Plants as corrosion inhibitors for metals in corrosive media

The protection of metals from corrosion is widely carried out by adding green inhibitors, that is, natural plant extracts. The extracts were tested to contain corrosion, utilizing modes such as gravimetric, polarization, and impedance spectroscopies. The performance of extracts was studied for their selection as corrosion inhibitors. The surface of the protected metal was explored using X-ray photoelectron, scanning electron microscopy, and atomic force microscopy. The surface characterization acts as the supportive tolls for the experimental results. Furthermore, theoretical analysis also provides deep insight into the corrosion inhibition at the molecular level, and this is done via analyzing the inhibitor-metal interaction. The extracts contains many heteroatoms that act as adsorption centers, through which inhibitors are adsorbed over the metal surface and protect it from corrosion. The heteroatoms and p-electron clouds, as the center for chemical adsorption and the polar sites, provide physical adsorption. Natural plant extracts are discussed in this chapter to fetter corrosion for arange of metals (steel, alloys, and so on).