Advanced Protective Films Based on Binary ZnO-NiO@polyaniline Nanocomposite for Acidic Chloride Steel Corrosion: An Integrated Study of Theoretical and Practical Investigations

Due to their thermal stability characteristics, polymer/composite materials have typically been employed as corrosion inhibitors in a variety of industries, including the maritime, oil, and engineering sectors. Herein, protective films based on binary ZnO-NiO@polyaniline (ZnNiO@PANE) nanocomposite were intended with a respectable yield. The produced nanocomposite was described using a variety of spectroscopic characterization methods, including dynamic light scattering (DLS), ultraviolet–visible spectroscopy (UV-Vis), Fourier-transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS) approaches, in addition to other physicochemical methods, including X-ray powder diffraction (XRD), transmission Electron Microscopy (TEM), field emission scanning electron microscopy (FESEM), and selected area electron diffraction (SAED). By using open-circuit potentials (OCP) vs. time, electrochemical impedance spectroscopic (EIS), and potentiodynamic polarization (PDP) methods, the inhibitory effects of individual PANE and ZnNiO@PANE on the mild steel alloy corrosion in HCl/NaCl solution were assessed. The ZnNiO@PANE composite performed as mixed-type inhibitors, according to PDP findings. PANE polymer and ZnNiO@PANE composite at an optimal dose of 200 mg/L each produced protective abilities of 84.64% and 97.89%, respectively. The Langmuir isotherm model is used to explain the adsorption of ZnNiO@PANE onto MS alloy. DFT calculations showed that the prepared materials’ efficiency accurately reflects their ability to contribute electrons, whereas Monte Carlo (MC) simulations showed that the suitability and extent of adsorption of the ZnNiO@PANE molecule at the metal interface determine the materials’ corrosion protection process.