Expired terazosin as environmentally safe corrosion inhibitor for 1018 carbon steel in 1 M HCl solution: Experimental and computational studies

Abstract

The corrosion inhibition performance of expired terazosin as an environmentally safe corrosion inhibitor in aqueous 1 M HCl solution for 1018 Carbon steel (CS) was assessed with coupons weight measurement (WL), combined with techniques of electrochemical (electrochemical impedance spectroscopy (EIS) and Potentiodynamic polarization). Through weight loss and electrochemical tests, the corrosion inhibition effect of expired terazosin against CS in an acidic solution was investigated. The weight loss approach at 150 ppm at 25 °C resulted in the highest inhibition efficiency (%IE) reach to 94.8 %. Potentiodynamic polarization findings indicate that this study investigated terazosin ability to behave as a mixed-type inhibitor. Nyquist diagrams showed that as the dose increased, the charge transfer resistance increased and the capacitance of the double layer decreased. It was discovered that the inhibition process conforms to the Langmuir isotherm, demonstrating that a monolayer was formed on the CS surface. Quantum chemical analysis and the Monte Carlo simulation can support the inhibitory mechanism. Theoretical estimates sustain the experimental result. This proves that the use of Expired Terazosin is a good impediment to the corroding of CS in HCl solvent.