| Abstrakt: |
In this study, three different TiO2 nanostructures, including nanowires, nanoparticles, and thin films, were synthesized by three different processes. The morphology and crystal structure of the three different TiO2 structures deposited on quartz glasses were characterized by XRD, SEM, FTIR, and BET. It has been found that nanowires and nanoparticles showed only the anatase phase, while the thin films exhibited both anatase and rutile phases. The three TiO2 nanostructures were then used to fabricate gas sensors for ammonia (NH3) detection at different concentrations and various conditions. The samples fabricated with TiO2 thin film toward 50 ppm NH3 showed a response value of 5% at room temperature, whereas the other two samples exhibited much higher values toward similar condition NH3 at room temperature. Samples with nanowires showed a threefold increase and samples with nanoparticles exhibit a twofold increase in response value. We have found that the response of all samples increases with the elevating operating temperature up to 200 °C. Increasing the operating temperature improved the nanoparticle sensing conditions more than the other two samples. The samples using nanoparticles showed a 33% increase in response toward 50 ppm NH3 at 200 °C compared to the samples with thin films at similar conditions. Further, response and recovery time were investigated and reported in this study. [ABSTRACT FROM AUTHOR] |
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