Green Corrosion Inhibitors: Reviews and Applications

The present work has been focused on the environmental, health as well as economic aspect and hence planned to use some of the eco-friendly corrosion inhibition behaviour of aqueous and alcoholic extract of six plants selected namely Gloriosa Superba Linn (GSL), Madhuca longifolia (ML), Alangium lamarckiii (AL), Holoptelea integrifolia (HI), Pithecellobium dulce (PD) and Schreabera swietenioids (SS) on mild steel surface in 1N HCl solution were investigated by mass loss with different time of contact, various temperature and evaluated by electrochemical impedance and Tafel studies. Polarization measurement revealed that the plant extracts which can act as mixed type inhibitor. An EIS plot indicates that the increase of inhibitor concentration increased the charge transfer resistance and decreased double layer capacitance. Organic moieties present in the extract were also found responsible performance of the inhibitor which was well supported by FTIR studies. The inhibitive effect of the ML, GSL, PD, AL, HI, and SS (both extracts) could be attributed to the presence of phytochemical constituent in the plants which is absorbed on the surface of the mild steel. The nature of Protective film formed on the MS surface has been confirmed by SEM analysis. The surface coverage values were tested graphically to fit for a suitable adsorption isotherm.