Synthesis of CeO2 Nanoparticles from Psidium guajava Leaf Extract for Corrosion Inhibition of Zinc in Hydrochloric Acid through Electrochemical Analysis

Abstract

Abstract CeO2 NPs were synthesized using a green method with Psidium guajava plant leaf extract. The crystal structure was characterized using XRD, EDAX, UV-Vis, SEM, and FTIR. The XRD results indicate that the samples have a cubic fluorite structure in the Fm-3m space group.The Debye-Scherer and Williamson-Hall plot analysis determined the crystal size of the CeO2 NPs to be 12 nm.The FTIR spectra showed the functional groups and corresponding bands of the prepared NPs and the band extension. The UV-Vis spectra showed a strong absorption peak at 358 nm, indicating that CeO2 has good optical properties with a band gap of 3.46 eV. The PL spectrum of the CeO2 NPs showed the presence of eight intense peaks corresponding to emission bands around defects and at low density. The SEM image showed that the CeO2 NPs were relatively spherical and uniform. The EDAX spectrum revealed the purity and complete chemical composition of the CeO2 NPs. The corrosion inhibition effect of CeO2 NPs on zinc metal immersed in 1.0 M HCl was evaluated at room temperature employing the weight loss method and different adsorption isotherms. Arise in inhibitor concentration of the controlled towards a corresponding increase in the effectiveness of corrosion inhibition.The corrosion current density (Icorr) values decreased as the inhibitor concentration increased, and the corrosion rate decreased. Confirmation of a protective film over the zinc metal surface was achieved using electrochemical techniques such as AC impedance and polarization studies.