The copper electrodissolution and passivation processes in carbonate (CO32−)-bicarbonate (HCO3−) solutions at different ionic strength and hydrodynamic conditions have been studied by electrochemical impedance spectroscopy (EIS). Impedance diagrams suggest the formation of a first porous cuprous oxide (Cu2O) layer. Through this film, there is a diffusional process of Cu(II) soluble species which, together with the electrooxidation of Cu(I) to Cu(II), leads to the formation of a thicker and complex passive film. Capacitance values obtained by the application of a transfer function analysis using nonlinear fitting routines reflect the different stages during the film transformation into a stable passive one. This passive film exhibits a p-type semiconductor behavior.

This content is only available as a PDF.
NACE International
2002
You do not currently have access to this content.