Insights of 2-(Benzoxazol-2-ylthio)-N-(4-phenyl-5-phenylazo-thiazol-2-yl)-acetamide as a novel corrosion inhibitor for J55 carbon steel in hydrochloric acid: Experimental, Spectroscopic analysis, and theoretical studies

Abstract

The inhibitory efficacy of 2-(Benzoxazol-2-ylthio)-N-(4-phenyl-5-phenylazo-thiazol-2-yl)-acetamide (BNP) was systematically explored through weight loss measurements, potentiodynamic polarization (PP), and electrochemical impedance spectroscopy (EIS), in relation to the corrosion mitigation of J55 carbon steel (J55CS) within hydrochloric acid (HCl) environments. This research employs a combination of experimental techniques, including gravimetric analysis, electrochemical tests, and theoretical considerations. It has been determined that BNP has an inhibitory effect on the corrosion of J55CS in strong HCl, reaching 91.8% at 18 × 10−6 M at 298 K. The inhibitory efficiency displays a notable enhancement as the concentration of the BNP is elevated within the range of 3–18 × 10−6 M. Conversely, the IE% experiences a raised when the temperature is raised. This augmentation can be attributed to the inherent ability of BNP to facilitate the formation of inhibitory films on the surface of J55CS. An analysis of Tafel plots reveals that the BNP adheres to a mixed-type inhibitor. The adsorption of BNP obeyed the Temkin adsorption isotherm. The investigated isotherm plots revealed that the adsorption process for BNP on the metal surface was endothermic, spontaneous, and chemical adsorption. Theoretical modeling [density functional theory (DFT) and Monte Carlo (MC)] revealed the correlation between the BNP molecular chemical structure and its anticorrosive property.