Electrochemical and adsorption study of environmentally friendly inhibitor used for low carbon steel

Low-carbon steel is susceptible to corrosion in various technical applications, particularly in the petroleum industry. Typically, classic approaches like coatings have downsides, include­ing toxicity and environmental issues. Plant-based corrosion inhibitors are emerging as new, green, and affordable corrosion preventatives. In this study, an inhibitor of Portulaca oleracea roots was extracted and added in different concentrations of 200, 400, 600, 800 and 1000 ppm to study the adsorption mechanism at low carbon steel in 3.5 % NaCl. The effectiveness of inhibition and the rate of corrosion were assessed by using the potentio­metric polarization method. Corrosion rate measurements showed a decrease from 0.149 to 0.021 mm year-1, respectively, and the maximum efficiency of 85.7 % was obtained at 1000 ppm of Portulaca oleracea extract. The data were tested for Langmuir, Flory-Huggins, El-Awady and Freundlich isotherms, and the Langmuir isotherm provided the best fit, indicating that the layer of inhibitor formed on the metal surface is a monolayer. According to the findings, the extract of Portulaca oleracea is very effective for suppressing corrosion of low-carbon steel in a 3.5 % NaCl solution.