Frontiers and advances in green and sustainable inhibitors for corrosion applications: A critical review

This review summarizes advances, opportunities, and recent progress in green and sustainable corrosion inhibitors for non-ferrous metals and alloys in different corrosive environments. These corrosion inhibitors usually consist of plant extracts usually comprises of organic compounds encompassing heterocyclic, multiple bonds, and various other functional groups. Due to the existence of multiple functional groups and heteroatoms, organic compounds adsorption becomes favorable on the surface of the metal, which efficiently reduces the deterioration of metals. In this review article, literature based on corrosion inhibition of non-ferrous metal/alloys by green inhibitors has been assessed, and the significant findings and performance of these inhibitors for aluminium/ NaOH and copper/ HNO₃ have been emphasized. The application and role of density functional theory has also been discussed in the prediction of Inhibition efficiency of major constituents green inhibitors. In addition, the possible mechanism of corrosion inhibition from literature is also summarized to understand the role of green inhibitors. The non-toxic nature of the phytochemicals makes them suitable candidates as green and sustainable corrosion inhibitors.