Theoretical and electrochemical analysis on inhibition effect of benzotriazole and 1,2,4-triazole on cobalt surface

• Published in: Colloids and surfaces. A, Physicochemical and engineering aspects Vol. 591; p. 124516
• Main Authors: Yin, Da, Yang, Liu, Niu, Xinhuan, Ma, Yingzhuo, Liu, Mengrui, Sun, Xiaoqin, Gao, Baohong, Tan, Baimei
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 20-04-2020
• Subjects: Cobalt; Corrosion inhibition; DFT; Monte Carlo simulation; DFT; Corrosion inhibition; Cobalt; Monte Carlo simulation
• ISSN: 0927-7757; 1873-4359
• DOI: 10.1016/j.colsurfa.2020.124516

The adsorption models of BTA and TAZ on Co (111) surface in aqueous phase were established by Mont Carlo simulation. Nyquist plots of cobalt inhibitors with different concentrations were simulated by EIS measurements.
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•Quantum chemical parameters of BTA and TAZ were evaluated by DFT theory.•N atoms of BTA and TAZ are the coordination sites of the inhibitors.•Adsorption energy of BTA and TAZ in gaseous and aqueous phases on Co(111) surface was calculated by Mont Carlo simulation.•Inhibition efficiency of BTA and TAZ was calculated by electrochemical experiments.
In this study, the corrosion inhibition effects of benzotriazole (BTA) and 1,2,4-triazole (TAZ) at molecular level were evaluated by quantum chemical method. Density Functional Theory (DFT) at BLYP/3.5DNP level and Monte Carlo simulation were performed to analyze the adsorption mechanism of inhibitors on cobalt surface. The electronic parameters of BTA and TAZ were calculated, and their inhibitory effects were investigated by chemical reactivity parameters, respectively. The reactive centers were analyzed based on Fukui functions, indicating that the N atoms are the coordination sites of the inhibitors. Besides, atom densities of different crystal orientations of cobalt were calculated, and the densest Co (111) surface was selected by Monte Carlo simulations for calculation. Under the circumstance of gaseous and aqueous phases, the adsorption models of BTA and TAZ were established. Also, the interaction energy between inhibitors and cobalt was calculated. The results of potentiodynamic polarization curve and electrochemical impedance spectroscopy (EIS) are consistent with the theoretical calculations. The inhibitory effect of BTA on cobalt surface is greater than that of TAZ. This information helps to gain further insight about corrosion system.