Corrosion inhibition of mild steel by Calotropis procera leaves extract in a CO₂ saturated sodium chloride solution

Abstract

The Calotropis procera leaves extract (CPLE) was investigated as a corrosion inhibitor for mild steel in a CO₂-saturated 3.5 wt% NaCl solution using various electrochemical techniques. The results show that the CPLE is an effective inhibitor with inhibition efficiency of 80% using 50 ppm. Polarization studies show that the CPLE acts as a mixed inhibitor, and the adsorption of CPLE follows Langmuir adsorption isotherm. Molecular dynamics simulations reveal that the presence of N, O in the CPLE as well as π-electron systems coupled with high adsorption energies of interaction of the CPLE with steel are responsible for corrosion inhibition performance.

Key words:

• Steel corrosion
• molecular simulation
• electrochemical techniques
• adsorption, polarization
• natural corrosion inhibitor