Potential of Azadirachta indica as a green corrosion inhibitor against mild steel, aluminum, and tin: a review

Azadirachta indica (AZI, commonly recognized as “Neem”) is noteworthy both for its chemical and for its biological actions. It is one of the most fruitful sources of secondary metabolites in nature. To date, more than 300 natural products have been isolated from different sections of the tree, with new compounds added to the list every year. As a contribution to the current interest on green corrosion inhibitors, the present study aims at broadening the application of plant extracts for metallic corrosion inhibition by investigating the inhibiting properties of A. indica especially for mild steel, aluminum, and tin. In the present article, we discuss the potential of AZI extract as a corrosion inhibitor on metal surfaces, especially of mild steel, aluminum, and tin. The adsorption isotherm studies, chemical composition of AZI, effect of temperature on inhibition efficiency and computational analysis related with AZI adsorption on metals have also been discussed in detail. This work will further help in the understanding of the adsorption mechanism involved and hence inhibition effect of plant extract against metal corrosion.