A general ultra large scale strategy for low temperature sol–gel synthesis of nearly monodispersed metal ions doped γ-Fe₂O₃ nanoparticles

A general sol–gel strategy was established for the synthesis of metal ions doped γ-Fe₂O₃ nanoparticles with narrow particle size distribution. The unique chemistry of the route guarantees the simple preparation procedure for the preparation of doped γ-Fe₂O₃ nanoparticles, which includes the boiling of the ethanolic solution of precursor salts after the addition of gelation agent, and the following drying of the obtained sol solution. On the other hand, it guarantees the production of the nanoparticles with nearly monodispersed state and median size of about 5 nm on an ultra large scale of about 60 g in a single reaction. The doping of metal ions in γ-Fe₂O₃ allows the great promotion of phase transformation temperature from γ-Fe₂O₃ to α-Fe₂O₃. Due to the advantages of this strategy over other routes, it is very promising to be applied in the industrial production of undoped and doped γ-Fe₂O₃ nanoparticles as a general route.