Synthesis and study of physicochemical properties of Fe_3O_4@ZnFe_2O_4 core/shell nanoparticles

摘要

In this work, Fe_3O_4@ZnFe_2O_4 core/shell nanoparticles were obtained by depositing ZnO by the wet chemistry method on the surface of Fe_3O_4 nanoparticles seeds obtained by the chemical bath deposition method. Fe_3O_4 and Fe_3O_4@ZnFe_2O_4 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 Fe_3 O_4@ZnFe_2O_4 nanoparticles formed an urchin-like spheres morphology (corre-sponding to Fe_3O_4) with a homogeneous shell of ZnFe_2O_4. XRD analysis showed a magnetite crystal structure for Fe_3O_4 and a franklinite (ZnFe_2O_4) crystal structure for the shell. Fe_3O_4@ZnFe_2O_4 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 Fe_3O_4 and two indirect band gaps of 1.85 eV and 2.54 eV for Fe_3O_4@ZnFe_2O_4. The FTIR results showed the effect of heat treatment on Fe_3O_4@ZnFe_2O_4 core/shell nanoparticles. A simple method was used for the synthesis of Fe_3O_4@ZnFe_2O_4.