Guardians Against Corrosion: Exploring Diphenylpyrazoles Through Experimental and DFT Analysis

Document Type : Original Article

Authors

1 Department of Electromechanical Engineering, University of Technology-Iraq, P.O. Box: 10001, Baghdad, Iraq

2 Technical Engineering College, Middle Technical University, P.O. Box: 10001, Baghdad, Iraq

3 Production and Metallurgy Engineering Department, University of Technology, P.O. Box: 10001, Baghdad, Iraq

4 College of Engineering, University of Warith Al-Anbiyaa, P.O. Box: 56001, Karbalaa, Iraq

5 Department of Medical Instruments Engineering Techniques, Al-Farahidi University, P.O. Box:10001, Baghdad, Iraq

6 Al-Ameed University College, P. O. Box: 56001, Karbala, Iraq

7 Energy and Renewable Energies Technology Center, University of Technology, P.O. Box: 10001, Baghdad, Iraq

8 Department of Chemical and Process Engineering, Faculty of Engineering and Build Environment, Universiti Kebangsaan Malaysia, P.O. Box:43600, Bangi, Selangor, Malaysia

Abstract

This study investigates the potential of 5-amino-1,3-diphenylpyrazole and nitrogen-enriched 5-hydroxy-1,3-diphenylpyrazole to inhibit corrosion of mild steel in acidic environments. A comprehensive approach combining weight loss measurements and Density Functional Theory (DFT) calculations was employed to analyze the inhibitory effect under various concentrations, immersion times, and temperatures. At an optimal concentration of 0.5 mM, 5-amino-1,3-diphenylpyrazole displayed an impressive 94.7% inhibition efficiency, while 5-hydroxy-1,3-diphenylpyrazole achieved 86.4% efficiency at 303 K after 10 hours of exposure. Both compounds exhibited a mixed-type inhibition behavior, with increasing efficiency observed at higher concentrations. DFT calculations provided insights into the interaction between the molecules and the metal surface, along with their electronic properties, aiding in understanding the corrosion inhibition process. The investigation revealed that Langmuir isotherms govern the adsorption mechanism, and the calculated thermodynamic parameters suggest a complex interplay at the metal/solution interface, involving both chemisorption and physisorption. These findings provide valuable knowledge about the mechanisms of corrosion inhibition by these molecules, paving the way for the development of effective strategies to protect mild steel in corrosive environments.

