Steel In Acidic Environment Research Articles

Eco-friendly corrosion inhibition of steel using phenolic compounds from Cynara syriaca

This study evaluates the corrosion inhibition performance of the n-butanol (n-BuOH) fraction derived from Cynara syriaca on mild steel in acidic environments. The n-BuOH fraction achieved up to 94 % inhibition at 500 ppm, as assessed through gravimetric analysis, potentiodynamic polarization (PDP), and electrochemical impedance spectroscopy (EIS). Key phenolic compounds, including kaempferol, naringenin, myricetin, chlorogenic acid, and quercetin, were identified by UPLC-MS/MS. These compounds form stable flavonoid-metal complexes, as confirmed by UV–Vis spectroscopy. FT-IR and SEM-EDS analyses revealed the formation of protective coatings and interactions with the steel surface. Polarization curves indicate that the n-BuOH fraction acts as a mixed-type inhibitor, predominantly affecting the anodic reaction. The inhibition efficiency decreased from 93.89 % to 73.43 % with increasing temperatures. Thermodynamic analysis showed an increase in activation energy (Ea = 58.20 kJ/ mol) and a positive ΔH value of 56.17 kJ/mol, which can be attributed to the increased thickness of the double layer, enhancing the activation energy of the corrosion process. A Gibbs free energy (ΔG0ads) value of −25.48 kJ/mol confirms that the adsorption process is spontaneous and involves both physisorption and chemisorption. pKa analysis identified specific adsorption sites. This research underscores the potential of the n-BuOH fraction as a novel, eco-friendly corrosion inhibitor, offering valuable insights for sustainable corrosion control strategies.

Exploring the potent corrosion inhibition properties of phenolic Schiff bases on mild steel in acidic environments, part A: coupling experimental and theoretical investigations.

In this study, we conduct a comparative investigation into the corrosion inhibition properties of two Schiff base compounds, namely 4,4'-((1E,1'E)-(ethane-1,2 diylbis(azaneylylidene))bis(methaneylylidene))diphenol (PSB5) and (1E,1'E)-N,N'-(ethane-1,2 diyl)bis(1-(4-nitrophenyl)methanimine) (PSB6), on mild steel in an acidic environment. The inhibitory efficiency and adsorption behavior of the inhibitors were assessed through electrochemical and gravimetric analyses. The inhibitors' deposition was further verified by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The findings of electrochemical tests demonstrate that these chemical compounds are potent inhibitors, with 96.5% inhibition provided by PSB5 at 10-3M. Therefore, PSB5 and PSB6 inhibitors are likely of mixed-form, as evidenced by changes in their Ecorr values of 59.8 mV and 33.0 mV, respectively when compared to the blank solution. Furthermore, the adsorption of these inhibitors onto the MS surface, as determined by the Langmuir adsorption isotherm, yielded free energy values of - 38.40 kJ mol-1 for PSB5 and - 35.20 kJ mol-1 for PSB6. These findings highlight a robust and spontaneous adsorption process for both inhibitors. Surface analysis using SEM-EDS revealed the preservation of the mild steel surface morphology and the adsorption of inhibitors. Theoretical investigations utilizing density functional theory (DFT) and molecular dynamics (MD) simulations supported and complemented the experimental findings. This research enhances the understanding of the corrosion protection potential of Schiff base compounds and their potential applications in various industries.

N, S-Codoped Carbon Quantum Dots with High Inhibition Efficiency: Implications for Corrosion Mitigation of Carbon Steel in Acidic Environments.

