Tiazofurin drug as a new and non-toxic corrosion inhibitor for mild steel in HCl solution: Experimental and quantum chemical investigations

Abstract

The corrosion inhibition performance of tiazofurin, as a new corrosion inhibitor, was evaluated using weight loss measurements, electrochemical methods, X-ray photoelectron spectroscopy (XPS), quantum chemical analysis, and scanning electron microscopy (SEM). The inhibitive performance increases with tiazofurin concentration but decreases with temperature. At a concentration of 400 ppm, the maximum inhibition efficiency (∼97%) is achieved. Adsorption of tiazofurin obeys the Langmuir adsorption isotherm, and thermodynamic parameters show that the adsorption is governed by physiochemisorption. Based on the XPS analysis and theoretical quantum chemical studies, tiazofurin molecules adsorb to the steel surface presumably due to the donor–acceptor interactions between the S and N atoms of tiazofurin and vacant d-orbitals of Fe atoms. Electron microscopy examinations also validated the meaningful decrease in the corrosion rate in the presence of tiazofurin.