Electrochemical Synthesis of Iron Oxide Nanoparticles: Doping with Zn2+ and Gd3+ Cations and In-situ Capping with Polyethylene Glycol

Development of a facile synthesis rout for preparation of polymer coted, metal ion doped magnetic nanoparticles, which have proper magnetic and physicochemical properties for bio-medical uses, is one of the most active research areas in advanced magnetic nano-materials. In this work, we demonstrate an easy electrochemical method for fabrication of PEG-coated Zn2+ or Gd3+ doped magnetic iron oxides (i.e. PEG/Zn-MIOs and PEG/Gd-MIOs). Characterization of the synthesized MIOs was carried out by X-ray diffraction (XRD), Energy-dispersive X-ray spectroscopy (EDAX), Fourier transform infrared spectroscopy (FTIR), Field-emission electron microscopy (FE-SEM), thermal gravimetric analysis (TGA), and vibrating sample magnetometry (VSM) analyses. The XRD and EDAX analyses proved that the electro-synthesized MIOs were magnetite (Fe3O4) doped with 8.6% Zn2+ and/or 19.7% Gd3+. The PEG layer on the Zn-MIOs and/or Gd-MIOs surface was evidenced by FT-IR. FE-SEM showed a spherical morphology with average diameters of 20 nm and 25 nm for PEG/Zn-MIOs and PEG/Gd-MIOs, respectively. TGA data demonstrated that the PEG content of Gd-MIOs was about 10% by weight. Superparamagnetic nature of both prepared magnetic powders was verified by VSM measurements. In final, the analyses results supported that the prepared magnetic nano-particles have suitable size, crystal phase, surface layer and magnetism for bio-medical uses.