Investigation of copper corrosion inhibition with frequency-dependent alternating-current scanning electrochemical microscopy

Abstract

Alternating current scanning electrochemical microscopy (AC-SECM) is used to investigate the inhibition of copper corrosion by four potential inhibitors, namely benzotriazole (BTAH), 5-methyl-benzotriazole (MBTAH), 2-mercaptobenzimidazole (MBI), and ethyl xanthate (EX). It is shown that the formation of inhibitor films on the metal can be followed from the decrease of the substrate's local electrochemical activity associated with the formation of inhibitor-containing surface layers. Sensitive imaging can be performed that accounts for changes in electrochemical activity of the modified surfaces, as well as for their corrosive attack from the environment. AC-SECM is shown to be a powerful technique for the investigation of corrosion processes.