Amino acid compounds as eco-friendly corrosion inhibitor for N80 steel in HCl solution: Electrochemical and theoretical approaches

Abstract

Amino acid compounds, namely, 1-(1H-benzo[d]imidazole-2-yl)-N-((furan-2-yl)methylene)methanamine (BIFM) and 1-(1H-benzo[d]imidazole-2-yl)-N-((furan-2-yl)methylene)-2-phenylethanamine (BIFP) were synthesized and studied as inhibitors for N80 steel corrosion in 15% HCl solution using potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques. Polarization studies showed that both studied inhibitors were of mixed type in nature. The adsorption of inhibitors on the N80 steel surface obeys Langmuir adsorption isotherm. The potential of zero charge (EPZC) for the N80 steel was determined by electrochemical impedance spectroscopy method. Scanning electron microscopy (SEM) and Atomic Force Microscopy (AFM) were used to characterize the surface morphology of uninhibited and inhibited N80 steel specimens. The Density Functional Theory (DFT) was employed for theoretical calculations.