The environmental friendliness, economic feasibility, and high efficiency of carbon quantum dots (CQDs) render them as highly promising candidates for corrosion inhibitors. The present study proposed the fabrication of nitrogen- and sulfur-codoped CQDs via an one-step hydrothermal method using l-cysteine and 4-aminosalicylic acid as precursors. The structure, particle size, and surface ligands of the prepared CQDs were determined through spectroscopy and transmission electron microscopy characterization. Subsequently, the inhibition performance of the CQDs on carbon steel in a 0.5 M sulfuric acid solution was evaluated through weight loss measurement, electrochemical methods, and surface analysis. The CQDs exhibited remarkable inhibition efficiencies of 97.9% at 293 K and 98.9% at 313 K, with a concentration of 150 ppm. In addition, the obtained CQDs demonstrated a combined physisorption and chemisorption adsorption behavior, which complied with the Langmuir adsorption isotherm. These findings provide insight into the inhibition mechanism and highlight the potential of codoped CQDs for corrosion mitigation applications in acidic environments.

Eco-friendly Chlorella vulgaris extracts for corrosion protection of steel in acidic environments

This study evaluates the potential of Chlorella vulgaris sp. extracts as eco-friendly corrosion inhibitors for API 5L 42 Steel in a 1M HCl acidic environment, offering sustainable alternatives for industrial applications. Two corrosion inhibitors were obtained through solvent extraction methods: M1 (methanol) and M2 (methanol/chloroform). The extracts were characterized using infrared spectroscopy, the analysis revealed hydroxyl, methyl and vinyl groups as the most representative. The effect of corrosion inhibition was study by electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization. The results show significant reductions in corrosion current density and increases in charge transfer resistance, with M2 achieving the highest protection efficiency of 91.20 % and a charge transfer resistance of 501.80 Ω at a 120 ppm concentration, while M1 reached 88.22 % efficiency with a charge transfer resistance of 102.30 Ω. Uv–Vis measurements were performed to determine the electronic transitions of the metal-inhibitor system for each of the extracts. ANOVA highlighted the significant influence of biomass concentration on corrosion resistance. The adsorption of M1 and M2 extracts on the carbon steel surface obeyed the Langmuir isotherm and Gibbs free energy calculations indicated a physisorption mechanism for both extracts. Surface morphology analysis by Scanning electron microscope (SEM) revealed less pitting and reduced surface roughness as inhibitor concentration increased. These findings underscore the potential of Chlorella vulgaris extracts, particularly M2 at 120 ppm, as effective and sustainable corrosion inhibitors for steel in acidic environments.

Assessment of Eichhornia crassipes as a Green Corrosion Inhibitor for AISI 1005 Steel in Acidic Environments

Assessment of Eichhornia crassipes as a Green Corrosion Inhibitor for AISI 1005 Steel in Acidic Environments

Synthesized Heterocyclic Compounds as Corrosion Inhibitors for Steel in Acidic Environments: A Mini-Review

Corrosion is a significant problem in various industries, leading to the degradation of steel structures and causing significant economic losses. Heterocyclic compounds, which contain heteroatoms such as nitrogen, sulfur, and oxygen, have been found to be effective corrosion inhibitors for steel in acidic environments. This mini-review discusses the synthesis and use of heterocyclic compounds as corrosion inhibitors for steel in acidic solutions. The review highlights the potential of these compounds as effective and low-cost corrosion inhibitors for various industries.

Eggshell waste extract as potential natural corrosion inhibitor for AISI 1020 steel in acidic environment

Eggshell waste extract as potential natural corrosion inhibitor for AISI 1020 steel in acidic environment

Imidazole derivative for corrosion protection: A comprehensive theoretical and experimental study on mild steel in acidic environments

