The influence of low concentration of 2-(5-methyl-2-nitro-1H-imidazol-1-yl)ethyl benzoate on corrosion brass in 0.5 M H2SO4 solution

Abstract

The effect of 2-(5-methyl-2-nitro-1H-imidazol-1-yl)ethyl benzoate (IMDZ-B) at low concentration on brass corrosion in 0.5 M H2SO4 medium at 298 K, was inspected using current-potential measurement, electrochemical impedance technique, and surface analysis. These techniques indicated that this compound inhibits the corrosion of brass at low concentration, which its inhibition efficiency reaches 91.02% at 10−5 M. In addition, the current-potential curves indicate a large plateau of passivation, where its current density decreases from 1.25 mA cm−2 for a free solution to 0.05 mA cm−2 with the presence of 10−5 M of IMDZ-B. This finding was elucidated by the formation of a film where it becomes compact with the increase of inhibitor concentrations. The influence of the electrolyte temperature and the immersion time was also deliberate and demonstrated that IMDZ-B receipts its inhibition performance at great temperature and improves with immersion time. Indeed, it is obtained that IMDZ-B adsorption obeys the Langmuir isotherm and acts via chemical adsorption. Additionally, the surface morphology and chemical composition of brass were examined via SEM morphology coupled with EDAX analysis at different immersion times and indicated that IMDZ-B reacts by the formation of a protective film at the brass surface and confirms the electrochemical results. Finally, DFT calculations and Molecular dynamics simulations revealed that the IMDZ-B compound contain highly reactive centers distributed on imidazole group, and a strong interaction between their molecules and the brass surface.