Probing molecular adsorption/interactions and anti-corrosion performance of poppy extract in acidic environments

In recent years, environmental regulations have forced the researchers to gradually replace the traditional toxic inhibitors with the green/sustainable products based on the plant sources, ion liquids, and biopolymers (such as alginate, chitosan, and Polydopamine). Application of the green inhibitors based on the extracts of the plants in the acidic solution has been found to be the most feasible and cost-effective way for the metals corrosion mitigation. However, most of the plant-based inhibitors are not as efficient as the synthetic inhibitors like bio-polymers due to the presence of so many in-active components in their extracts. Here, we introduce the most powerful plant-based inhibitors extracted from the Papaver somniferum leaves/stems (called poppy) which are rich in some well-known bio-active medicines such as codeine, morphine, noscapine, oripavine, papaverine, thebaine which are full of Nitrogen-based functionalities. This study aims at studying the impact of Papaver somniferum (known as poppy) leaves and stems extract (PSLSE) addition to the 1 M HCl solution in which the mild steel is immersed. Surface characterizations including FE-SEM, EDX, AFM, CA measurements, FT-IR,(1) GIXRD,(2) UV-Vis(3) spectroscopy were carried out. The inhibition potent of the extract was reviewed by EIS4 and PDS.(5) Moreover, to explore the adsorption action of the poppy extract on the metal surface, the theoretical simulations based on the Monte Carlo (MC), molecular dynamics (MD) and density functional theory (DFT) were done. Surface characterizations proved the inhibitor adsorption on the metallic surface beside the formation of protective complexes such as ternary iron cyanide. EIS investigations indicated the excellent protection provided by PSLSE addition. The magnificent inhibition of around 97.64% was reached in the 600 ppm and 1000 ppm PSLSE samples. A mixed-type action with a dominant performance on the cathodic inhibition was observed. The simulation studies supported the successful interfacial adsorption of inhibitive compounds over the surface. (C) 2020 Elsevier B.V. All rights reserved.