Study of the synergistic effect of Mangifera indica leaves extract and zinc ions on the mild steel corrosion inhibition in simulated seawater: Computational and electrochemical studies

Computational Exploration of Phenolic Compounds in Corrosion Inhibition: A Case Study of Hydroxytyrosol and Tyrosol

The corrosion of materials remains a critical challenge with significant economic and infrastructural impacts. A comprehensive understanding of adsorption characteristics of phytochemicals can facilitate the effective design of high-performing environmentally friendly inhibitors. This study conducted a computational exploration of hydroxytyrosol (HTR) and tyrosol (TRS) (potent phenolic compounds found in olive leaf extracts), focusing on their adsorption and reactivity on iron surfaces. Utilizing self-consistent-charge density-functional tight-binding (SCC-DFTB) simulations, molecular dynamics (MD) simulations, and quantum chemical calculations (QCCs), we investigated the molecules' structural and electronic attributes and interactions with iron surfaces. The SCC-DFTB results highlighted that HTR and TRS coordinated with iron atoms when adsorbed individually, but only HTR maintained bonding when adsorbed alongside TRS. At their individual adsorption, HTR and TRS had interaction energies of -1.874 and -1.598 eV, which became more negative when put together (-1.976 eV). The MD simulations revealed parallel adsorption under aqueous and vacuum conditions, with HTR demonstrating higher adsorption energy. The analysis of quantum chemical parameters, including global and local reactivity descriptors, offered crucial insights into molecular reactivity, stability, and interaction-prone atomic sites. QCCs revealed that the fraction of transferred electron ∆N aligned with SCC-DFTB results, while other parameters of purely isolated molecules failed to predict the same. These findings pave the way for potential advancements in anticorrosion strategies leveraging phenolic compounds.

Insights into the Anticorrosion Performance of Solanum lyratum Leaf Extract for Copper in Sulfuric Acid Medium

In this paper, Solanum lyratum leaves were prepared into a corrosion inhibitor by a pure water extraction method. As a natural plant, S. lyratum leaf extract as a corrosion inhibitor has green features. S. lyratum leaf extract (SLLE) can effectively inhibit the corrosion of Cu in H₂SO₄ solution. The protective effect on copper in 0.5 mol/L H₂SO₄ solution was studied by electrochemical measurement, Fourier transform infrared spectrometry (FTIR), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), atomic force microscopy (AFM), and theoretical calculation. These results showed that the maximum corrosion inhibition efficiency (η) of SLLE for copper obtained in the electrochemical measurement at different temperatures is more than 90%. The adsorption of SLLE on copper surfaces conforms to the Langmuir isotherm adsorption model. FTIR and XPS showed the bonding information. SEM and AFM proved that the SLLE can protect the copper from corrosion media. The interaction and inhibition mechanism between the SLLE and copper surface was further revealed at the molecular level by theoretical calculation.

Application of molecular dynamics simulation for exploring the roles of plant biomolecules in promoting environmental health

Understanding the dynamic changes of plant biomolecules is vital for exploring their mechanisms in the environment. Molecular dynamics (MD) simulation has been widely used to study structural evolution and corresponding properties of plant biomolecules at the microscopic scale. Here, this review (i) outlines structural properties of plant biomolecules, and the crucial role of MD simulation in advancing studies of the biomolecules; (ii) describes the development of MD simulation in plant biomolecules, determinants of simulation, and analysis parameters; (iii) introduces the applications of MD simulation in plant biomolecules, including the response of the biomolecules to multiple stresses, their roles in corrosive environments, and their contributions in improving environmental health; (iv) reviews techniques integrated with MD simulation, such as molecular biology, quantum mechanics, molecular docking, and machine learning modeling, which bridge gaps in MD simulation. Finally, we make suggestions on determination of force field types, investigation of plant biomolecule mechanisms, and use of MD simulation in combination with other techniques. This review provides comprehensive summaries of the mechanisms of plant biomolecules in the environment revealed by MD simulation and validates it as an applicable tool for bridging gaps between macroscopic and microscopic behavior, providing insights into the wide application of MD simulation in plant biomolecules.

