Room Temperature Formaldehyde Sensing of Hollow SnO2/ZnO Heterojunctions Under UV-LED Activation
Room Temperature Formaldehyde Sensing of Hollow SnO2/ZnO Heterojunctions Under UV-LED Activation
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DOI：
10.1109/jsen.2019.2916879
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发表时间：
2019-09
影响因子：
4.3
通讯作者：
Lijia Zhao;Yupeng Chen;Xinyu Li;Xiaogan Li;Shiwei Lin;Tie Li;M. Rumyantseva;A. Gaskov
中科院分区：
文献类型：
--
作者：
Lijia Zhao;Yupeng Chen;Xinyu Li;Xiaogan Li;Shiwei Lin;Tie Li;M. Rumyantseva;A. Gaskov
The room temperature gas sensing properties of the hollow SnO2/ZnO heterojunction-based chemiresistive sensors under ultraviolet ${\left ({UV}\right)}$ radiation were investigated. The hollow SnO2/ZnO heterojunctions were fabricated using the template-assisted process followed with a hydrothermal treatment. The sensor using this core-shell SnO2/ZnO heterojunctions showed a much higher response to formaldehyde under UV illumination compared to that without UV. Moreover, the response of this hollow heterojunctions-based sensor to formaldehyde is higher than the respective pure SnO2 and ZnO hollow microspheres-based sensors under same conditions indicating the synthetic effect of the formed heterojunctions on the enhanced sensitivity. More strikingly, the response of the SnO2/ZnO heterojunctions-based sensors showed a much smaller response to ethanol, methanol, and toluene indicating an excellent selectivity whereas there is a large influence from ethanol if the sensor worked under the conventional heating method. It could be attributed to the lower oxidizing ability of the adsorbed, ionized oxygen with a negative monovalence on the oxide surface and thus a selective photo-catalytic conversion of formaldehyde over the other possible interferents. The long-term stability of the sensor operated under UV light was also studied.
