Exploring sustainable corrosion inhibition of copper in saline environment: An examination of hydroquinazolinones via experimental and ab initio DFT simulations

Copper's potential in various applications is constrained due to environmental degradation, particularly in high-salinity environments, representing a sustainability concern. Herein, two novel hydroquinazolinones, namely 1-((4-hydroxynaphthalen-1-yl)methyl)-2-phenyl-2,3-dihydroquinazolin-4(1H)-one (DQ-H) and 1-((4-hydroxynaphthalen-1-yl)methyl)-2-(p-tolyl)-2,3-dihydroquinazolin-4(1H)-one (DQ-CH3), were analyzed for their ability to inhibit copper corrosion in a 3.5 % NaCl solution. The compounds, characterized by 1H and 13C NMR, were evaluated via potentiodynamic polarization curves, electrochemical impedance spectroscopy, and weight loss measurements. Comprehensive analyses utilizing scanning electron microscopy, Fourier Transform Infrared, and UV–vis spectroscopy have revealed insights into the surface morphology and the interactive nature of inhibitor molecules with the copper surface. Our findings highlight the formation of a strong, sustainable inhibitor film on the copper surface due to the addition of hydroquinazolinones, thereby exhibiting an enhanced polarization resistance and decreased double-layer capacitance. Both DQ-H and DQ-CH3 demonstrated a considerable inhibition effect, with efficiencies of 92 % and 94 % respectively, illustrating their potential for sustainable copper protection. Electrochemical impedance spectroscopy (EIS) results indicated a significant increase in polarization resistance from 605.7 (blank) to 9403 and 12861 Ω cm2, after the addition of DQ-H and DQ-CH3, respectively. Furthermore, the adsorption attributes of the compounds on the Cu(1 1 1) surface were examined using first-principles density functional theory simulation, revealing several covalent bonds formation. Our work aims to contribute to sustainability efforts in materials science by offering a corrosion-protective solution that is less harmful to the environment and more efficient in preserving copper's durability, particularly in saline environments.