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Vol.57, No.11, 732 ~ 741, 2019
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| Title |
| Low-Temperature H2S Sensors Based on Si-Coated SnO2 Nanowires |
| Myung Sik Choi , Ali Mirzaei , Jae Hoon Bang , Han Gil Na , Changhyun Jin , Wansik Oum , Seungmin Han , Sang Sub Kim , Hyoun Woo Kim |
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| Abstract |
| To attain high life standards, it is important to develop high-performance non-toxic gas sensors for public safety, environmental pollutant control, industrial processes, etc. Because reports on single element semiconductor-coated semiconducting metal oxides for sensing applications are rare, we synthesized SnO2 nanowires and coated them with a 5 nm-thick or 10 nm-thick Si layer for H2S gas sensing studies. SnO2 nanowires were successfully synthesized using a highly pure metallic Sn powder at high temperature in a tube furnace by the vapor-liquid-solid method and Si was deposited on the nanowires by the sputtering technique. The desired morphology and composition of the synthesized nanowires were confirmed by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and energy-dispersive X-ray spectroscopy. Moreover, the gas sensing characteristics of pristine and Si-coated SnO2 nanowires toward H2S, CO, H2, C6H6, C2H5OH and C6H7 gases were investigated. The sensing results revealed a good response to H2S at the optimum operational temperature of 100 °C. Notably, Si-coated SnO2 nanowire sensors showed a better response to H2S than pristine SnO2 nanowires. The mechanism of H2S sensing is discussed in detail here. This study shows that the Si coating on the SnO2 nanowire enhances its sensing performance and decreases the sensing temperature required for H2S gas detection.
(Received May 3, 2019; Accepted September 7, 2019) |
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| Key Words |
| SnO2, nanowires, Si, coating, H2S, gas sensor, semiconductor |
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