Facile Synthesis of Porous α-Fe2O3 Nanorods and Their Application in Ethanol Sensors

A facile solution approach was employed to synthesize alpha-FeOOH nanorods by using FeSO4 center dot 7H(2)O and CH3COONa without templates at low temperature (40 degrees C). The porous alpha-Fe2O3 nanorods were successfully obtained by calcining the alpha-FeOOH precursors at 300 degrees C for 2 h. The as-prepared products were characterized by thermogravimetry-differential thermal analysis, X-ray powder diffraction, transmission electron microscopy (TEM), high-resolution TEM, and N-2 adsorption-desorption analysis techniques. The as-prepared porous alpha-Fe2O3 nanorods have a tiny crystal size (5 nm) and a pore size distribution of 1 - 10 nm, resulting in a high specific surface area of 221.9 m(2).g(-1). A possible growth mechanism of the porous alpha-Fe2O3 nanorods was proposed. The gas-sensing measurement results demonstrated that the porous alpha-Fe2O3 nanorods presented a much higher response than the alpha-Fe2O3 nanoparticles and showed excellent selectivity and stability to ethanol vapor. Due to the fact that it has exciting gas-sensing properties and can be obtained easily, the as-prepared porous alpha-Fe2O3 nanorod would be an ideal candidate for application in ethanol sensors.