Large-Amplitude Fourier Transformed High-Harmonic Alternating Current Cyclic Voltammetry:Kinetic Discrimination of Interfering Faradaic Processes at Glassy Carbon and at Boron-Doped Diamond Electrodes

摘要

Significant advantages of Fourier transformed large-amplitude ac higher (second to eighth) harmonics relative to responses obtained with conventional small-amplitude ac or dc cyclic voltammetric methods have been demonstrated with respect to (i) the suppression of capacitive background currents,(ii) the separation of the reversible reduction of [Ru(NH_3)_6]~(3+) from the overlapping irreversible oxygen reduction process under conditions where aerobic oxygen remains present in the electrochemical cell,and (iii) the kinetic resolution of the reversible [Ru(NH_3)_6]~(3+/2+) process in mixtures of [Fe(CN)_6]~(3-) and [Ru(NH_3)_6]~(3+) at appropriately treated boron-doped diamond electrodes,even when highly unfavorable [Fe(CN)_6]~(3-) to [Ru(NH_3)_6]~(3+) concentration ratios are employed.Theoretical support for the basis of kinetic discrimination in large-amplitude higher harmonic ac cyclic voltammetry is provided.