8/10/2019 PPT Isfache 2014- Diah Susanti
http://slidepdf.com/reader/full/ppt-isfache-2014-diah-susanti 1/25
L/O/G/O
Preparat ion o f CO gas senso r f rom ZnOMater ial Syn thesized via Therm o -Oxidat ion
Process
Diah Susanti*, Endah Lutfiana, HaniffudinNurdiansah, Hariyati Purwaningsih, Lukman
Noerochiem#Materials and Metallurgical EngineeringDepartment,ITS Surabaya
*Corresponding Author :[email protected]
8/10/2019 PPT Isfache 2014- Diah Susanti
http://slidepdf.com/reader/full/ppt-isfache-2014-diah-susanti 2/25
Introduction
8/10/2019 PPT Isfache 2014- Diah Susanti
http://slidepdf.com/reader/full/ppt-isfache-2014-diah-susanti 3/25
Purposes of the Research
• Synthesis ZnO via Thermo – OxidationProcess
• Arrange a CO gas sensor based on ZnOmaterial
• Analyzed the correlations between ZnOstructure and sensitivity towards CO gas
8/10/2019 PPT Isfache 2014- Diah Susanti
http://slidepdf.com/reader/full/ppt-isfache-2014-diah-susanti 4/25
Literature : CO Toxicity
8/10/2019 PPT Isfache 2014- Diah Susanti
http://slidepdf.com/reader/full/ppt-isfache-2014-diah-susanti 5/25
Literature : CO Reaction
Hb(aq) + CO(g) → HbCO(aq)
8/10/2019 PPT Isfache 2014- Diah Susanti
http://slidepdf.com/reader/full/ppt-isfache-2014-diah-susanti 6/25
Literature ZnO
Tabel 2.1 Characteristic
of ZnO (Wikipedia, 2013)
ZnO Powder
8/10/2019 PPT Isfache 2014- Diah Susanti
http://slidepdf.com/reader/full/ppt-isfache-2014-diah-susanti 7/25
Literature Sensor
S =[ − ]
A sensor is a device that detectsevents or changes in quantitiesand provides a correspondingoutput, generally as an electricalor optical signal
SensitivityEquation
Rg : Resis tanc e af tergas exposure
Ro : Resis tance beforegas exposure
8/10/2019 PPT Isfache 2014- Diah Susanti
http://slidepdf.com/reader/full/ppt-isfache-2014-diah-susanti 8/25
Oxidation: 1/2 O 2 g + e - O ad- Reduction : CO + O ad- CO 2
g + e -
Literature Gas Sensor Mechanism
8/10/2019 PPT Isfache 2014- Diah Susanti
http://slidepdf.com/reader/full/ppt-isfache-2014-diah-susanti 9/25
Flow Chart of Experiment
Specimen is already to used
Sintered at T : 500 0C for 1 hour
Pelletizing using hydraulic compaction machine with pressure 200 bar to obtainpellets with dimension 14 mm in diameters and 3 mm in thickness
Crushed and sieved until the sizes less than 80µm
Hold for 40 minutes
Zn powder ( 2mg), heated at muffle furnace with various temperature of 800, 850,
and 9000
C
8/10/2019 PPT Isfache 2014- Diah Susanti
http://slidepdf.com/reader/full/ppt-isfache-2014-diah-susanti 10/25
Synthesis of ZnO
Zn powder < 45 µ Muffle Furnace T : 800, 850,900 oC ,40 minutes Crushing ZnOPowder
Shieving < 80 µ
8/10/2019 PPT Isfache 2014- Diah Susanti
http://slidepdf.com/reader/full/ppt-isfache-2014-diah-susanti 11/25
Powder Compaction (200Bar)
(SEM),(XRD),(BET)
Making A Pellet Sensor
SensitivityTesting
Sintering at 500 oC
8/10/2019 PPT Isfache 2014- Diah Susanti
http://slidepdf.com/reader/full/ppt-isfache-2014-diah-susanti 12/25
Testing
Testing
SEM
XRD
Sensitivity
Testing
BET
8/10/2019 PPT Isfache 2014- Diah Susanti
http://slidepdf.com/reader/full/ppt-isfache-2014-diah-susanti 13/25
1. Gasometer of CO2. Vacuum Pump3. Mass Flow
Controller4. Thermocontroller5. Chamber6. Electrical
MeasuringInstrument
Sensitivity Testing
1 2
3 4 5 6
8/10/2019 PPT Isfache 2014- Diah Susanti
http://slidepdf.com/reader/full/ppt-isfache-2014-diah-susanti 14/25
Flow Chart of Sensitivity Testing
Repeated step above for different operating temperature 50 and 1000
C
Repeated this step at different CO gas concentration 100, 250 and 500 ppm
Calculate the Rg using potentiostat
Flowing the CO gases at 10 ppm concentration
Calculate the R 0 using potentiostat
Put the ZnO pellet into the chamber, and then vacumm it and set the operation
temperature at 300
C using thermocontroller
8/10/2019 PPT Isfache 2014- Diah Susanti
http://slidepdf.com/reader/full/ppt-isfache-2014-diah-susanti 15/25
Picture of ZnO Pellet
8/10/2019 PPT Isfache 2014- Diah Susanti
http://slidepdf.com/reader/full/ppt-isfache-2014-diah-susanti 16/25
XRD Testing :Before Exposure
Fig.1 Comparison of thediffraction patterns of ZnOpellets synthesized at 800 0C,850 0C, and 900 0C beforesensitivity test towards COgas.
