Original scientific paper

https://doi.org/10.5599/jese.584

Electrochemical behavior of tantalum in potassium hydroxide solutions

Irena Mickova ; Faculty of Technology and Metallurgy, University “Ss. Cyril and Methodius” Rudjer Boskovic 16, 1000 Skopje, Republic of Macedonia

Abstract

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.

Keywords

Ta; KOH; open circuit potentials; cyclic voltammetry; ellipsometry

Hrčak ID:

204434

URI

https://hrcak.srce.hr/204434

Publication date:

16.8.2018.

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