Design and implementation of a preconcentrator with Zeolite NaY for sensitivity enhancement of commercial gas sensors at low NO2 concentrations

Reza Goldoust | Saeideh Rahbarpour

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URL :   http://research.shahed.ac.ir/WSR/WebPages/Report/PaperView.aspx?PaperID=106175
Date :  2019/01/08
Publish in :     Materials Research Express
DOI :  https://doi.org/10.1088/2053-1591/aae3a4
Link :  https://iopscience.iop.org/article/10.1088/2053-1591/aae3a4
Keywords :gas preconcentrator, NO2, zeolite NaY, trace detection, sensitivity enhancement

Abstract :

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Detection of low concentration levels of NO2 was done using zeolite NaY in a preconcentrating structure. NO2 gas is one of the air pollutants that significantly affects the quality of human health, even at low concentrations, which necessitates its low detection with commercial gas sensors. In this work, we have reported responses of a commercial NO2 sensor to low concentration levels of NO2. Responses were improved by a designed and fabricated preconcentration system more than ~40 times. The preconcentrator was composed of different sections in which the most important part was zeolite NaY as a NO2 adsorbent: it adsorbed NO2 molecules from the air polluted with 300 ppb NO2 during the adsorption cycle, then by applying a heating pulse, it was forced to release preadsorbed NO2 species into a smaller chamber in which a commercial gas sensor was placed to monitor the variations of NO2. In this process, the sensor response increased noticeably. The practical conditions affecting preconcentrator performance, such as duration of adsorption time, heating rate, and the air circulation flow were investigated. Results were described and it is shown that NO2 detection at ppb levels with high sensitivity is possible with such a low price preconcentration system.