Electrodeposition of Polyaniline on Tantalum: Redox Behavior, Morphology and Capacitive Properties.

Polyaniline (PANI) is among the most widely studied conducting polymers due to its potential technological applications in various fields. Recently, PANI-based hybrid materials have played an important role in the development of energy storage and conversion systems. The aim of the present work is the investigation of the simultaneous electrochemical growth of PANI and TaO on the Ta substrate and the characterization of the morphology, redox behavior and pseudocapacitive properties of the resulting micro- or nanostructured composite thin films.

Temporal patterning of the potential induced by localized corrosion of iron passivity in acid media. Growth and breakdown of the oxide film described in terms of a point defect model.

This work analyses the nature of temporal patterning of the anodic potential induced by chlorides during polarization of iron under current-controlled conditions in acid solutions. It is shown that potential oscillations emerged as a result of the local chloride attack of a thin oxide layer, which covers the iron surface in its passive state. The mechanism by which both the local oxide breakdown and the subsequent localized active dissolution (pitting) occur is explained by considering a point defect model (PDM) developed to describe the oxide growth and breakdown.

Dynamical response of the sinusoidally perturbed electrodissolution/passivation of iron in sulfuric acid solutions: Entrainment, spike generation, and quasiperiodicity.

The iron/sulfuric acid (Fe/2 M H(2)SO(4)) system exhibits periodic current oscillations of relaxation type within the potential transition region formed between the active and passive states of the iron electrode when it is polarized in the 2 M sulfuric acid solution. In the present work the dynamical response of the Fe/2 M H(2)SO(4) electrochemical oscillator is investigated when the applied potential at the iron electrode is sinusoidally perturbed. The behavior of the periodically perturbed Fe/2 M H(2)SO(4) oscillator differs significantly from the response of other forced oscillators, as the potential amplitude E(p) and the frequency ratio omega(p)/omega(0) vary.