A strategy to prepare ultrafine dispersed Fe2O3 nanoparticles

In this article, a novel strategy was applied to prepare dispersed ultrafine α-Fe2O3 nanoparticles. The initial Fe(OH)3 nanoparticles were synthesized by the reaction of NaOH and FeCl3 in alcohol. With the new-formed nanoparticles as nuclei, NaCl crystallized and encapsulated the particles into solid cages. As a result, the nanoparticles were prevented from aggregating and growing. The composite of Fe(OH)3 and NaCl was calcined and then washed by water to obtain the pure α-Fe2O3 nanoparticles. The best product was highly dispersed nanoparticles, with an average size of 2.26 nm and a narrow distribution from 1.9 nm to 2.6 nm. The cage effect was confirmed again by the control experiments.