title: Wide bandgap mesoporous hematite nanowire bundles as a sensitive and rapid response ethanol sensor.
abstract: In this study, α-Fe2O3 nanowires were synthesized using mesoporous SBA-15 silica as the hard templates with the nanocasting method, and then mesoporous α-Fe2O3 nanowire bundles (NWBs) were separated from the well-dispersed α-Fe2O3 nanowires (NWs) by the centrifugation technique. Both samples were characterized by x-ray diffraction, transmission electron microscopy (TEM), nitrogen adsorption/desorption isotherm and UV-vis spectra. All results indicated that the α-Fe2O3 NWBs with mesoporous structure presented a higher BET surface area (95 m(2) g(-1)) and wider bandgap (2.08 eV) than those of α-Fe2O3 NWs (32 m(2) g(-1) and 1.91 eV). The bandgap of α-Fe2O3 NWBs was in accordance with the bulk α-Fe2O3, while the BET surface area was much higher. The results from the gas-sensing measurement revealed that the α-Fe2O3 NWBs based gas sensor exhibited a high sensitivity of 21.7, fast response-recovery of 7.5 s and 1 s, and good selectivity to ethanol at 340 °C. The sensitivity (21.7) for ethanol of α-Fe2O3 NWBs was much better than that of the α-Fe2O3 NWs (12.2), which should be attributed to the higher BET surface area and wider bandgap of α-Fe2O3 NWBs.
authors.affiliation: College of Materials Science and Engineering, China Jiliang University, Hangzhou, 310018, People's Republic of China.
authors.forename: Danping
authors.initials: D
authors.lastname: Li
authors.forename: Beibei
authors.initials: B
authors.lastname: Zhang
authors.forename: Jingcai
authors.initials: J
authors.lastname: Xu
authors.forename: Yanbing
authors.initials: Y
authors.lastname: Han
authors.forename: Hongxiao
authors.initials: H
authors.lastname: Jin
authors.forename: Dingfeng
authors.initials: D
authors.lastname: Jin
authors.forename: Xiaoling
authors.initials: X
authors.lastname: Peng
authors.forename: Hongliang
authors.initials: H
authors.lastname: Ge
authors.forename: Xinqing
authors.initials: X
authors.lastname: Wang