Electrochemical behavior of tantalum in potassium hydroxide solutions

The electrochemical behavior of tantalum in various concentrations of KOH solutions (0.1 M - 10 M), was investigated using the evolution of the open circuit potential in time, cyclic voltammetry and ellipsometric measurements. Depending on KOH concentrations, the open circuit potential measurement...

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Bibliographic Details
Main Author: Irena Ljubomir Mickova
Format: Article
Language:English
Published: International Association of Physical Chemists (IAPC) 2018-08-01
Series:Journal of Electrochemical Science and Engineering
Subjects:
Online Access:http://pub.iapchem.org/ojs/index.php/JESE/article/view/584
Description
Summary:The electrochemical behavior of tantalum in various concentrations of KOH solutions (0.1 M - 10 M), was investigated using the evolution of the open circuit potential in time, cyclic voltammetry and ellipsometric measurements. Depending on KOH concentrations, the open circuit potential measurements have shown three distinct behaviors concerning oxide film formation on the electrode surface and its dissolution. The cyclic voltammetry measurements were performed in various potential ranges, from -1.4 to 8 V, different concentrations of KOH solutions (0.1-10 M) and sweep rates ranging from 0.005 V/s to 1 V/s. In the passive region, very stable passive films were formed, which reduction has not been possible during cathodic polarization even at highly concentrated KOH solutions. In the trans-passive region, the very strong peak at 1.65 V was monitored, which nature and chemical composition is still not well known.
ISSN:1847-9286