An electrochemical and Raman spectroscopic investigation of synergetic effects in the corrosion inhibition of copper

The synergetic inhibition of copper corrosion by benxotriazole (BTA) and bmzylamine (BZA) in chloride and cyanide media is assessed by voltammetric and ac impedance measurements. BZA enhancer the performance of the strong inhibitor BTA by accelerating the growth of a protective surface layer; used alone, BZA is ineIktive as an inhibitor. The competitive adsorption of aggressive anions and inhibitors is studied by surface enhanced Ratnan scattering (SERS). The dramatic increase in corrosion caused by low concentrations of cyanide ions is shown to he due to the displacement of BTA from the copper electrode surface; comparisons are made with the behaviour of mereaptobenzoxazole (MBO).