Electrochemical investigation of the synergistic effect between Cichorium intybus leaves extract and zinc acetate on the corrosion inhibition of carbon steel in 3.5% NaCl solution

Cichorium intybus leaves extract (CIE) was used as a green corrosion inhibitor for corrosion control of carbon steel in 3.5% NaCl solution. Then the synergistic effect between Zn acetate and CIE was studied by electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization techniques. The corrosion rates and the inhibition efficiencies were calculated from the electrochemical measurements. The results obtained show that the extract solution of the plant could serve as an effective inhibitor for the corrosion inhibition of steel in 3.5% NaCl solution. It was observed from the EIS measurements that the increase of inhibitor concentration resulted in the increase of charge transfer resistance. The highest inhibition efficiency was obtained using 200 ppm Zn acetate and 200 ppm CIE together indicating the synergistic effect. Polarization study revealed that CIE and Zn acetate behaved as mixed type inhibitor with dominant effect on the anodic reactions