Functionalized graphene oxide as a new generation corrosion inhibitor for industrial pickling process: DFT and experimental approach

The present work deals with the synthesis of p-aminophenol functionalized graphene oxide (PAP-GO) and its inhibition behavior on mild steel corrosion in 1 M HCl using experimental and computational techniques. The morphology and chemical structure of the synthesized PAP-GO were analyzed by FT-IR, XRD, TEM, Raman, and XPS spectra. Electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization experimental methods were employed to study the corrosion inhibition efficiency of PAP-GO. EIS study suggests that the inhibition efficiencies of PAP-GO and p-aminophenol (PA) increase with increasing their concentrations. It was observed that PAP-GO acts as better inhibitor for mild steel corrosion and it showed maximum inhibition efficiency of 92.86% at as low as 25 mgL⁻¹ concentration. Potentiodynamic polarization study revealed that PAP-GO acts as mixed type inhibitor and predominantly shows cathodic behavior. PAP-GO adsorption onto the mild steel surface was examined using X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDX) techniques. The electrochemical and surface studies were supported by DFT calculations and MD simulations methods. A good correlation between the finding of computational and experimental results were derived.