Keywords

Main Subjects


  1. Mahdi BS, Abbass MK, Mohsin MK, Al-Azzawi WK, Hanoon MM, Al-Kaabi MH, Shaker LM, Al-Amiery AA, Isahak WN, Kadhum AA, Takriff MS. Corrosion inhibition of mild steel in hydrochloric acid environment using terephthaldehyde based on Schiff base: Gravimetric, thermodynamic, and computational studies. Molecules. 2022; 27(15):4857. https://doi.org/10.3390/molecules27154857. 
  2. A. Jawad Q, S. Zinad D, DawoodSalim R, A Al-Amiery A, Sumer Gaaz T, Takriff MS, H. Kadhum AA. Synthesis, characterization, and corrosion inhibition potential of novel thiosemicarbazone on mild steel in sulfuric acid environment. Coatings. 2019; 9(11):729. https://doi.org/10.3390/ coatings 9110729. 
  3. Al-Baghdadi SB, Noori FT, Ahmed WK, Al-Amiery AA. Thiadiazole as a potential corrosion inhibitor for mild steel in 1 M HCl. J Adv Electrochem. 2016; 18:67-9. 
  4. Resen AM, Hanoon M, Salim RD, Al-Amiery AA, Shaker LM, Kadhum AA. Gravimetrical, theoretical, and surface morphological investigations of corrosion inhibition effect of 4-(benzoimidazole-2-yl) pyridine on mild steel in hydrochloric acid. KOM Corr Mater Protect J. 2020; 64(4):122-30. https://doi.org/10. 2478/ kom- 2020- 0018. 
  5. Junaedi S, Al-Amiery AA, Kadihum A, Kadhum AA, Mohamad AB. Inhibition effects of a synthesized novel 4-aminoantipyrine derivative on the corrosion of mild steel in hydrochloric acid solution 
    together with quantum chemical studies. Inter J Mol Sci. 2013; 14(6):11915-28. https://doi.org/10.3390/ ijms 140611915. 
  6. Solomon MM, Uzoma IE, Olugbuyiro JA, Ademosun OT. A censorious appraisal of the oil well acidizing corrosion inhibitors. J Petrol Sci Eng. 2022; 215:110711. https://doi.org/10.1016/j.petrol. 2022. 110711 2. 
  7. Alamri AH. Localized corrosion and mitigation approach of steel materials used in oil and gas pipelines–An overview. Eng Fail Anal. 2020; 116:104735. https://doi.org/10.1016/j.engfailanal. 2020.104735. 
  8. Alamiery AA, Isahak WN, Aljibori HS, Al-Asadi HA, Kadhum AA. Effect of the structure, immersion time and temperature on the corrosion inhibition of 4-pyrrol-1-yl-n-(2, 5-dimethyl-pyrrol-1-yl) benzoyl-amine in 1.0 m HCl solution. Inter J Corr Scale Inhib. 2021; 10(2):700-13. https://doi.org/10.17675/2305-6894-2021-10-2-14. 
  9. Al-Azzawi WK, Al Adily AJ, Sayyid FF, Al-Azzawi RK, Kzar MH, Jawoosh HN, Al-Amiery AA, Kadhum AA, Isahak WN, Takriff MS. Evaluation of corrosion inhibition characteristics of an N-propionanilide derivative for mild steel in 1 M HCl: Gravimetrical and computational studies. Int J Corro Scale Inhib. 2022; 11(3):1100-14. https://doi. org/ 10.17675/2305-6894-2022-11-3-12. 
  10. Khudhair AK, Mustafa AM, Hanoon MM, Al-Amiery A, Shaker LM, Gazz T, Mohamad AB, Kadhum AH, Takriff MS. Experimental and theoretical investigation on the corrosion inhibitor potential of N-MEH for mild steel in HCl. Prog Color Colorant Coat. 2022; 15(2):111-22. https://doi.org/10. 30509/PCCC.2021.166815.1111. 
  11. Mustafa AM, Sayyid FF, Betti N, Hanoon MM, Al-Amiery A, Kadhum AA, Takriff MS. Inhibition evaluation of 5-(4-(1H-pyrrol-1-yl) phenyl)-2-mercapto-1,3,4-oxadiazole for the corrosion of mild steel in an acidic environment: thermodynamic and DFT aspects. Tribologia-Finnish J Tribol. 2021; 38(3-4):39-47. https://doi.org/10.30678/fjt.105330. 
