Effect of 2-Mercaptobenzimidazole Concentration on Electrochemical Behavior of Brass (Cu–40Zn) Surface in Acid Medium

Abstract

Electrochemical behavior of brass electrode (Cu-40Zn) in oxalic acid solution was studied in the absence and presence of organic inhibitor 2-Mercaptobenzimidazole (2-MBI) with different concentrations at ambient temperature using voltammetry, general corrosion (Rp) and electrochemical impedance spectroscopy (EIS). The results showed that the electrochemical behavior of brass surface is similar to the copper one in the same conditions and revealed also the absence of the complexity phenomenon between the brass and the oxalate. Evolution of abandonment potential presents two different behaviors of electrode surface according to the concentration of organic inhibitor (2-MBI). Polarization curves showed that the addition of organic inhibitor (2-MBI) decreases the current density and shifts the anodic and cathodic branches towards more positive and more negative potentials. The plot of C/θ against the inhibitor concentration (C) shows that (2-MBI) strongly physisorbed on the brass electrode according to Langmuir isotherm. Measurements of polarization resistance and impedances show that the optimal concentration of the inhibitor is (0.5 mM) which gives a protection rate exceeds 89%.

Adsorption and Corrosion Inhibition Properties of Butanolic Extract of Elaeoselinum thapsioides and Its Synergistic Effect with Reutera lutea (Desf.) Maires (Apiaceae) on A283 carbon Steel in Hydrochloric Acid Solution

“…Simulation of EIS data and fitting curves were carried out using EC-Lab software. Inhibition efficiency ( IE R % ) was calculated using following formula [26,33]:…”