Amaranthus, Althermanthea and Cionuraerecta extracts: green inhibitors for mild steel corrosion in HCl solution

Application of biodegradable sources like plant extracts as green inhibitor can improve the corrosion resistance of mild steel, particularly in acidic environment. In the present study, the aqueous plant extracts of Amaranthus, Althermanthea and Cionuraerecta (L.) Griseb as green source were used to inhibit corrosion of mild steel in 0.5 mol·L−1HCl media via electrochemical techniques (EIS and polarization) and surface analyses (SEM). The existence of numerous electron donor atoms, especially oxygen in the molecules of several aerial part of extracts is responsible for its operative adsorption behavior on metal surface over chelation with iron atoms. The data obtained from experimental part confirmed that coinciding with an increase in extracts concentration and immersion time, the corrosion inhibitory ability also improved and reached to the high value of 91 present. The results on SEM analyses obviously proved that Amaranthus molecules adsorption on the metallic surface significantly reduced its dissolution rate, creating a clean and smooth surface.

Keywords:

inhibitor , green corrosion , herbal plant