1. ZnO-nanowires modified polypyrrole films as highly selective and sensitive chlorine sensors.
- Author
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Joshi, Aditee, Aswal, D. K., Gupta, S. K., Yakhmi, J. V., and Gangal, S. A.
- Subjects
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NANOWIRES , *ZINC oxide , *CHLORINE , *PARTICLES (Nuclear physics) , *NANOSTRUCTURED materials - Abstract
Room temperature sensing characteristics of the polypyrrole (PPy) films modified with different weight percentages of ZnO nanowires (ZnO-NWs) have been studied for various oxidizing (NO2 and Cl2) as well as reducing (H2S, NH3, CH4, and CO) gases. We demonstrate that ZnO-NW (50 wt %):PPy composite films are highly selective to Cl2 along with high-sensitivity (40 at 10 ppm), fast-response (55 s), and highly reproducible response curves. It has been shown that negatively charged O2- surfaces of ZnO-NW transfer electrons to PPy, making it in a highly reduced form. A strong localization of charge carriers in the reduced PPy makes composite film highly resistive (>1010 Ω cm) as well insensitive to interaction with most of the gases except Cl2. Cl2 being highly oxidizing gas interacts with composite films and causes a sharp reduction in its resistivity. [ABSTRACT FROM AUTHOR]
- Published
- 2009
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