Electroactive ceramic carbon electrode modified with ionic liquid

The electrode based on silicate carbon composite material was modified with redox probe (t-butylferrocene) solution in ionic liquid (1-butyl-3-methylimidazolium hexafluorophosphate or 1-decyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide). After immersion into an aqueous solution it was studied by cyclic voltammetry. It exhibits electrochemical signal connected with electrode reaction of the redox probe dissolved in ionic liquid. The heterogeneous structure of electrode material enhances substantially efficiency of the electrode process in comparison to the drop deposited on flat electrode surface. The midpeak potential depends on the hydrophobicity of the anion present in the aqueous solution indicating significant contribution of anion injection into the ionic liquid following the electron transfer. The efficiency of the electrode process is much larger than that of similar electrode modified with the redox probe solution in less viscous organic polar solvent. (C) 2005 Elsevier B.V. All rights reserved.