Effect of Benzotriazole on Dissolution of Copper in the Presence of Fluid Flow: I. Experimental

The influence of benzotriazole anodic behavior of copper in IN H₂SO₄ was investigated experimentally under conditions of high rate dissolution and in the presence of fluid flow. Results, which include both electrochemical measurements and visual observations, suggest that during dissolution a dual layer forms on the surface. An inner barrier layer, which imparts to benzotriazole its useful property of inhibition, was found to conduct by a high field mechanism. The thickness of the inner layer varied linearly with applied potential, indicating that the field strength in the film remained constant. An outer layer, which consists of a porous film of copper benzotriazolate, was found to respond to hydrodynamic conditions. The outer film is responsible for deviations in mass-transfer rate from the Levich equation during dissolution experiments with a rotating disk electrode.