Enhanced Corrosion Inhibition of Mild Steel in HCl Solution by Novel Anthraquinone Derivative: Comprehensive Experimental and Theoretical Investigations.

Organic inhibitors are valuable tools for preventing the corrosion of metals. Consequently, the effectiveness of 42-(bis((3,5-dimethyl-1H-pyrazol-1-yl)methyl)amino)anthracene-9,10-dione, and its corrosion resistance for mild steel in an acidic solution of 1M HCl, was assessed. In addition to analyzing the morphological surface properties and using theoretical techniques, the current study employed polarization curves and electrochemical impedance spectroscopy for analysis. Quantum chemical calculations, including DFT calculations at B3LYP 6-311G (d,p) and Monte Carlo simulations, were used to establish a link between the electronic characteristics of the compound and the experimental findings. The results demonstrated that these compounds were efficient corrosion inhibitors, with an inhibition efficiency of 96% as determined by the EIS method. To understand the corrosion resistance behavior of the anthraquinone inhibitor, the surface morphology of mild steel was examined using scanning electron microscopy in the presence and absence of the inhibitor. It was also found that the inhibitor functions as a mix-type inhibitor. Finally, a strong correlation was discovered between the experimental and theoretical outcomes. [ABSTRACT FROM AUTHOR]