Anodic Dissolution Mechanism of Copper in Weak Alkaline Carbonate Solutions Using Channel Flow Multi-Electrode

摘要

The anodic dissolution mechanism of copper in weak alkaline carbonate solution containing chloride ion was investigated using channel flow multi-electrode. Anodic polarization curves of copper indicated three Tafel regions. The region I has a slope of 60 mV/decade in the potential range from -0.3 to -0.1 V and the current in this region depended on pH (partial deriv log i/partial deriv pH = 1). The region II has a slope of 60-120 mV/decade in the potential range from -0.1 to -0.1 V and the current in this region depended on concentration of chloride ion (partial deriv log i/partial deriv log (Cl~-) = 1). Active dissolution mechanism of copper in weak alkaline carbonate solution containing chloride ion was proposed on the basis of these results. The chronopotentiograms indicated that film formation of Cu(I) in region I and Cu(II) in region II occurred during dissolution of Cu~+ and Cu~(2+) at steady state.