caa a22 4500 475814932 CHVBK 20180406123807.0 cr unu---uuuuu 170329e20000601xx s 000 0 eng 10.1023/A:1003893122201 doi (NATIONALLICENCE)springer-10.1023/A:1003893122201 Electrochemical behaviour of cobalt in aqueous solutions of different pH [Elektronische Daten] [W.A. Badawy, F.M. Al-Kharafi, J.R. Al-Ajmi] A systematic study of the corrosion and passivation behaviour of cobalt in aqueous solutions of different pH was carried out. Open circuit potential measurements, polarization experiments and electrochemical spectroscopic (EIS) investigations were employed. The experimental results show that the metal surface is always covered by a native passive film which consists of CoO. The formation of the oxide film obeys a two-electron charge transfer process. The dissolution of the barrier film is controlled by the pH of the solution. In neutral and basic solutions the barrier film is stable. In these media a barrier film thickening with the formation of secondary layer is considered. In acidic solutions, the passive film is unstable and dissolves via a pure chemical process. The mechanism of the corrosion and passivation processes taking place at the electrode/electrolyte interface in the different solutions is discussed. X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) were used to confirm the electrochemical measurements and the suggested mechanisms. Kluwer Academic Publishers, 2000 cobalt nationallicence corrosion nationallicence impedance nationallicence passivation nationallicence polarization nationallicence XPS nationallicence Badawy W.A. Department of Chemistry, Faculty of Science, University of Kuwait, PO Box 5969, 13060, Safat, Kuwait aut Al-Kharafi F.M. Department of Chemistry, Faculty of Science, University of Kuwait, PO Box 5969, 13060, Safat, Kuwait aut Al-Ajmi J.R. Department of Chemistry, Faculty of Science, University of Kuwait, PO Box 5969, 13060, Safat, Kuwait aut Journal of Applied Electrochemistry Kluwer Academic Publishers 30/6(2000-06-01), 693-704 0021-891X 30:6<693 2000 30 10800 https://doi.org/10.1023/A:1003893122201 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1023/A:1003893122201 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Badawy W.A. Department of Chemistry, Faculty of Science, University of Kuwait, PO Box 5969, 13060, Safat, Kuwait aut NATIONALLICENCE 700 1- Al-Kharafi F.M. Department of Chemistry, Faculty of Science, University of Kuwait, PO Box 5969, 13060, Safat, Kuwait aut NATIONALLICENCE 700 1- Al-Ajmi J.R. Department of Chemistry, Faculty of Science, University of Kuwait, PO Box 5969, 13060, Safat, Kuwait aut NATIONALLICENCE 773 0- Journal of Applied Electrochemistry Kluwer Academic Publishers 30/6(2000-06-01), 693-704 0021-891X 30:6<693 2000 30 10800 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer