Experimental and computational investigations of a novel quinoline derivative as a corrosion inhibitor for mild steel in salty water

[Display omitted] •A novel quinoline-based (QATETA) as a corrosion inhibitor for mild steel, has been synthesized and fully characterized.•QATETA was examined, gravimetrically, electrochemically thermodynamically and computationally in salty water (3.5% NaCl).•The results indicated that QATETA has high inhibition efficiency, and the inhibition was concentration-dependent. The inhibition efficiency of N- and/or O-containing compounds for the corrosion of metals and alloys in aggressive media is an essential theme. For this purpose, a newly synthesized and fully characterized multidentate ligand, N,N'-((ethane-1,2-diylbis(azanediyl))bis(ethane-2,1-diyl))bis(quinoline-2-carboxamide) (QATETA), derived from quinaldic acid and triethylenetetramine (TETA) was examined gravimetrically and electrochemically as an inhibitor for the corrosion for mild steel in aqueous sodium chloride (3.5 %). Moreover, the reactivity and efficiency of QATETA were also theoretically investigated using density functional theory and Monte Carlo simulations methods. The results indicate that the corrosion inhibition of QATETA was concentration-dependent. In addition, QATETA was categorized as a mixed type inhibitor. Thermodynamic calculations confirmed that the adsorption of QATETA on the metal surface is a spontaneous process obeying Langmuir adsorption isotherm. Furthermore, computational simulations have corroborated the experimental results. Both physical and chemical adsorption mechanisms are suggested.