The inhibition efficiency derivative imidazole, 2-mercapto-5,5-diphenyl-3,5-dihydro-4 H-imidazol-4-one (AM0), against corrosion in a hydrochloric acid (HCl) environment was studied. The research focused on the compound's ability to adsorb onto mild steel surfaces. Various experimental techniques, including potentiodynamic polarization (PDP), electrochemical frequency modulation (EFM), and impedance spectroscopy (EIS), were employed to analyze the inhibitory effects. Results showed that the effectiveness of AM0 increased with concentration, reaching an inhibitory efficiency of 95.1 %. Polarization studies revealed that the inhibitor displayed mixed-type behavior. The adsorption process was modeled using the Langmuir adsorption model. Surface characterization techniques such as scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDS), and X-ray photoelectron spectroscopy (XPS) were utilized to examine the inhibited corrosion surfaces. Theoretical calculations based on density functional theory (DFT) and density functional tight binding (DFTB) suggested that inhibitors with electron-accepting capabilities exhibited strong interactions with the iron surface, shedding light on specific bond formations that contribute to the stability and interaction dynamics at the molecular interface. This study provides valuable information on the corrosion inhibition potential of the new imidazole compound, offering important pointers for the development of effective corrosion inhibitors in acidic environments.

Optimization, molecular dynamics and quantum parameters simulations of Zingiber officinale rhizome as a green corrosion inhibitor

This study combines experimental and theoretical approaches to investigate ginger root extract (GRE) as an eco-friendly corrosion inhibitor for mild steel in acidic environments at temperatures ranging from 303 to 333 K. Experimental techniques, including weight loss measurements, were used to assess the inhibiting performance and adsorption behavior of GRE, while GC-MS, FT-IR, and UV–visible spectrophotometric methods provided further characterization. Results indicated that the inhibition efficiency of GRE increased with higher concentrations and decreased with temperature, highlighting its potential to effectively prevent corrosion in H2SO4 medium. GC-MS analysis identified four major phenolic compounds—6-gingerol, 6-isoshogaol, zingerone, and vanillyl glycol—and two secondary metabolites, α-Farnesene and β-Bisabolene. Among these, 6-gingerol, the most active and abundant constituent, was selected for computational studies. Optimal corrosion inhibition of 81.3 % was achieved at 303 K with a GRE concentration of 10 g/L for 1 h. Thermodynamic activation parameters suggested a temperature-dependent process, and alignment with the Langmuir isotherm indicated a physical adsorption mechanism. Quantum chemical calculations for 6-gingerol revealed highest occupied molecular orbital energy (EHOMO) and lowest unoccupied molecular orbital energy (ELUMO) values of -6.286 eV and -0.366 eV, respectively, in its protonated state, and -8.338 eV and -0.247 eV, respectively, in its neutral state. Molecular simulations showed a binding affinity of -4.736 kJ/mol between 6-gingerol and the steel surface, supporting the experimental findings and underscoring the potential of GRE as an effective corrosion inhibitor.

Advanced evaluation of novel quinoline derivatives for corrosion inhibition of mild steel in acidic environments: A comprehensive electrochemical, computational, and surface study

Corrosion poses a significant threat to the integrity and longevity of iron and its alloys, which are crucial materials for modern industry and infrastructure. This study investigates the effectiveness of two recently synthesized inhibitors based on quinoline structures: MPQ (2-methyl-5-(propoxymethyl) quinolin-8-ol) and AAQ ((((2-aminoethyl)amino)methyl)-2-methylquinolin-8-ol) in protecting steel against environmental degradation, particularly in acidic and chloride-rich conditions such as hydrochloric acid. The inhibitors exhibited significant corrosion inhibition efficiencies of 92.37 % for MPQ and 84.13 % for AAQ, as demonstrated through electrochemical analysis. Surface characterization techniques, including SEM-EDX(Scanning Electron Microscopy with Energy Dispersive X-ray analysis), AFM (Atomic Force Microscopy), and contact angle measurements, revealed the formation of a protective barrier film that reduces the corrosion rate. Additionally, theoretical calculations using the Gaussian package provided insights into the adsorption behaviors and protective mechanisms of the inhibitors on mild steel surfaces. The findings contribute to the ongoing search for viable corrosion inhibitors, offering prospects for application in industries and critical infrastructures to enhance corrosion protection and durability.

