New insights into copper corrosion in presence of benzotriazole and chloride ions

Abstract

ABSTRACTThe effect of Cl– concentration and temperature on the copper corrosion in NaCl solution in presence of 40 mg L–1 benzotriazole was investigated using cyclic voltammetry, electrochemical impedance spectroscopy, electrochemical noise (EN) and scanning electron microscopy (SEM). Results revealed that the charge transfer resistance decreased with increasing the Cl– concentration and temperature. The EN generated at low Cl– concentration and low temperature had small noise amplitude, while the EN showed large potential oscillation amplitude in the case of high Cl– concentration and high temperature. A parameter, named corrosion active energy CAE, was proposed to further study the relationship between the EN feature and corrosion rate and corrosion severity (SEM). The variation trend of corrosion active energy CAE with Cl– concentration and temperature was found to be opposite with energy gap Eg and charge transfer resistance. Thus, CAE shows a promising potential to in situ evaluate the corrosion rate and corrosion severity.