In this work, pure α-Fe2O3 and Er2O3-Fe2O3 nanotubes were synthesized by a simple single-capillary electrospin- ning technology followed by calcination treatment. The morphologies and crystal structures of the as-pre...In this work, pure α-Fe2O3 and Er2O3-Fe2O3 nanotubes were synthesized by a simple single-capillary electrospin- ning technology followed by calcination treatment. The morphologies and crystal structures of the as-prepared samples were characterized by scanning electron microscopy and x-ray diffraction, respectively. The gas-sensing properties of the as-prepared samples have been researched, and the result shows that the Er2O3-Fe2O3 nanotubes exhibit much better sen- sitivity to ethanol. The response value of Er2O3-Fe2O3 nanotubes to 10 ppm ethanol is 21 at the operating temperature 240α, which is 14 times larger than that of pure α-Fe2O3 nanotubes （response value is 1.5）. The ethanol sensing properties of α-Fe2O3 nanotubes are remarkably enhanced by doping Er, and the lowest detection limit of Er2O3-Fe2O3 nanotubes is 300 ppb, to which the response value is about 2. The response and recovery times are about 4 s and 70 s to 10 ppm ethanol, respectively. In addition, the Er2O3-Fe2O3 nanotubes possess good selectivity and long-term stability.展开更多
Porous Zn O was obtained by hydrothermal method. The results of scanning electron microscope revealed the porous structure in the as-prepared materials. The acetone sensing test results of porous Zn O show that porous...Porous Zn O was obtained by hydrothermal method. The results of scanning electron microscope revealed the porous structure in the as-prepared materials. The acetone sensing test results of porous Zn O show that porous Zn O possesses excellent acetone gas sensing properties. The response is 35.5 at the optimum operating temperature of 320？C to 100 ppm acetone. The response and recovery times to 50 ppm acetone are 2 s and 8 s, respectively. The lowest detecting limit to acetone is 0.25 ppm, and the response value is 3.8. Moreover, the sensors also exhibit excellent selectivity and long-time stability to acetone.展开更多
Porousα-Fe_(2)O_(3) nanowires are synthesized by a simple wet chemical method with a precursor of peroxyacetyl nitrate(PAN),andα-Fe_(2)O_(3) nanoparticles are also synthesized in the same way except for the addition...Porousα-Fe_(2)O_(3) nanowires are synthesized by a simple wet chemical method with a precursor of peroxyacetyl nitrate(PAN),andα-Fe_(2)O_(3) 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 porousα-Fe_(2)O_(3) nanowires have a higher sensitivity compared toα-Fe_(2)O_(3) nanoparticles at 260℃.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 porousα-Fe_(2)O_(3) nanowires benefit for the gas-absorption and electrical-signal-transfer,and thus improve the sensor sensitivity consequentially.展开更多
Abstract： The pristine In2O3 nanotubes were synthesized by electrospinning and subsequent calcination. Scanning electron microscope, X-ray powder diffraction and transmission electron micrograph were employed to anal...Abstract： The pristine In2O3 nanotubes were synthesized by electrospinning and subsequent calcination. Scanning electron microscope, X-ray powder diffraction and transmission electron micrograph were employed to analyze the morphology and crystal structure of the as-synthesized nanotubes. Gas-sensing properties of the as-synthesized In203 nanotubes were investigated by exposing the corresponding sensors to toluene, acetone, ethanol, formalde- hyde, ammonia and carbon monoxide at 340 ℃. The results show that the gas sensor possesses a good selectivity to toluene at 340 ℃. The response of the In2O3 nanotube gas sensor to 40 ppm is about 5.88. The response and recovery times are about 3 s and 17 s, respectively.展开更多
基金supported by Jilin Provincial Science and Technology Department,China(Grant No.20140204027GX)the Challenge Cup for College Students,China(Grant No.450060497053)
文摘In this work, pure α-Fe2O3 and Er2O3-Fe2O3 nanotubes were synthesized by a simple single-capillary electrospin- ning technology followed by calcination treatment. The morphologies and crystal structures of the as-prepared samples were characterized by scanning electron microscopy and x-ray diffraction, respectively. The gas-sensing properties of the as-prepared samples have been researched, and the result shows that the Er2O3-Fe2O3 nanotubes exhibit much better sen- sitivity to ethanol. The response value of Er2O3-Fe2O3 nanotubes to 10 ppm ethanol is 21 at the operating temperature 240α, which is 14 times larger than that of pure α-Fe2O3 nanotubes （response value is 1.5）. The ethanol sensing properties of α-Fe2O3 nanotubes are remarkably enhanced by doping Er, and the lowest detection limit of Er2O3-Fe2O3 nanotubes is 300 ppb, to which the response value is about 2. The response and recovery times are about 4 s and 70 s to 10 ppm ethanol, respectively. In addition, the Er2O3-Fe2O3 nanotubes possess good selectivity and long-term stability.
基金Projected supported by the Project of Challenge Cup for College Students,China(Grant No.450060497053)
文摘Porous Zn O was obtained by hydrothermal method. The results of scanning electron microscope revealed the porous structure in the as-prepared materials. The acetone sensing test results of porous Zn O show that porous Zn O possesses excellent acetone gas sensing properties. The response is 35.5 at the optimum operating temperature of 320？C to 100 ppm acetone. The response and recovery times to 50 ppm acetone are 2 s and 8 s, respectively. The lowest detecting limit to acetone is 0.25 ppm, and the response value is 3.8. Moreover, the sensors also exhibit excellent selectivity and long-time stability to acetone.
基金Supported by the Jilin Environment Office(No 2009-22),Jilin Provincial Science and Technology Department(No 20100344)the National Innovation Experiment Program for University Students(No 2010C65188).
文摘Porousα-Fe_(2)O_(3) nanowires are synthesized by a simple wet chemical method with a precursor of peroxyacetyl nitrate(PAN),andα-Fe_(2)O_(3) 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 porousα-Fe_(2)O_(3) nanowires have a higher sensitivity compared toα-Fe_(2)O_(3) nanoparticles at 260℃.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 porousα-Fe_(2)O_(3) nanowires benefit for the gas-absorption and electrical-signal-transfer,and thus improve the sensor sensitivity consequentially.
基金Project supported by the Jilin Environment Office(No.2009-22)the Jilin Provincial Science and Technology Department(Nos.20100344,20140204027GX)
文摘Abstract： The pristine In2O3 nanotubes were synthesized by electrospinning and subsequent calcination. Scanning electron microscope, X-ray powder diffraction and transmission electron micrograph were employed to analyze the morphology and crystal structure of the as-synthesized nanotubes. Gas-sensing properties of the as-synthesized In203 nanotubes were investigated by exposing the corresponding sensors to toluene, acetone, ethanol, formalde- hyde, ammonia and carbon monoxide at 340 ℃. The results show that the gas sensor possesses a good selectivity to toluene at 340 ℃. The response of the In2O3 nanotube gas sensor to 40 ppm is about 5.88. The response and recovery times are about 3 s and 17 s, respectively.
