Synergistic inhibition of azoles compounds on chloride-induced atmospheric corrosion of copper: Experimental and theoretical characterization

Synergistic implementation of corrosion inhibitors is an efficient and economic method for metal protection. The adsorption dynamics and inhibition behavior of 2-phenyl imidazoline (2-PI) and benzotriazole (BTA) are investigated in atmospheric and aqueous environments by electrochemical and quartz crystal microbalance sensors. Moreover, their synergistic mechanisms are illustrated from molecule scales by theoretical calculations. Electrochemical tests show that 2-PI and BTA exhibit promising synergistic effects on the corrosion of copper with inhibition efficiency up to 99.1% in 0.1 mol/L NaCl solution and 94.1% in the atmosphere, respectively. In addition, the adsorption kinetics of inhibitors on copper obey a pseudo-first-order kinetic model characteristic of exponential damping. Quantum chemical and molecule dynamic calculations also suggest that there exists an intermolecular interaction between 2-PI and BTA molecules in a parallel adsorption manner when they are co-adsorbed on the surface of copper.