The surface chemistry of BTAOH and BTAH corrosion inhibitors adsorbed on copper from 3% NaCl aqueous solution was investigated. Surface and subsurface chemical structure, composition, and layer thickness were obtained from angle-resolved XPS measurements. In the BTAH-containing solution, the surface structure was composed of the Cu(I)BTA-complex layer, the Cu2O underlayer, and the Cu substrate. On the other hand, the BTAOH does not form analogous complex. Tougaard analysis reveals that after one hour of sample immersion, the BTAH forms three-times thicker protective layer compared to BTAOH.
The formation of protective layers on copper, zinc and copper-zinc alloys in aerated near neutral NaCl solution containing benzotriazole (BTA) was studied using potentiodynamic measurements, electrochemical impedance spectroscopy and XPS spectroscopy. The addition of benzotriazole affects the dissolution of the materials investigated. Benzotriazole, generally known as an inhibitor of copper corrosion, is also shown to be an efficient inhibitor for copper-zinc alloys and zinc metal. The surface layer formed on alloys in BTA-inhibited solution comprised both oxide and polymer components.