Hematite nanoparticle clusters with remarkably high magnetization synthesized from water-treatment waste by one-step "sharp high-temperature dehydration"

Abstract

Hematite (α-Fe2O3) nanoparticle clusters with an exceptionally high magnetization (51 emu g-1), comparable to that of nanoscale Fe3O4 and γ-Fe2O3, were synthesized for the first time. This material was prepared from water-treatment waste (iron removal precipitate) after single-step exposure to high temperature without any support (template, catalyst, surfactant, or others). The key factor was the using of a new approach, namely, "sharp high-temperature dehydration" of iron hydroxides containing adsorbed water.