Mitigation of corrosion of carbon steel in acidic solutions using an aqueous extract of Tilia cordata as green corrosion inhibitor

The effectiveness of using Tilia cordata extract as a green corrosion inhibitor for carbon steel in 1 M hydrochloric acid solutions was demonstrated by employing some chemical and electrochemical techniques. The surface morphology of C-steel specimens was examined. The results showed that Tilia cordata has corrosion inhibition characteristics with efficiency of 96% as the concentration of Tilia cordata extract increased to 300 mg L −1 . Charge transfer resistance ( R ct ) value increases while both the capacitance of the double layer ( C dl ) and corrosion current ( i corr ) values decrease with increasing the extract concentration. The effect of temperature was studied in the range 30–60 °C. Some thermodynamic parameters were calculated and discussed. The adsorption of extract on the C-steel surface was found to obey Langmuir adsorption isotherm. Polarization results showed that the investigated extract acts as mixed type inhibitor. All the different used techniques gave similar results.