ELECTROCHEMICAL DEPOSITION OF BITE FILMS FROM CHOLINE CHLORIDE – MALONIC ACID MIXTURE AS IONIC LIQUID

摘要

A study of bismuth telluride electrodeposition on platinum and copper electrodes in a ionic liquid based on choline chloride and malonic acid mixture (1:1 moles) bath containing 1-50 mM BiCl3 and 10-50 mM TeO2 at 50-850C is reported. The mechanism of Bi, Te and BiTe electrodeposition on Pt electrode was comparatively investigated by cyclic voltammetry. From cyclic voltammograms carried out in order to characterize the cathodic process it was found that singular tellurium deposition is performed at more positive potentials than bismuth deposition. The deposition of BiTe from ionic liquid occurs on a Te-covered Pt. Also, Nyquist and Bode impedance spectra showed differences in Pt behavior due to its polarization at various cathodic potentials. The bismuth telluride films were deposited on copper plates by electrolysis under potentiostatic conditions. The morphology of these BiTe films was determined by AFM, SEM and TEM microscopy.