Mild Steel Corrosion Mitigation in Sulphuric Acid via Benign Isolated Phytochemicals from Viscum album

Abstract

We present the evaluation of four Eco-friendly corrosion inhibitors for the corrosion mitigation of mild steel in acid media. The corrosion inhibition of mild steel by ethanol extracts from Viscum album (EEVA) and some of its isolated phytochemical components; phytates extract (PEVA), saponins extract (SEVA), and flavonoids extracts (FEVA) have been studied using gravi-metric and gasometric techniques. The results of the study reveal that these ecofriendly and benign extracts function as good inhibitors for mild steel corrosion in sulphuric acid. Inhibition efficiency of the extracts increases with inhibitor concentration and temperature rise. The trend of inhibition efficiency in lower inhibitor concentration is EEVA > PEVA > SEVA > FEVA and at higher concentration, the order was SEVA > PEVA > EEVA > FEVA. The presence of the plant extracts decreases the corrosion activation energy in the solution which indicates chemical adsorption mechanism. The adsorption of the components of the extracts is consistent with Temkin isotherm. The interaction between the isolated extracts is synergistic at lower inhibitor concentration and antagonistic at higher concentrations. The Kads values for PEVA and SEVA are higher than those of EEVA and FEVA. This implies that PEVA and SEVA are more efficiently adsorbed on the mild steel surface.