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

Abstract

A facile solution approach was employed to synthesize α-FeOOH nanorods by using FeSO4·7H2O and CH3COONa without templates at low temperature (40 °C). The porous α-Fe2O3 nanorods were successfully obtained by calcining the α-FeOOH precursors at 300 °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 N2 adsorption−desorption analysis techniques. The as-prepared porous α-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 m2·g−1. A possible growth mechanism of the porous α-Fe2O3 nanorods was proposed. The gas-sensing measurement results demonstrated that the porous α-Fe2O3 nanorods presented a much higher response than the α-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 α-Fe2O3 nanorod would be an ideal candidate for application in ethanol sensors.