Application of Myrtus Extracts as a Suitable Green Inhibitor for Corrosion of Steel in HCl Solution

The inhibition effect of Myrtus extract on steel corrosion in 1.0 M HCl solution was investigated by means of weight loss measurements, electrochemical polarization, electrochemical impedance microscopy and chemical quantum study. The results showed that Myrtus acts as a good inhibitor and the inhibition efficiency of this compound increases with increasing inhibitor concentration and in the presence of 1000 mg/L of the inhibitor will increase to 82%. Polarization curves showed that Myrtus extract acts as an efficient mixed type inhibitor. EIS plots indicated that the polarization resistance increased and double-layer capacitance decreased upon the addition of Myrtus to the solution. The adsorption of Myrtus on the steel surface was found to obey Temkin adsorption isotherm and the values of free adsorption energy indicate the spontaneous and chemical adsorption of inhibitors on mild steel surface. Also, quantum chemical calculations were used to correlate the adsorption of two compounds of Myrtus extract with its electronic structural parameters.