Cross-Interference of VOCs in SnO2-Based NO Sensors

Renjun Si; Yan Li; Jie Tian; Changshu Tan; Shaofeng Chen; Ming Lei; Feng Xie; Xin Guo; Shunping Zhang

doi:10.3390/nano13050908

Cross-Interference of VOCs in SnO₂-Based NO Sensors

Nanomaterials (Basel). 2023 Feb 28;13(5):908. doi: 10.3390/nano13050908.

Authors

Renjun Si¹, Yan Li², Jie Tian², Changshu Tan², Shaofeng Chen¹, Ming Lei^{1

3}, Feng Xie^{1

3}, Xin Guo⁴, Shunping Zhang^{1

3}

Affiliations

¹ State Key Laboratory of Material Processing and Die & Mould Technology, Department of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, China.
² Shenzhen Power Supply Co., Ltd., Shenzhen 518002, China.
³ Nanomaterial and Smart Sensor Research Laboratory, Department of Materials Science and Engineering, Huazhong University of Science and Technology, Luo-Yu Road 1037, Wuhan 430074, China.
⁴ Laboratory of Solid State Ionics, School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, China.

Abstract

In this work, we studied the influence of cross-interference effects between VOCs and NO on the performance of SnO₂ and Pt-SnO₂-based gas sensors. Sensing films were fabricated by screen printing. The results show that the response of the SnO₂ sensors to NO under air is higher than that of Pt-SnO₂, but the response to VOCs is lower than that of Pt-SnO₂. The Pt-SnO₂ sensor was significantly more responsive to VOCs in the NO background than in air. In the traditional single-component gas test, the pure SnO₂ sensor showed good selectivity to VOCs and NO at 300 °C and 150 °C, respectively. Loading noble metal Pt improved the sensitivity to VOCs at high temperature, but also significantly increased the interference to NO sensitivity at low temperature. The explanation for this phenomenon is that the noble metal Pt can catalyze the reaction between NO and VOCs to generate more O^-, which further promotes the adsorption of VOCs. Therefore, selectivity cannot be simply determined by single-component gas testing alone. Mutual interference between mixed gases needs to be taken into account.

Keywords: NO; Pt doping; VOCs; cross-interference; selectivity.

Abstract

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