Enhanced Corrosion Resistance of Mild Steel in Acidic Media Using PVA‐Chitosan‐Dopamine Composite Coatings

AbstractIn this study, corrosion control of mild steel in acidic media was conducted in the presence of polyvinyl alcohol (PVA)‐chitosan and PVA‐chitosan‐dopamine composite coatings. Weight loss, polarization, and electrochemical impedance spectroscopy (EIS) studies were conducted to study the protective mechanisms and performance of PVA‐chitosan coatings. The results showed a substantial reduction in weight loss, corrosion rates, and corrosion current densities for coated specimens indicating the effectiveness of the composite coatings. PVA‐chitosan and PVA‐chitosan‐dopamine coatings showed high inhibition efficiencies (IE) up to 90.65 % and 96.01 % respectively. The electrochemical findings were supported using surface characterization techniques such as SEM to obtain a complete understanding of the coatings’ morphology and composition. The topographical analysis confirmed that dopamine significantly influenced the surface morphology and behavior of the nanocomposite. The FTIR spectrum of composite B, which combined PVA and chitosan, exhibited notable changes, including a decrease in both the intensity and frequency of the OH band. The potential of PVA‐chitosan‐dopamine coatings as effective corrosion inhibitors for mild steel in acidic environments offered practical solutions for diverse industrial applications.

Enhancing corrosion resistance of 316L stainless steel through electrochemical deposition of polyaniline coatings in acidic environments

Stainless steel is widely used because of its excellent corrosion resistance in typical environments. However, it is susceptible to corrosion in acidic media, therefore, to address this issue, the electrochemical deposition of polyaniline coatings on 316L stainless steel was investigated using cyclic voltammetry at different potential windows and scan rates. The successful polymerization and surface morphology were analyzed using Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM), respectively. Moreover, thermal stability of the PANI coating was assessed through thermo gravimetric analysis while the corrosion behavior of bare and coated steels immersed in 1M H2SO4 was studied using electrochemical impedance spectroscopy (EIS). Based on the Nyquist plots obtained from the EIS revealed that the corrosion resistance of the PANI coating improved significantly with a decrease in scan rate and by limiting the upper potential, especially during longer exposure times up to 72 h. Results suggest that controlling the deposition parameters and optimizing the electrochemical conditions can lead to even greater improvements in the corrosion resistance of the stainless steel. These findings offer valuable insights for researchers and engineers in the field of materials science and corrosion protection, enabling them to develop more precise and efficient strategies for enhancing the durability and performance of stainless steel in acidic environments.

Investigating the efficacy of phenolic Schiff bases as corrosion inhibitors for mild steel in acidic environments: Integrating experimental and theoretical approaches (Part B)

Our research employs a holistic methodology to assess the efficacy of a series of phenolic Schiff bases as corrosion inhibitors for mild steel in a 1 M HCl solution. Through complementary studies, we aim to unravel the corrosion inhibition mechanism by investigating neutral, protonated, and complex forms of inhibitors using advanced computational and statistical methods. This initial investigation specifically involves evaluating the effectiveness of two phenolic Schiff bases through weight loss tests (WL) and electrochemical techniques. The study focuses on the corrosion inhibitory properties of two phenolic Schiff bases, namely 4,4′-((1E,1′E)-(ethane-1,2-diylbis(azaneylylidene))bis(methaneylylidene))diphenol (PSB7) and (1E,1′E)-N,N'-(ethane-1,2-diyl)bis(1-(4-nitrophenyl)methanimine) (PSB8), on mild steel (MS). Results from weight loss and electrochemical methods indicate that inhibition efficiency improves with decreasing temperature and increasing inhibitor concentration, reaching 94 % (for PSB7) and 93 % (for PSB8) at 303 K and 1 × 10−3 M, respectively. Consequently, both PSB7 and PSB8 function effectively as inhibitors in a mixed form. The adherence of both inhibitors to the surface follows the Langmuir adsorption isotherm model. Additionally, SEM and EDS experiments provide evidence of adsorption on the surface. The findings from Density Functional Theory (DFT) and Molecular Dynamic Simulations (MDS) consistently match the actual data, maintaining the order of inhibition efficiency (PSB7 > PSB8).

