Experimental, adsorption, quantum chemical and molecular dynamics simulation studies on the corrosion inhibition performance of Vincamine on J55 steel in acidic medium

Abstract

The effect of Vincamine (VCA) as an inhibitor for the corrosion of J55 steel in 1 M HCl was examined utilizing gravimetric and electrochemical methods. Surface morphology was studied using Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and atomic force microscopy (AFM) techniques. The outcome showed that VCA hindered the dissolution of J55 steel in the acidic medium. From the gravimetric method, results showed that inhibition efficacy depended on the concentration of VCA and the temperature of the medium. Electrochemical impedance spectroscopy (EIS) studies revealed a rise in resistance of charge transfer, with a corresponding decline in the capacitance of double layer when there is a rise in the concentration of VCA. Polarization results indicated that VCA exhibited mixed-type corrosion inhibitor characteristics. The range of inhibition efficiencies obtained is; 79.4 to 90.2% for EIS studies, 76.0 to 91.4% for weight loss and 77.4 to 88.6% for polarization studies at 30 °C. SEM, FTIR, and AFM investigations established the adsorption of VCA on the surface of J55, thereby reducing the deterioration reaction. The adsorption of VCA on the surface of J55 steel followed the Freundlich adsorption isotherm. The adsorption characteristics were theoretically evaluated by quantum chemical studies and molecular dynamics (MD) simulation to relate the restraint capability of VCA with its electronic structural parameters.