Ceramic carbon electrode modified with butyloferrocene

Abstract

Ceramic carbon electrode modified with butyloferrocene was prepared and studied. The electrode consists of graphite powder, homogeneously dispersed in hydrophobic silica matrix. The latter was obtained from organically modified silicate - methyltrimethoxysilane by sol-gel process. After gelation and drying it was filled with redox liquid - butyloferrocene by immersion. The properties of the electrode were investigated by cyclic voltammetry and chronoamperometry in aqueous salt solution of different concentration. The cyclic polarization of the electrode in aqueous electrolyte results in peak shaped voltammogram, stable during continuous potential cycling. The modification of the electrode with butyloferrocene diluted by hydrophobic non-electroactive solvent like hexadecane leads to a decrease of the current. The specific voltammogram features were attributed to the redox process of butyloferrocene. The magnitude of the current is proportional to the aqueous electrolyte concentration. It has been concluded that the electrooxidation of redox liquid within hydrophobic silicate matrix is followed by anion transfer from aqueous phase. The electrode process occurs at the three phase junction formed by graphite particles and liquid organic-aqueous interface supported by hydrophobic silicate.