Impedance studies of copper electro-reduction on a disc-shaped ultramicroelectrode in industrial electrolytes

Abstract

The electrodeposition of copper from industrial sulphate electrolytes has been studied using electrochemical impedance spectroscopy on the gold disc ultramicroelectrode. The influence of dc potential E dc , temperature, cupric ions and animal glue concentration on electrochemical impedances has been investigated. The mechanism of the copper electro-reduction process in industrial electrolytes has been proposed and experimental impedance data have been analyzed by proper equivalent circuits. According to our knowledge the faradaic and non-faradaic impedance parameters of the process on ultramicroelectrode's have been estimated for the first time in complex matrix copper industrial electrolytes. The role of animal glue in copper industrial electrolytes has been discussed in the present paper.

An operando ORP-EIS study of the copper reduction reaction supported by thiourea and chlorides as electrorefining additives

“…Their model observes the complete electrochemical reduction as one time constant in the data, other time constants arise from adsorption/desorption phenomena and the presence of additives [22,23,25]. Gladysz et al investigated electrorefining electrolyte, likewise without TU, to study the effect of animal glue and temperature on the copper deposition process [26]. Gladysz predicates his analysis on Reid's fundamental research [27].…”

Laboratory and Pilot Scale Tests of a New Potential-Controlled Method of Copper Industrial Electrolysis

“…This was subject of a large number of publications and presentations at the conferences. [1][2][3][4][5][6][7][8][9][10][11][12][13][14] Potential-controlled copper electrorefining and electrowinning processes have been studied subsequently by the same research group. Current publication is the first in a series where the results of pilot scale copper potential-controlled electrolysis investigations are discussed.…”

“…18 The above limitation of the current density of current-controlled copper electrodeposition process is removed when the process is carried out under potential controlled regime. As it was shown in our previous studies [2][3][4][5][6][7][8][9][10][11][12][13][14] high quality and purity of copper deposits are obtained using potential-controlled electrolysis even at the potentials where limiting current density is achieved. In the current study a very rare results obtained in the industrial electrolytes are presented at the very high negative potentials which in turn leads to the very high cathode current densities of copper electroreduction.…”