Electrochemical Studies and Inhibitory Effects of Millet Extract on Copper for Prolonged Service Life
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Abstract
This research assesses the efficacy of millet extract as a copper corrosion inhibitor under exposure to 1M hydrochloric acid (HCl) to provide an eco-friendly substitute to the use of manmade corrosion inhibitors. Open Circuit Potential (OCP), Linear Sweep Voltammetry (LSV), and Tafel polarization techniques were employed under various temperatures (30°C - 50°C) to examine the performance of various concentrations of millet extract (0 mL, 0.1 mL 0.2 mL, and 0.3 mL). The results showed a significant decrease in both the current density (Jcorr) and the corrosion rate (CR) as the concentration of the inhibitor was raised. The highest percentage inhibition was about 98% using the 0.3 mL concentration, showing a very strong protection. The findings of the adsorption study showed that the inhibitor follows both the Langmuir and Freundlich adsorption isotherms, inferring the possibility of multilayer adsorption on the copper surface. The formation of a protective film that prevents the dissolution of the metal was supported by the optical micrographs.
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References
Fateh, A. Aliofkhazraei, M. & Rezvanian A. R. (2020). Review of corrosive environments for copper and its corrosion inhibitors,” Arabian Journal of Chemistry 13(1), 481–544
Yan, T., Zhang, S., Feng, L., Qiang, Y., Lu, L., Fu, D., Wen, Y., Chen, J., Li W., & Tan, B. (2020). Investigation of imidazole derivatives as corrosion inhibitors of copper in sulfuric acid: Combination of experimental and theoretical researches,” Journal of the Taiwan Institute of Chemical Engineering. 106, 118-129
Xu Y. (2018) “Experimental and theoretical investigations of some pyrazolo-pyrimidine derivatives as corrosion inhibitors on copper in sulfuric acid solution,” Applied Surface Science 459, 612–620.
Trabanelli, G. (1991). Whitney award lecture: inhibitors—an old remedy for a new challenge. Corrosion, 47, 410–419,
Zhou., L. (2020). Phenothiazine drugs as novel and eco-friendly corrosion inhibitors for copper in sulfuric acid solution, Journal of the Taiwan Institute of Chemical Engineering. 113, 253-263
Goni L. K. M. O. (2021). Bioinspired Heterocyclic Compounds as Corrosion Inhibitors: A Comprehensive Review.,” Chemistry, an Asian Journal. 16, 1324-1364
Baorong H. (2017). “The cost of corrosion in China,” Materials Degradation. 1, 1-10
Messaoudi H. (2020). Surface analysis and adsorption behavior of caffeine as an environmentally friendly corrosion inhibitor at the copper/aqueous chloride solution interface. Journal of Adhesion Science and Technology 20:2216-2244
Pedeferri P. & Pedeferri, P. (2018). Cathodic and anodic protection,” Corrosion Science Engineering, 383–422.
Martin N. and Mohamed, A. (2024). Sacrificial Anodes and Environmental Effects,” Evolution Manufacturing Design Operation Practice Resources Environment Sustainability. 81–106
Kadhim, A. Al-Amiery, A. A. Alazawi, R. Al-Ghezi, M. K. S. & Abass, R. H. (2021). Corrosion inhibitors. A review,” International Journal of Corrosion Scale Inhibition 10, 54–67
Derna A. M. “Green Extract of Mate Tea as Corrosion Inhibitor of Copper and Aluminum,” null, 2017,
Bilgiç, S. “Plant extracts as corrosion inhibitors against copper corrosion – An overview. (2023). International Journal Corrosion ans Scale Inhibition, 12, 1224–1260.
Savita A (2016). Strychnos nuxvomica, Piper longum and Mucuna pruriens seed extracts as eco-friendly corrosion inhibitors for copper in nitric acid,” RSC Advance 6, 95644-95655
Syam, S. M. Elhenawy, A. A. Gad, E. Nady, H. & Eid, S. (2023). Combination of practical and theoretical measurements of albumin egg as an eco-friendly inhibitor for copper corrosion in alkaline solutions,” RSC Advances, 13, 33929-33942
Bozorg M. (2014). Myrtus Communis as Green Inhibitor of Copper Corrosion in Sulfuric Acid,” Industrial Engineering and Chemical Research, 11, 4295-4303
Nwanonenyi S. C. (2017). Corrosion inhibitive behavior and adsorption of millet (Panicum miliaceum) starch on mild steel in hydrochloric acid environment,” Journal Bio-and Tribo-Corrosion, 3, 1–11
Chiter, F. Costa, D. Maurice,V. & Marcus, P. (2021). Corrosion inhibition of locally de-passivated surfaces by DFT study of 2-mercaptobenzothiazole on copper,” Materials Degradation. 5, 52-62
Hsissou R. (2022). Synthesis characterization and highly protective efficiency of tetraglycidyloxy pentanal epoxy prepolymer as a potential corrosion inhibitor for mild steel in 1 M HCl medium,” Polymers (Basel)., 14, 3100-3110
Dong, L. Yuanhua, L. Yigang, D. & Dezhi, Z. (2011). Corrosion inhibition of carbon steel in hydrochloric acid solution by rice bran extracts,” Anti-Corrosion Methods Materials. 58, 205–210
Jero, D., Caussé, N. & Pébère, N. (2024). Film-forming amines as corrosion inhibitors: a state-of-the-art review,” npj Materials Degradation. 8, 111-121,
Kalam, S. Abu-Khamsin, S. A. Kamal, M. S. & Patil, S. (2021). Surfactant Adsorption Isotherms: A Review,” ACS Omega, 48, 32342–32348
Saadi, R. Saadi, Z. Fazaeli, R. and Fard N. E. (2015). Monolayer and multilayer adsorption isotherm models for sorption from aqueous media. Korean Journal Chem. Engineering. 32, 787–799
Molavi H. & Salimi, M. S. (2025). Investigation the effect of exchange solvents on the adsorption performances of Ce-MOFs towards organic dyes,” Scientific Report. 15, 7074, 2025.
Quy Huong, D. Duong, T. & Nam P. C. (2019). Effect of the Structure and Temperature on Corrosion Inhibition of Thiourea Derivatives in 1.0 M HCl Solution,” ACS Omega, 4,14478–14489,
Wang., L. (2023). Adsorption mechanism of quaternary ammonium corrosion inhibitor on carbon steel surface using ToF-SIMS and XPS,” Corrosion Science 213, 110952