Abstract

An ethylene-glycol-mediated self-assembly process is adopted to synthesize 3D flowerlike nanostructures of iron oxide (see figure) using inexpensive and nontoxic ferric chloride. A two-stage growth process is identified during the morphological evolution of the iron oxide precursor. α-Fe2O3, γ-Fe2O3, and Fe3O4 with the same flowerlike structure are readily obtained from the same precursor but by different calcination procedures. The as-obtained iron oxides show excellent ability to remove various pollutants from water.