SERS, XPS, AND ELECTROANALYTICAL STUDIES OF THE CHEMISORPTION OF BENZOTRIAZOLE ON A FRESHLY ETCHED SURFACE AND AN OXIDIZED SURFACE OF COPPER

Chemical reaction of benzotriazole on a freshly etched surface of metallic copper has been investigated by surface-enhanced Raman scattering (SERS), X-ray photoelectron spectroscopy (XPS), cyclic voltammetry, and other techniques. We found that the freshly etched copper surface could chemisorb benzotriazole (BTAH) from solution in 15 s forming a surface layer of Cu(0)BTAH. As the system was exposed to air, the surface species easily reacted with the coadsorbed oxygen in 2 min, resulting in a polymeric film of Cu+BTA-. The reaction of benzotriazole with the cleaned surface is faster than with the oxidized surface of copper. SERS study also indicates that the thin complex film formed on a freshly etched copper possesses better anticorrosion properties.