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 (Rct) value increases while both the capacitance of the double layer (Cdl) and corrosion current (icorr) 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.