Main Article Content



n-Hexane extracts of Costus lucanusianus stem and leaves were used for corrosion inhibition of mild steel and aluminium in 1 M HCl at concentrations of 0.1 g/L, 0.2 g/L, 0.5 g/L, 0.7 g/L and 1 g/L using thermo-gravimetric analysis (303 K – 333 K). In 1g/L, n-Hexane stem extract had maximum inhibition efficiency of 85 % at 333 K and 78% at 303 K for mild steel and aluminium respectively. Addition of extracts to acid solution increased values of Ea. Positive values of ΔH indicated endothermic adsorption process. Negative values of ΔS indicated decrease in disorderliness of the system. Negative values of ΔG (-2.95 KJ/mol to -4.10 KJ/mol) indicated physisorption mechanism. The adsorption was found to obey Freundlich isotherm. GCMS analysis showed major components of the extracts labelled n-Hexane stem extract (n-HSE) and n-Hexane leave extract (n-HLE) as 2,2'-methylenebis-1H–isoindole-1,3(2H)-dione (33.29%) and triacontanoic acid methylester (61.01%) respectively. Quantum chemical calculations were performed using Density Functional Theory with complete geometry optimization for calculations of EHOMO, ELUMO and energy gap. The energy gaps were 3.03 eV and 5.34 eV for n-HSE and n-HLE respectively. The softness (σ) values indicated that components of n-HSE are soft molecules; and are more reactive than n-HLE. This observation was consistent with results obtained from experimental inhibition efficiencies.

Corrosion, density functional theory, freundlich, thermo-gravimetric, thermodynamics, adsorption isotherm

Article Details

How to Cite
Original Research Article


Valdez B, Zlatev R, Schorr M, Rosas N, Dobrev T, Monev M, Krastev I. Rapid method for corrosion protection determination of VCI films. Anti-Corrosion Methods and Materials. 2006;53(6):362–366. Available:

Kavitha V, Gunavathy N. Aluminium corrosion inhibition by Daucus carota pulp extract in 1 M hydrochloric acid medium. International Journal of Scientific Research in Science and Technology. 2016;2(6):249–256. Available:

Auci G. Inhibition effect of N, N'-methylenediacrylamide on corrosion behaviour of mild steel in 0.5 M HCl. Materials Chemistry and Physics. 2008;112:234–238. Available:

Umoren SA, Solomon MM, Obot IB, Suleiman RK. Comparative studies on the corrosion inhibition efficacy of ethanolic extracts of date palm leaves and seeds on carbon steel corrosion in 15 % HCl solution. Journal of Adhesion Science and Technology. 2018; 4243:1–18. Available:

Corrales-Luna M, Le Manh T, Romero-Romo M, Palomar-Pardavé M, Arce-Estrada E. 1-Ethyl 3-methylimidazolium thiocyanate ionic liquid as corrosion inhibitor of API 5L X52 steel in H2SO4 and HCl media. Corrosion Science. 2019;153:85–99. Available:

Rani BEA, Basu BBJ. Green inhibitors for corrosion protection of metals and alloys: an overview. International Journal of Corrosion. 2012;1–15. Available:

Vosta J, Eliasek J. Study on corrosion inhibition from aspect of quantum chemistry. Corrosion Science. 1971;11(4):223–229. Available:

Lukovits I, Bakó I, Shaban A, Kálmán E. Polynomial model of the inhibition mechanism of thiourea derivatives. Electrochimica Acta. 1998;43:131–136. Available:

Kraka E, Cremer D. Computer design of anticancer drugs. Journal of American Chemical Society. 2000;122(34):8245–8264. Available:

Gece G. The use of quantum chemical methods in corrosion inhibitor studies. Corrosion Science. 2008;50(11):2981–2992. Available:

Karelson M, Lobanov V, Katritzky A. Quantum chemical descriptors in QSAR/ QSPR studies. Chemical Reviews. 1996; 96(3):1027–1044. Available:

Awad MK, Mustafa MR, Elnga MM. Computational simulation of the molecular structure of some triazoles as inhibitors for the corrosion of metal surface. Journal of Molecular Structure. 2010;959(1-3):66–74. Available:

