The inhibition of copper corrosion in 3% NaCl solution was studied by using a benzotriazole (BTAH) and 1-hydroxybenzotriazole (BTAOH) inhibitors. Experiments showed that BTAH is a more effective inhibitor of the corrosion than BTAOH. Simulations reveal that the two inhibitors display very simiar molecular electronic properties. Superior inhibition effectiveness of BTAH was attributed to interplay of planar molecular structure, adsorption and intermolecular bonding, which cooperatively may result in formation of thin and protective film on the surface.
The formation of protective layers on copper, zinc and copper–zinc alloys at open circuit potential in aerated, near neutral NaCl solution containing benzotriazole was studied using electrochemical impedance and XPS spectroscopy. Benzotriazole (BTAH), generally known as an inhibitor of copper corrosion, also proved to be an efficient inhibitor for copper–zinc alloys and zinc metal. A tentative structural model describing the improved corrosion resistance of Cu, Cu–xZn alloys and Zn in BTAH containing chloride solution is proposed.