Baran, Mehmet FiratYildiz, ResitArslanhan, SelimSolmaz, Ramazan2026-05-152026-05-1520261876-10701876-1089https://hdl.handle.net/20.500.12514/10950https://doi.org/10.1016/j.jtice.2026.106774Background: Corrosion results in material losses, safety issues, and adverse effects on human health and the environment. Therefore, preventing corrosion is a critical necessity. Although many methods and corrosion inhibitors have been employed to mitigate these negative effects, extracts of natural products have attracted increasing attention in recent years due to their natural origin, cost-effectiveness, and minimal adverse impacts on human health and the environment. Methods: The effect of Papaver rhoeas extract (PR), a natural plant-derived inhibitor, on mild steel (MS) corrosion in 1 M HCl solution was investigated at various extract concentrations and temperatures using various electrochemical methods. The steel surface after exposing to corrosive medium was characterized by SEM, AFM, EDX, XPS and contact angle measurements. Quantum chemical calculations were performed to support the experimental data. Significant findings: It was reported that the inhibition efficiency (eta%) of RP increased with increasing inhibitor concentration, reaching 98% at 1000 ppm. Notably, after an extended 120 h of exposure, the eta% peaked to 99.3%. The PR extract function as a mixed-type corrosion inhibitor. The value of Delta G degrees ads was-27.34 kJ mol-1, which indicated combinations of both physical and chemical interactions between the metal surface and extract molecules.en10.1016/j.jtice.2026.106774info:eu-repo/semantics/closedAccessQuantum Chemical Calculations, Density Functional TheoryAdsorptionPapaver Rhoeas ExtractRenewable Plant-Derived Corrosion InhibitorMild SteelArticle2-s2.0-105036015305