Nanoflower structures of ZnO–SnO2 arranged on nanoporous Al2O3 for sensing ethanol and methanol gases
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- 作者：Hsing-Cheng Chang ; Yu-Liang Hsu ; Wen-Chieh Huang ; Ya-Hui Chen…
- 刊名：Microsystem Technologies
- 出版年：2017
- 出版时间：February 2017
- 年：2017
- 卷：23
- 期：2
- 页码：499-506
- 全文大小：
- 刊物类别：Engineering
- 刊物主题：Electronics and Microelectronics, Instrumentation; Nanotechnology; Mechanical Engineering;
- 出版者：Springer Berlin Heidelberg
- ISSN：1432-1858
- 卷排序：23
文摘
A compound sensing structure based on nanoflower-like ZnO–SnO2 coated on the top of nanoporous anodic aluminum oxide (AAO) layer to form ZnO–SnO2–AAO composite as a gas sensing structure is developed for detecting ethanol and methanol simultaneously. The ZnO–SnO2 powders were synthesized by hydrothermal synthesis method. The SnO2 was grown densely and uniformly that has unique loose and porous nano structures to increase the accessible surface area for improving gas diffusion and mass transport. A solenoid-type heater was designed to surround the sensing column for controlling operation temperature to promote gas sensitivity. The ethanol and methanol responses of ZnO–SnO2–AAO are high because the porous AAO greatly improves the specific adsorption surface area, and the ZnO produces more electron donor states or oxygen vacancies to enhance oxygen adsorption as well as the heterojunction of SnO2 and ZnO grains offers access to facile electronic interaction to enhance the surface reaction between adsorbed oxygen and current-carrying electrons. By analyzing a series of temperature-varied cyclic tests, the optimal operation temperatures of 180 °C for sensing ethanol and 260 °C for sensing methanol were obtained to have the strongest output responses. The developed ZnO–SnO2–AAO gas sensing composites include the advantages: simple fabrication process, low cost, high specific surface area and porosity, rapid detection, high sensitivity, stable stability, and good repeatability.