Synthesis and Improved Acetone Sensing Properties of Porous α-Fe 2 O 3 Nanowires

Porous α-Fe2O3 nanowires are synthesized by a simple wet chemical method with a precursor of peroxyacetyl nitrate (PAN), and α-Fe2O3 nanoparticles are also synthesized in the same way except for the addition of PAN. Gas sensors are fabricated by coating the samples on ceramic tubes with Au signal electrodes and Ni-Cr heaters. A sensing investigation reveals that the porous α-Fe2O3 nanowires have a higher sensitivity compared to α-Fe2O3 nanoparticles at 260°C. The corresponding sensor response (Ra/Rg) is 18.2 at the maximum to 100 ppm acetone, and the response and recovery times are about 8 and 12 s, respectively. The porous and one-dimensional nanostructures of the porous α-Fe2O3 nanowires benefit for the gas-absorption and electrical-signal-transfer, and thus improve the sensor sensitivity consequentially.