2-Mercaptobenzoxazole as a copper corrosion inhibitor in chloride solution: Electrochemistry, 3D-profilometry, and XPS surface analysis

• Corrosion of Cu follows kinetic-controlled and diffusion-controlled processes.
• The diffusion coefficient through solid surface layer was reported.
• 2-Mercaptobenzimidazole is a mixed-type corrosion inhibitor.
• Cu(I) ions and 2-mercaptobenzoxazole form Cu(I)–MBOH complex on the Cu surface.
• The thickness of the 2-mercaptobenzoxazole surface layer is 1.4 ± 0.4 nm.

2-Mercaptobenzoxazole (MBOH) was studied as a corrosion inhibitor for Cu in 3 wt.% NaCl solution using EIS, a potentiodynamic curve, 3D-profilometry, and XPS measurements. It was shown that Cu corrosion in solution containing MBOH follows kinetic-controlled and diffusion-controlled processes and that MBOH is a mixed-type inhibitor. The diffusion coefficient of the Cu ions travelling through the solid surface layers was estimated to be on the order of 10−15–10−14 cm2 s−1. It was also demonstrated that the Cu(I)–MBOH complex is formed on the Cu surface and that the thickness of this surface layer is 1.4 ± 0.4 nm.