Abstract
The gas sensing properties of ZnO nanostructures synthesized at various reaction times are reported in this study. The response of ZnO nanostructures to H 2 , NH 3 , H 2 S and NO 2 gases was investigated at different operating temperatures and gas concentrations. Surface morphology analyses showed that the geometry of the nanostructures transforms with the synthesis reaction time. Topography analyses demonstrated a surface roughness of approximately 68.25, 70.31, 74.75 nm for the samples synthesized for 24, 48 and 72 h, respectively. The dependence of the morphology on the H 2 , NH 3 , NO 2 and H 2 S gas sensing performance was observed. The alteration of the nanostructures diameter/geometry demonstrated a change in both the magnitude and temperature of the maximum sensor response. The 72 h ZnO sensing material revealed improved response and higher sensitivity and selectivity to H 2 S gas, while the 24 h sensing material revealed enhanced response and selectivity to NO 2 gas at 300 °C. Moreover, the 72 h sensing material exhibited a higher sensitivity of 144.22 ppm -1 at 300 °C. These findings disclosed that by varying the synthesis reaction time, the sensing properties, such as the response, sensitivity and selectivity of the ZnO nanostructures could be tuned.
Original language | English |
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Pages (from-to) | 210-223 |
Number of pages | 14 |
Journal | Applied Surface Science |
Volume | 386 |
DOIs | |
Publication status | Published - 15 Nov 2016 |
Keywords
- H S sensing
- Nanorods
- ZnO-nanostructures
ASJC Scopus subject areas
- General Chemistry
- Condensed Matter Physics
- General Physics and Astronomy
- Surfaces and Interfaces
- Surfaces, Coatings and Films