Large-scale and high oriented α-Fe2O3 porous nanorod arrays: One-pot synthesis, formation mechanism, and properties

Large-scale α-Fe2O3 porous nanorod array precursors with high-orientation have been successfully prepared using one-pot hydrothermal method without any template. Upon calcination, α-Fe2O3 porous nanorod arrays have been fabricated. Synthesized samples were characterized by X-ray diffraction, field emission scanning electron microscopy, (High-resolution) transmission electron microscopy and Thermal-gravimetric analyses. The feature sizes of the porous nanorods are around 20–30 nm in lateral direction and 110–120 nm in length. The longer axis direction, which is the growth direction of α-Fe2O3 nanorod arrays was determined to be [1¯ 2 0] by transmission electron microscopy. The effects of the reaction time, reaction temperature, and acetic acid on the morphologies of porous nanorod arrays were systematically investigated. A possible formation mechanism was proposed by orientation attachment. The synthesized α-Fe2O3 porous nanorod arrays exhibited a high adsorption capacity for the model organic pollutant of Methyl orange. Therefore, α-Fe2O3 porous nanorod arrays have a potential application in waste water treatment.

► High-oriented porous nanorod arrays were made by a template-free hydrothermal method.
► The obtained arrays have a high absorption capacity to the pollutant of MO.
► We proposed an orientation attachment mechanism for the formation of the arrays.