The effect of carboxylate compounds on Volta potential and corrosion inhibition of Mg containing different levels of iron

Abstract Corrosion protection and surface properties of Magnesium (Mg) containing 51ppm Fe (HP-Mg) and 341 ppm Fe (CP-Mg) were assessed by EIS, AFM/SKPFM, and photoluminescence spectroscopy in NaCl solutions with/without fumarate (Fum), 2,5-pyridinedicarboxylate (PDCA) and salicylate (Sal) carboxylates. The PDCA was effective in corrosion inhibition of HP-Mg and CP-Mg, while the Sal was efficient in inhibition of CP-Mg only. Volta potential (VPD) changes on Mg were evaluated considering the contribution of molecular dipoles and chemical dipoles due to interaction of carboxylate groups present in carboxylates with Mg. VPD of CP-Mg increased due to adsorption of Fe(III)-salicylate complexes and salicylate molecules.