ZnO Nanopowders as Chemical Sensor to Malathion Vapor
A. Al-Mohammada, R. Darwicha, M. Rukiahb, S. Abo Shakera and M. Kakhiaa
aNano-materials Labs, Department of Physics, Atomic Energy Commission of Syria, 17th Nissan Street, B.O. Box 6091, Damascus, Syrian Arab Republic
bDepartment of Chemistry, Atomic Energy Commission of Syria, 17th Nissan Street, B.O. Box 6091, Damascus, Syrian Arab Republic
Received: November 27, 2012; In final form: October 31, 2013
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Thick films of zinc oxide (ZnO) nanopowders have been prepared by high energy ball-milling for various spans of mill time (3-18 h). The morphology and crystal structure of the prepared ZnO powder were characterized by scanning electron microscope and X-ray diffraction. The ZnO thick films were then used to construct a gas sensor for O,O-dimethyl dithiophosphate of diethyl mercaptosuccinate (malathion) at different operating temperatures. The sensor response at 100 ppm of malathion was found to reach a maximum as large as 80 at 6 h of high energy ball-milling, four times larger than that found for ethanol. Scanning electron microscope observation of the granular state and pore size distribution analyses indicated that increasing high energy ball-milling time gave rise especially to an increase in the volume of pores in the pore size range of 6-35 nm. It is suggested that such a change in nanostructure is responsible for the marked promotion of the response to malathion.

DOI: 10.12693/APhysPolA.125.131
PACS numbers: 81.16.Be, 84.37.+q, 81.20.Ev, 81.20.Wk, 07.07.Df