Abstract: Herein, Pomegranate Peel plant extract was assessed as a low-cost, green and efficient corrosion inhibitor for mild carbon steel in 1 M hydrochloric acid solution using weight loss, potentiodynamic polarization, an atomic absorption Spectroscopy test, surface roughness test, and surface studies by optical microscopy (LOM). Increasing Pomegranate Peel extract concentration increases the charge transfer resistance as a result of the adsorption of Pomegranate Peel extract on the mild carbon steel surface. The polarisation results showed the mixed-type inhibition behavior of the studied extract with an inhibition efficiency (%IE) of 90.193% achieved with the addition of 4% vol. of Pomegranate Peel plant extract. The adsorption isotherm model of Pomegranate Peel plant extract on a mild carbon steel surface followed the Langmuir adsorption isotherm in an HCl solution. The inhibition mechanism of Pomegranate Peel plant extract was explained according to the increase in the IE% with concentration and the activation parameters which suggested significant chemisorption of the Pomegranate Peel plant extract on the mild carbon steel surface. LOM studies confirmed the formation of a protective layer of Pomegranate Peel plant extract on a mild carbon steel surface. Results obtained by different techniques showed good agreement that confirms the potential use of Pomegranate Peel plant extract as a corrosion inhibitor for mild carbon steel in an acidic media.
Conclusions: Pomegranate peel plant extract, as an organic inhibitor, exhibits excellent inhibition performance when exposed to a series of techniques. In an immersion test, the inhibiting efficiency increases to (83.18%) with organic inhibitor at a concentration of 4% vol. Whereas, from the Tafel polarisation outcomes, the least corrosion current density is 23.358 µA/ cm2 with an organic inhibitor at a concentration of 4% vol. The adsorption according to Langmuir isotherm is a preferable deposition of an organic inhibitor, including physical adsorption. From the results of atomic absorption spectroscopy, the organic inhibitor produces a barrier that isolates from the HCl medium, and less Fe+2 is dissolved in the organic inhibitor: 29.9 mg/ l. Results of the surface roughness test reveal that the roughness is reduced to 0.049 µm with an organic inhibitor at a concentration of 4% vol