Hydrogen sulfide gas detection by Au-decorated ZnO nanotube: a computational study and comparison to experimental observations |
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| Authors: | Gang Liu Ya Wang Jianpeng Li Ying Liu Maryam Salehabadi |
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| Affiliation: | 1. Institute of Chemical and Industrial Bioengineering, Jilin Engineering Normal University, Changchun, China liugang20919@163.com;3. Institute of Chemical and Industrial Bioengineering, Jilin Engineering Normal University, Changchun, China;4. Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, China;5. University of Applied Science and Technology of Jovain Industrial and Agricultural, Jovain, Iran |
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| Abstract: | Based on the experimental reports, Au-decoration on the ZnO nanostructures dramatically increases the electronic sensitivity to H2S gas. In the current study, we computationally scrutinized the mechanism of Au-decoration on a ZnO nanotube (ZON) and the influence on its sensing behavior toward H2S gas. The intrinsic ZON weakly interacted with the H2S gas with an adsorption energy of ?11.2 kcal/mol. The interaction showed no effect on the HOMO–LUMO gap and conductivity of ZON. The predicted response of intrinsic ZON toward H2S gas is 6.3, which increases to 78.1 by the Au-decoration at 298 K. The corresponding experimental values are about 5.0 and 80.0, indicating excellent agreement with our findings. We showed that the Au atom catalyzes the reaction 3O2?+?2H2S?→?2SO2?+?2H2O. Our calculated energy barrier (at 298 K) is about 12.3 kcal/mol for this reaction. The gap and electrical conductance Au-ZON largely changed by this reaction are attributed to the electron donation and back-donation processes. The obtained recovery time is about 1.35 ms for desorption of generated gases from the surface of the Au-ZON sensor. |
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| Keywords: | Electronic properties ZnO nanostructures density functional gas sensor |
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