Insight Into Adsorption and Corrosion Mitigation Mechanism of Oxadiazoles for N80 Steel in Acidic Medium: DFT, Molecular Dynamics Simulation, and Electrochemical Studies

Density functional theory (DFT), molecular dynamics simulations (MDS), mass loss (ML), and electrochemical studies were performed to assess the corrosion preventive ability of oxadiazole derivatives, 1-(1((5-phenyl-1,3,4-oxadiazol-2-yl)methyl)-1H-benzo[d]imidazol-2-yl)-3-(thiophene-2-yl)prop-2-en-1-one (PBTP) and 3-(furan-2-yl)-1-(1((5-phenyl-1,3,4-oxadiazol-2-yl)methyl)-1H-benzo[d]imidazol-2-yl)prop-2-en-1-one (FPBP) on N80 steel (NS) in 15% HCl medium. The compounds PBTP and FPBP exhibited corrosion preventive ability of 97.13% and 94.16% for NS in the presence of 250 ppm concentration at 298 K temperature. Corrosion inhibition efficiency of both compounds increases with increase in concentration and decreases with increase in temperature. Adsorption of both inhibitors followed Langmuir adsorption isotherm. Potentiodynamic polarization studies suggested that both inhibitors behave as mixed type (anodic as well as cathodic) inhibitors. The analysis of field emission scanning electron microscopy (FESEM), atomic force microscopy (AFM), and x-ray photoelectron spectroscopy (XPS) verified the development of the inhibitor protective layer at the NS surface to prevent its corrosion. The computational studies are in good agreement with the experimental results.