Theoretical and electrochemical analysis on inhibition effects of benzotriazole derivatives (un- and methyl) on copper surface

Abstract

The corrosion inhibition effects of benzotriazole (BTA) and its derivative-methylbenzotriazole (M-BTA) at molecular level were studied using quantum chemical method. The adsorption mechanism of inhibitors on copper surface was evaluated by Density Functional Theory (DFT) at BLYP/3.5DNP level and Monte Carlo simulation. The inhibition effects of BTA and M-BTA were investigated by chemical reactivity parameters. Both inhibitors have a considerable excess of negative charges around the nitrogen atoms N7 and N8, indicating that they are the coordination sites of the inhibitors. Under the circumstance of gaseous and aqueous phases molecules, the BTA adsorption and M-BTA adsorption on Cu (111) surface was further simulated by Monte Carlo simulations. In addition, the interaction energy between inhibitors and copper was calculated. The electrochemical measurement results confirm that the inhibition effect of 15mM M-BTA is greater than that of BTA, and the inhibition efficiency is up to 96.05%, which is helpful for further study of corrosion system.