Molecular dynamic simulation studies and surface characterization of carbon steel corrosion with changing green inhibitors concentrations and temperatures

A new and innovative various plants extracts Trigonella foenum graecum (Fenugreek), Punica granatum (Pomegranate), Sinapis alba (Mustard), and Piper nigrum (Black pepper) were prepared to study their anti-corrosion action against the carbon steel in 8 M H3PO4 as green inhibitors using Galvano-static polarization measurements. The structure of extract phytochemicals was characterized by Fourier Transform Infrared Analysis (FT-IR) and Gas chromatography/mass spectroscopy (GC–MS). The resulted data suggested that the rise in concentration of Punica granatum (Pomegranate) concentration in the solution (0.45 g/l), as well as the temperature to 313 K, increased the inhibition efficiency proportionally which maximized to 62.08% as mass transfer increased. Adsorption process follows Villamile, Florry-Huggins, and kinetic adsorption isotherm. Ea, Qads, ΔGads values, and according to the nature of the green inhibitors mixed phenomenon of physisorption and chemisorption was assured. The surface studies were carried out by scanning electron microscope (SEM) and surface roughness (profilometer) technique ensure the plant extract effectiveness in Carbone steel surface damage/ roughness reduction. The plant extract chemical structure and its existence on the carbon steel surface were certified via UV–Vis analysis and EDX (Energy Dispersive X-Ray). Besides, molecular dynamics simulations (MD) supported the adsorption of plant extract compounds on the metal-based adsorbent.