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Ceramic Carbon Electrode Modified with Redox Probe and Salt Solution in Hydrophobic Polar Solvent

Shul G., Opallo M.

Polish Journal of Chemistry

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2004

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Vol. 78 / nr 9

1449-1456

EN

Ceramic carbon electrode modified with redox probe and salt solution in hydrophobic polar solvent was prepared and studied. The electrode consisting of graphite powder, homogeneously dispersed in hydrophobic silicate matrix, was prepared from the mixture of methyltrimethoxysilane based sol and graphite powder by sol-gel method. Then it was immersed in t-butylferrocene and tetrabutylammonium perchlorate solution in nitrobenzene. The electrode properties were investigated by cyclic voltammetry and chronoamperometry in KNO3 solutions of different concentration. Linear polarization of the electrode towards positive potentials results in peak shaped symmetric voltammogram originating from electrooxidation of t-butylferrocene. The peak current is few times larger than that obtained when organic phase does not contain salt. It is also proportional to the concentration of the redox probe in organic phase and salt in aqueous phase, whereas the midpeak potential is almost not affected by these factors. The reasons of these effects are discussed.

2

Silicate solvated by an organic solvent as electrolyte or electrode material

Opallo M.

Materials Science

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2003

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Vol. 21, No. 4

453-460

EN

Preparation and properties of silicate gels solvated by organic solvents as electrolytes or electrode materials were summarised. A silicate matrix based on tetraalkoxysilane, trialkoxysilane modified with organic groups or a mixture of these two, modified by organic solvents or solutions is the principal komponent of all the systems studied. The material used as the electrolyte is filled with a salt solution in an organic polar solvent or in the case of hybrid organic-inorganic silicate matrix it is functionalised with tetraalkylammonium groups with a pure solvent. The electrodes are made of a composite material consisting of graphite particles, silicate matrix functionalised with methyl groups and filled with a pure or diluted redox liquid.

3

Electrochemical redox reactions in solvated silica sol-gel glass

Opallo M.

Materials Science

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2002

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Vol. 20, No. 1

7-14

EN

The studies of the electrochemical redox reactions in solvated silica sol-gel glass were reviewed. The methodology of the experiments with emphasis on the direct preparation of the solid electrolyte and the application ultramicroelectrodes was described. Generally, the level of the electrochemical signal is not much below that observed in liquid electrolyte. The current depends on time elapsed after gelation, namely the longer time, the smaller current. The differences between electrochemical behaviour of the redox couples in monoliths and thin layers were described.