Insight on the corrosion inhibition performance of Glebionis coronaria plant extract in various acidic mediums

Glebionis Coronaria extract (GCE) has been evaluated as a potential green corrosion inhibitor for carbon steel in 1 M HCl and 0.5 M H 2 SO 4 mediums. Phytochemical screening, total flavonoids, polyphenols contents investigation, and FT-IR analysis were assessed to explore the diversity of the secondary metabolite compounds present in the GCE extract. The assembled data evinced the phytochemical abundance of the aqueous extract in terms of organic secondary metabolites including flavonoids, tannins, polyphenols, and coumarin. EIS and PDP measurements were performed in both acidic media in the presence of GCE, yielding a maximum efficiency of 79% and 86.6% for the hydrochloric and sulfuric media, respectively, using 2 g/L of GCE at 293 K, suggesting the mixed type action of GCE via adsorption towards the steel surface following the Langmuir model. The rise in IE% was noted with the increase of temperature in both media, reaching 84.4% and 92.2% for the hydrochloric and sulfuric media, respectively, at 313 K using the optimal concentration. The thermodynamic parameters disclosed the chemisorption action occurred at the steel-solution interface. Synergistic behavior between GCE and KI was evaluated for the lowest concentration of GCE in each medium, unveiling the cooperative action established between the halide ions and GCE. Surface morphology examination of carbon steel was conducted using the SEM–EDX technique in both media, and the results complement the study findings by demonstrating the establishment of a preventive coating through the adsorption process of GCE molecules onto the surface of the carbon steel. Graphical abstract