Electrochemistry of poly(vinylferrocene) formed by direct electrochemical reduction at a glassy carbon electrode

Abstract

A thin film of poly(vinylferrocene) (PVF) is prepared by direct electrochemical reduction of vinylferrocene in acetonitrile at a glassy carbon electrode using cyclic sweep voltammetry between +0.8 and -2.8 V (vs. Ag/AgCl). PVF films of varying surface coverages, up to a maximum of 2.2×10 ^-9 mol cm ^-2 of ferrocene, can be obtained by controlling the number of sweep cycles. These films are highly stable and electroactive, possessing electrochemical characteristics which are strongly affected by the nature of counter ions in aqueous media. The concentration of the ferrocenyl group at the polymer modified electrode is estimated as 5.9 mol dm ^-3 , assuming a dry density of 1.25 g cm ^-3 for the polymers. These easily prepared, highly stable, redox-active thin films effectively block the access of an osmium redox probe to the electrode surface.