Aggregation Control of Hydrophilic Maghemite (γ-Fe2O3) Nanoparticles by Surface Doping Using Cerium Atoms

摘要

The high-power ultrasonic irradiation of preformed magnetite (Fe₃O₄) nanoparticles in the presence of monoelectronic Ce-containing ceric ammonium nitrate [CeIV(NH₄)₂(NO₃)₆] oxidant in MeCOMe afforded hydrophilic 50 nm-sized colloidal, highly stable maghemite (γ-Fe₂O₃) nanoparticles. An “inorganic” Ce atom doping of the NP surface has been proposed in order to rationalize the observed nanoparticle antiaggregation phenomenon. Quite importantly, this method did not require the use of any organic ligand and/or polymer for the passivation of the nanoparticle surface.