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 MgCo 2 O 4 and ZnCo 2 O 4 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 MgCo 2 O 4 and ZnCo 2 O 4 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 MgCo 2 O₄ at 330nm and ZnCo 2 O₄ at 318 nm and 458 nm confirming their optical characteristics. The polarization and electrochemical impedance results of the MgCo 2 O 4 and ZnCo 2 O 4 NPs samples show that MgCo 2 O 4 NPs exhibit superior corrosion inhibition activity, with a relative E corr 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 MgCo 2 O 4 and ZnCo 2 O 4 spinel nanoparticles as innovative, sustainable and efficient corrosion inhibitors for mild steel offering a promising solution for industrial applications aggressive acidic environments. • The observed crystallite sizes of MgCo 2 O 4 and ZnCo 2 O 4 are 17.5 nm and 18.9 nm, respectively. • SEM results indicating the formation of flake-like structures were observed in both materials. • The MgCo 2 O₄ and ZnCo 2 O₄ nanoparticles exhibit a absorption peak around 330 nm, 318 nm and 458 nm respectively. • The EIS results of the MgCo 2 O 4 and ZnCo 2 O 4 NPs compared to both materials MgCo 2 O 4 NPs exhibit superior corrosion inhibition activity.