Insight into the corrosion inhibition mechanism and adsorption behavior of aldehyde derivatives for mild steel in 1.0 M HCl and 0.5 M H2SO4

The inhibition effect of dimethylaminocinnamaldehyde (DACA) on the corrosion of mild steel in 1.0 M HCl and 0.5 M H2SO4 solutions was studied by electrochemical techniques and quantum chemical calculation, polari-zation studies revealed that DACA behaves as a mixed-type inhibitor. Electrochemical impedance spectroscopy (EIS) results indicated that DACA is a good inhibitor in 1.0 M HCl and 0.5 M H2SO4 of the steel surface and inhibition efficiency follows the order: H2SO4 >HCl. The adsorption of the studied inhibitor on a mild steel surface follows Langmuir's adsorption isotherm and involved a chemisorption mode. SEM/EDX observations of the electrode surface confirm the existence of a film on the metal surface. Furthermore, DFT calculations revealed that DACA is in good correlation with the experimental results and Molecular dynamics simulations showed a strong interaction between this molecule and the mild steel surface.