Electrochemical, surface analysis, computational and anticorrosive studies of novel naphthalene derivative on carbon steel surface

Abstract

In the present research, the inhibitive potency of (E)-1-(phenyldiazenyl)naphthalen-2-ol (EPNO) for carbon steel (CS) in molar HCl acid was investigated using potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS). Based on the examination of Tafel data, it was revealed that EPNO displayed a mixed-type nature. EIS plots evinced that increasing the concentration of EPNO resulted in a significant 12-fold increase in polarization resistance (Rp) and a corresponding alteration in the double layer capacitance (Cdl) from 116.2 to 45.9 Fcm -2 . The inclusion of 10 -3 M of EPNO to the solution resulted in a maximum inhibition efficiency of 91.7%. Thermodynamic activation descriptors were also assessed as a function of EPNO concentration. The adsorption of EPNO on the CS substrate followed the Langmuir isotherm. The formation of a barrier layer was confirmed by scanning electron microscopy (SEM) coupled with energy-dispersive X-ray spectroscopy (EDX) and UV-Visible assays. Overall, the findings revealed that EPNO effectively provided an adequate protection to CS and mitigated its corrosion. Finally, the theoretical studies based on the density functional theory (DFT), the molecular dynamics (MD) and the Monte Carlo (MC) simulations were also performed for understanding the adsorption mechanism of EPNO onto Fe-surface.