Verbena officinalis (VO) leaf extract as an anti-corrosion inhibitor for carbon steel in acidic environment

In the present work, Verbena Officinalis (VO) leaf extract was used as potential corrosion inhibitor for the corrosion of carbon steel (CS) in 0.5 M H2SO4 medium. Further, the corrosion inhibiting nature of VO leaf extract towards the CS was evaluated using mass loss (ML), potentiodynamic polarization (PDP), electrical impedance spectroscopy (EIS) and surface morphological analyses using atomic force microscope (AFM) and X-ray photoelectron spectroscopy (XPS) techniques. Calculation of activation energy Ea∗\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\left( {{\ ext{E}}_{{\ ext{a}}}^{*} } \\right)$$\\end{document} using Arrhenius equation shows the increase in activation energy when adding the VO leaf extract in 0.5 M H2SO4 medium and the maximum activation energy (Ea∗\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${\ ext{E}}_{{\ ext{a}}}^{*}$$\\end{document} = 49.9 kJ mol−1) was observed for 1000 mg L−1 VO leaf extract in acid medium. The negative free energy values suggested the spontaneous and the stability of the adsorbed layer of VO leaf extract on the CS surface. Using EIS measurements, high percent inhibitory effectiveness of 91.1% for 1000 ppm solutions was achieved. With an increase in VO leaf extract dose, the double layer capacitance (Cdl) values fall while the values of charge transfer (Rct) increase. This showed that a protective layer of VO leaf extract on CS surface was formed. The polarization curves showed that the VO leaf extract acts as a mixed-type inhibitor. It is discovered that the adsorption of VO leaf extract molecules adhering to the CS surface followed the Langmuir isotherm. The anti-corrosion action of VO leaf extract is fully demonstrated by some surface techniques.

Facile synthesis, corrosion inhibition, adsorption and DFT studies of 2-(4-(methylsulfanyl) phenyl) −4, 5-diphenyl-1H-imidazole for mild steel in acidic environment

A green, solvent-free, cost effective one-pot synthesis method is employed to produce the innovative corrosion-inhibiting compound 2-(4-(methylsulfanyl)phenyl)-4,5-diphenyl-1H-imidazole (MDPI). The molecular structure of MDPI can be identified using CHN analyses, FT-IR, 1H and 13C NMR spectra. Various electrochemical and gravimetric techniques are utilized to evaluate the anti-corrosion properties of MDPI. The results indicate that MDPI effectively inhibits the corrosion of mild steel under all tested conditions. At 306 K, MDPI achieved a maximum corrosion inhibition efficiency of 98.01 % at a concentration of 10 mM. MDPI exhibited strong adsorption and excellent anti-corrosion properties, forming a protective layer on the mild steel surface. The Langmuir adsorption isotherm, with a ΔGoads value of −39.55 kJ/M was found to be more suitable for this study, indicating that the process occurred by physisorption. Tafel curves indicated that MDPI functions as a mixed-type corrosion inhibitor. Surface characteristics were analyzed using scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), and atomic force microscopy (AFM). Quantum chemistry studies revealed a HOMO-LUMO energy gap of 3.926 eV, corroborating the anti-corrosion effectiveness of MDPI in hydrochloric acid solution. MDPI exhibited promising anti-corrosion activity due to its heterocyclic ring containing nitrogen heteroatoms as well as a methylsulfanyl functional group.

