Performance of Organic Molecules as Corrosion Inhibitors for CS: A Comprehensive Review

Organic molecules have occupied an important place by researchers and chemists in the field of corrosion inhibition of metals in various corrosive media such as HCl. Owing to the property of adsorption on the metal surface by the interaction of heteroatoms (O, N, P, S), rings, and double bonds exist in the molecules with the vacant orbital on a metallic surface. These interactions lead to the adsorption of molecules on the metal surface, forming an inhibitory layer, thus decreasing the corrosion rate of the metal, and increasing the inhibition efficiency. The review begins with a history of corrosion inhibitor molecules, then the effect of structure, substitution, heteroatoms, and chain length existing in the molecules on the inhibition efficiency. Comparative study of the inhibitory performance of corrosion inhibiting molecules using weight loss (WL), electrochemical impedance spectroscopy (EIS) techniques, and Potentiodynamique polarization (PDP). Adsorption isotherm models and global quantum chemical descriptors (GQCD) were applied to understand the relation between inhibition efficiency and molecular structure. This summary investigates and evaluates specific organic molecules and their inhibition efficiency in corrosive environments.