Corrosion inhibition of a novel antihistamine-based compound for mild steel in hydrochloric acid solution: experimental and computational studies

Focused on the assessment of the diphenhydramine hydrochloride (DPH) capabilities as an alternative to conventional and harmful industrial corrosion inhibitors, electrochemical techniques were employed. The optimum concentration of 1000 ppm was determined by molecular simulation and validated through electrochemical experiments. The results acquired from the electrochemical impedance spectroscopy (EIS) study showed that DPH at a concentration of 1000 ppm has a corrosion efficiency of 91.43% after 6 h immersion. The DPH molecules' orientation on the surface was assessed based on EIS predicting horizontal adsorption on the surface. Molecular simulations were done to explore the adsorption mechanism of DPH. The DPH molecules' orientation on the surface was also assessed based on computational studies confirming the horizontal adsorption predicted by EIS.

Insight into the anti-corrosion performance of two food flavors as eco-friendly and ultra-high performance inhibitors for copper in sulfuric acid medium

2,5-dihydroxy-1,4-dithiane (DDD) and 2,5-dimethy- [1.4] dithiane-2,5-diol (DTDD) two food flavors as environmentally-friendly inhibitors for Cu in 0.5 mol/L H₂SO₄ media were researched via theoretical calculation and experimental ways. Electrochemical measurement data showed that DDD and DTDD can exhibit high level anti-corrosion feature. The anti-corrosion efficiency of DDD and DTDD were as high as 99.6% and 98.9%, respectively. The atomic force microscope (AFM) and scanning electron microscope (SEM) tests showed that the Cu specimens were immersed in the H₂SO₄ with 5 mM DDD and DTDD for 30 h at the 298 K, and the Cu specimen surface was still smooth. Besides, the adsorption of DDD and DTDD at the interface of Cu/solution was comply with Langmuir adsorption. Theoretical calculation data showed that DDD exhibit more ascendant anti-corrosion feature than DTDD.

Stachys byzantina extract: A green biocompatible molecules source for graphene skeletons generation on the carbon steel for superior corrosion mitigation

The presence of bio-active compounds in Stachys byzantina (SB) extract has made it a powerful source of green inhibitors in controlling steel corrosion. In this study, it has been attempted to create a highly durable corrosion protective film on the surface of the metal with SB and divalent zinc (II) cations and investigated them by Electrochemical Impedance Spectroscopy (EIS) and Potentiodynamic polarization (PP) tests, and surface analysis methods. EIS results show that after 24 h of placing the steel samples in 3.5% NaCl solution containing 700 SB - 300 ZN, the synergistic corrosion inhibition behavior was about 92%. Besides, the results of the PP demonstrated a significant reduction of the i_corr. Furthermore, surface analyses such as Field Emission Scanning Electron Microscopy/Energy Dispersive X-ray Spectroscopy (FE-SEM/EDS) and Atomic Force Microscopy (AFM) images illustrated the low metal surface degradation, which indicates that the mix of SB and Zn caused a protective layer creation on the surface, especially for SB 700 - Zn 300. Also, new compounds of graphitic materials' structure were made using SB extract which is a natural-based chemical, and investigated by Fourier-Transform Infrared Spectroscopy (FTIR) test, Grazing Incidence X-ray Diffraction (GIXRD) technique, Ultraviolet-visible spectroscopy (UV-Vis) analysis, and Raman spectroscopy.

Insight into anti-corrosion nature of Betel leaves water extracts as the novel and eco-friendly inhibitors

In this paper, the simple and low-cost water extraction way was used to acquisition Betel leaves extracts (BLE). The water as the extraction solvent has the characteristics of low price, environmentally friendly, and good solubility for other extraction solvents. BLE was researched as an environmental-friendly inhibitor via various experimental methods and theoretical calculations. Electrochemical experiments manifest that BLE can restrain reactions of the cathode and anode of Q235 steel. The BLE concentration was 400 mg/L, the anti-corrosion efficiency was close to 94%. The experimental data show that BLE can show high-quality anti-corrosion nature for Q235 steel immersing in 1 M hydrochloric acid (HCl) environment at a certain temperature range. The morphology maps of scanning electron microscope (SEM) and atomic force microscopy (AFM) strongly proves the data of electrochemical experiments. In addition, the BLE adsorption at the Q235 steel surface belongs to the Langmuir mono-layer adsorption. Quantum chemical calculations (QCC) and molecular dynamics simulations (MDS) effectually manifest that BLE can show decent anti corrosion character.