Xanthione: A new and effective corrosion inhibitor for mild steel in sulphuric acid solution

Electrochemical and theoretical investigations of favipiravir drug performance as ecologically benign corrosion inhibitor for aluminum alloy in acid solution

Aluminum-silicon alloys have become a preferred option in the automotive and aerospace industries thanks to their fault-tolerant process ability and reasonable static characteristics at relatively affordable costs. This study aimed to investigate the use of favipiravir (FAV) drug as a biocompatible and eco-friendly inhibitor to protect aluminum alloy (AlSi) surface in an aggressive acid environment (1.0 M HCl). The electrochemical measurements declare that FAV is categorized as an inhibitor of mixed type with a cathodic effect. At 100 ppm, FAV had the highest inhibitory efficiency (96.45%). FAV is associated with lower double-layer capacitance values and more excellent charge-transfer resistance. These results show that AlSi corrosion in 1.0 M HCl is reduced in the presence of FAV. The Langmuir model is well-suited to the FAV adsorption behavior (R² ≈ 1). Chemisorption is the primary adsorption in this environment. The theoretical calculation studies corrosion inhibitors' molecular structure and behavior. Different quantum chemical properties of the FAV have been calculated, including energy difference (ΔE), softness, global hardness, and energy of back-donation depending on the highest occupied and lowest unoccupied molecular orbitals. In addition, Mulliken and Fukui's population analysis and the Molecular Electrostatic Potential map represent the electron distribution and the molecule's active centers. Experimental findings and quantum chemical computations matched, and FAV is recommended as a green corrosion inhibitor.

Novel ZrO2-glycine nanocomposite as eco-friendly high temperature corrosion inhibitor for mild steel in hydrochloric acid solution

We report the green synthesis of novel ZrO₂-Glycine nanocomposite referred to as ZrO₂-Gly NC followed by its characterization using X-ray diffraction (XRD), Fourier transforms infrared (FT-IR) spectroscopy, SEM/EDX, and transmission electron microscopy (TEM) techniques. Further, the inhibition effect of the varying concentration of ZrO₂-Gly NC on the corrosion of mild steel (MS) in 1 M HCl was investigated by weight loss and electrochemical measurements at 40-80 °C. The percentage inhibition efficacy of NC increased with the increase of concentration and temperature and reached about 81.01% at 500 ppm at 70 °C which decreased at 80 °C and exhibited 73.5% inhibition efficiencies. According to the polarization measurements, the investigated ZrO₂-Gly NC works as a mixed-type inhibitor with predominantly inhibiting cathodic reaction. Also, the adsorption isotherm analysis indicated that the adsorption was spontaneous and followed the Langmuir adsorption isotherm. Furthermore, the contact angle measurement revealed the water-repelling property of the investigated inhibitor. The surface morphological study via SEM-EDS micrograph affirmed the appearance of a smooth surface in presence of inhibited media suggesting the formation of protective film by the adsorption of ZrO₂-Gly NC on the surface of the MS even at higher temperature.

Spilanthes acmella Leaves Extract for Corrosion Inhibition in Acid Medium

In the present study, the corrosion inhibition effect of Spilanthes acmella aqueous leaves extract (SA-LE) on mild steel was investigated in 1.0 M HCl solution at different temperature using weight loss, Tafel polarization, linear polarization resistance (LPR), and electrochemical impedance (EIS) measurements. Adsorption of inhibitor on the surface of the mild steel obeyed both Langmuir and Temkin adsorption isotherms. The thermodynamic and kinetic parameters were also calculated to determine the mechanism of corrosion inhibition. The inhibition efficiency was found to increase with an increase in the inhibitor concentration i.e., Spilanthes acmella aqueous leaves extract, however, the inhibition efficiency decreased with an increase in the temperature. The phytochemical constituents with functional groups including electronegative hetero atoms such as N, O, and S in the extract adsorbed on the metal surface are found responsible for the effective performance of the inhibitor, which was confirmed by Fourier-transform infrared spectroscopy (FT-IR) and ultraviolet–visible spectroscopic (UV-Vis) studies. Protective film formation against corrosion was confirmed by scanning electron microscopy (SEM), atomic force microscopy (AFM), and contact angle studies. The result shows that the leaves extract acts as corrosion inhibitor and is able to promote surface protection by blocking active sites on the metal.

Corrosion Resistance of Aluminum against Acid Activation: Impact of Benzothiazole-Substituted Gallium Phthalocyanine

This study describes the adsorption behavior of organic inhibitors at the aluminum-HCl solution interface and their corrosion inhibition performance. The organic inhibitors employed are: 4-(benzo [d]thiazol-2ylthio)phthalonitrile (BTThio) and tetrakis[(benzo[d]thiazol-2-yl-thio)phthalo- cyaninato]gallium(III) chloride (ClGaBTThioPc). The corrosion behavior of these inhibitors is investigated using electrochemical and computational techniques. Open circuit potential results reveal predominant cathodic character for the mechanism of aluminum corrosion inhibition by the inhibitors. Inhibition efficiency values from potentiodynamic polarization measurements increase from 46.9 to 70.8% for BTThio and 59.7 to 81.0% for ClGaBTThioPc within the concentration range of 2 to 10 μM. Scanning electron microscopy (SEM) measurements reveal protection of the metal surface from acid attack, in the presence of the inhibitors and energy dispersive X-ray (EDX) measurements show that the most probable way by which the inhibitors protect the metal surface would be by shielding it from the corrosion attacks of Cl⁻ from the acid. Quantum chemical parameters corroborate well with experimental findings.

Investigation of myrrh extract as a new corrosion inhibitor for α-brass in 3.5% NaCl solution polluted by 16 ppm sulfide

The performance of extract of myrrh plant as corrosion inhibitor for Cu–Zn alloy in 3.5 wt% NaCl solution polluted by 16 ppm sulfide. The results demonstrated that the corrosion rate of Cu–Zn alloy was decreased in the presence of myrrh extract.

Investigation of the corrosion inhibition of carbon steel in hydrochloric acid solution by using ginger roots extract

The inhibitive effect and adsorption behavior of ginger roots extract (GRE) on the corrosion of carbon steel in 1.0 M HCl solution at different temperatures were investigated.

Electrochemical and theoretical study of the inhibition effect of two synthesized thiosemicarbazide derivatives on carbon steel corrosion in hydrochloric acid solution

The inhibition effect of two synthesized thiosemicarbazide derivatives on carbon steel corrosion was studied experimentally (FFT-Voltammetry) and theoretically.