Nanoobjects embedded in silicate films for biphasic electrodes
|Joanna Niedziolka-Jonsson 1, Maria A. Murphy , Frank Marken , Marcin Opallo 1|
1. Polish Academy of Sciences, Institute of Physical Chemistry, Kasprzaka 44/52, Warszawa 01-224, Poland
Liquid | liquid ion transfer processes can be observed at electrodes with an immobilised liquid phase [1-3]. Therefore the development of suitable electrode support is highly desirable [4,5]. Two novel types of electrode surface modification based on conducting ITO nanoparticles or carbon nanofibres embedded in a hydrophobic silicate film are presented. The first method employs layer-by-layer deposition of the ITO nanoparticles onto an ITO support. This procedure is followed by sol-gel deposition of a hydrophobic methyltrimethoxysilane (MTMOS) film. The second method involves deposition of a film of a carbon nanofibres (CNF) - silica nanoparticles suspension in a MTMOS sol. AFM and FEGSEM images demonstrate the presence of porous ITO nanoparticles or CNF films. The porous surfaces gives a unique and highly conducting matrix for redox liquid immobilisation. After modification of these electrodes with t-butylferrocene or cobalt (II) tetraphenylporphyrin in phenylpropylpyridine, their electrochemical behavior in the presence of aqueous electrolyte media was examined. The current for the conversion of redox active compounds is increased by two orders of magnitude in comparison to electrodes based only on hydrophobic silicates. Therefore a high efficiency of the liquid | liquid ion-transfer electrode process is possible.
 C. E. Banks, T. J. Davies, R. G. Evans, G. Hignett, A. J. Wain, N. S. Lawrence, J. D. Wadhawan, F. Marken, R. G. Compton, Phys. Chem. Chem. Phys., 5 (2003) 4053.
Presentation: Short communication at SMCBS'2005 Workshop, by Joanna Niedziolka-Jonsson
See On-line Journal of SMCBS'2005 Workshop
Submitted: 2005-07-08 11:18 Revised: 2009-06-07 00:44