An Exploration about the Interaction of Mild Steel with Hydrochloric Acid in the Presence of N-(Benzo[d]thiazole-2-yl)-1-phenylethan-1-imines

Cost effective inhibition of mild steel corrosion employing eco-friendly materials is a high priority subject for industries these days. Therefore, in this work, a series of N-(benzo[d]thiazole-2-yl)-1-phenylethan-1-imines [N-(benzo[d]thiazole-2-yl)-1-phenylethan-1-imine (BTPEI), N-(benzo[d]thiazole-2-yl)-1-(3-chlorophenyl) ethan-1-imine (BTCPEI), N-(benzo[d]thiazole-2-yl)-1-(m-tolyl) ethan-1-imine (BTTEI), and N-(benzo[d]thiazole-2-ylimino) ethyl) aniline (BTPIA)] for mild steel protection in 1 M HCl were explored by adopting methods like gravimetric analysis, adsorption isotherms, and electrochemical methods, for example, electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization. Different spectral characterization methods such as FTIR and 1H NMR were used to confirm the synthesized derivatives. The experimental results affirmed that all of the inhibitors are proven to be very efficient for combating corrosion for mild steel in acidic media. The determined thermodynamic and activation parameters were used to provide a further understanding of the mechanism of inhibitive activity. The computed Gibbs free energy values suggested strong chemical interaction of inhibitors with the mild steel surface, thereby supporting chemisorption. Potentiodynamic polarization data explained the mixed type nature of all of the inhibitors. Impedance measurements point out that protective film deposits on the mild steel in the presence of the inhibitors. Studies like scanning electron microscope (SEM) with electron dispersive X-ray spectroscopy (EDS), atomic force microscopy (AFM), and X-ray photoelectron spectroscopy (XPS) further supported the adsorption inhibitive mechanism. The theoretical findings such as density functional theory (DFT), Fukui indices, and molecular dynamics (MD) provided good agreement with different experimental techniques.