中國(guó)有色金屬學(xué)報(bào)(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 21 No. 1 January 2011 |
anhydrous ethanol containing hydrogen sulfate ions
（1. School of Metallurgical Science and Engineering, Central South University, Changsha 410083, China;
2. School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China）
Abstract:The electrochemical behaviors of Ta in tetrabutylammonium hydrogen sulfate (TBAHS) ethanol solutions were studied using potentiodynamic polarization, cyclic voltammetry, potentiostatic current time transient and impedance techniques. The results revealed that no active-passive transition is presented in the cyclic voltammogram, and the anodic current density increases with the increase of solution temperature, TBAHS concentration, potential scan rate and water content. The apparent activation energy is about 43.389 kJ/mol and the dissolution process is diffusion-controlled. Potentiostatic measurements showed that the current density gradually decays to a steady value when the potential is low; however, when the potential is higher than a certain value, the current density initially declines to a minimum value and then increases gradually. The resistance of passive film decreases with increasing potential, and inductive loops are presented when the potential is higher than 2.0 V.
Key words: anhydrous ethanol; electrochemical impedance spectra; polarization curve; tantalum; tetrabutylammonium hydrogen sulfate
