Inhibition of Mild Steel Corrosion Using Plectranthus tenuiflorus (Shara) Plant as Safe and Green Inhibitor in Acidic solutions

Abstract

Plectranthus tenuiflorus (Shara) plant was investigated as safe (green) inhibitor on the corrosion of mild steel in 2.0 M H2SO4 solution using weight loss and hydrogen gas evolution technique. The results showed that Shara plant aqueous extract is good inhibitor for mild steel in this medium. The inhibition efficiency increases with the inhibitor concentration and decreases with rising temperature. The inhibition is attributed to adsorption of the inhibitor molecules on mild steel surface. Adsorption characteristics of the aqueous extract of Shara plant were approximated by Langmuir adsorption isotherm. Effect of temperature is studied in the range (30-70) º C and determination of activation parameters is also discussed.