Lukovits I, Shaban A, Kalman E. Thiosemicarbazides and thiosemicarbazones: non-linear quantitative structure efficiency model of corrosion inhibition. Electrochimica Acta. 2005;50:4128–4133. Available:

Musa AY, Jalgham RT, Mohamad AB. Molecular dynamic and quantum chemical calculations for phthalazine derivatives as corrosion inhibitors of mild steel in 1 M HCl. Corrosion Science. 2012;56:176–183. Available:

Ituen EI, Udo UE. Phytochemical profile, adsorption and inhibitive behaviour of costus afer extracts on aluminium corrosion in hydrochloric acid. Pelagia Research Library. 2012;3(6):1394–1405. Available:

Barbouchi M, Benzidia B, Aouidate A, Ghaleb A, El M, Choukrad M. Theoretical modeling and experimental studies of Terebinth extracts as green corrosion inhibitor for iron in 3 % NaCl medium. Journal of King Saud University – Science. 2020;32(7):2995–3004. Available:

Belghiti ME, Echihi S, Dafali A, Karzazi Y, Bakasse M, Elalaoui-Elabdallaoui H. Computational simulation and statistical analysis on the relationship between corrosion inhibition efficiency and molecular structure of some hydrazine derivatives in phosphoric acid on mild steel surface. Applied Surface Science. 2019;491:707–722. Available:

Saraswat V, Yadav M, Obot IB. Investigations on eco-friendly corrosion inhibitors for aluminium in acid environment: Electrochemical, DFT and Monte Carlo simulation approach. Colloids and Surfaces A: Physicochemical and Engineering Aspects. 2020;599(4):124881–124899 Available:

Cao Z, Tang Y, Cang H, Xu J, Lu G, Jing W. Novel benzimidazole derivatives as corrosion inhibitors of mild steel in the acidic media. Part II: Theoretical studies. Corrosion Science. 2014;83:292–298. Available:

Geetha K, Udhayakumar R. A green tactic for inhibition of corrosion on aluminium in bore well water by aqueous extract of Bauhinia Blakeana leaves. Indian Journal of Chemical Technology. 2021;28:36–46. Available:

Eddy NO, Awe FE, Siaka AA, Magaji L, Ebenso EE. Chemical information from GC-MS studies of ethanol extract of Andrographis paniculata and their corrosion inhibition potentials on aluminium in HCl solution. International Journal of Electrochemical Science. 2011;6:4316–4328.

Mahgoub FM, Hefnawy AM, Alrazzaq EHA. Corrosion inhibition of mild steel in acidic solution by leaves and stem extract of Acacia nilotica. Desalination and Water Treatment. 2019;169:49–58. DOI: 10.5004/dwt.2019.24681

Akalezi CO, Oguzie EE. Evaluation of anticorrosion properties of Chrysophyllum Albidum leaves extract for mild steel protection in acidic media. International Journal of Industrial Chemistry. 2016;7:81–92. Available:

Ali IH, Suleiman HA. Effects of acid extract of leaves of Juniperus procera on corrosion inhibition of carbon steel in HCl solution. International Journal of Electrochemical Science. 2018;13:3910–3922. Available:

Ugi BU. Effects of Nitrogen Atoms in Vindoline Alkaloids as Fe2+ Ions Inhibitor in Corrosion of Gray Iron in Dilute HCl Environment: Potentiodynamic Polarization, Gravimetric Analysis and SEM. Journal of Materials and Environmental Science. 2020; 11(8):1274–1285. Available:

Uwah I, Ikeuba A, Ugi B, Udowo V. Comparative study of the inhibition effects of alkaloid and non-alkaloid fractions of the ethanolic extracts of Costus afer stem on the corrosion of aluminium in 5 M HCl solution. Global Journal of Pure and Applied Sciences. 2013;19(1):23–31. Available:

Obot IB, Obi-Egbedi NO. Theoretical study of benzimidazole and its derivatives and their potential activity as corrosion inhibitors. Corrosion Science. 2010;52(2):657–660. Available:

Abdollahi F, Foroughi MM, Zandi SM, Kazemipour M. Electrochemical Investigation of Meloxicam Drug as a Corrosion Inhibitor for Mild Steel in Hydrochloric and Sulfuric Acid Solutions. Progress in Color, Colorant and Coatings. 2020;13(3):155–165. Available:

