ZnO and TiO_(2) nanofibers are synthesized via electrospinning methods and characterized by x−ray diffraction,scanning electron microscopy,and transmission electron microscopy.Humidity sensors with double-layer sensin...ZnO and TiO_(2) nanofibers are synthesized via electrospinning methods and characterized by x−ray diffraction,scanning electron microscopy,and transmission electron microscopy.Humidity sensors with double-layer sensing films are fabricated by spinning the ZnO and TiO_(2) nanofibers on ceramic substrates sequentially.Compared with sensors loading only one type of nanofiber,the double-layer sensors exhibit much better sensing properties.The corresponding impedance changes more than four orders of magnitude within the whole humidity range from 11%to 95%relative humidity,and the response and recovery times are about 11 and 7 s,respectively.Maximum hysteresis is around 1.5%RH,and excellent stability is also observed after 180 days.The humidity sensing mechanism is discussed in terms of the sensor structure.The experimental results provide a possible route for the design and fabrication of high performance humidity sensors based on one-dimensional nanomaterials.展开更多
ZnO-SnO_(2) composite nanofibers are synthesized via an electrospinning method and characterized by x-ray diffraction,scanning electron microscopy,and transmission electron microscopy.Micro sensors are fabricated by s...ZnO-SnO_(2) composite nanofibers are synthesized via an electrospinning method and characterized by x-ray diffraction,scanning electron microscopy,and transmission electron microscopy.Micro sensors are fabricated by spinning the nanofibers on Si substrates with Pt signal and heater electrodes.The sensors with small areas(600μm×200μm)can detect CO down to 1 ppm at 360℃.The corresponding sensitivity,response time,and recovery time are 3.2,6 s,and 11 s,respectively.Importantly,the sensors can operate at high humidity conditions.The sensitivity only decreases to 2.3 when the sensors are exposed to 1 ppm CO at 95%relative humidity.These excellent sensing properties are due to combining the benefits of one-dimensional nanomaterials and the ZnO-SnO_(2) grain boundary in the nanofibers.展开更多
基金by Special Fund for Agro-scientific Research in the Public Interest of China(No 200903023)Development and Extension of Practical Low-Cost Low-Power Automatic Drip Irrigation Controller(2010GA780046)Research and Application Demonstration of Orchard Water and Fertilizer Drip Irrigation Controller(2010B020314007).
文摘ZnO and TiO_(2) nanofibers are synthesized via electrospinning methods and characterized by x−ray diffraction,scanning electron microscopy,and transmission electron microscopy.Humidity sensors with double-layer sensing films are fabricated by spinning the ZnO and TiO_(2) nanofibers on ceramic substrates sequentially.Compared with sensors loading only one type of nanofiber,the double-layer sensors exhibit much better sensing properties.The corresponding impedance changes more than four orders of magnitude within the whole humidity range from 11%to 95%relative humidity,and the response and recovery times are about 11 and 7 s,respectively.Maximum hysteresis is around 1.5%RH,and excellent stability is also observed after 180 days.The humidity sensing mechanism is discussed in terms of the sensor structure.The experimental results provide a possible route for the design and fabrication of high performance humidity sensors based on one-dimensional nanomaterials.
基金Supported by the Special Fund for Agro-scientific Research in the Public Interest of China(No 200903023)Science and Technology Projects in Guangdong Province(2010B020314007)the Cooperation Projects of Industry,Education and Academy Sponsored by Guangdong Province and Ministry(2011B090400359).
文摘ZnO-SnO_(2) composite nanofibers are synthesized via an electrospinning method and characterized by x-ray diffraction,scanning electron microscopy,and transmission electron microscopy.Micro sensors are fabricated by spinning the nanofibers on Si substrates with Pt signal and heater electrodes.The sensors with small areas(600μm×200μm)can detect CO down to 1 ppm at 360℃.The corresponding sensitivity,response time,and recovery time are 3.2,6 s,and 11 s,respectively.Importantly,the sensors can operate at high humidity conditions.The sensitivity only decreases to 2.3 when the sensors are exposed to 1 ppm CO at 95%relative humidity.These excellent sensing properties are due to combining the benefits of one-dimensional nanomaterials and the ZnO-SnO_(2) grain boundary in the nanofibers.
