Current Trend Review in the Application of Pyridine-Based Molecule as Robust Steel Corrosion Inhibitors

Pyridine-based molecule are extensively used in different sectors especially biological and medicinal fields. Recently, pyridine-based molecule showed very high corrosion inhibition efficiency. Because of their structure features and the presence of the nitrogen atom, the efficiency of these compounds’ adsorption is greatly influenced. These N-heterocyclic molecules can adsorb heavily on metallic surfaces, and their inhibitory efficiency is strongly increased in the presence of substituents and functionals groups. The presence of nonbonded electrons of nitrogen, and π electrons of the aromatic ring, assure their chemical adsorption associated with physical adsorption on the metal surface. These substances impede corrosion by creating a compact, thin hydrophobic layer that prevents corrosive agents from penetrating. This article provides a concise summary of current (2020–2022) accomplishments regarding the use of these molecule as metal corrosion inhibitors. Also, theoretical method and adsorption isotherms have been reviewed. The pyridine derivatives act generally as mixed-type corrosion inhibitors by impeding the anodic and/or cathodic Tafel reactions, consequently retarding the overall rate of corrosion. The majority of these molecules follow the Langmuir adsorption isotherm model. The calculated reactivity descriptors of pyridine-based molecule enable the understanding of the adsorption mechanism by analyzing donor–acceptor interactions, and the local reactivity allow the identification of the electrophilic, nucleophilic or radical attacks.