Controllable fabrication and growth mechanism of hematite cubes

Monodispersed and single‐crystalline hematite (α‐Fe 2 O 3 ) cubes have been successfully prepared by a template‐free hydrothermal synthetic route with FeCl 3 and CH 3 COONH 4 . The influences of the reactant concentration, reaction temperature, and reaction time on the crystal growth were systematically investigated. The results show that the monodisperse hematite cubes with high crystalline and narrow size distribution could be fabricated at the hydrothermal temperature of 160 °C for 24 h while the concentrations of FeCl 3 and CH 3 COONH 4 were in the range of 0.03‐0.5 M and 0.05‐0.1 M, respectively. In addition, the formation mechanism of hematite cube is also proposed, where the CH 3 COONH 4 plays a role of shape controller in the formation of cube hematite structure. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)