Andrographis echioides leaves extract as an eco-friendly corrosion inhibitor for mild steel in acid medium

Abstract

There is a growing trend to utilize plant extracts as corrosion inhibitors. The inhibitive performance of extract of Andrographis echioides (AE) on the corrosion of mild steel in 1.0 M HCl were studied using mass loss and electrochemical measurements. Results confirmed that the extract of Andrographis echioides (AE) acts as an effective corrosion inhibitor in the acid environment. The weight loss studies show the trend indicating that the Andrographis echioides (AE) leaves extract adsorption on mild steel followed the Langmuir and Temkin adsorption isotherms. Potentiodynamic polarization and electrochemical impedance studies confirmed that the system follows mixed mode of inhibition. Surface characterization techniques (FT-IR, UV–Visible, AFM and Contact angle) are also used to ascertain the nature of the protective film.