  12. Al-Baghdadi SB, Hashim FG, Salam AQ, Abed TK, Gaaz TS, Al-Amiery AA, Kadhum AA, Reda KS, Ahmed WK. Synthesis and corrosion inhibition application of NATN on mild steel surface in acidic media complemented with DFT studies. Results Phys. 2018; 8:1178-84. https://doi.org/10.1016/j.rinp.2018. 02.007. 
  13. Abdulsahib YM, Eltmimi AJ, Alhabeeb SA, Hanoon MM, Al-Amiery AA, Allami T, Kadhum AA. Experimental and theoretical investigations on the inhibition efficiency of N-(2, 4-dihydroxy-tolueneylidene)-4-methylpyridin-2-amine for the corrosion of mild steel in hydrochloric acid. Inter J Corr Scale Inhib. 2021; 10(3):885-99. https://doi. org/10.17675/2305-6894-2021-10-3-3. 
  14. Zinad DS, Salim RD, Betti N, Shaker LM, Al-Amiery AA. Comparative investigations of the corrosion inhibition efficiency of a 1-phenyl-2-(1-phenyl-ethylidene) hydrazine and its analog against mild steel corrosion in hydrochloric acid solution. Prog Color Colorant Coat. 2022; 15(1):53-63. https://doi. org/10.30509/pccc.2021.166786.1108.
  15. Salim RD, Betti N, Hanoon M, Al-Amiery AA. 2-(2, 4-Dimethoxybenzylidene)-N-phenylhydrazinecarbo-thioamide as an efficient corrosion inhibitor for mild steel in acidic environment. Progr Color Colorant Coat. 2022; 15(1):45-52. https://doi.org/10.30509/ pccc. 2021.166775.1105. 
  16. Al-Amiery AA, Shaker LM, Kadhum AH, Takriff MS. Exploration of furan derivative for application as corrosion inhibitor for mild steel in hydrochloric acid solution: Effect of immersion time and temperature on efficiency. Mater Today: Proc. 2021; 42:2968-73. https://doi.org/10.1016/j.matpr.2020.12.807. 
  17. Resen AM, Hanoon MM, Alani WK, Kadhim A, Mohammed AA, Gaaz TS, Kadhum AA, Al-Amiery AA, Takriff MS. Exploration of 8-piperazine-1-ylmethylumbelliferone for application as a corrosion inhibitor for mild steel in hydrochloric acid solution. Inter J Corr Scale Inhib. 2021; 10(1):368-87. https://doi.org/10.17675/2305-6894-2021-10-1-21 
  18. Alamiery A. Corrosion inhibition effect of 2-N-phenylamino-5-(3-phenyl-3-oxo-1-propyl)-1, 3, 4-oxadiazole on mild steel in 1 M hydrochloric acid medium: Insight from gravimetric and DFT investigations. Mater Sci Energy Technol. 2021; 4:398-406. https://doi.org/10.1016/j.mset. 2021. 09.002. 
  19. Al-Amiery, A.A., Mohamad, A.B., Kadhum, A.A.H. et al. Experimental and theoretical study on the corrosion inhibition of mild steel by nonanedioic acid derivative in hydrochloric acid solution. Sci Rep. 2022; 12: 4705. https://doi.org/10.1038/s41598-022-08146-8.
  20. Yang HM. Role of organic and eco-friendly inhibitors on the corrosion mitigation of steel in acidic environments-a state-of-art review. Molecules. 2021; 26(11):3473. https://doi.org/10.3390/ molecules 26113473. 
  21. Vyshnevska Yu P, Brazhnyk IV. Corrosion prevention and control using in situ phase layers formation via application of the complexing‚Äźtype inhibitors. Appl. Res. 2023. https://doi.org/10. 1002/appl.202300027. 
  22. Espinoza-Vázquez A, Rodríguez-Gómez FJ, Martínez-Cruz IK, Ángeles-Beltrán D, Negrón-Silva GE, Palomar-Pardavé M, Romero LL, Pérez-Martínez D, Navarrete-López AM. Adsorption and corrosion inhibition behaviour of new theophylline–triazole-based derivatives for steel in acidic medium. R Soc Open Sci. 2019; 6(3):181738.
  23. Hassan HH, Abdelghani E, Amin MA. Inhibition of mild steel corrosion in hydrochloric acid solution by triazole derivatives: Part I. Polarization and EIS studies. Electrochimica Acta.2007; 52(22): 6359-6366.
