Eco-Friendly Corrosion Inhibition Using Plant-Derived Extracts: Insight into Chemistry and Adsorption Mechanisms

The increasing emphasis on environmental sustainability has driven extensive research into green alternatives for corrosion control in industrial systems. Plant-derived extracts have gained considerable attention as eco-friendly corrosion inhibitors due to their biodegradability, low toxicity, renewability, and cost effectiveness. This review presents a detailed discussion of the application of plant-based extracts for corrosion inhibition of metals exposed to aggressive environments. Particular focus is given to the chemical constituents responsible for inhibition, such as alkaloids, flavonoids, phenolic compounds, tannins, and terpenoids, and their ability to interact with metal surfaces. Fundamental aspects of corrosion processes, adsorption mechanisms, isotherm models, and thermodynamic parameters governing inhibitor performance are critically examined. In addition, commonly used surface analytical techniques and electrochemical methods for evaluating inhibition efficiency are discussed. The review further analyzes reported performance trends, challenges, and limitations associated with plant-derived inhibitors. Finally, future research directions are highlighted, emphasizing the role of computational modeling, hybrid inhibitor systems, and standardized evaluation protocols to enhance reliability and industrial applicability.