The application of 2-(3-nitrophenyl)imidazo[1,2-α]pyridine as an effective corrosion-defender for steel in acidic environment

Metal corrosion in acidic settings presents serious problems for many industrial areas. The creation of corrosion inhibitors that are efficient, long-lasting, and ecologically benign is essential. This study introduces a novel corrosion inhibitor, 2-(3-nitrophenyl)imidazo[1,2-α]pyridine (NIP), which was synthesized for protecting mild steel in 1 M HCl. The synthesized NIP was evaluated using Electrochemical Impedance Spectroscopy (EIS), Potentio-dynamic Polarization (PDP), Scanning electron microscopy (SEM), Energy X-ray analysis (EDX), and theoretical approache, including Density Functional Theory (DFT) and Monte Carlo simulations (MCs). NIP demonstrated outstanding protection behavior, reaching a peak of 91.47 % at a concentration of 1.00 mM. PDP studies classified NIP as a mixed-type inhibitor that effectively mitigated both anodic and cathodic reactions. SEM and EDX analysis confirmed the formation of a protective layer on the surface of the structural steels, composed mainly of nitrogen and oxides, indicating the presence of the inhibiting agent. DFT calculations identified the imidazole ring and heteroatoms (N and O) as the active sites for corrosion inhibition. The adsorption behavior of NIP on the metal surface has been studied by means of Monte Carlo simulations. The inhibitory efficiency of NIP was evaluated across a temperature range of 298–323 K, and the results showed a decrease in efficacy with increasing temperature, which provides crucial information for practical applications. The Langmuir model fit indicated a mixed mode of physical and chemical adsorption, with a calculated ΔG°ads value of −33.76 kJ/mol. This novel approach pinpointed reactive sites within the NIP, enhancing our understanding of its protective mechanism at the molecular level.

Investigation of Garcinia kola Exudates as Corrosion Inhibitor for Mild Steel in Acidic Environment

This study investigated the performance of Garcinia kola exudates in preventing mild steel exposed to acid concentrated water and soil. The study was performed in order to find an alternative coating substance that can reduce the corrosion of mild steel pipes exposed to corrosive water and soil media. Various mild steel specimens were cut into portions and coated with the exudates at 25 - 50µm thickness. To accelerate the rate of corrosion, 0.5M hydrochloric acid (HCl) was added to tap water in a container. Also, the same concentration of HCl was equally added to soil samples. Uncoated mild steel specimens were immersed in the acid concentrated water and soil, servicing as control sample. The rate of corrosion was monitored for 30 days (720 hours). The inhibition efficiency of the exudates for both corrosive media was compared. Results showed that the weight loss and corrosion rate of mild steel decreased with increase in coating thickness. Comparatively, weight loss and corrosion rate in the uncoated specimens were higher than the coated specimens. For uncoated specimens, the corrosion rate was 0.2793mm/yr and 0.4150mm/yr for specimen immersed in water and soil respectively, but at 25µm coating thickness, it decreased to 0.01369mm/yr and 0.2870mm/yr for specimens in water and soil. Also, at 50µm coating thickness, corrosion rate decreased to 0.0052mm/yr and 0.0318mm/yr for specimens in water and soil, respectively. The inhibition efficiency increased with coating thickness, ranging from 51.00 – 98.15% for specimens immersed in water and 30.84 – 92.33% for specimens buried in soil at 25µm – 50µm coating thickness. The results demonstrated that Garcinia kola exudates can be used as corrosion inhibitor for mild steel exposed to corrosive media.

Thiol-ene Click Chemistry Synthesis of L-Cysteine-Grafted Graphene Oxide As a New Corrosion Inhibitor for Q235 Steel in Acidic Environment.

l-cysteine, as an eco-friendly and nontoxic corrosion inhibitor, was directly covalently linked to the carbon/carbon double bonds of the GO flakes by a thiol-ene click reaction to avoid decreasing the number of hydrophilic oxygen-containing polar functionalities. The corrosion inhibition performances of Cys-GO toward Q235 steel (QS) in diluted hydrochloric acid were studied by electrochemical methods. The corrosion was a charge transfer-controlled process, and Cys-GO manifested as a mixed-type corrosion inhibitor. The corrosion inhibition efficiency (η) for QS showed a first-increase-and-then-decrease trend with increasing Cys-GO concentrations. The optimum concentration of Cys-GO was 15 mg L-1, and the according η value was up to 90%. The Cys-GO adsorbed on the QS surface to form a protective barrier was responsible for the efficient corrosion inhibition. Langmuir adsorption isotherm model was fitted well with the experiment data, indicating a monolayer adsorption. Furthermore, the coordinate covalent bonds, π-back-donation effect, and electrostatic attraction were responsible for the Cys-GO adsorption on the QS surface.

