Corrosion of Copper in 0.1 M Hydrochloric Acid Solution with Benzotriazole as Corrosion Inhibitor

Abstract

Corrosion inhibition properties of benzotriazole were studied in 0.1 M hydrochloric acid solution for copper samples with different roughness levels using open-circuit potential, potentiodynamic polarization, electrochemical impedance, and weight loss measurements. According to the results, inhibition properties were improved because of an increase in surface roughness leading to an increase in inhibition efficiency (up to 99 and 91% for the rough and smooth surfaces, respectively). Adsorption of benzotriazole on copper surfaces follows Langmuir isotherm. Due to roughening, the adsorption free energy changed from ‒25.9 kJ mol–1 for the polished samples to –27.6 kJ mol–1 for the rough sample. Adsorption of the inhibitor on both surfaces was mainly physisorption. Adsorption entropy values for polished and shot-peened samples were 11.4 and 13 J mol–1 K–1, respectively. All data obtained from weight loss, Tafel polarization, and EIS tests were in good agreement. FTIR test, showed a peak between 740 and 745 cm–1 that is associated with C–H bonds. The intensity of peak was higher in the case of shot-peened samples.