Sodium 2-Oxo-3-(3-oxo-1-phenylbutyl)-2H-chromen-4-olate as Green Corrosion Inhibitor for Mild Steel in 1 M HCl Medium: A Combined Experimental and Theoretical Study

The effect of Sodium 2-oxo-3-(3-oxo-1-phenylbutyl)-2 H -chromen-4-olate against the corrosion of mild steel in 1 M HCl solution was investigated using weight loss and electrochemical methods. The results show that inhibition efficiency increases with increased inhibitor concentration from 50 ppm to 300 ppm. The adsorption of inhibitor obeyed Langmuir adsorption isotherm model and the thermodynamic parameters are also calculated. Polarization measurements showed that the used inhibitor is mixed type. The surface morphologies were examined by scanning electron microscope and atomic force microscope. It confirms the formation of a compact protective film of inhibitor on the metal surface thereby inhibiting the corrosion. FT-IR spectroscopy could be involved in determining the interaction of inhibitor with the metal surface. Further, the computational calculations are performed to find a relation between their electronic and structural properties. Computational and experimental results are in good agreement. Graphical Abstract