Electrode modified with ionic liquid covalently bonded to silicate matrix for accumulation of electroactive anions

A thin silicate film containing imidazolium cationic groups surface was obtained by sol–gel processing of ionic liquid – 1-methyl-3-(3-trimethoxysilylpropyl)imidazolium bis(trifluoromethyl-sulfonyl)imide together with tetramethyl orthosilicate on the indium tin oxide electrode. The formation of silicate film was confirmed by FTIR spectroscopy. This electrode when immersed into aqueous solution act as a sponge for Fe(CN)63− dissolved in aqueous solution. The corresponding voltammetric peak current is by almost two orders of magnitude larger than for electrode covered by ionic liquid precursor only. The repelling of Ru(NH3)63+ cations by this electrode is also demonstrated.