Our study focuses on enhancing the antioxidant potential of saffron petals extract (SPE) as a sustainable corrosion inhibitor for aluminium (Al) in a 3.5% NaCl solution. The phytochemical screening ...and antioxidant activity are identified. Various investigative methodologies, including experimental techniques such as Electrochemical Impedance Spectroscopy (EIS) and Potentiodynamic Polarization (PDP), were employed to evaluate the effectiveness of this compound in inhibiting corrosion. Computational analysis, involving Density Functional Theory (DFT) and Molecular Dynamics (MD) simulations, were utilized to carry out a Theoretical study on the main constituents of SPE. The surface characteristics and composition of the corroded Al were examined using a combination of Scanning Electron Microscopy (SEM), Energy-Dispersive X-ray Spectroscopy (EDX) and Fourier Transform Infrared Spectroscopy (FT-IR). The Electrochemical results suggest that the effectiveness of the inhibitor was dependent on its concentration, reaching 95.11% at 500 ppm of SPE. The PDP indicates that mixed inhibition control effectively slowed down the corrosion of Al. Furthermore, the adsorption behaviour of SPE onto Al follows to the Langmuir isotherm model. SEM, EDX and FT-IR analyses further verified significant alterations in the surface morphology and roughness of Al and confirming the successful formation of a protective layer on the Al surface. Ultraviolet-Visible spectroscopy (UV-Vis) reveals evidence of interaction between Al and the SPE molecules. Computational studies substantiated these observations, demonstrating the reactivity and adsorption patterns of the evaluated major bioactive molecules of SPE on the Al surface.
Display omitted
•The experimental results confirmed the inhibition efficiency of SPE.•SPE demonstrated exceptional inhibitory performance over 24 hours of immersion.•SEM and FT-IR confirmed the formation of a protective layer by SPE and Al cations.•MD and DFT offered valuable insights into the adsorption of some SPE's molecules.
Three new heterocyclic diazepines (CC–diCl, CC–Cl and CC–F) were synthesized for the first time from the natural product curcumin and evaluated as non-toxic corrosion inhibitors for carbon steel (CS) ...in 1 M HCl. The evaluation was carried out using electrochemical impedance spectroscopy, polarization curves (PDP) measurement, weight loss (WL) and scanning electron microscopy studies. The molecular modeling methods: density functional theory calculations and Monte Carlo simulations were performed to obtain a good insight into the inhibition process. Results obtained from electrochemical techniques and WL tests revealed that, the studied diazepines were effective corrosion inhibitors for CS in the tested medium. Among the evaluated diazepines, CC–diCl showed the highest efficiency. According to the PDP results, the diazepines behaved as mixed-type (cathodic and anodic) inhibitors. A complete thermodynamic study was also performed on the diazepine with the highest efficiency CC–diCl to gain a better understanding of the inhibition process. The adsorption of the diazepines onto CS surface obeyed a Langmuir adsorption isotherm. A good correlation was obtained between the molecular modeling studies and inhibition efficiency (
IE
%) of the tested diazepines.
Argania spinosa
press cake, kernels and hulls extracts are excellent corrosion inhibitors for steel. In this work electrochemical methods are used to study the inhibition of corrosion on steel in 1 M ...HCl. It has shown that Argan press cake, kernels and hulls extracts suppress both the anodic and cathodic process and they behave as mixed-type inhibitors. The inhibition efficiency was found to increase with inhibitors content. Data obtained from EIS measurements, were analyzed to model the corrosion inhibition process through appropriate equivalent circuit model; a constant phase element has been used. The values of the inhibition efficiency calculated from these techniques are in reasonably good agreement. The adsorption isotherm of natural compounds on the steel surface was found to obey Langmuir’s adsorption isotherm.
The corrosion inhibition properties of 2-hydroxy-1-(2-hydroxy-4-sulfo-1-naphthylazo)-3-naphthoic acid (HHSNNA) for C38 steel in HCl 1 M solution were analyzed by electrochemical impedance ...spectroscopy (EIS), potentiodynamic polarization and gravimetric methods. It was found that the presence of HHSNNA hugely decreases the corrosion rate, while its inhibition efficiency (E%) increases with concentration to attain 93.8 % at 10
−3
M. The high inhibitory efficiency of HHSNNA was related with the adsorption of HHSNNA molecules at the metal/solution interface and a protective film formation. Adsorption behavior of the inhibitor on the surface followed the Langmuir adsorption isotherm. This compound is classified as the mixed type corrosion inhibitor with predominant control of the cathodic reaction. Data, obtained from EIS measurements, were analyzed to model the corrosion inhibition process through an appropriate equivalent circuit model.
The inhibitive action of verbena essential oil (VEO) on the corrosion of mild Steel in 1
M
HCl solutions in the temperature range 298 to 328 K was measured by use of the weight-loss method, ...potentiodynamic polarization, and electrochemical impedance spectroscopy. Results showed that VEO inhibited corrosion of C38 steel in 1
M
HCl solution and that inhibition efficiency increased with increasing concentration of inhibitor but decreased proportionally with temperature. Potentiodynamic polarization studies suggested VEO is a mixed-type inhibitor, with the anodic type predominating. Nyquist plots were depressed semicircles with their centre below the real axis. Adsorption of VEO by the C38 steel surface followed the Langmuir adsorption isotherm. Kinetic data for dissolution were investigated.
A polyethylene terephthalate membrane electrode based on clinoptilolite as the ionophore was prepared and was deposited on a gold electrode. This one was characterised with electrochemical impedance ...spectroscopy and modelled with an equivalent electric circuit. The detection of ammonium at low concentrations and the interaction with the other cations were made by impedance measurements. The study of the interaction of ammonium ions in presence with the cations such as Na
+
, Ca
2+
and K
+
in the same concentration showed that the electrode is selective and sensitive for very low concentrations 10
−7
mol/l, but the membrane is saturated for concentrations greater than 10
−2
M. The life expectancy of the membrane exceeded 50 days when we changed the PBS solution after 44 days.