  24. Ramesh S, Rajeswari S. Corrosion inhibition of mild steel in neutral aqueous solution by new triazole derivatives. Electrochim Acta. 2004; 49(5): 811-820. https://doi.org/10.1016/j.electacta.2003.09.035.
  25. Qiu LG, Xie AJ, Shen YH. A novel triazole-based cationic gemini surfactant: synthesis and effect on corrosion inhibition of carbon steel in hydrochloric acid. Mater Chem Phys. 2005; 91(2-3):269-273. https://doi.org/10.1016/j.matchemphys.2004.11.022.
  26. Abdulazeez MS, Abdullahe ZS, Dawood MA, Handel ZK, Mahmood RI, Osamah S, Kadhum AH, Shaker LM, Al-Amiery AA. Corrosion inhibition of low carbon steel in HCl medium using a thiadiazole derivative: weight loss, DFT studies and antibacterial studies. Int J Corr Scale Inhib. 2021; 10(4):1812-28. https://doi.org/10.17675/2305-6894-2021-10-4-27 
  27. Mahmood D, Al-Okbi AK, Hanon MM, Rida KS, Alkaim AF, Al-Amiery AA, Kadhum A, Kadhum AA. Carbethoxythiazole corrosion inhibitor: as an experimentally model and DFT theory. J Eng Appl Sci. 2018; 13(11):3952. https://doi.org/10.3923/ JEASCI.2018.3952.3959. 
  28. ASTM International, Standard Practice for Preparing, Cleaning, and Evaluating Corrosion Test, 2011, 1–9. 
  29. NACE International, Laboratory Corrosion Testing of Metals in Static Chemical Cleaning Solutions at Temperatures below 93°C (200°F), TM0193-2016-SG, 2000.
  30. Alamiery A, Mahmoudi E, Allami T. Corrosion inhibition of low-carbon steel in hydrochloric acid environment using a Schiff base derived from pyrrole: gravimetric and computational studies. Inter J Corr Scale Inhib. 2021; 10(2):749-65. https://doi. org/10.17675/2305-6894-2021-10-2-17  
  31. Gaussian09 RA. 1, mjfrisch, gw trucks, hbschlegel, gescuseria, ma robb, jrcheeseman, g. Scalmani, v. Barone, b. Mennucci, gapetersson et al., gaussian. Inc., Wallingford CT. 2009; 121:150-66.
  32. Manamela KM, Murulana LC, Kabanda MM, Ebenso EE. Adsorptive and DFT studies of some imidazolium based ionic liquids as corrosion inhibitors for zinc in acidic medium. Inter J Electrochem Sci. 2014; 9(6):3029-46.
  33. Koopmans T. Ordering of wave functions and eigenenergies to the individual electrons of an atom. Physica. 1933; 1:104-13. https://doi.org/10.1016/ S0031- 8914(34)90011-2.
  34. Eltmimi AJ, Alamiery A, Allami AJ, Yusop RM, Kadhum AH, Allami T. Inhibitive effects of a novel efficient Schiff base on mild steel in hydrochloric acid environment. Inter J Corr Scale Inhib. 2021; 10(2):634-48. https://doi.org/10.17675/2305-6894- 2021-10-2-10.
  35. Singh AK, Pandey AK, Banerjee P, Saha SK, Chugh B, Thakur S, Pani B, Chaubey P, Singh G. Eco-friendly disposal of expired anti-tuberculosis drug isoniazid and its role in the protection of metal. J Environ Chem Eng. 2019; 7(2):102971. https://doi. org/10.1016/j.jece.2019.102971.
  36. Benabdellah M, Tounsi A, Khaled KF, Hammouti B. Thermodynamic, chemical and electrochemical investigations of 2-mercapto benzimidazole as corrosion inhibitor for mild steel in hydrochloric acid solutions. Arabian J Chem. 2011; 4(1):17-24. https://doi.org/10.1016/j.arabjc.2010.06.010.
  37. Dawood MA, Alasady ZM, Abdulazeez MS, Ahmed DS, Sulaiman GM, Kadhum AA, Shaker LM, Alamiery AA. The corrosion inhibition effect of a pyridine derivative for low carbon steel in 1 M HCl medium: Complemented with antibacterial studies. Int J Corr Scale Inhib. 2021; 10(4):1766-82. https://doi.org/10.17675/2305-6894-2021-10-4-25. 
  38. Alamiery AA. Anticorrosion effect of thiosemicarbazide derivative on mild steel in 1 M hydrochloric acid and 0.5 M sulfuric Acid: Gravimetrical and theoretical studies. Mater Sci Energy Technol. 2021; 4:263-73. https://doi.org/10. 1016/ j.mset.2021.07.004. 
  39. Alamiery AA, Isahak WN, Aljibori HS, Al-Asadi HA, Kadhum AA. Effect of the structure, immersion time and temperature on the corrosion inhibition of 4-pyrrol-1-yl-n-(2, 5-dimethyl-pyrrol-1-yl) benzoyl-amine in 1.0 m HCl solution. Inter J Corr Scale Inhib. 2021; 10(2):700-13. https://doi.org/10.17675/2305. 
  40. Haldhar R, Prasad D, Saxena A, Singh P. Valerianawallichii root extract as a green & sustainable corrosion inhibitor for mild steel in acidic environments: experimental and theoretical study. Mater Chem Front. 2018; 2(6):1225-37. https://doi. org/10.1039/C8QM00120K. 
  41. Singh AK, Shukla SK, Ebenso EE. Cefacetrile as corrosion inhibitor for mild steel in acidic media. Inter J Electrochem Sci. 2011; 6(11):5689-700.
  42. Al-Bghdadi SB, Hanoon MM, Odah JF, Shaker LM, Al-Amiery AA. Benzylidene as efficient corrosion inhibition of mild steel in acidic solution. Multidisciplinary Digital Publishing Institute Proceedings. 2019; 41(1):27. https://doi.org/10.3390/ ecsoc-23-06472. 
  43. Mahdi BS, Aljibori HS, Abbass MK, Al-Azzawi WK, Kadhum AH, Hanoon MM, Isahak WN, Al-Amiery AA, Majdi HS. Gravimetric analysis and quantum chemical assessment of 4-aminoantipyrine derivatives as corrosion inhibitors. Int J Corr Scale Inhib. 2022; 11(3):1191-213. https://doi.org/10.17675/2305-6894-2022-11-3-17. 
  44. Alamiery AA. Study of corrosion behavior of N'-(2-(2-oxomethylpyrrol-1-yl) ethyl) piperidine for mild steel in the acid environment. Biointerface Res Appl Chem 2022; 12(3):3638-46. https://doi.org/10.33263/ BRIAC123.36383646. 
  45. Sharma SK, Peter A, Obot IB. Potential of Azadirachtaindica as a green corrosion inhibitor against mild steel, aluminum, and tin: a review. J Anal Sci Technol. 2015; 6(1):1-6. https://doi.org/ 10.1186/s40543-015-0067-0. 
  46. Adejo SO, Yiase SG, Leke L, Onuche M, Atondo MV, Uzah TT. Corrosion studies of mild steel in sulphuric acid medium by acidimetric method. Inter J Corr Scale Inhib. 2019; 8(1):50-61. 
  47. Adejo SO. Proposing a new empirical adsorption isotherm known as Adejo-Ekwenchi isotherm. J Appl Chem. 2014; 6(5):66-71. https://doi.org/10.9790/ 5736-0656671.
  48. Siaka AA, Eddy NO, Idris SO, Mohammed A, Elinge CM, Atiku FA. FTIR spectroscopic information on the corrosion inhi-bition potentials of ampicillin in HCl solution. Innov Sci Eng. 2012;2 :41-8.
  49. Al-Senani GM. Corrosion inhibition of carbon steel in acidic chloride medium by Cucumissativus (cucumber) peel extract. Int J Electrochem Sci. 2016; 11(1):291-302. 
  50. Langmuir I. The constitution and fundamental properties of solids and liquids. II. Liquids. J Am Chem Soc. 1917; 39(9):1848-906. https://doi.org/ 10.1021/ja02254a006.
  51. Ho YS, Porter JF, McKay G. Equilibrium isotherm studies for the sorption of divalent metal ions onto peat: copper, nickel and lead single component systems. Water Air Soil Poll. 2002; 141:1-33.
  52. Popova A, Christov M, Vasilev A, Zwetanova A. Mono-and dicationicbenzothiazolic quaternary ammonium bromides as mild steel corrosion inhibitors. Part I: Gravimetric and voltammetric results. Corr Sci. 2011; 53(2):679-86.
