Adsorption and Corrosion Inhibitive Properties of Some Aldehyde Derivatives on Mild Steel in 1 M HCl Solution: Electrochemical and Computational Investigations

The inhibitory behavior of three aldehyde derivatives, namely, 4-chlorobenzaldehyde (CBA), 4-methoxybenzaldehyde (MBA) and naphthalene-2-carbaldehyde (NCA) were investigated against mild steel corrosion in 1 M HCl by using Tafel plots, electrochemical impedance spectroscopy (EIS) and quantum chemical calculations. The experimental findings show that all examined compounds have excellent inhibiting effect for mild steel in the corrosive hydrochloric acid. Tafel plots display the features of these compounds are considered as inhibitors of the mixed-type; and their adsorption mode on the mild steel/1 M HCl interface is consistent with the Langmuir isotherm model. Adsorption and thermodynamic parameters were also evaluated. Density function theory (DFT) using B3LYP/6-311G(d,p) was studied in order to determine the correlation between the corrosion inhibition properties of the investigated derivatives and their molecular structures. Experimental findings support the outcomes obtained from DFT exploration. Graphical Abstract