An experimental and theoretical investigation on a Schiff Base-Cobalt complex as corrosion inhibitor in HCl solution on mild steel

This study investigates experimental and theoretical of a Schiff base-cobalt complex, namely Bis (N-(2-2aminoethylamino) ethanol) -2-Hydroxy-5-methoxybenzaldehyde) cobalt (III) chloride (CS) on corrosion inhibition of mild steel in 0.5 M HCl. Potentiodynamic polarization was applied to study inhibition efficiency. Results revealed that CS is a good inhibitor for mild steel corrosion in 0.5 M HCl; showing a maximum efficiency 84% at concentration of 400 ppm. FTIR observations of the mild steel surface applied to confirm the formation of protective film and the synergy effect of ions on the metal surface. The scanning electron micrographs (SEM) images showed significant effect of the inhibitor. Quantum chemical studies show CS is a softer base than corresponding ligand and also it shows superiority of complex over the corresponding ligand.