Effect of spinach (Spinacia oleracea) leaf extract on the aluminum (Al) as a green corrosion inhibitor in HCl medium

Green corrosion inhibitors have recently attracted much attention due to their non-toxic properties, especially plant extracts. This study used spinach leaf extract (Spinacia oleracea) as a corrosion inhibitor on aluminum in an HCl medium. Spinach leaf extract (Spinacia oleracea) was obtained by maceration method, using ethanol as the solvent, which was then distilled to purify the extract. The corrosion inhibition properties were studied by the gravimetric method. The results showed that spinach leaf extract (Spinacia oleracea) can efficiently decrease the corrosion rate of aluminum in an HCl medium, achieving a maximum efficiency of 96.7742 %. Spinach leaf extract (Spinacia oleracea) formed a protective layer on the aluminum surface via adsorption and chemisorption, thus increasing surface coverage and blocking mass transfers. As the inhibitor concentration increases, the corrosion rate decreases, and the corrosion inhibition efficiency increases. This study shows that spinach leaf extract (Spinacia oleracea) is a viable organic corrosion inhibitor option with high efficiency.