Fast-LPG Sensors at Room Temperature by α-Fe₂O₃/CNT Nanocomposite Thin Films

Abstract

We present performance of a room temperature LPG sensor based on -Fe 2 O 3 /CNT (carbon nanotube) nanocomposite films. The nanocomposite film was fabricated via the metallic Fe catalyst particle on CNTs in which both the catalyst particles and the CNT were simultaneously synthesized by chemical vapor deposition (CVD) synthesis and were subsequently annealed in air to create -Fe 2 O 3 . These methods are simple, inexpensive, and suitable for large-scale production. The structure, surface morphologies, and LPG response of nanocomposite films were investigated. Raman spectroscopy and XPS analysis showed the formation of -Fe 2 O 3 on small CNTs (SWNTs). Morphological analysis using FE-SEM and AFM revealed the formation of the porous surface along with roughness surface. Additionally, the sensing performance of -Fe 2 O 3 /CNTs showed that it could detect LPG concentration at lower value than 25% of LEL with response/recovery time of less than 30 seconds at room temperature. These results suggest that the -Fe 2 O 3 /CNTs films are challenging materials for monitoring LPG operating at room temperature.

Novel Preparation and Characterization of Fe₂O₃/CNT Thin Films for Flammable Gas Sensors

“…Fig. 1(c) shows that the O1s peak of Fe/CNTs is 532.4 eV (O-C=O, C=O), while those of annealed Fe/CNTs are 530.4 eV (O-Fe), implying a formation of Fe 2 O 3 after at annealing in 250 o C and 350 o C, respectively [7]. Fig.…”

Gas sensing properties of hematite nanoparticles synthesized via different techniques

“…The loss of electrons resulted from the O 2 molecules adsorption on the n-type α-Fe 2 O 3 surface, which creates an electronic depletion layer and a high potential energy barrier on the surface of the material, which further leads to an increase in the electrical resistance of the sensor. 36 …”

“…The loss of electrons resulted from the O 2 molecules adsorption on the n-type a-Fe 2 O 3 surface, which creates an electronic depletion layer and a high potential energy barrier on the surface of the material, which further leads to an increase in the electrical resistance of the sensor. 36 Aer the exposure of the sensor to ethanol gas, a reaction occurred between adsorbed C 2 H 5 OH and O − oxygen species according to eqn (5).…”

Fe2O3nanoparticles anchored on thermally oxidized MWCNTs as anode material for lithium-ion battery

“…The peak at 529.8 eV is attributed to Fe-O in α-Fe 2 O 3 [34]. The peak at 531.2 eV is ascribed to oxygen bridges (-O-) on the interface of OMWCNTs [43,44], which possibly is assigned to Fe-O-C bonds [45,46]. The peak at 533.2 eV is ascribed to the remaining C=O on OMWCNTs [43].…”