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dc.contributor.authorBannov, Alexander G.cs
dc.contributor.authorJašek, Ondřejcs
dc.contributor.authorPrášek, Jancs
dc.contributor.authorBuršík, Jiřícs
dc.contributor.authorZajíčková, Lenkacs
dc.date.accessioned2020-08-04T11:03:54Z
dc.date.available2020-08-04T11:03:54Z
dc.date.issued2018-09-17cs
dc.identifier.citationJournal of Sensors. 2018, vol. 2018, issue 7497619, p. 1-14.en
dc.identifier.issn1687-7268cs
dc.identifier.other150641cs
dc.identifier.urihttp://hdl.handle.net/11012/193261
dc.description.abstractThe ammonia adsorption on the nanostructured carbon thin film was significantly influenced by the choice of deposition temperature and deposition time of thin film synthesis. The thin films were prepared on Si/SiO2 substrates by chemical vapour deposition in Ar/C2H2 gas mixture using iron catalytic nanoparticles. The analysis of the grown layer by the scanning and transmission electron microscopy showed the transition from long multiwalled nanotubes (MWCNTs) to bamboo-like hollow carbon nanofiber structure with the decrease of the deposition temperature from 700 to 600°C. Further, the material was analyzed by energy-dispersive X-ray spectroscopy and Raman spectroscopy confirmed the transition from graphitic sp structure to highly defective structure at lower deposition temperature. The resistance of the prepared layer strongly depends on deposition temperature ( Td ) and deposition time ( td ). High resistance layer, 38.6 k, was formed at Td 600°C and td 10 min, while at Td 700°C and td 60 min, the resistance decreased to 860 ohms. Such behaviour is consistent with MWCNTs being responsible for the formation of the conductive network. Such system was studied using chemiresistor ammonia gas sensor configuration. The sensor resistance increased when exposed to ammonia in all the cases, but their response varied considerably. A decrease in deposition time, from 60 to 10 min, and the deposition temperature, from 700 to 600°C, led to the 10-fold increase in the sensor response. The measurements carried out at room temperature showed the higher sensor response than the measurements carried out at 200°C. This behaviour can be explained by the change in adsorption-desorption equilibrium at different temperatures. Analysis of dependence of the sensor response on the ammonia concentration proved that the underlying resistance change mechanism is chemisorption of ammonia molecules on the carbon network corresponding to the Langmuir isotherm.en
dc.formattextcs
dc.format.extent1-14cs
dc.format.mimetypeapplication/pdfcs
dc.language.isoencs
dc.publisherHindawics
dc.relation.ispartofJournal of Sensorscs
dc.relation.urihttp://dx.doi.org/10.1155/2018/7497619cs
dc.rightsCreative Commons Attribution 4.0 Internationalcs
dc.rights.urihttp://creativecommons.org/licenses/by/4.0/cs
dc.subjectammoniaen
dc.subjectnanofibrous carbonen
dc.subjectMWCNTsen
dc.subjectgas sensoren
dc.titleEnhanced Ammonia Adsorption on Directly Deposited Nanofibrous Carbon Filmsen
thesis.grantorVysoké učení technické v Brně. Středoevropský technologický institut VUT. Chytré nanonástrojecs
thesis.grantorVysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií. oddělení-MEL-SIXcs
sync.item.dbidVAV-150641en
sync.item.dbtypeVAVen
sync.item.insts2020.08.04 13:03:54en
sync.item.modts2020.08.04 12:23:49en
dc.coverage.issue7497619cs
dc.coverage.volume2018cs
dc.identifier.doi10.1155/2018/7497619cs
dc.rights.accessopenAccesscs
dc.rights.sherpahttp://www.sherpa.ac.uk/romeo/issn/1687-7268/cs
dc.type.driverarticleen
dc.type.statusPeer-revieweden
dc.type.versionpublishedVersionen


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Except where otherwise noted, this item's license is described as Creative Commons Attribution 4.0 International