Elucidating the role of novel halogenated hydroquinazolinone derivatives in mitigating copper corrosion in saline conditions: A joint assessment of experimental outcomes and computational analysis

Corrosion of copper in marine environments represents a significant challenge, necessitating the exploration of efficient corrosion inhibitors. This study probes the efficacy of three hydroquinazolinone derivatives - 2-(4chlorophenyl)-1-((4-hydroxynaphthalen-1-yl)methyl)-2,3-dihydroquinazolin-4(1H)-one (DQ-Cl), 2-(4-bromophenyl)-1-((4-hydroxynaphthalen-1-yl)methyl)-2,3-dihydroquinazolin-4(1H)-one (DQ-Br), and 2-(2-chlorophenyl)-1-((4-hydroxynaphthalen-1-yl)methyl)-2,3-dihydroquinazolin-4(1H)-one (DQ-Cl') - as inhibitors against copper corrosion in 3.5 wt% NaCl solutions, employing a multifaceted approach including chemical and electrochemical analyses, surface morphology examinations, spectroscopic investigations, and theoretical computations. Our chemical and electrochemical findings demonstrated substantial reductions in corrosion rates and current densities upon employing the inhibitors. At maximum concentration of 10-3 mol/L, the hydroquinazolinone derivatives DQ-Br, DQ-Cl, and DQ-Cl' demonstrated exceptional inhibition efficiency of 97%, 95% and 94%, respectively, as evidenced from potentiodynamic polarisation tests. Despite the typical influence of temperature on corrosion processes, the hydroquinazolinone derivatives showed a remarkable stability; their inhibitory performance was minimally affected and remained impressively high even under increased temperature conditions. Complementary to the experimental work, thermodynamic parameters extracted from Arrhenius and transition state equations underscored an endothermic adsorption mechanism. Langmuir isotherm fitting of the adsorption data corroborated the effective interactions of inhibitors with the copper surface. SEM imagery corroborated these results, evidencing well-preserved copper surfaces under inhibitor influence. Further evidence came from FT-IR spectra, indicating the functional groups' contribution to the adsorption process. UV-Vis spectroscopy provided insights into the formation of Cu-inhibitor coordinate complexes. The quantum chemical calculations, molecular dynamic (MD) simulations, and sigma-profiles analysis offered deeper insights into the reactivity of the inhibitor molecules; these comprehensive theoretical approaches revealed how molecular structures and electronic characteristics significantly contribute to the efficiency of the corrosion inhibition, thus further strengthening the experimental findings. Collectively, the present work highlights the potential of hydroquinazolinone derivatives as potent inhibitors, paving the way for future applications in combating copper corrosion in marine environments.

Automated summary

This study investigates the efficacy of three hydroquinazolinone derivatives as corrosion inhibitors for copper. The results show that these inhibitors can significantly reduce the corrosion rates and current densities of copper. At high concentrations, these inhibitors demonstrate inhibition efficiencies of up to 97% and exhibit exceptional stability. Surface morphology examinations, spectroscopic investigations, and theoretical computations further confirm the effective interactions between the inhibitors and the copper surface.