Corrosion Inhibition of Mild Steel in Alkaline Medium Using Soursop (Annona muricata) Leaf Extract: A Green Approach
Keywords:
Green corrosion inhibitor, Annona muricata, mild steel, phytochemicals, chemisorption, inhibition efficiencyAbstract
The quest for eco-friendly, cost-effective, and sustainable corrosion control solutions has intensified due to environmental concerns associated with synthetic inhibitors. This study investigates the inhibitory performance of ethanolic extract of soursop (Annona muricata) leaves on mild steel corrosion in potassium hydroxide (KOH) medium. Qualitative phytochemical analysis revealed the presence of alkaloids, flavonoids, tannins, terpenoids, saponins, cardiac glycosides, and anthraquinones compounds rich in heteroatoms (nitrogen and oxygen) and π-electron systems. FTIR spectroscopy confirmed O–H (3406 cm⁻¹), C=O (1718 cm⁻¹), C=C (1636 cm⁻¹), and C–O/C–N (1066–1245 cm⁻¹) functional groups. Weight loss measurements (triplicate, n=3) demonstrated that inhibition efficiency (IE) increases with longer immersion time (14.19- 68.17%), higher temperature (8.20-74.83%), increased alkaline concentration (19.72-57.19%), higher extract concentration (26.73-61.36%), and larger media volume (30.29-67.29%). Electrochemical impedance spectroscopy (EIS) revealed that charge transfer resistance (Rct) increased from 124 ± 8 Ω·cm² (uninhibited) to 482 ± 20 Ω·cm² (5% v/v extract), corresponding to IE of 74.3%. Potentiodynamic polarization showed mixed-type inhibition with cathodic predominance (IE = 76.2% at 5% v/v extract). Adsorption followed the Langmuir isotherm (R² > 0.99), with ΔG°ads values ranging from −35.2 to −42.1 kJ·mol⁻¹, confirming chemisorption. Activation energy increased from 28.4 kJ·mol⁻¹ (uninhibited) to 52.7 kJ·mol⁻¹ (inhibited). SEM revealed smoother surfaces (roughness reduced by 77%). All results were statistically significant (p < 0.05). This study establishes Annona muricata leaf extract as a promising, renewable, and highly effective green corrosion inhibitor for mild steel in alkaline environments.
Downloads
References
References
Bender, R., Féron, D., Mills, D., Ritter, S., Bäßler, R., Bettge, D., & Zheludkevich, M. (2022). Corrosion challenges towards a sustainable society. Materials and corrosion, 73(11), 1730-1751.
Li, F. M., Huang, L., Zaman, S., Guo, W., Liu, H., Guo, X., & Xia, B. Y. (2022). Corrosion chemistry of electrocatalysts. Advanced Materials, 34(52), 2200840
Wang, J., Du, M., Li, G., & Shi, P. (2022). Research progress on microbiological inhibition of corrosion: A review. Journal of cleaner production, 373, 133658.
Fazal, B. R., Becker, T., Kinsella, B., & Lepkova, K. (2022). A review of plant extracts as green corrosion inhibitors for CO2 corrosion of carbon steel. npj Materials Degradation, 6(1), 5.
Wei, X. X., Zhang, B., Wu, B., Wang, Y. J., Tian, X. H., Yang, L. X., ... & Ma, X. L. (2022). Enhanced corrosion resistance by engineering crystallography on metals. Nature Communications, 13(1), 726.
Orji, A., Olamide, A. M., & Al-Abbas, F. M. (2025, November). The Use of Artificial Intelligence in Corrosion Management (State of the Art). In MECC 2025 (pp. 1-28). Association for Materials Protection and Performance
Olugbade, T. O., Omiyale, B. O., & Ojo, O. T. (2022). Corrosion, corrosion fatigue, and protection of magnesium alloys: mechanisms, measurements, and mitigation. Journal of Materials Engineering and Performance, 31(3), 1707-1727.
Sun, J., Tang, H., Wang, C., Han, Z., & Li, S. (2022). Effects of alloying elements and microstructure on stainless steel corrosion: a review. Steel research international, 93(5), 2100450.
Deng, P., Mo, W., Ouyang, Z., Ling, K., Luo, B., & Bai, Z. (2023). Microstructural evolution and corrosion mechanism of micro-alloyed 2024 (Zr, Sc, Ag) aluminum alloys. Corrosion Science, 224, 111476
Ech-chihbi, E., Salim, R., Ouakki, M., Koudad, M., Guo, L., Azam, M., ... & Taleb, M. (2023). Corrosion resistance assessment of copper, mild steel, and aluminum alloy 2024-T3 in acidic solution by a novel imidazothiazole derivative. Materials Today Sustainability, 24, 100524.
Mondou, E., Proietti, A., Charvillat, C., Berziou, C., Feaugas, X., Sinopoli, D., & Blanc, C. (2023). Understanding the mechanisms of intergranular corrosion in 2024 Al alloy at the polycrystal scale. Corrosion Science, 221, 111338.
Hussein Farh, H. M., Ben Seghier, M. E. A., Taiwo, R., & Zayed, T. (2023). Analysis and ranking of corrosion causes for water pipelines: a critical review. NPJ Clean Water, 6(1), 65
Wen, L., Wang, Y., Zhou, Y., Ouyang, J. H., Guo, L., & Jia, D. (2010). Corrosion evaluation of microarc oxidation coatings formed on 2024 aluminium alloy. Corrosion Science, 52(8), 2687-2696.
Husaini, M. (2025). Biogenic nano-inhibitors for sustainable and green corrosion protection of metals. EHEI-Journal of Science & Technology, 5(2), 91-109.
