In-situ electrochemical atomic force microscopy studies of aqueous corrosion and inhibition of copper

The corrosion of copper surfaces immersed in various electrolytes under pot entiodynamic conditions at room temperature is studied by in-situ electroch emical atomic force microscopy (ECAFM). The ECAFM experimental settings use d to study corrosion are discussed, and the composition of the different co rrosion layers is identified by in-situ voltamperometric analysis. In sulfu ric acid and sodium sulfate solutions, an important species displacement co ntrolled via more or less complex dissolution - precipitation reactions is pointed out at the surface of the electrode. In addition, it is shown that this atomic movement irreversibly changes the relief of the metallic surfac e. Conversely, when the surface is passivated both in a berate solution and in a sodium heptanoate solution, the oxidation process at the metallic ele ctrode is weaker and reversible. Moreover, the inhibiting action of sodium heptanoate is confirmed: a copper metallic soap overlayer appears on the su rface via a dissolution-precipitation mechanism. (C) 2000 Elsevier Science S.A. All rights reserved.