Characterization and electrochemical properties of iron-doped tetrahedral amorphous carbon (ta-C) thin films

dc.contributorAalto-yliopistofi
dc.contributorAalto Universityen
dc.contributor.authorEtula, Jarkkoen_US
dc.contributor.authorWester, Niklasen_US
dc.contributor.authorSainio, Samien_US
dc.contributor.authorLaurila, Tomien_US
dc.contributor.authorKoskinen, Jarien_US
dc.contributor.departmentDepartment of Chemistry and Materials Scienceen
dc.contributor.departmentDepartment of Chemistryen
dc.contributor.departmentDepartment of Electrical Engineering and Automationen
dc.contributor.groupauthorPhysical Characteristics of Surfaces and Interfacesen
dc.contributor.groupauthorMicrosystems Technologyen
dc.date.accessioned2018-09-04T11:13:28Z
dc.date.available2018-09-04T11:13:28Z
dc.date.issued2018-01-01en_US
dc.descriptionElectronic supplementary information (ESI) available: Deposition method calibration data, XRR details, additional XPS data, TEM images, CV curves, calculated CV rate constants. See DOI: 10.1039/c8ra04719g
dc.description.abstractIron-doped tetrahedral amorphous carbon thin films (Fe/ta-C) were deposited with varying iron content using a pulsed filtered cathodic vacuum arc system (p-FCVA). The aim of this study was to understand effects of iron on both the physical and electrochemical properties of the otherwise inert sp3-rich ta-C matrix. As indicated by X-ray photoelectron spectroscopy (XPS), even ∼0.4 at% surface iron had a profound electrochemical impact on both the potential window of ta-C in H2SO4 and KOH, as well as pseudocapacitance. It also substantially enhanced the electron transport and re-enabled facile outer sphere redox reaction kinetics in comparison to un-doped ta-C, as measured with electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) using outer-sphere probes Ru(NH3)6, IrCl6, and FcMeOH. These increases in surface iron loading were linked to increased surface oxygen content and iron oxides. Unlike few other metals, an iron content even up to 10 at% was not found to result in the formation of sp2-rich amorphous carbon films as investigated by Raman spectroscopy. Atomic force microscopy (AFM) and transmission electron microscopy (TEM) investigations found all films to be amorphous and ultrasmooth with Rq values always in the range of 0.1-0.2 nm. As even very small amounts of Fe were shown to dominate the electrochemistry of ta-C, implications of this study are very useful e.g. in carbon nanostructure synthesis, where irregular traces of iron can be readily incorporated into the final structures.en
dc.description.versionPeer revieweden
dc.format.extent8
dc.format.extent26356-26363
dc.format.mimetypeapplication/pdfen_US
dc.identifier.citationEtula, J, Wester, N, Sainio, S, Laurila, T & Koskinen, J 2018, ' Characterization and electrochemical properties of iron-doped tetrahedral amorphous carbon (ta-C) thin films ', RSC Advances, vol. 8, no. 46, pp. 26356-26363 . https://doi.org/10.1039/c8ra04719gen
dc.identifier.doi10.1039/c8ra04719gen_US
dc.identifier.issn2046-2069
dc.identifier.otherPURE UUID: 5d23c50c-efd4-4c05-bfb7-8f8b5b8e85b9en_US
dc.identifier.otherPURE ITEMURL: https://research.aalto.fi/en/publications/5d23c50c-efd4-4c05-bfb7-8f8b5b8e85b9en_US
dc.identifier.otherPURE LINK: http://www.scopus.com/inward/record.url?scp=85050341624&partnerID=8YFLogxKen_US
dc.identifier.otherPURE FILEURL: https://research.aalto.fi/files/27527537/CHEM_Etula_etal_Characterization_and_electrochemical_RSC_Advances_8_26356_2018.pdfen_US
dc.identifier.urihttps://aaltodoc.aalto.fi/handle/123456789/33808
dc.identifier.urnURN:NBN:fi:aalto-201809044928
dc.language.isoenen
dc.relation.ispartofseriesRSC Advancesen
dc.relation.ispartofseriesVolume 8, issue 46en
dc.rightsopenAccessen
dc.titleCharacterization and electrochemical properties of iron-doped tetrahedral amorphous carbon (ta-C) thin filmsen
dc.typeA1 Alkuperäisartikkeli tieteellisessä aikakauslehdessäfi
dc.type.versionpublishedVersion
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