Development Of WO3 Catalytic Film For Detection Of Ethanol

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dc.contributor.authorLim, Guat Wei
dc.date.accessioned2018-12-27T06:32:45Z
dc.date.available2018-12-27T06:32:45Z
dc.date.issued2011-11
dc.description.abstractTungsten oxide (WO3) films deposited on alumina substrate were prepared by chemical vapor deposition (CVD) using tungsten hexacarbonyl (W(CO)6) powder as precursor. The structural characterization was performed using X-ray diffraction (XRD), field emission scanning electron microscope (FESEM) and atomic force microscope (AFM). The responses of WO3 films towards 500 ppm of ethanol vapor were investigated at operating temperatures of 150 to 550oC. Optimization on the preparation condition parameters was performed using one-factor-at-a-time technique. The results showed that sensitivity of the developed WO3 film varied according to its preparation condition which included deposition temperature (200 to 350oC), annealing temperature (500 to 700oC) and ratio Ar(W(CO)6)/O2 (1/6 to 1/3). The results indicated that WO3 film deposited at 350oC with annealing temperature of 600oC and gas flow ratio of Ar(W(CO)6)/O2 of 1/6 was the best sensor with the optimum working temperature of 450oC. This sensor film was further investigated under various conditions such as operating temperature (150 to 550oC) and concentrations of ethanol vapor (500 to 3000 ppm), response and recovery time, selectivity and lastly stability of gas sensor. It was found that the WO3 sensor film was more selective to ethanol vapor than methanol and acetone. It also showed a short response time of 12 seconds and recovery time of 134 seconds. The sensitivity of the sensor film increased with concentration up to 2500ppm of ethanol vapor and then it leveled off. It also exhibited high repeatability, reliable sensitivity after being used for up to 35 days. This study demonstrated the WO3 films were potential sensors for the detection of VOCs.en_US
dc.identifier.urihttp://hdl.handle.net/123456789/7402
dc.language.isoenen_US
dc.publisherUniversiti Sains Malaysiaen_US
dc.subjectDevelopment of WO3 catalytic filmen_US
dc.subjectfor detection of ethanolen_US
dc.titleDevelopment Of WO3 Catalytic Film For Detection Of Ethanolen_US
dc.typeThesisen_US
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