Anomalous gas sensing behaviors to reducing agents of hydrothermally grown α-Fe2O3 nanorodsShow others and affiliations
2018 (English)In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 273, p. 1237-1245Article in journal (Refereed) Published
Abstract [en]
α-Fe2O3 nanorods have been grown by hydrothermal method, dispersed in ethanol and drop casted on a pre-patterned alumina substrate with Pt electrodes. Their morphology, crystalline and electronic properties have been investigated by Scanning Electron Microscopy, Raman and X-ray Photoelectron Spectroscopies and X-ray Diffraction. The so-fabricated devices have been used for hydrogen gas sensing, showing their ability to detect H2 at operating temperatures > 200 °C, at relative humidity values comprised from 0% to 50%. The sensing behavior of α-Fe2O3 nanorods is compatible with an n to p conductivity transition when the operating temperature is increased up to 300 °C. Outstanding p-type hydrogen sensing performances of α-Fe2O3 have been observed and reported. Besides H2 detection, the α-Fe2O3 nanorods-based device is a good humidity sensor, at room temperature (n-type) and at 400 °C (p-type). CO and ethanol sensing performances have been investigated at different operating temperatures and relative humidity values. CO and ethanol anomalous acceptor-like behaviors at 200 °C in humid air has been explained by the interactions of these target gases with the water molecules adsorbed on the metal oxide surfaces. An explanation of the n–p behavior transition at T > 200 °C in terms of band bending is reported.
Place, publisher, year, edition, pages
Elsevier, 2018. Vol. 273, p. 1237-1245
Keywords [en]
Hematite, n-p transition, Hydrothermal, Hydrogen sensing
National Category
Other Physics Topics
Research subject
Experimental Physics
Identifiers
URN: urn:nbn:se:ltu:diva-70265DOI: 10.1016/j.snb.2018.07.042ISI: 000441519000153Scopus ID: 2-s2.0-85049771394OAI: oai:DiVA.org:ltu-70265DiVA, id: diva2:1237230
Note
Validerad;2018;Nivå 2;2018-08-08 (andbra)
2018-08-082018-08-082021-03-31Bibliographically approved