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

We present performance of a room temperature LPG sensor based on alpha-Fe2O3/CNT (carbon nanotube) nanocomposite films. The nanocomposite filmwas 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 alpha-Fe2O3. Thesemethods 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 alpha-Fe2O3 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 alpha-Fe2O3/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 alpha-Fe2O3/CNTs films are challenging materials for monitoring LPG operating at room temperature.