Corrosion inhibition of brass electrode in 3% NaCl medium using novel quinoline derivatives based on D-glucose: Synthesis, characterization, and mechanistic insights through experimental and computational approaches

Abstract

Two novel quinoline derivatives, namely P1 and P2, were successfully synthesized using D-Glucose as a starting material. The synthesized compounds were subjected to characterization using carbon-13 nuclear magnetic resonance (13C NMR) and proton nuclear magnetic resonance (1H NMR) spectroscopy techniques. Their anticorrosive properties for brass electrode in 3% NaCl medium were evaluated by different physicochemical and electrochemical characterization techniques. Further, reactivity and interaction mechanisms between P1 or P2andthe first zinc (Zn) and copper (Cu) layer atoms present in the brass surface were studied by the density functional theory (DFT) calculations and molecular dynamic (MD) simulations. The electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization curves (PC) indicated that P1 and P2acted as barrier of the anticorrosive of brass area and its inhibition efficiencies reaches a maximum of 96.9 and 97.2% for P1 and P2 at optimal concentration, respectively. The adsorption of P1 and P2 onto the brass surface followed the Langmuir adsorption isotherms, indicating monolayer adsorption. Additionally, the adsorption process was characterized as chemisorption, suggesting a strong chemical interaction between the compounds and the metal surface. SEM/EDS analysis indicated a significant difference in brass area in the presence of 10−3M of P1 and P2 due to the formation of a layer protective barrier. Finally, the corrosion inhibition mechanism was explored and comprehended through the integration of experimental data and computational approaches.