Journal of Bio- and Tribo-Corrosion, cilt.10, sa.2, 2024 (Scopus)
The inhibitory effect of ethyl 2-(2-oxo-3-phenylquinoxalin-1(2H)-yl) acetate (PQXA) on the corrosion of carbon steel (CS35) in a 1 M HCl electrolyte was investigated using weight loss, potentiodynamic polarization (PDP), electrochemical impedance spectroscopy (EIS), surface morphology, and UV–visible spectroscopy techniques. Quantum chemical calculations were also conducted to corroborate the experimental findings. The experimental results indicate that PQXA has excellent effectiveness in inhibiting the corrosion of CS35 in 1 M HCl. The inhibition efficiency demonstrated improvement with increasing concentration, reaching a maximum of 94.7% at a concentration of 10−3M at 303 K. The PDP measurements show that PQXA acts as a mixed-type inhibitor. Adsorption of PQXA on the CS35 surface conforms to the Langmuir isotherm model. UV–visible spectroscopy examinations confirmed chemical interactions between the PQXA and CS35, while the SEM/EDX analyses revealed the formation of the protective film of the inhibitor on the CS35 surface. Moreover, theoretical investigations employing density functional theory (DFT) and molecular dynamics (MD) simulation were conducted to define the nature of adsorption, the possible adsorption orientation of quinoxaline molecules on the CS35 surface, and the correlation between inhibition effectiveness and molecular structure.