LAUSR

Abstract Performance of orange peel extracts (OPE) to retard the magnesium alloys corrosion is thoroughly evaluated by Electrochemical impedance spectra (EIS) and potentiodynamic polarization curves. OPE would be an effective inhibitor with the efficiency of 85.7% at very low concentration of 0.030 g L −1. The inhibition effect of selected three pure components including in OPE is much inferior or comparable with that of OPE, whereas the cost of pure compounds is too expensive to be afforded. The protective self-assembly film would be formed on the magnesium surface by immersion in OPE. Structure characterization is performed by scanning electron microscopy (SEM), atomic force microscopy (AFM), and X-ray diffractometer (XRD). The adsorption of OPE on magnesium surface follows the Langmuir adsorption rule with both chemical and physical interactions. The interaction between three selected pure compounds and magnesium alloys is further calculated by density functional theory (DFT). Moreover, the possible inhibition mechanism is constructed on the basis of above results along with the FTIR measurements. The low cost and green inhibitor is explored in this work, which would replace the expensive inhibitors with the similar or better performance.