Synthesis and characterization of a new eco-friendly dopamine derivative schiff base as an effective corrosion inhibitor for mild steel in acidic environment

The natural corrosion inhibitor behaviour of a newly synthesized dopamine derivative Schiff base (4-DBAB) has been inspected on mild steel in aggressive 1 M HCl using linear polarization, electrochemical impedance spectroscopy and potentiodynamic polarization techniques. The Schiff base was synthesized by eco-friendly pathway. Characterization of the synthesized new non-toxic inhibitor was performed using FT-IR and 1H-NMR spectroscopy techniques. The anti-corrosive efficiencies at optimum concentration of 4-DBAB inhibitor was 87.4% after 1 h and 98.4% after 120 h by impedance technique in acidic solution. The potential of zero charge of mild steel was also determined to elucidate the inhibition mechanism in the presence of the highest 4-DBAB solution. The atomic force microscopy and field emission scanning electron microscopy researches performed on surface morphology to provide additional support on the interaction between the mild steel surface and 4-DBAB molecules. Adsorption behaviour of the inhibitor was also studied at different durations by experimental inhibition results and showed the Langmuir isotherm involving chemisorption. Highlights A new dopamine-derived Schiff base (4-DBAB) with natural and environmentally friendly corrosion inhibition properties was synthesized. (Synthesis of eco-friendly compound). 4-DBAB demonstrated a high anti-corrosive efficiency after 120 hours in aggressive 1M HCl, as determined by impedance technique. (Exceptional corrosion inhibition). The determination of the potential of zero charge of mild steel provided insights into the inhibition mechanism in the presence of the highest 4-DBAB solution. (Mechanism elucidation). AFM and FE-SEM studies on surface morphology supported the interaction between the mild steel and 4-DBAB molecules, affirming its corrosion inhibition properties. (Surface interaction analysis).

Synthesis and evaluation of a novel pyridinyl thiazolidine derivative as an antioxidant and corrosion inhibitor for mild steel in acidic environments

A new synthesized (Z)-2-((3,5-dichloropyridin-2-yl)imino)thiazolidin-4-one (DICPT) was evaluated as an antioxidant and a corrosion inhibitor for mild steel (M.STL) in a 0.5 M HCl solution. The antioxidant activity of newly synthesized DICPT was screened using a DPPH assay, and the results showed that DICPT has good antioxidant activity. Electrochemical assessments were conducted utilizing potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS). A new compound, DICPT, was synthesized, and its chemical structure was established and validated through various spectroscopic techniques, including including infrared (FTIR), nuclear magnetic resonance (NMR), and mass spectroscopy. PDP measurements revealed DICPT to be a mixed-type inhibitor. Charge transfer resistance (Rct) increased when inhibitor concentrations increased, according to EIS tests. The inhibition efficiency (%I) showed a corresponding rise with increasing inhibitor concentration, peaking at approximately 94.2 % at 3 × 10−5 M. Langmuir’s adsorption isotherm was found to govern the preferred adsorption mode of DICPT molecules onto the metal surface. UV–visible spectra confirmed the chemical interaction between DICPT molecules and the M.STL surface. AFM investigation indicated the formation of a protective layer on the metal surface, shielding it from corrosive environmental factors. Quantum chemical calculations were compared to experimental results to learn more about how corrosion is stopped and how well it works. Our study demonstrates the innovation of DICPT as a dual-function compound, offering both antioxidant and corrosion protection properties. This research contributes to the development of effective corrosion inhibitors for industrial applications.