Experimental and theoretical study on some azo chromotropic acid dyes compounds as inhibitor for carbon steel corrosion in sulfuric acid

Three azo dyes compounds based on chromotropic acid have been synthesized and their chemical structures confirmed by spectra tools (FTIR and 1H-NMR). Their corrosion inhibition effect has been studied on carbon steel corrosion in 0.5 M sulfuric acid solution using potentiodynamic polarization and weight loss techniques. The findings have shown that the azo dyes tested are effective inhibitors of corrosion. With increased concentration, the inhibition effectiveness of all the azo dyes studied rises. Surface morphology has been studied. Also, the azo compounds inhibitors were investigated using density functional theory (DFT). The calculated quantum chemical parameters were calculated. The theoretical results are consistent with the experimental data reported.