<正>SnO_2 thin film sensors were fabricated by a thermal evaporation method.The sensors were heated for thermal oxidation.For high porosity,SnO_2 thin film sensors were treated in a N_2 atmosphere.The sensors th...<正>SnO_2 thin film sensors were fabricated by a thermal evaporation method.The sensors were heated for thermal oxidation.For high porosity,SnO_2 thin film sensors were treated in a N_2 atmosphere.The sensors that were treated with O_2 after being treated with N_2 showed 70 % sensitivity for 1×10~ -6) of H_2S,which is higher than the sensors that were only treated with O_2.The Ni metal,as a catalyst,was evaporated on the thin film Sn on the Al_2O_3 substrate.The sensor was heated to grow the Sn nanowire in a tube furnace with N_2 flow.Sn nanowire was heated for oxidation.The sensitivity of SnO_2 nanowire sensor was measured for 500×10~ -9) of H_2S.The selectivity of the SnO_2 nanowire sensor was compared with the thin film and the thick film SnO_2.Each sensor was measured for H_2S,CO,and NH_3 in this study.展开更多
In this paper,an improvement in sensitivity and recovery of the single-walled carbon nanotube (SWNT)-based gas sensors was reported.The sensors were fabricated from SWNT powder by a screen-printing method,followed by ...In this paper,an improvement in sensitivity and recovery of the single-walled carbon nanotube (SWNT)-based gas sensors was reported.The sensors were fabricated from SWNT powder by a screen-printing method,followed by annealing for 2 h in open-air at various temperatures.The Raman spectra of the SWNT bundles and the response to ammonia (NH_3) exposure of the sensors indicated that the annealing at a relevant temperature improved the sensor sensitivity.The sensor annealed at 200℃exhibited a high sensitivity in NH_3 detection.After 20 min of exposure to NH_3 at room temperature,the resistance of the sensor increased up to 12% in comparison with its initial value.By evacuating combined with maintaining the flux of carrier gas at 300 sccm,the sensor recovery was significantly speeded.The sensor resistance retrieved to its initial value after only 25 min degassing. These results would be considered in the development of the SWNT-based gas sensors.展开更多
文摘<正>SnO_2 thin film sensors were fabricated by a thermal evaporation method.The sensors were heated for thermal oxidation.For high porosity,SnO_2 thin film sensors were treated in a N_2 atmosphere.The sensors that were treated with O_2 after being treated with N_2 showed 70 % sensitivity for 1×10~ -6) of H_2S,which is higher than the sensors that were only treated with O_2.The Ni metal,as a catalyst,was evaporated on the thin film Sn on the Al_2O_3 substrate.The sensor was heated to grow the Sn nanowire in a tube furnace with N_2 flow.Sn nanowire was heated for oxidation.The sensitivity of SnO_2 nanowire sensor was measured for 500×10~ -9) of H_2S.The selectivity of the SnO_2 nanowire sensor was compared with the thin film and the thick film SnO_2.Each sensor was measured for H_2S,CO,and NH_3 in this study.
文摘In this paper,an improvement in sensitivity and recovery of the single-walled carbon nanotube (SWNT)-based gas sensors was reported.The sensors were fabricated from SWNT powder by a screen-printing method,followed by annealing for 2 h in open-air at various temperatures.The Raman spectra of the SWNT bundles and the response to ammonia (NH_3) exposure of the sensors indicated that the annealing at a relevant temperature improved the sensor sensitivity.The sensor annealed at 200℃exhibited a high sensitivity in NH_3 detection.After 20 min of exposure to NH_3 at room temperature,the resistance of the sensor increased up to 12% in comparison with its initial value.By evacuating combined with maintaining the flux of carrier gas at 300 sccm,the sensor recovery was significantly speeded.The sensor resistance retrieved to its initial value after only 25 min degassing. These results would be considered in the development of the SWNT-based gas sensors.
