Electrical response of naostructured zinc oxide in the presence of hydrogen sulfide gas.

Date

4-2010

Degree

Bachelor of Science in Applied Physics

College

College of Arts and Sciences (CAS)

Adviser/Committee Chair

Marvin U. Herrera

Co-adviser

Armida V. Gillado

Abstract

The properties of the sensing material play a significant role in the development of reliable gas sensors. In this study, nanostructured zinc oxide (ZnO) was successfully fabricated using electrodeposition technique. ZnO was deposited on pencil graphite electrode with varying applied voltage and deposition time. The voltages applied were 300 V, 500 V and 700 V and the deposition times used were 5 min, 7.5 min, 10 min, 12.5 min, 15 min and 17.5 min. There were a total of 18 ZnO samples electrodeposited at certain voltage and deposition time. The hydrogen sulfide (H2S) sensing properties of the ZnO deposits were investigated under room temperature and found to be affected by the surface morphology, volume of the deposits, and the electrodeposition parameters such as the applied voltage and deposition time. The structural and morphological properties of the deposits were investigated using XRD and SEM, respectively. X-ray diffraction revealed the wurtzite hexagonal structure of the electrodeposited ZnO. It also showed that ZnO was the only detectable phase in the XRD pattern. SEM images showed that the ZnO deposits were porous and nanostructured with particle size ranging from 100 nm to 350 nm. The electrodeposited ZnO showed very high response to I-12S gas having minimum and maximum gas response of 5.72180 and 82.84032, respectively. The ZnO deposited at 700 V and 12.5 min deposition time exhibited the best H2S sensing performance at 82.84032 gas response. Thickness of the ZnO deposits was also obtained and this showed that H2S gas response is linearly dependent on the volume of the ZnO deposits.

Language

English

Location

UPLB Main Library Special Collections Section (USCS)

Call Number

Thesis

Document Type

Thesis

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