Material dependent and temperature driven adsorption switching (p- to n-type) using CNT/ZnO composite-based chemiresistive methanol gas sensor

SENSORS AND ACTUATORS B-CHEMICAL

卷:336

Article

Sinha, Madhumita¹  Neogi, Samya^2,3  Mahapatra, Rajat¹  Krishnamurthy, Satheesh⁴  Ghosh, Ranajit^2,3 

[1] Natl Inst Technol Durgapur, Dept Elect & Commun Engn, Durgapur 713209, India

[2] Cent Mech Engn Res Inst CMERI, CSIR, Durgapur 713209, India

[3] Acad Sci & Innovat Res AcSIR, CSIR CMERI Campus, Durgapur 713209, India

[4] Open Univ, Sch Engn & Innovat, Milton Keynes MK7 6AA, Bucks, England

关键词: Carbon nanotubes;    ZnO nanostructure;    Chemiresistive sensor;    Adsorption switching;    p- to n- transition;    VOC detection;   

DOI  :  10.1016/j.snb.2021.129729

来源: Elsevier

【 摘 要 】

The present study correlates two simultaneous as well as significant observations coming out from a single sensing prototype concerning the detection of volatile organic compounds (VOCs) by a carbonaceous material based sensor. We have developed a composite based chemiresistive sensor utilizing two different components (carbon nanotube (CNT) and zinc oxide (ZnO)). This is reflected in a unique adsorption switching phenomena followed by a 'p- to n-' type transition characteristics above a certain operating temperature (150 degrees C) in the VOC detection process. Noticeably, by the virtue of adsorption switching, the CNT/ZnO composite is able to operate as a dual mode sensor, in which CNT dominates in low temperature region (<= 150 degrees C) and ZnO at high temperature region (>150 degrees C) with a realistic detection ability. The highly reproducible sensors (29 prototypes) are selective towards methanol (Response, R similar to 73 +/- 3 %) and shows 8-fold enhancement in response value compared to neighbouring VOC i.e., ethanol at an operating temperature of 150 degrees C with a very low bias voltage of 10 mV. Finally, the adsorption switching phenomena (physisorption to chemisorption) has been explained by Fourier Transform Infrared Spectroscopy (FTIR) study and activation energy values along with 'p- to n-' type transition is compared qualitatively with a typical full wave rectification process.

【 授权许可】

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