Exploring the Experimental and Theoretical Studies and Inhibition Mechanism of Passiflora Incarnata Extract as a Novel Green Inhibitor for API 5CT N80 in an Aggressive Environment

Corrosion is a crucial problem worldwide that heavily affects natural and industrial environments and can cause machinery breakdown and deterioration of construction assemblies, thus threatening the lives of humans and accelerating the consumption of natural metal reservoirs. In this study, we deployed passiflora incarnata extract (PIE) as an eco-friendly green inhibitor to prevent API 5CT N80 (CS-N80) corrosion in 1 M HCl. The chromatograms of the gas chromatography-mass spectroscopy analysis of PIE have identified 25 compounds. The weight loss method reveals that 150 ppm of the extract offers 90.4% inhibition efficiency (IE) to CS-N80 immersed in 1 M HCl solution at 25 °C. However, at higher temperatures (45 °C), % IE increases and reaches 92.1%. The electrochemical characterization of the adsorbed layer on CS-N80 was tested by utilizing electrochemical methods (electrochemical impedance spectroscopy and polarization) in 1 M HCl. Polarization diagrams displayed that PIE is a mixed-type inhibitor that retards CS-N80 corrosion. Temkin adsorption isotherm is the best fit for adsorbed PIE on the CS-N80 surface. IE was improved by raising the temperature (chemical adsorption). Examining the morphology of CS-N80 sheets through scanning electron microscopy, energy-dispersive X-ray, X-ray photoelectron spectroscopy, and Fourier transform infrared analysis furnishes valuable insights into their surface characteristics. The results of a quantum chemical computation show that the three PIE components have strong anticorrosion properties. According to findings from molecular dynamics simulations, the three PIE components can have a high binding energy and can be adsorbed in a parallel manner at the Fe(110) surface. All tests have shown that the PIE composite conversion adsorbed with a self-healing property and lower corrosion current density was precipitated on the steel surface.