Evaluation of the Corrosion Inhibition Performance of Benzotriazole for Copper

Abstract

Benzotriazole (BTA) is widely used as a corrosion inhibitor for Cu and its alloys. Although BTA exhibits excellent anti–corrosion properties even at low concentrations, its corrosion inhibition mechanism has not yet been fully understood. Furthermore, its effectiveness depends on the solution environment and treatment conditions, and studies on the corrosion behavior of Cu after BTA treatment remain insufficient. In this study, the corrosion behaviors of Cu in BTA–containing solutions and after BTA treatment were evaluated using electrochemical measurements. Additionally, the structure of the protective layer formed by BTA treatment was analyzed using time–of–flight secondary ion mass spectrometry (TOF–SIMS) to investigate the corrosion inhibition mechanism of the Cu–BTA film. Polarization and electrochemical impedance spectroscopy (EIS) measurements revealed that the formation of the Cu–BTA film significantly suppressed Cu dissolution and the oxygen reduction reaction in BTA–containing solutions, with particularly high inhibition efficiency observed at pH 8 and pH 11. Furthermore, TOF–SIMS analysis confirmed that a Cu–BTA film formed on the Cu oxide layer after BTA treatment, contributing to corrosion inhibition. A comparison of the effects of BTA concentration, treatment time, temperature, and pH demonstrated that BTA provides sufficient anti–corrosion performance at concentrations of 10 ppm or higher, and effective corrosion inhibition can be achieved even with short treatment times. These findings provide fundamental insights for optimizing Cu corrosion protection technologies using BTA.