Some aspects of the role of inhibitors in the corrosion of copper in tap water as observed by cyclic voltammetry

Cyclic voltammetric examination of the corrosion and inhibition of copper in hard and soft tap-waters in the presence of a commercial inhibitor containing benzotriazole (BTA) and triethanolamine (TEA), or its separate components, is presented. The anodic and cathodic reactions are both strongly inhibited, although the anodic reaction more so. BTA is by far the dominant inhibiting component. The inhibitor forms a polymerized reactive adsorbed surface film. Inhibition of the cathodic reaction (oxygen reduction) is not due to electron resistivity of the inhibitor, but rather, by heavily reduced surface coverage of adsorbed oxygen over a wide range of oxygen reduction overpotential. (C) 2015 Elsevier Ltd. All rights reserved.