Comparative study of green corrosion inhibition effect on mild steel in different acid medium by Laburnum waterier Vossii leaves extract

This paper deals with the comparative study of inhibitory effect of ethanol extract of Laburnum watereri Vossii leaves on the corrosion of mild steel in 1 N HCl and 1N H2SO4. Plant extracts are the rich sources of ingredients which have high inhibition efficiency on corrosion of mild steel. The leaf exarct suppressed the corrosion of mild steel in both acid media. The inhibition effect of leaf extract were studied at different temperatures viz., 308 K, 313 K, 323 K and 333 K by weight loss method, Tafel polarization method, Nyquist impedance measurements, FT-IR spectroscopy and SEM analysis. The results of weight loss studies correlated well with those of impedance and polarization studies. The inhibition efficiency increased with increasing concentration of the inhibitor in both acid media. Further, the adsorption has been found to follow Freundlich adsorption isotherm in both acid media. Polarization studies indicate that leaf extract of LWV LE acts as a anodic type inhibitor in both acid media. The protective film formed on the steel surface was confirmed by FT-IR spectroscopy and SEM studies. The highest inhibition efficiency exhibited by LWVL extract is 94%. This plant extract can be considered as an eco-friendly and effective green corrosion inhibitor for mild steel in acid media.