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Suche nach „[C.] [Dosche]“ hat 3 Publikationen gefunden
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    MobilNachhaltigTC Plattling MoMo

    Zeitschriftenartikel

    H. Bülter, Michael Sternad, Santos Sardinha, Eduardo dos, J. Witt, C. Dosche, M. Wilkening, G. Wittstock

    Investigation of the Electron Transfer at Si Electrodes: Impact and Removal of the Native SiO 2 Layer

    Journal of The Electrochemical Society, vol. 163, no. 3

    DOI: 10.1149/2.0731603jes

    Abstract anzeigen

    Silicon is considered as one of the promising alternatives to graphite as negative electrode material in lithium-ion batteries. The electron transfer at uncharged microstructured and planar Si was characterized using the feedback mode of scanning electrochemical microscopy (SECM) and 2,5-di-tert-butyl-1,4-dimethoxybenzene as redox mediator. Approach curves and images demonstrate that the electron transfer rate constants at pristine Si are relatively small due to the native SiO2 surface layer. In addition, the electron transfer rate constants show local variations because of the heterogeneous coverage of SiO2. The SiO2 layer is at least partially removed by mechanical contact and abrasion with the microelectrode probe. After SiO2 removal by the microelectrode or by a hydrofluoric acid dip, the electron transfer rate constants increase strongly and remain heterogeneous. Moreover, the surface of the Si electrodes is at least stable over hours after SiO2 removal. The consequences for investigating the formation of the solid electrolyte interphase (SEI) on Si are discussed.

    NachhaltigEuropan Campus Rottal-Inn

    Vortrag

    G. Wittstock, G. Denuault, Stefan Mátéfi-Tempfli, H. Bülter, M. Mátéfi-Tempfli, A. Lesch, I. Schmidt, C. Dosche, M. Ahlf, K. Al-Shamery, A. Fanget, L. Forró

    Oxygen evolution at vertically aligned core-shell iron-iron oxide nanowire arrays

    24th ECS Meeting: Photoelectrochemistry and Photoassisted Electrocatalysis, San Francisco, CA, USA

    NachhaltigEuropan Campus Rottal-Inn

    Zeitschriftenartikel

    H. Bülter, G. Denuault, Stefan Mátéfi-Tempfli, M. Mátéfi-Tempfli, C. Dosche, G. Wittstock

    Electrochemical analysis of nanostructured iron oxides using cyclic voltammetry and scanning electrochemical microscopy

    Electrochimica Acta, vol. 222, pp. 1326-1334

    Abstract anzeigen

    Iron oxides in general and especially hematite, α-Fe2O3, have become promising materials for the alkaline water electrolysis and photoelectrochemical water splitting, respectively. In the present study electrocatalytic electrodes with a thin film of α-Fe2O3 and with vertically aligned α-Fe2O3 nanowires were prepared. Cyclic voltammograms of the α-Fe2O3 nanowires revealed differences including a series of three unreported cathodic signals when compared to previously published voltammograms for polycrystalline iron oxides. The generation-collection mode of scanning electrochemical microscopy (SECM) using nanostructured Pt microdisc probes was exploited to detect soluble reaction products formed at the voltammetric peaks of the α-Fe2O3 electrode. SECM tip-substrate voltammetry unexpectedly showed that the reduction of FeVI to FeIII on the cathodic sweep is accompanied by significant O2 evolution.