An electrochemical, long-term immersion, and XPS study of 2-mercaptobenzothiazole as a copper corrosion inhibitor in chloride solution

• The corrosion process of inhibited Cu is under kinetic and diffusion control.
• 2-Mercaptobenzothiazole is a mixed-type corrosion inhibitor.
• 2-Mercaptobenzothiazole significantly reduces surface roughness.
• General and no localized corrosion occurs in the inhibited solution.
• The thickness of the 2-mercaptobenzothiazole surface layer is 1.5 ± 0.5 nm.

Using EIS, potentiodynamic curve, 3D-profilometry, and XPS measurements, 2-mercaptobenzothiazole (MBTH) was studied as a corrosion inhibitor for Cu in 3 wt.% NaCl solution. Electrochemical measurements showed that Cu corrosion in MBTH-inhibited solution follows kinetic-controlled and diffusion-controlled processes, that MBTH acts as a mixed-type inhibitor after 100 h of immersion and that it significantly reduces surface roughness after half a year of immersion compared with non-inhibited solution. It is also shown that the N atom and exocyclic S atom of the MBTH are involved in the molecule adsorption. The MBTH surface layer thickness was estimated to be 1.5 ± 0.5 nm.