Green Corrosion Mitigation of Carbon Steel in Acidic Medium Using Leaf Extract of Moringa oleifera

International Journal of Chemistry | Vol. 13, No. 8, August 2022 | pp. 57–64

DOI: 10.46882/2022/IJC/000166

Article Type: Original Research Paper

Title: Green Corrosion Mitigation of Carbon Steel in Acidic Medium Using Leaf Extract of Moringa oleifera

Names of Authors: M. A. Haruna¹, S. K. Bhattacharya²*

Authors’ Affiliations:
¹Department of Chemistry, Federal University of Technology, Minna, Nigeria.
²Department of Chemistry, Indian Institute of Technology, Kharagpur, India.

Abstract: The utilization of toxic synthetic chemical inhibitors in industrial acid descaling operations creates substantial environmental and safety hazards, driving research into sustainable green alternatives. The corrosion mitigation performance of the aqueous leaf extract of Moringa oleifera (MO-Extract) on carbon steel in 0.5 M H₂SO₄ was investigated via gravimetric weight loss and electrochemical test protocols. Potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) measurements were recorded across varying inhibitor dosages (0.2 to 2.0 g/L) and system temperatures (303 to 333 K). Weight loss metrics revealed that protection efficiency increased with extract concentration, peaking at 91.4% at a dose of 2.0 g/L. Polarization diagrams established that MO-Extract functions as a mixed-type inhibitor, suppressing both anodic iron dissolution and cathodic hydrogen gas evolution pathways. EIS scans confirmed that charge-transfer resistance (Rct) increased with higher extract amounts, indicating the formation of a robust organic protective film on the steel face. The adsorption behavior of the bioactive compounds conformed to the Langmuir isotherm model, yielding a negative standard free energy of adsorption (delta G°ads = -20.8 kJ/mol), denoting a spontaneous physical adsorption mechanism driven by the presence of rich plant polyphenols.

Keywords: Carbon steel; Corrosion inhibition; Moringa oleifera; Electrochemical impedance spectroscopy; Polarization; Adsorption isotherm

Manuscript Timeline: Received: August 14, 2021; Revised: September 25, 2021; Accepted: October 15, 2021; Published: August 03, 2022.

Citation: Haruna, M. A., & Bhattacharya, S. K. (2022). Green Corrosion Mitigation of Carbon Steel in Acidic Medium Using Leaf Extract of Moringa oleifera. International Journal of Chemistry, 13(8), 57–64.

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