Synthesis and study of physicochemical properties of Fe3O4@ZnFe2O4 core/shell nanoparticles

In this work, Fe3O4@ZnFe2O4 core/shell nanoparticles were obtained by depositing ZnO by the wet chemistry method on the surface of Fe3O4 nanoparticles seeds obtained by the chemical bath deposition method. Fe3O4 and Fe3O4@ZnFe2O4 were characterized by Field Emission Scanning Electron Microscopy, Energy Dispersive X-ray Spectrometry, Transmission Electron Microscopy, X-ray Diffraction, Ultraviolet-Visible Spectroscopy, Diffuse Reflectance, and Fourier Transformed Infrared Spectroscopy (FTIR). The Fe3O4@ZnFe2O4 nanoparticles formed an urchin-like spheres morphology (corresponding to Fe3O4) with a homogeneous shell of ZnFe2O4. XRD analysis showed a magnetite crystal structure for Fe3O4 and a franklinite (ZnFe2O4) crystal structure for the shell. Fe3O4@ZnFe2O4 showed higher crystallinity when applying a heat treatment, showing a crystal size of 9.12 nm with heat treatment and 9.43 nm without heat treatment. The diffuse reflectance results suggested an indirect band gap of 1.85 eV for Fe3O4 and two indirect band gaps of 1.85 eV and 2.54 eV for Fe3O4@ZnFe2O4. The FTIR results showed the effect of heat treatment on Fe3O4@ZnFe2O4 core/shell nanoparticles. A simple method was used for the synthesis of Fe3O4@ZnFe2O4.