Green Corrosion Inhibition of Carbon Steel by Expired Sulfaquinoxalineq Drug in 1 M HCl Medium: A Comprehensive Study

Expired Sulfaquinoxalineq drug (ESD) was used as a green corrosion inhibitor for carbon steel (CS) in 1.0 M HCl. Chemical, electrochemical and microscopic tools were employed to measure the inhibition productivity of ESD on CS. The calculated inhibition efficiency (% IE) of the drug was raised with its concentrations. The highest IE of 93.2% was achieved at a drug concentration of 300 ppm, both in the case of weight loss (WL) and electrochemical impedance spectroscopy (EIS). The used expired drug behaved as mixed-kind inhibitor with cathodic priority. EIS spectra displayed a single capacitive loop, indicating that the corrosion process is primarily controlled by charge transfer. The acquired higher % IEs were ascribed to strong adsorption of the drug’ molecules on the CS surface and such adsorption was agreed with Langmuir isotherm. Thermodynamic and kinetic parameters were calculated that confirm the mechanism of physical adsorption. The kinetics and mechanisms of corrosion of aluminum and its inhibition by such drugs were explained Quantum chemical calculations were performed and analyzed, providing support for the experimental findings. The predicted corrosion efficiencies of this compound closely aligned with the experimental measurements.