Investigation of 3-(1,3-oxazol-5-yl)aniline as a highly efficient corrosion inhibitor for mild steel in 1 M HCl solution

Abstract

Abstract Mild steel corrosion in acidic environments presents a significant challenge with detrimental consequences for both industrial infrastructure and the environment. Effective corrosion control measures are crucial to prolonging the lifespan of equipment. Inhibition techniques have proven to be an efficient method for protecting mild steel from corrosion, particularly in acidic conditions. This study investigates the efficacy of 3-(1,3-oxazol-5-yl)aniline (3-OYA) as a corrosion inhibitor for mild steel in a hydrochloric acid (HCl) solution. Traditional weight-loss tests, as well as electrochemical techniques, such as potentiodynamic polarization and electrochemical impedance spectroscopy, were employed to evaluate the corrosion inhibition performance. The results reveal that 3-OYA, at a concentration of 0.05 mM, exhibits an outstanding protection efficacy of 93.5%. This remarkable performance can be attributed to the formation of a protective adsorption layer on the mild steel surface, effectively inhibiting the corrosion rate and enhancing inhibitory efficacy. The inhibition efficiency was found to increase with increasing inhibitor concentration, while it decreased with rising temperature. Langmuir adsorption isotherm analysis confirmed the high adsorption–inhibition activity of 3-OYA. The $\Delta {G}_{ads}^o$ value indicated the occurrence of both physical and chemical adsorption mechanisms on the mild steel surface. Furthermore, density functional theory (DFT) calculations were utilized to determine the quantum chemical parameters and establish a correlation between the inhibition activity and the molecular structure. The consistency between the experimental and theoretical analyses reinforces the robustness of our findings.