Applying the deconvolution approach in order to enhance RRDE time resolution: Experimental noise and imposed limitations

Abstract

The ring electrode of an RRDE setup is commonly used to detect redox active species produced at the disk electrode. It is especially useful when some side processes occur at the disk (e.g. passivation film growth) along with a main electrochemical reaction of interest, which produces a soluble redox-active specie. Unfortunately, the detected ring current signal is a delayed and smeared-out representation of the disk faradaic process so that fast changes of its magnitude cannot be studied. The deconvolution approach is a mathematical data processing procedure that enables reconstruction of the disk signal with a hypothetically infinite accuracy. There are, however, practical limitations arising mainly from inevitable presence of noise in the measured ring current used for the reconstruction. In this paper the deconvolution approach is discussed in details and its applicability is investigated basing on a series of experiments with a model system. A procedure to filter out spurious artifacts from the reconstructed disk signal is proposed and tested.