Corrosion Inhibition of Indigofera Tinctoria Leaf Extract on Mild Steel in 1M HCL Solution
M. Prema
PG and Research Department of Chemistry, Holy Cross College (Affiliated to Bharathidasan University), Tiruchirappalli–620002, Tamil Nadu, India.
S. Vidhya *
PG and Research Department of Chemistry, Holy Cross College (Affiliated to Bharathidasan University), Tiruchirappalli–620002, Tamil Nadu, India.
A. Leema Rose
PG and Research Department of Chemistry, Holy Cross College (Affiliated to Bharathidasan University), Tiruchirappalli–620002, Tamil Nadu, India.
F. Janeeta Priya
PG and Research Department of Chemistry, Holy Cross College (Affiliated to Bharathidasan University), Tiruchirappalli–620002, Tamil Nadu, India.
J. Morris Princey
PG and Research Department of Chemistry, Holy Cross College (Affiliated to Bharathidasan University), Tiruchirappalli–620002, Tamil Nadu, India.
A. Arputharaj
St.Joseph's College Autonomous, Tiruchirappalli, India.
P. Aparna
PG and Research Department of Chemistry, Holy Cross College (Affiliated to Bharathidasan University), Tiruchirappalli–620002, Tamil Nadu, India.
T. R. Amsica
PG and Research Department of Chemistry, Holy Cross College (Affiliated to Bharathidasan University), Tiruchirappalli–620002, Tamil Nadu, India.
*Author to whom correspondence should be addressed.
Abstract
In the present work, the dissolution prevention of mild steel induced by Indigofera tinctoria Leaves (ITL) extract was analysed using different techniques such as weight loss, electrochemical impedance spectroscopy and potentiodynamic polarisation in 1M HCl solution at various contact periods and temperatures (303-333K). The result exhibits that Indigofera tinctoria Leaves acts as a mild steel inhibitor that performs well in 1M HCl solution. Inhibition efficiency of mild steel in 1M HCl increases as more inhibitor is added. The Highest percentage of inhibition efficiency was found to be 54.3% a 500 ppm concentration at a temperature of 303 K. Thermodynamic parameters Ea, Qads, Gads, H, and S suggest that the adsorption of Indigofera tinctoria leaves extract is exothermic, spontaneous, and a chemisorption process. The Langmuir adsorption isotherm governs the adsorption of Indigofera tinctoria leaves on a mild steel surface. Also, the electrochemical study exhibits that it acts as a cathodic inhibitor in a 1M HCl medium. Thin film formation on the surface of metal may also be confirmed by UV, FT-IR, and SEM studies.
Keywords: Mild steel, phytochemical screening, inhibition efficiency, weight loss