The deep investigation of structural and electrochemical analysis on the anti-corrosion behavior of MgCo2O4 and ZnCo2O4 spinel nanoparticles in acid medium

In this work, spinel shaped MgCo2O4 and ZnCo2O4 nanoparticles were synthesized by co-precipitation route and applied as protective coatings on the mild steel surface to enhance its corrosion inhibition efficiency in acidic environments. Several analytical techniques including X-ray Diffraction (XRD), UV–Visible spectroscopy, Fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM), Energy dispersive X-ray Spectroscopy (EDX) and Electrochemical impedance spectroscopy (EIS) were employed to characterize the structural morphological and electrochemical properties of the prepared nanoparticles. The single crystalline phases of MgCo2O4 and ZnCo2O4 were verified by X-ray diffraction (XRD) analysis. SEM analysis reveals the formation of flake-like structures in both materials which indicates their potential to provide enhanced surface coverage. UV–Visible spectroscopy demonstrated distinct absorption peaks for MgCo2O₄ at 330 nm and ZnCo2O₄ at 318 nm and 458 nm confirming their optical characteristics. The polarization and electrochemical impedance results of the MgCo2O4 and ZnCo2O4 NPs samples show that MgCo2O4 NPs exhibit superior corrosion inhibition activity, with a relative Ecorr value of −472.945 mV and an electrochemical impedance value of 49.22 Ω. This enhanced efficiency is attributed to the robust surface passivation facilitated by the spinel structure. This finding highlight the potential of MgCo2O4 and ZnCo2O4 spinel nanoparticles as innovative, sustainable and efficient corrosion inhibitors for mild steel offering a promising solution for industrial applications aggressive acidic environments. [Display omitted] •The observed crystallite sizes of MgCo2O4 and ZnCo2O4 are 17.5 nm and 18.9 nm, respectively and flake-like structures were obtained from SEM results.•The MgCo2O4 and ZnCo2O4 NPs exhibit a absorption peak around 330 nm, 318 nm and 458 nm respectively.•The EIS results of the MgCo2O4 and ZnCo2O4 NPs compared to both materials MgCo2O4 NPs exhibit superior corrosion inhibition activity.