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In this paper, we compared the corrosion inhibiting effect of two essential oils on mild steel in 1 M HCl. The essential oils are extracted from natural plants harvested in Morocco and prepared through distillation. To carry out this work, we used gravimetric and electrochemical methods, including current-potential plots and impedance spectroscopy. The results obtained show that both essential oils are a good corrosion inhibitor and that the inhibition efficiency of wormwood essential oil reaches a value of more than 80 % at 298 K. To learn the fundamentals of how inhibitors interact with metal surfaces, wormwood essential oil adsorption on a mild steel surface was also investigated. The Langmuir isotherm model is revealed to be how the essential oils adsorb on the metal surface. The effect of temperature on the performance of mild steel in 1 M HCl with wormwood essential oil was examined in the temperature range of 313 to 353 K. Additionally, calculations and discussions are made to provide some thermodynamic data for the adsorption processes. This work enters the framework for the use of non-toxic products in green chemistry. [ABSTRACT FROM AUTHOR]

[Display omitted] • Juniperus oxycedrus essential oil was extracted through hydrodistillation for use as a potential and ecofriendly corrosion inhibitor for mild steel in 1 M HCl solution. • Juniperus oxycedrus essential oil presents excellent inhibition efficiency (for PDP and EIS) at 2 g/L. • SEM/EDS analysis showed that the Juniperus oxycedrus could effectively block the Cl- ions attack by chemisorption on the MS surface. • DFT, MC, MDs, and experimental data lead to use and investigate the essential oil as a potential anticorrosive protection for MS in 1 M HCl solution. This study focuses on exploring the corrosion inhibiting properties of the essential oil derived from Juniperus Oxycedrus (JO) originating from the Middle Atlas region in Morocco (Ait Attab) on mild steel in a 1.0 M HCl acid medium. This essential oil was analyzed using gas chromatography-mass spectrometry, which identified the major components of the inhibitor, primarily including bornyl acetate/C 12 H 20 O 2 (31.17 %), Bicyclo [2.2.1] heptan-2-one, 1,7,7-trimethyl- (1S)/C 10 H 16 O (30.16 %), and α-pinene/C 10 H 16 (9.88 %). The corrosion inhibition behavior was assessed using electrochemical measurements (potentiodynamic polarization measurements (PDP) and electrochemical impedance spectroscopy (EIS)) and thermodynamic parameters and kinetic (ΔHa, ΔSa et Ea). The result demonstrates that the essential oil of (JO) exhibits intriguing anticorrosive action, with an inhibition efficiency of 89.6 % at an inhibitor concentration of 2 g/L at 298°K. Additionally, the essential oil acts as a mixed-type inhibitor. Furthermore, EIS data and SEM/EDS analysis revealed that the nature of the adsorption of essential oil molecules on the mild steel surface is controlled by Langmuir adsorption isotherm, forming a protective film that shields the steel from acid attack. Density functional theory (DFT), molecular dynamic (MD) and Monte Carlo (MC) simulations were used to support the experimental results. The global and local chemical reactivity descriptors of the individual inhibitors were calculated using B3LYP functional, while the adsorption energy of the inhibitors on the steel surface were performed using MD and MC methods. [ABSTRACT FROM AUTHOR]

• Gum Arabic variants as a potential green inhibitors for mild steel corrosion. • The adsorption process of GAMo, GAMau, and GASe follows Langmuir isotherm. • The Gum Arabic variants are a mixed-type of corrosion inhibitors with physical/chemical adsorption. • Surface characteristics analysis confirmed the formation of a protective layer on mild steel. Corrosion prevention in the food industry is a significant issue given the harsh conditions under which many production processes are performed. Therefore, we developed a methodology to test and analyze the novel type of green corrosion inhibitors for mild steel (M.S) in an acidic medium based on the Arabic gum (GA) variants from Morocco (GAMo), Mauritania (GAMau), and Senegal (GASe) in which these three variants were characterized by FTIR analysis, Weight loss (WL) measurements and electrochemical tests such as potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS) methods were also used to investigate the inhibition power of these compounds for the corrosion of M.S in 1 M HCl. The surface characterization of M.S surface submerged in the optimal solution of the three compounds was carried out using XPS and AFM analyses. The results from this corrosion test demonstrate that these chemical compounds might be used as mixed-type corrosion inhibitors achieving the highest inhibition at 1 g/L, and the η max of GAMo, GASe and GAMau reached up to 96%, 95% and 94%, respectively. Spectroscopic and gravimetric analyses revealed that the highest corrosion inhibition for the GAMo variant due to the physical and chemical mechanism according to the pattern: GAMo > GASe > GAMau. The Langmuir adsorption isotherm governs the adsorption of all GA variants on mild steel surfaces, increasing the polarization resistance and inhibition efficiency and decreasing the double-layer capacitance in a concentration-dependent manner. A CPE, Q determined by fit and graphical methods plotted by synthetic data, was utilized. Using atomic force microscopy (AFM) and X-ray photoelectron spectroscopy, the formation of a protective layer on the steel surface was further confirmed (XPS). The final QSAR model for the Arabic gum indicated the same effect of lipophilicity on corrosion inhibition. Overall, the current study provides valuable information on the AG variants to be used as a novel class of green corrosion inhibitors for the biotechnology and food industry. [ABSTRACT FROM AUTHOR]