摘要

A process for synthesizing Fe2O3 based on electrospinning and the hard-template method was proposed such that the crystal phase of Fe2O3 could be tailored with precision. Mesoporous gamma-Fe2O3, alpha-/gamma-Fe2O3, and alpha-Fe2O3 nanofibers could be fabricated successfully by changing the synthesis parameters. Scanning electron microscopy, transmission electron microscopy, X-ray diffraction analyses, Raman spectroscopy, and nitrogen adsorption-desorption analyses were used to characterize the structures of the synthesized products. The optimal calcination conditions for preparing alpha-/gamma-Fe2O3 nanofibers with the highest ethanol response were determined through ethanol-sensing measurements. The mixed-phase material exhibited a significantly higher sensitivity than the corresponding purephase ones. The superior ethanol-sensing performance of the alpha-/gamma-Fe2O3 nanofibers suggested that they may be suitable for use in alcohol sensing. Hence, a novel strategy for improving the sensing performance of metal oxide semiconductors is to assemble the different crystalline forms of the same metal oxide in one structure. Finally, the mechanism responsible for the sensing performance of alpha-/gamma-Fe2O3 being higher than those of gamma-Fe2O3 and alpha-Fe2O3 was elucidated on the basis of data from X-ray photoelectron spectroscopy and resistance measurements.