A Thermodynamical and Electrochemical Investigation of Quinoxaline Derivatives as Corrosion Inhibitors for Mild Steel in 1 M Hydrochloric Acid Solution

Research Article

H. Lgaz M. Saadouni, R. Salghi

Abstract

The influence of four quinoxaline derivatives (QNs) namely, (E)-1-benzyl-3-(4-methoxystyryl)quinoxalin-2(1H)-one (QN1), (E)-3-(2-(furan-2-yl)vinyl)quinoxalin-2(1H)-one (QN2), (E)-3-(4-methoxystyryl)quinoxalin-2(1H)-one (QN3), and (E)-3-styrylquinoxalin-2(1H)-one (QN4) on the mild steel corrosion in 1 M HCl was studied by weight loss and electrochemical methods. Results showed that QN1 shows maximum inhibition efficiency of 93% at 5×10-3 M concentration. Polarization study revealed that the QNs act as mixed type inhibitors. EIS measurements showed that the studied compounds inhibit mild steel corrosion by adsorbing on the steel surface. Results showed that inhibition efficiency increases with concentration and decreases with the rises of the temperature from 303 to 333K. Adsorption of QNs on the mild steel surface obeyed the Langmuir adsorption isotherm.

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