Scanning microelectrochemical characterization of the anti-corrosion performance of inhibitor films formed by 2-mercaptobenzimidazole on copper

Abstract

The aim of this work is to explore the applicability of the scanning electrochemical microscope (SECM) to characterize the inhibiting effect of 2-mercaptobenzimidazole against the corrosion of copper. SECM was operated in the feedback mode by using ferrocene-methanol as redox mediator, and the sample was left unbiased at all times. The kinetic changes in the corrosion processes were monitored over time from the Z-approach curves. Furthermore, inhibitor-modified copper samples presenting various surface finishes were imaged by SECM and the scanning vibrating electrode technique (SVET), allowing changes both in the surface activity of metal-inhibitor films and in the extent of corrosion attack to be spatially-resolved. Differences in the local electrochemical activity between inhibitor-free and inhibitor-covered areas of the sample were successfully monitored