and rGORESULTS

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

18

SCHEMATIC ILLUSTRATIONRESULTS

The enhance efficiency of the CdS/rGO/CC could be due to

Intimate integration with carbon cloth

Facilitate charge separation and transportBridging effect

LINEAR SCAN VOLTAMOGRAM RESULTS

-5.00E-025.92E-02 1.69E-01 2.79E-01 3.89E-010

50

100

150

200

250

300

ON-OFF OFF ON

Potential (V)

Phot

ocur

rent

(A)

-2.00E-01-4.02E-02 1.20E-01 2.80E-01 4.40E-010

50

100

150

200

250

300

ON-OFF OFF ON

Potential (V)Ph

otoc

urre

nt (

A)

CdS/CC CdS/rGO/CC

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ELECTRON IMPEDANCE SPECTRARESULTS

-5.00E-024.54E-02 1.40E-01 2.36E-01 3.31E-01 4.27E-010

50

100

150

200

250

300

CdS/CC CdS/rGO/CC

Potential (V)

Phot

ocur

rent

(A)

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

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APPLICATIONPHOTOELECTROCHEMICAL SENSING

-50

0

50

100

150

200

Elapse times (s)

Phot

ocur

rent

(A)

Light on

Light off 0.0 M 1.0 M

23

RESULTSSCHEMATIC ILLUSTRATION OF Cu DETECTION

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RESULTSLINEAR 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.

25

CONCLUSIONCdS/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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REFERENCES1. Abergel, D. S. L., Apalkov, V., Berashevich, J., Ziegler, K., & Chakarborty, T. (2010). Properties of Graphene: A

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1477-1480.6. A. J. Nozik, Physica E: Low-dimensional Systems and Nanostructures, 2002, 14, 115-120.7. Q. Shen, X. Zhao, S. Zhou, W. Hou and J.-J. Zhu, The Journal of Physical Chemistry C, 2011, 115, 17958-

17964.8. N.-J. Song, C.-M. Chen, C. Lu, Z. Liu, Q.-Q. Kong and R. Cai, J. Mater. Chem. A, 2014, 2, 16563-16568.9. K. M. Gattas-Asfura and R. M. Leblanc, Chemical communications, 2003, DOI: 10.1039/b308991f, 2684.10.Y. Hao, L. Liu, Y. Long, J. Wang, Y.-N. Liu and F. Zhou, Biosensors and Bioelectronics, 2013, 41, 723-729.11.J. Wang and X. Jiang, Sensors and Actuators B: Chemical, 2015, 207, Part A, 552-555.12.J. Chen, A. Zheng, Y. Gao, C. He, G. Wu, Y. Chen, X. Kai and C. Zhu, Spectrochimica Acta Part A: Molecular and

Biomolecular Spectroscopy, 2008, 69, 1044-1052.13.Y.-h. Zhang, H.-s. Zhang, X.-f. Guo and H. Wang, Microchemical Journal, 2008, 89, 142-147.14.K. Zhang, J. Guo, J. Nie, B. Du and D. Xu, Sensors and Actuators B: Chemical, 2014, 190, 279-287.15.F. Huang, F. Pu, X. Lu, H. Zhang, Y. Xia, W. Huang and Z. Li, Sensors and Actuators B: Chemical, 2013, 183,

601-607.

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THANK YOU

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RESULTSPHOTOELECTROCHEMICAL SELECTIVITY TEST

0

0.01

0.02

0.03

0.04

0.05

0.06

0.07

0.08

0.09

0.1

-0.03458-0.015850.00227-0.04085-0.0141

0.01683

-0.03438

0.08688

-0.007920.00635

-0.01683

Intensity

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