Bashir S, Sharma V, Ghelichkhah Z, Obot IB, Kumar S. Inhibition performances of nicotinamide against aluminium corrosion in an acidic medium. Portugaliae Electrochimica Acta. 2020;38(2):107–123. DOI: 10.4152/pea.202002107

Bensouda Z, Elassiri E, Galai M, Sfaira M, Farah A, Touhami ME. Corrosion Inhibition of Mild Steel in 1 M HCl Solution by Artemisia abrotanum Essential Oil as an Eco-Friendly Inhibitor. Journal of Materials and Environmental Sciences. 2018;9(6):1851–1865. Available:

Santosa A, Almeida T, Cotting F, Aoki IV, Melo HG, Capelossi VR. Evaluation of Castor Bark Powder as a Corrosion Inhibitor for Carbon Steel in Acidic Media. Materials Research. 2017;20:492–505. Available:

Deyab M. Effect of cationic surfactant and inorganic anions on the electrochemical behaviour of carbon steel in formation water. Corrosion Science. 2007;49(5):2315–2328. Available:

Luo X, Ci C, Li J, Lin K, Du S, Zhang H, Liu Y. 4-aminoazobenzene modified natural glucomannan as a green eco-friendly inhibitor for the mild steel in 0.5 M HCl solution. Corrosion Science. 2019;151:132–142. Available:

Obot IB, Obi-Egbedi NO. Adsorption properties and inhibition of aluminium corrosion in sulphuric acid solution by ketoconazole: Experimental and theoretical investigation. Corrosion Science. 2010;52(1): 198–204. Available:

Benabdellah M, Tounsi A, Khaled KF, Hammouti B. Thermodynamic chemical and electrochemical investigations of 2-mercapto benzimidazole as corrosion inhibitor for aluminium in hydrochloric acid solutions. Arabian Journal of Chemistry. 2011;4(1):17–24. Available:

Oguzie EE, Akalezi CO, Okoro SC, Ayuk AA, Ejike EN. Adsorption and corrosion inhibiting effect of Dacryodis edulis extracts on low-carbon-steel corrosion in acidic medium. Journal of Colloid and Interface Science. 2010; 349(1):283–292. Available:

Umoren SA. Inhibition of aluminium and mild steel corrosion in acidic medium using gum Arabic. Cellulose. 2008;15:751–761. Available:

Obot IB. Chemical investigation of xanthene and phenanthroline derivatives as corrosion inhibitors for aluminium in sulphuric acid. Ph.D Thesis. University of Ibadan; 2011.

Ameh PO, Koha PU, Eddy NO. Experimental and quantum chemical studies on the corrosion inhibition potential of phthalic acid for aluminium in 0.1 M H2SO4. Chemical Sciences Journal. 2015;6(3):1–8. DOI: 10.4172/2150-3494.1000100

Gadow HS, Motawea MM. Investigation of the corrosion inhibition of carbon steel in hydrochloric acid solution by using ginger roots extract, Royal Society of Chemistry Advances. 2017;7(40):24576–24588. Available:

Srinivasulu A, Kasthuri PK. Study of inhibition and adsorption properties of mild steel corrosion by expired pharmaceutical gentamicin drug in hydrochloric acid media. Oriental Journal of Chemistry. 2017;33(5): 2616–2624. Available:

Cookey GA, Tambari BL, Iboroma DS. Evaluation of corrosion inhibition potentials of green tip forest lily (Clivia no-bilis) leaves extract on mild steel in acid media,. Journal of applied Sciences and Environmental Management. 2018;22(1):90–94. Available:

Ituen E, Akaranta O, James A. Evaluation of performance of corrosion inhibitors using adsorption isotherm models: An overview. Chemical Science International Journal. 2017; 18(1):1–34. Available:

Faustin M, Maciuk A, Salvin P, Roos C, Lebrini M. Corrosion inhibition of C38 steel by alkaloids extract of Geissospermum laeve in 1 M hydrochloric acid: Electrochemical and phytochemical studies. Corrosion Science. 2015;92:287–300. Available:

Fitoz A, Nazır H, Özgür M, Emregül E, Emregul K. An experimental and theoretical approach towards understanding the inhibitive behavior of a nitrile substituted coumarin compound as an effective acidic media inhibitor. Corrosion Science. 2018;133:451–464. Available:

Kumar S, Vashisht H, Olasunkanmi L, Bahadur I, Verma H, Goyal M, Ebenso E. Polyurethane Based Triblock Copolymers as Corrosion Inhibitors for Mild Steel in 0.5 M H2SO4. Industrial and Engineering Chemistry Research. 2017;56(2):441–456. Available:

Mohammed NR, Fadwa MA, Atega MA. Corrosion inhibition of 316 stainless steel in 20% (W/W) HCl solution using Dithizone. American Journal of Applied Chemistry. 2014; 2(1):1–5. DOI: 10.11648/j.ajac.20140201.11

Ugi BU, Obeten ME. Inhibitory impact of crude phytochemical compounds of Symphytum officinali (Comfrey) leaves on the corrosion of copper by Hydrogen tetraoxosulphate (IV) (H2SO4) acid solution. SSRG International Journal of Applied Chemistry. 2018;5(2):22–33. Available:

El-Awady GY, El-Said IA, Fouda AS. Anion surfactants as corrosion inhibitors for aluminium dissolution in HCl solutions. International Journal of Electrochemical Science. 2008;3:174–190.

El-Sherif RM, Badawy WA. Mechanism of corrosion and corrosion inhibition of tin in aqueous solution containing tartaric acid. International Journal of Electrochemical Science. 2011;6:6469–6482. Available:

Ebenso EE. Synergistic effect of halide aluminium in H2SO4 using 2-acetylphenothiazine. Materials Chemistry and Physics. 2003;79:58–70. Available:

Ozoemena CP, Charles M, Ugwuoke MC, Akpan G. Adsorption and quantum chemical studies on the inhibition potentials of Afzelia africana seed extract for the corrosion of aluminium in 2 M HCl solutions. International Journal of Research and Innovation in Applied Science. 2019;4(11):24–32. Available:

Khaled KF. Corrosion control of copper in nitric acid solutions using some amino acids: A combined experimental and theoretical study. Corrosion Science. 2010;52(10):3225–3234. Available:

Guo L, Tan B, Li W, Li Q, Zheng X, Bassey I. Banana leaves water extracts as inhibitor for X70 steel corrosion in HCl medium. Journal of Molecular Liquids. 2020;327:114828–114839. Available:

Wang Z. The inhibition effect of bis-benzimidazole compound for aluminium in 0.5 M HCl solution. International Journal of Electrochemical Science. 2012;7:11149–11160.

Obi-Egbedi NO, Obot IB, El-Khajary MI, Umoren SA, Ebenso EE. Computational simulation and statistical analysis on the relationship between corrosion inhibition efficiency and molecular structure of some phenanthroline derivatives on aluminium surface. International Journal of Electrochemical Science. 2011;6:5649– 5675.

Sasikumar Y, Adekunle A, Olasunkanmi L, Bahadur I, Baskar R, Kabanda M, Ebenso E. Experimental, quantum chemical and monte carlo simulation studies on the corrosion inhibition of some alkyl imidazolium ionic liquids containing tetrafluoroborate anion on aluminium in acidic medium. Journal of Molecular Liquids. 2015;211:105–118. Available:

Boekom E, Essien KE, Ekpo VF, Obot A. Kinetics, molecular dynamics and adsorption behaviour of pyridine on aluminium in 0.1M HCl solution. Elixir Applied Chemistry. 2020; 142:54382–54387.

Abakedi OU, Mkpenie VN, Ukpong EG. Anti-corrosion behaviour of 4(p-tolyldiazenyl)-2-((E)-(p-tolylimino)methyl) phenol on aluminium in 1M H2SO4: Experimental and theoretical studies. Scientific African. 2020;7: 1–14. Available:

Lukovits I, Kalman E, Zucchi F. Corrosion inhibitors: Correlation between electronic structure and efficiency. Corrosion Science. 2001;57(1):3–8. Available:

Emregül KC, Hayvalí M. Studies on the effect of a newly synthesized Schiff base compound from phenazone and vanillin on the corrosion of steel in 2 M HCl. Corrosion Science. 2006; 48(4):797–812. Available: