Electrochemical, surface morphological and computational evaluation on carbohydrazide Schiff bases as corrosion inhibitor for mild steel in acidic medium

Abstract

Anticorrosion and adsorption behaviour of synthesized carbohydrazide Schiff bases, namely (Z)-N′-(4-hydroxy-3-methoxybenzylidene)-6-methyl-2-oxo-4-phenyl-1,2,3,4-tetrahydropyrimidine-5-carbohydrazide(MBTC) and (Z)-N′-(3,4-dichlorobenzylidene)-6-methyl-2-oxo-4-phenyl-1,2,3,4-tetrahydropyrimidine-5-carbohydrazide (CBTC) was examined for mild steel (MS) in 15% HCl medium. The corrosion inhibition study was performed by using gravimetric, thermodynamic, electrochemical and theoretical studies including density functional theory (DFT), molecular dynamic simulation (MDS) and Monte Carlo simulations (MCS). The outcomes in terms of corrosion inhibition efficiency using electrochemical impedance spectroscopy (EIS) method at 303 K and 150 ppm concentration were 96.75% for MBTC and 95.14% for CBTC. Both inhibitors adsorbed on the MS surface through physical as well as chemical adsorption and followed the Langmuir isotherm. The mixed-type nature of both inhibitors was identified by polarization results. Surface analysis was done using FESEM, EDX, AFM and XPS studies and results showed that a protective layer of inhibitor molecules was developed over the surface of MS. The results of DFT, MCS and MDS are in accordance with experimental results obtained by weight loss and electrochemical methods.

Highly Biodegradable Corrosion Inhibitors Derived from Sunflower Oil for Mild Steel Corrosion in CO2- and H2S-Saturated Oilfield-Produced Water

“…Potentiodynamic polarization analysis can help determine the effectiveness of a corrosion inhibitor by evaluating changes in the corrosion current density, corrosion potential, and polarization resistance. − Moreover, it can provide insights into the mechanism of action of a corrosion inhibitor, such as whether it acts as an anodic or cathodic inhibitor or both. , By comparison of the Tafel curves obtained in the presence and absence of an inhibitor, the effectiveness of a corrosion inhibitor can be evaluated by monitoring its impact on the corrosion current density and corrosion potential of the metal surface. By analysis of these parameters, it is possible to determine the ability of the inhibitor to reduce the corrosion current density ( i corr ) and shift the potential at which corrosion occurs toward more positive values, indicating a reduction in the corrosion activity. , This information helps in determining the inhibitive efficiency of the corrosion inhibitor. , Tafel curves, which plot i corr against the polarization potential ( E corr ) on a logarithmic scale, provide valuable insights into the corrosion process, including the anodic and cathodic reaction rates, the sensitivity of the reactions to potential changes, and the overall corrosion rate. Tafel curves of MS in CO 2 - and H 2 S-saturated water without and with different concentrations of PyQAs and PiQAs are exhibited in Figure .…”

“…By analysis of these parameters, it is possible to determine the ability of the inhibitor to reduce the corrosion current density (i corr ) and shift the potential at which corrosion occurs toward more positive values, indicating a reduction in the corrosion activity. 57,58 This information helps in determining the inhibitive efficiency of the corrosion inhibitor. 55,59 Tafel curves, which plot i corr against the polarization potential (E corr ) on a logarithmic scale, provide valuable insights into the corrosion process, including the anodic and cathodic reaction rates, the sensitivity of the reactions to potential changes, and the overall corrosion rate.…”

Design of New Ecofriendly Schiff Base Inhibitors for Carbon Steel Corrosion Protection in Acidic Solutions: Electrochemical, Surface, and Theoretical Studies

“…Schiff bases derived from amino acids were extensively recognized as green corrosion inhibitors mainly owing to their nontoxic nature and biodegradable characteristics. There have been many studies on the use of Schiff bases as corrosion inhibitors. − The outstanding performance of amino acid derivatives as anticorrosion agents in various media motivates our laboratory team to seek the materials with the highest inhibition efficiencies to supplement our previous research in this field. In this context, the current study details the synthesis of three Schiff bases derived from amino acids and 4-aminoacetophenone, namely, ( S , E )-2-(1-(4-aminophenyl)­ethylideneamino)-4-(methylthio)­butanoic acid ( AIP ), ( S , Z )-2-((1-(4-aminophenyl)­ethylidene)­amino)-3-(1 H -indol-3-yl)­propanoic acid ( AMB ), and ( S )-2-((1-(4-aminophenyl)­ethylidene)­amino)-3-(1 H -imidazol-4-yl)­propanoic acid ( AImP ).…”

Magnetic BiFeO3 Nanoparticles: A Robust and Efficient Nanocatalyst for the Green One-Pot Three-Component Synthesis of Highly Substituted 3,4-Dihydropyrimidine-2(1H)-one/thione Derivatives

“…The synthesis of nitrogen-containing 3,4-dihydropyrimidine-2(1H)-one/thione compounds (DHPMs/DHPMTs) commenced several years ago, driven by the recognition of the 3,4-dihydropyrimidinone skeleton's presence in compounds with diverse biological properties, corrosion inhibition, etc. [1][2][3] While some initial progress has been achieved, there is still a need for further exploration and expansion of the synthesis process, thus warranting continued investigation. Indeed, heterocyclic compounds occupy a crucial and indispensable domain within the field of chemistry.…”

“…Indeed, heterocyclic compounds occupy a crucial and indispensable domain within the field of chemistry. [2][3][4][5][6][7] Their fundamental role as building blocks has a significant impact on various scientific and applied disciplines. 8 Notably, a substantial number of medicinal and naturally occurring compounds possessing biological activity feature inherent heterocyclic structures.…”