Husaini, M., Siaka, A. A., & Muhammad, S. L. (2025). Multifunctional Polymer Nanocomposites for Anti-Corrosion Applications in Aggressive Environments: Design Strategies, Mechanisms, and Future Perspectives. EHEI-Journal of Science & Technology, 5(2), 145-162
1. Harb, M. B., Abubshait, S., Etteyeb, N., Kamoun, M., & Dhouib, A. (2020). Olive leaf extract as a green corrosion inhibitor of reinforced concrete contaminated with seawater. Arabian Journal of Chemistry, 13(3), 4846-4856.
Hoai, N. T., Van Hien, P., Vu, N. S. H., Son, D. L., Van Man, T., Tri, M. D., & Nam, N. D. (2019). An improved corrosion resistance of steel in hydrochloric acid solution using Hibiscus sabdariffa leaf extract. Chemical Papers, 73(4), 909-925.
Loto, R. T., Mbah, E. H., & Ugada, J. I. (2021). Corrosion inhibition effect of citrus sinensis essential oil extract on plain carbon steel in dilute acid media. South African Journal of Chemical Engineering, 35, 159-164.
Hussain, N., & Acharya, M. (2026). Sustainable corrosion inhibition using leaf extract: a review of mechanistic aspects, and thermodynamic properties. Journal of Adhesion Science and Technology, 1-40.
Rutsa, V., Yimchunger, A. K., Sangtam, T., Venuh, V., Longkumer, L., Letro, L., ... & Singh, A. (2026). Plant extracts as environmentally benign corrosion inhibitors in protecting metals from acid media: a review. Chemical Papers, 1-17.
Barbu, C. A., Fierascu, I., Semenescu, A., & Cotrut, C. M. (2025). Critical Review Regarding the Application of Plant Extracts as Eco-Friendly Corrosion Inhibitors—A Sustainable Interdisciplinary Approach. Molecules, 30(18), 3722.
Singh, S., Mahish, P. K., Mishra, R. K., Verma, D. K., Berdimurodov, E., Saxena, A., & Chauhan, R. (2026). Optimizing the performance of silver nanoparticles synthesized from Butea monosperma var. lutea leaf extract: applications in corrosion prevention, dye remediation, and biomedicine. Chemical Papers, 1-27.
Sonde, C. U., Nnaji, N., Odoemelam, S. A., Ekuma, F. K., Ezeh, G. C., & Okoli, C. P. (2023). Methylene blue removal by agricultural wastes from Annona muricata and Treculia africana seeds. Biomass Conversion and Biorefinery, 13(16), 14901-14915.
Ojike, P. C., Ezeugo, J. O., & Ifediorah, E. I. (2026). Experimental Synthesis, Characterisation, and Inhibition Evaluation of Green Corrosion Inhibitors Using Bio-Extracts. Acta Chemica Malaysia (ACMY), 10(1), 20-27.
Krishnaraj, P., & Navada, M. K. (2026). Green Corrosion Inhibition of AZ91 Magnesium Alloy in Saline Solution Using Underexplored Tropical Leaf Extracts: Electrochemical and Surface Morphology Analysis.
Karimi, E., Jaafar, H. Z., & Ahmad, S. (2011). Phytochemical analysis and antimicrobial activities of methanolic extracts of leaf, stem and root from different varieties of Labisa pumila Benth. Molecules, 16(6), 4438-4450.
Syahputra, R. A., Sutiani, A., Silitonga, P. M., Rani, Z., & Kudadiri, A. (2021). Extraction and phytochemical screening of ethanol extract and simplicia of moringa leaf (Moringa oleifera Lam.) from sidikalang, north sumatera. International Journal of Science, Technology & Management, 2(6), 2072-2076.
Singh, G. P., Moon, A. P., Sengupta, S., Deo, G., Sangal, S., & Mondal, K. (2015). Corrosion behavior of IF steel in various media and its comparison with mild steel. Journal of Materials Engineering and Performance, 24(5), 1961-1974.
Amrullah, K. N. A., Ma’rifah, S. J., Azizah, N., Jamilah, Z., Safitri, D. A., Bawani, E. A., ... & Mahyantika, S. P. (2025). Characterization and Identification of Phytochemical Compounds Soursop Leaf Extract (Annona muricata L.). JSMARTech: Journal of Smart Bioprospecting and Technology, 6(2), 7-14.
Prabakaran, M., Kim, S. H., Kalaiselvi, K., Hemapriya, V., & Chung, I. M. (2016). Highly efficient Ligularia fischeri green extract for the protection against corrosion of mild steel in acidic medium: electrochemical and spectroscopic investigations. Journal of the Taiwan Institute of Chemical Engineers, 59, 553-562.
Revon, M. H. N., & Priyantha, N. (2026). Superior corrosion inhibition activity of CaO nanoparticles synthesized from natural sources toward stainless–steel Grade 202 in chloride-rich media. Discover Electrochemistry, 3(1), 23.
Farooq, S. A., Raina, A., Ul Haq, M. I., & Anand, A. (2022). Corrosion behaviour of engineering materials: a review of mitigation methodologies for different environments. Journal of The Institution of Engineers (India): Series D, 103(2), 639-661.
Canales, C. P. (2022). Electrochemical impedance spectroscopy and Its applications. 21st Century Nanostructured Materials—Physics, Chemistry, Classification, and Emerging Applications in Industry, Biomedicine, and Agriculture.
Khaled, K. F., & Hackerman, N. (2003). Investigation of the inhibitive effect of ortho-substituted anilines on corrosion of iron in 1 M HCl solutions. Electrochimica Acta, 48(19), 2715-2723.
Downloads
Published
Issue
Section
License
Copyright (c) 2026 Maureen Allen, kenechi nwosu-obieogu, Callistus Ude, Chinelo Onyekwulu (Author)
This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.
