Synthesis and Improved Acetone Sensing Properties of Porous α-Fe₂O₃ 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 (R_a/R_g) 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.