Ion transfer across liquid–liquid interface coupled to electrochemical redox reaction at carbon paste electrode

Abstract

Ion transfer processes across liquid|liquid phase boundary formed at electroactive carbon paste electrode immersed into an aqueous solution were studied by cyclic voltammetry and differential pulse voltammetry. The electrode material consists of graphite particles and redox probe (ferrocene, t-butylferrocene, or decamethylferrocene) solution in polar organic hydrophobic solvent o-nitrophenyloctylether as a binder. The anion transfer from the aqueous solution following electrooxidation of the redox probe or ejection of electrogenerated cation from the organic phase was detected by anion dependence of the redox potential of the redox probe dissolved in an organic phase. The contribution of both processes depends on the hydrophobicity of the redox probe and anion present in the aqueous phase.