  53. Mohammed A, Aljibori HS, Al-Hamid MAI, Al-Azzawi WK, Kadhum AAH, Alamiery A. N-Phenyl-N′-[5-phenyl-1,2,4-thiadiazol-3-yl]thiourea: corrosion inhibition of mild steel in 1 M HCl. Int J Corros Scale Inhib, 2024; 13(1):38-78. https://doi.org/10. 17675/ 2305-6894-2024-13-1-3.
  54. Vorobyova V, Overchenko T, Skiba M. Experimental and theoretical investigations of anti-corrosive properties of thymol. Chem Chem Techno. 2019; 13(2): 261-268. https://doi.org/10.23939/ chcht13. 02.261. 
  55. Sastri VS, Perumareddi JR. Molecular orbital theoretical studies of some organic corrosion inhibitors. Corrosion. 1997; 53(8): 33-48. https://doi. org/10.5006/1.3290294.
  56. Benali O, Larabi L, Traisnel M, Gengembre L, Harek Y. Electrochemical, theoretical and XPS studies of 2-mercapto-1-methylimidazole adsorption on carbon steel in 1 M HClO4. Appl Surf Sci. 2007; 253(14):6130-9.https://doi.org/10.1016/j.apsusc.2007. 01.075.
  57. Khaled KF, Al-Qahtani MM. The inhibitive effect of some tetrazole derivatives towards Al corrosion in acid solution: Chemical, electrochemical and theoretical studies. Mater Chem Phys. 2009; 113(1):150-8. https://doi.org/10.1016/j.matchemphys. 2008.07.060.
  58. Hmamou DB, Salghi R, Zarrouk A, Zarrok H, Touzani R, Hammouti B, El Assyry A. Investigation of corrosion inhibition of carbon steel in 0.5 M H2SO4 by new bipyrazole derivative using experimental and theoretical approaches. J Environ Chem Eng. 2015; 3(3):2031-41. https://doi.org/ 10.1016/j.jece.2015.03.018.
  59. Ma H, Chen S, Liu Z, Sun Y. Theoretical elucidation on the inhibition mechanism of pyridine–pyrazole compound: a HartreeFock study. J Mol Struct. 2006; 774(1-3):19-22. https://doi.org/10.1016/j. theochem. 2006.06.044.
  60. Mourya P, Singh P, Tewari AK, Rastogi RB, Singh MM. Relationship between structure and inhibition behaviour of quinolinium salts for mild steel corrosion: experimental and theoretical approach. Corr Sci. 2015; 95:71-87. https://doi.org/10. 1016/j.corsci.2015.02.034.
  61. Stern M, Geary AL. Electrochemical polarization: I. A theoretical analysis of the shape of polarization curves. J Electrochem Soc. 1957; 104(1):56. https://doi.org/10.1149/1.2428496.
  62. Olasunkanmi LO, Obot IB, Kabanda MM, Ebenso EE. Some quinoxalin-6-yl derivatives as corrosion inhibitors for mild steel in hydrochloric acid: experimental and theoretical studies. J Phys Chem C. 2015; 119(28):16004-19.
  63. Al-Moubaraki AH, Awaji H. 1-X-4-[4´-(-OCH3)-Styryl] pyridinium iodides, potent inhibitors for stainless steel corrosion in 2 M HCl acid solutions. International J Corr Scale Inhib. 2020; 9(2):460-501. https://doi.org/10.17675/2305-6894-2020-9-2-5.
  64. Hoseizadeh AR, Danaee I, Maddahy MH. Thermodynamic and adsorption behaviour of vitamin B1 as a corrosion inhibitor for AISI 4130 steel alloy in HCl solution. Zeitschrift Für Physikalische Chemie. 2013; 227(4):403-18.
  65. Hammouti B, Zarrouk A, Al-Deyab SS, Warad I. Temperature effect, activation energies and thermodynamics of adsorption of ethyl 2-(4-(2-ethoxy-2-oxoethyl)-2-p-tolylquinoxalin-1 (4H)-yl) acetate on Cu in HNO3. Orient J Chem. 2011; 27(1):23.
  66. Amjad Z, Landgraf RT, Penn JL. Calcium sulfate dihydrate (gypsum) scale inhibition by PAA, PAPEMP, and PAA/PAPEMP blend. Int J Corr Scale Inhib. 2014; 3(1):35-47. https://doi.org/10.17675/ 2305-6894-2014-3-1-035-047.
