Tunable formation of nanostructured SiC/SiOC core-shell for selective detection of SO2

SENSORS AND ACTUATORS B-CHEMICAL

卷:305

Article

Gaiardo, A.¹  Fabbri, B.²  Giberti, A.³  Valt, M.²  Gherardi, S.²  Guidi, V.²  Malagu, C.²  Bellutti, P.¹  Pepponi, G.¹  Casotti, D.²  Cruciani, G.²  Zonta, G.²  Landini, N.²  Barozzi, M.¹  Morandi, S.^4,5  Vanzetti, L.¹  Canteri, R.¹  Della Ciana, M.^2,6  Migliori, A.⁶  Demenev, E.¹ 

[1] Bruno Kessler Fdn, MNF, Via Sommar 18, I-38123 Trento, Italy

[2] Univ Ferrara, Dept Phys & Earth Sci, Via Saragat 1-C, I-44122 Ferrara, Italy

[3] MIST ER Scrl, Via P Gobetti 101, I-40129 Bologna, Italy

[4] Univ Torino, Dept Chem, INSTM, Via Quarello 15, I-10135 Turin, Italy

[5] Univ Torino, NIS Ctr, Via Quarello 15, I-10135 Turin, Italy

[6] CNR, Unit Bologna, Inst Microelect & Microsyst, Via Gobetti 101, I-40129 Bologna, Italy

关键词: Chemoresistive gas sensor;    SO2 detection;    Nanostructured SiC thick film;    SiC/SiOC core-shell;    High selectivity;   

DOI  :  10.1016/j.snb.2019.127485

来源: Elsevier

【 摘 要 】

Silicon carbide is a well-known material with high thermal, mechanical and chemical stability. These properties have allowed, over time, its wide use as an inert material to be employed as a substrate or support in different applications. In this work, we demonstrate that, under proper conditions, it is possible to activate the chemical reactivity of nanostructured SiC, which can be employed for chemoresistive purposes. With this aim, a commercial powder of SiC has been characterized from a morphological, structural and thermal point of view. Then, screen-printed thick films were obtained from SiC powder and thus tested as a functional material for chemoresistive gas sensors, in thermo-activation mode. The samples were exposed to 13 gases with important chemical differences. Analyses showed that SiC is an extremely selective functional material for the detection of sulphur dioxide (SO2) in concentrations within the ppm range. This interesting result was found at high working temperatures (600-800 degrees C), useful for harsh environments, and the measurements proved to be completely free from humidity negative interference. Thermo-gravimetric and X-ray photoelectron spectroscopy characterizations highlighted that the high selectivity of the SiC layer is promoted by the thermal formation of a SiC/SiOC core-shell, tunable by controlling temperature and humidity parameters. An interpretation of the gas sensing mechanism occurring between SO2 molecules and SiC/SiOC core-shell has been proposed. The unexpected chemical activity, identified for nanostructured SiC, can be exploited for the specific detection of SO2, since this gaseous compound plays an important role in air pollution, industrial processes and winemaking.

【 授权许可】

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