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Photomicroscopic measurement of the diffusion layer around mercury drop electrodes: Part II, choice of the optimal conditions
Author(s) -
Tercier M.L,
Buffle J.
Publication year - 1990
Publication title -
electroanalysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.574
H-Index - 128
eISSN - 1521-4109
pISSN - 1040-0397
DOI - 10.1002/elan.1140020204
Subject(s) - electrode , drop (telecommunication) , diffusion layer , mercury (programming language) , anode , analytical chemistry (journal) , materials science , electrochemistry , diffusion , capillary action , anodic stripping voltammetry , dropping mercury electrode , chemistry , mechanics , thermodynamics , chromatography , composite material , electrical engineering , computer science , physics , programming language , engineering
The special electrochemical system described in Part I was employed to determine the optimum conditions for the deposition step of anodic stripping voltammetric techniques with a sessile Hg drop electrode. Much care was taken to obtain a reproducible reduction flux that is predictable on sound theoretical grounds and, in particular, to minimize the screening effects of the capillary. This article illustrates how this can be achieved by coupling optical microscopy, photography, and video recording with computer‐controlled voltammetry. This set up allows to simultaneously observe the dynamic movement of the water flux around a Hg drop electrode, observe and determine the diffusion layer thickness during the reduction, and record the chronopotentiometric current‐time curves as a function of the stirring rate and geometric conditions of the cell. The best conditions for obtaining a reproducible reduction flux at the electrode are given for a sessile Hg drop. The system described here, however, can be applied for the determination of diffusion and hydrodynamic conditions around electrodes having other configurations.