caa a22 4500 47705191X CHVBK 20180405111341.0 cr unu---uuuuu 170330e19961101xx s 000 0 eng 10.1007/BF00243743 doi (NATIONALLICENCE)springer-10.1007/BF00243743 Influence of thiourea and thiourea ageing on the electrodeposition of copper from acid sulfate solutions studied by the ring-disc technique [Elektronische Daten] [G. Fabricius, K. Kontturi, G. Sundholm] The influence of the additive thiourea in freshly made and aged solutions on copper deposition from acid sulfate solutions was studied using a Pt/Pt rotating ring-disc electrode. In fresh thiourea solutions copper deposition is retarded, but the most distinct effect of thiourea is seen during dissolution of the deposits. The intermediate in copper dissolution, Cu+, is partly complexed with adsorbed thiourea. Thus Cu+ is adsorbed at the electrode surface and the current peak at the ring due to dissolving Cu+ becomes very small. The small peak indicates that active additive is present in the deposit. Thiourea containing solutions aged for only a few days have a distinct effect on the electrode reactions. At low concentrations of thiourea (1 mg dm−3 ) a correlation between ageing and growth of the Cu+ peak at the ring is clearly seen. At high thiourea concentrations (100 mg dm−3) a small growth of the Cu+ peak is seen during the first few days but upon further ageing of the thiourea solution copper deposition becomes strongly inhibited. The ring current can be used as a qualitative diagnostic criterion for the concentration and state of thiourea in copper sulfate solutions. Chapman & Hall, 1996 Fabricius G. Laboratory of Physical Chemistry and Electrochemistry, Helsinki University of Technology, Kemistintie 1A, FIN-02150, Espoo, Finland aut Kontturi K. Laboratory of Physical Chemistry and Electrochemistry, Helsinki University of Technology, Kemistintie 1A, FIN-02150, Espoo, Finland aut Sundholm G. Laboratory of Physical Chemistry and Electrochemistry, Helsinki University of Technology, Kemistintie 1A, FIN-02150, Espoo, Finland aut Journal of Applied Electrochemistry Kluwer Academic Publishers 26/11(1996-11-01), 1179-1183 0021-891X 26:11<1179 1996 26 10800 https://doi.org/10.1007/BF00243743 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00243743 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Fabricius G. Laboratory of Physical Chemistry and Electrochemistry, Helsinki University of Technology, Kemistintie 1A, FIN-02150, Espoo, Finland aut NATIONALLICENCE 700 1- Kontturi K. Laboratory of Physical Chemistry and Electrochemistry, Helsinki University of Technology, Kemistintie 1A, FIN-02150, Espoo, Finland aut NATIONALLICENCE 700 1- Sundholm G. Laboratory of Physical Chemistry and Electrochemistry, Helsinki University of Technology, Kemistintie 1A, FIN-02150, Espoo, Finland aut NATIONALLICENCE 773 0- Journal of Applied Electrochemistry Kluwer Academic Publishers 26/11(1996-11-01), 1179-1183 0021-891X 26:11<1179 1996 26 10800 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer