title: Assembly of crosslinked oxo-cyanoruthenate and zirconium oxide bilayers: Application in electrocatalytic films based on organically modified silica with templated pores.
abstract: Electrochemical deposition of crosslinked oxo-cyanoruthenate, Ru-O/CN-O, from a mixture of RuCl3and K4Ru(CN)6is known to yield a film on glassy carbon that promotes oxidations by a combination of electron and oxygen transfer. Layer-by-layer (LbL) deposition of this species and of a film formed by cycling of the electrode potential in a ZrO2solution systematically increases the number of catalytically active sites of the Ru-O/CN-O on the electrode. The evaluation of the electrocatalytic activity was by cyclic voltammetric oxidation of cysteine at pH 2. Plots of the anodic peak current vs. the square root of scan rate were indicative of linear diffusion control of this oxidation, even in the absence of ZrO2, but the slopes of these linear plots increased with bilayer number,n, of (ZrO2| Ru-O/CN-O)n. The latter observation is hypothesized to be due to an increased number of active sites for a given geometric electrode area, but proof required further study. To optimize utilization of the catalyst and to provide a size-exclusion characteristic to the electrode, the study was extended to LbL deposition of the composite in 50-nm pores of an organically modified silica film deposited by electrochemically assisted sol-gel processing using surface-bound poly(styrene sulfonate) nanospheres as a templating agent.
authors.affiliation: Department of Chemistry and Center for Biological Chemical Sciences, University of Warsaw, Pasteura 1, PL-02-093 Warsaw, Poland.
authors.forename: Iwona A
authors.initials: IA
authors.lastname: Rutkowska
authors.affiliation: Department of Chemistry and Center for Biological Chemical Sciences, University of Warsaw, Pasteura 1, PL-02-093 Warsaw, Poland.
authors.forename: Jakub P
authors.initials: JP
authors.lastname: Sek
authors.affiliation: Department of Chemistry and Biochemistry, Miami University, Oxford, OH 45056, USA.
authors.forename: B Layla
authors.initials: BL
authors.lastname: Mehdi
authors.affiliation: Department of Chemistry and Center for Biological Chemical Sciences, University of Warsaw, Pasteura 1, PL-02-093 Warsaw, Poland.
authors.forename: Pawel J
authors.initials: PJ
authors.lastname: Kulesza
authors.affiliation: Department of Chemistry and Biochemistry, Miami University, Oxford, OH 45056, USA.
authors.forename: James A
authors.initials: JA
authors.lastname: Cox
keywords: Cysteine oxidation; Electrocatalysis; Layer-by-layer assembly; Sol-gel processing