Schiff Base-Derived Organic Molecules as High-Performance Corrosion Inhibitors for Metals

Corrosion of metallic materials in aggressive environments remains a major challenge in many industrial sectors, including petroleum processing, marine engineering, chemical manufacturing, and infrastructure development. The use of corrosion inhibitors is one of the most effective and economical strategies for mitigating metal deterioration. Among various organic inhibitors, Schiff base compounds have attracted significant attention due to their unique molecular structures containing azomethine (–C=N–) functional groups, heteroatoms such as nitrogen, oxygen, and sulfur, and conjugated systems that facilitate strong adsorption on metal surfaces. These structural features enable Schiff bases to form protective films that block active corrosion sites and reduce metal dissolution in corrosive media. This review provides a comprehensive overview of the synthesis, structural characteristics, and corrosion inhibition mechanisms of Schiff base compounds and their metal complexes. Emphasis is placed on experimental techniques used to evaluate corrosion inhibition performance, including gravimetric measurements, electrochemical methods, and surface characterization techniques. The role of computational approaches such as density functional theory (DFT) and molecular dynamics simulations in understanding adsorption behavior and electronic properties is also discussed. Furthermore, the applications of Schiff base inhibitors on various metals, including mild steel, carbon steel, stainless steel, copper, and aluminum, are examined. Recent developments in environmentally friendly Schiff base inhibitors, including biopolymer-derived and green-synthesized compounds, are highlighted. Finally, the review discusses current challenges, research gaps, and future prospects for the development of efficient, sustainable, and industrially applicable Schiff base corrosion inhibitors