  67. Valle-Quitana JC, Dominguez-Patiño GF, Gonzalez-Rodriguez JG. Corrosion inhibition of carbon steel in 0.5 M H2SO4 by phtalocyanine blue. Inter Schol Res Not. 2014; 2014:432-451.
  68. Zhao P, Liang Q, Li Y. Electrochemical, SEM/EDS and quantum chemical study of phthalocyanines as corrosion inhibitors for mild steel in 1 mol/l HCl. Appl Surf Sci. 2005; 252(5):1596-607. https://doi. org/ 10.1016/j.apsusc.2005.02.121.
  69. Sakamoto K, Ohno-Okumura E. Syntheses and functional properties of phthalocyanines. Materials. 2009; 2(3):1127-79.
  70. De La Torre G, Vázquez P, Agullo-Lopez F, Torres T. Role of structural factors in the nonlinear optical properties of phthalocyanines and related compounds. Chem Rev. 2004; 104(9):3723-50. https://doi.org/10. 1021/cr030206t.
  71. García-Sánchez MA, Rojas-González F, Menchaca-Campos EC, Tello-Solís SR, Quiroz-Segoviano RI, Diaz-Alejo LA, Salas-Bañales E, Campero A. Crossed and linked histories of tetrapyrroli-cmacrocycles and their use for engineering pores within sol-gel matrices. Molecules. 2013; 18(1):588-653.
  72. Pesha T, Monama GR, Hato MJ, Maponya TC, Makhatha ME, Ramohlola KE, Molapo KM, Modibane KD, Thomas MS. Inhibition effect of phthalocyaninatocopper (II) and 4-tetranitro (phthalocyaninato) copper (II) inhibitors for protection of aluminium in acidic media. Inter J Electrochem Sci. 2019; 14(1):137-49. https://doi. org/10.20964/2019.01.17.
  73. Dibetsoe M, Olasunkanmi LO, Fayemi OE, Yesudass S, Ramaganthan B, Bahadur I, Adekunle AS, Kabanda MM, Ebenso EE. Some phthalocyanine and naphthalocyanine derivatives as corrosion inhibitors for aluminium in acidic medium: Experimental, quantum chemical calculations, QSAR studies and synergistic effect of iodide ions. Molecules. 2015; 20(9):15701-34.
  74. Xu J, Wang Y, Zhang Z. Potential and concentration dependent electrochemical dealloying of Al2Au in sodium chloride solutions. J Phys Chem C. 2012; 116(9):5689-99. https://doi.org/10.1021/jp210488t.
  75. Lagrenee M, Mernari B, Bouanis M, Traisnel M, Bentiss F. Study of the mechanism and inhibiting efficiency of 3, 5-bis (4-methylthiophenyl)-4H-1,2,4-triazole on mild steel corrosion in acidic media. Corr Sci. 2002; 44(3):573-88. https://doi.org/10.1016/ S0010-938X(01)00075-0.
  76. Mall ID, Srivastava VC, Agarwal NK, Mishra IM. Adsorptive removal of malachite green dye from aqueous solution by bagasse fly ash and activated carbon-kinetic study and equilibrium isotherm analyses. Colloid Surf A: Physicochem Eng Aspect. 2005; 264(1-3):17-28. https://doi.org/10.1016/j. colsurfa.2005.03.027.
  77. Noor EA, Al-Moubaraki AH. Thermodynamic study of metal corrosion and inhibitor adsorption processes in mild steel/1-methyl-4 [4′(-X)-styrylpyridinium iodides/hydrochloric acid systems. Mater Chem Phys. 2008; 110(1):145-54. https://doi.org/10.1016/j. matchemphys.2008.01.028.
  78. Yadav M, Kumar S, Sinha RR, Bahadur I, Ebenso EE. New pyrimidine derivatives as efficient organic inhibitors on mild steel corrosion in acidic medium: electrochemical, SEM, EDX, AFM and DFT studies. J Mol Liq. 2015; 211:135-45. https://doi.org/ 10. 1016/j.molliq.2015.06.063.
  79. Gao G, Liang C. Electrochemical and DFT studies of β-amino-alcohols as corrosion inhibitors for brass. Electrochimica Acta. 2007; 52(13):4554-9. https://doi.org/10.1016/j.electacta.2006.12.058.