Analysis of the temporal self-organizational phenomena observed during the electrodissolution of Zn in sulfuric acid solutions

This work aims to analyze the high-frequency current oscillations observed during the electrodissolution of zinc in sulfuric acid solutions. The current oscillations are emerged within a fixed potential region, Delta E-osc in the characteristic polarization curve, I = f(E) of the Zn vertical bar x M H2SO4 system at proper concentrations of the H2SO4. The Delta E-osc appears in the limiting current region under precipitation/dissolution conditions of the ZnSO4 center dot yH(2)O across the interface Zn vertical bar x M H2SO4, during the electrodissolution of Zn. The oscillation characteristics (frequency, amplitude, waveform, induction time needed for their emergence) are changing by varying certain parameters, such as the sulfuric acid concentration, the angular rotational speed of the Zn disc-electrode and a variable external resistance added to the solution resistance. The time series, I = f(t) are recorded under potentiostatic conditions within the Delta E-osc and, using techniques for the analysis of non-linear dynamical systems, are characterized as chaotic. We have proposed construction of recurrence plots and the recurrence quantification analysis as appropriate tools for characterizing current oscillations far from bifurcation points and unraveling dynamical transitions of the electrochemical system as the applied potential is varied. (C) 2018 Elsevier Ltd. All rights reserved.