8/10/2019 PPT Isfache 2014- Diah Susanti
http://slidepdf.com/reader/full/ppt-isfache-2014-diah-susanti 17/25
XRD Testing : After Exposure
Fig.2 Comparison of diffraction patternof ZnO pellets for sample with synthesistemperature variations 800 0C, 850 0C,900 0C, after exposure to CO gas.
8/10/2019 PPT Isfache 2014- Diah Susanti
http://slidepdf.com/reader/full/ppt-isfache-2014-diah-susanti 18/25
SEM Testing : ZnO BeforeCrushed
Fig.3 Bright field SEM images for ZnO before being crushed intopowder, synthesized at a) 800 0C, b) 850 0C, and c) 900 0C.
8/10/2019 PPT Isfache 2014- Diah Susanti
http://slidepdf.com/reader/full/ppt-isfache-2014-diah-susanti 19/25
SEM Testing : ZnO Before GasExposure
Fig. 4. Bright field SEM images of ZnO pellets for sample with varioussynthesis temperature a) 800 0C, b) 850 0C, and c) 900 0C before CO gasexposure
8/10/2019 PPT Isfache 2014- Diah Susanti
http://slidepdf.com/reader/full/ppt-isfache-2014-diah-susanti 20/25
SEM Testing : ZnO After GasExposure
Fig. 5. Bright field SEM images of ZnO pellets for sample with varioussynthesis temperature a) 800 0C, b) 850 0C, and c) 900 0C after CO gasexposure
8/10/2019 PPT Isfache 2014- Diah Susanti
http://slidepdf.com/reader/full/ppt-isfache-2014-diah-susanti 21/25
BET Testing
8/10/2019 PPT Isfache 2014- Diah Susanti
http://slidepdf.com/reader/full/ppt-isfache-2014-diah-susanti 22/25
Sensitivity Testing
Fig. 6. Thesensitivity test ofZnO-based CO gassensorsynthesized atvarioustemperatures 800,
850, and 900 0C atdifferent operatingtemperatures 30,50 and 100 0C andCO gasconcentration)a)10ppm, b)100ppm, c)250ppm, d)500ppm
8/10/2019 PPT Isfache 2014- Diah Susanti
http://slidepdf.com/reader/full/ppt-isfache-2014-diah-susanti 23/25
Conclusion• ZnO as material for CO gas sensor could be obtained through
thermo-oxidation process of Zinc powder.• XRD measurements confirmed the formation of ZnO of hexagonal
structure without any other impurities.• The ZnO sensor pellet synthesized at 800 0C performed the highest
sensitivity towards CO gas for its largest active surface area. It wasalso showed that the sensitivity towards CO gas increased withoperating temperature and CO gas concentration.
• SEM and XRD analysis have also revealed the potency of ZnOmaterial for CO gas sensor, since there was no significant change inthe morphology and structure of ZnO material after CO gasexposure.
• Therefore ZnO is a good candidate for CO gas sensor material sinceit is stable and inert to CO gas.
8/10/2019 PPT Isfache 2014- Diah Susanti
http://slidepdf.com/reader/full/ppt-isfache-2014-diah-susanti 24/25
Acknowledgements
• Authors gratefully acknowledge thefinancial and facility supports from Ministryof Education and Culture Republic of
Indonesia through InternationalCollaboration Research Grant 2014(BOPTN funding) and Institut Teknologi
Sepuluh Nopember (ITS) - SurabayaIndonesia, respectively.
8/10/2019 PPT Isfache 2014- Diah Susanti
http://slidepdf.com/reader/full/ppt-isfache-2014-diah-susanti 25/25
L/O/G/O
Th an k Yo u