基于银纳米线电极-rGO敏感材料的柔性NO2气体传感器

Flexible nitrogen dioxide gas sensor based on reduced graphene oxide sensing material using silver nanowire electrode

使用银纳米线作为材料制备柔性叉指电极,用还原氧化石墨烯(reduced graphene oxide, rGO)作为气体敏感材料制备出柔性气体传感器,并研究其对二氧化氮气体的响应特性以及柔韧性能.实验结果表明,制备的以银纳米线作为电极的r GO气体传感器可以实现室温下对浓度为5-50 ppm (1 ppm=10^–6)的NO2气体的检测,对50 ppm的NO2的响应能够达到1.19,传感器的重复性较好,恢复率能够保持在76%以上,传感器的灵敏度是0.00281 ppm^-1,对浓度为5 ppm的NO2气体的响应时间是990 s,恢复时间是1566 s.此外,传感器在0°-45°的弯曲角度下仍表现出优异的电学特性与气体传感性能,所制备的器件具有相对稳定的导电性和较好的弯曲耐受性.

In recent years, flexible gas sensors have aroused wide interest of researchers due to their enormous potential applications in wearable electronic devices. In this paper, a flexible gas sensor is prepared. We use silver nanowires as flexible interdigital electrodes for gas sensors and reduced graphene oxide as gas-sensing materials. We also study its gas sensitivity and flexibility properties such as responsiveness, recovery, and repeatability to nitrogen dioxide. The experimental results show that the silver nanowire flexible electrode and the reduced graphene oxide gas sensor prepared can detect the NO2 gas with a concentration of 5-50 ppm at room temperature. The response(Ra/Rg) of the sensor to 50 ppm NO2 is 1.19. It demonstrates high response ability and repeatability. The recovery rate can be kept above 76%. The sensitivity of the sensor is 0.00281 ppm-1. The response time and recovery time of the prepared AgNWs IDE-rGO sensor for 5 ppm NO2 gas are990 s and 1566 s, respectively. At the same time, the sensor still exhibits excellent gas sensing performance at a bending angle in range from 0° to 45°. The device has relatively stable conductivity and good bending tolerance.The sensing mechanism of the sensor can be attributed to the direct charge transfer between the reduced graphene oxide material and NO2 gas molecules. In addition, the high catalytic activity and excellent conductivity of Ag that is a common catalyst material, may also play an important role in improving the gas sensitivity of reduced graphene oxide materials. Silver nanowires, as a material for interdigital electrodes,provide excellent conductivity for device as well as support for the flexibility of device. It provides the fabricated sensor for good mechanical flexibility. And the gas-sensing performance of the AgNWs IDE-rGO sensor is mainly achieved by the use of reduced oxidized graphene material reduced by hydrazine hydrate. In summary, the silver nanowire flexible electrode and the graphene gas sensor prepared in this work are helpful in realizing the flexibility of the gas sensor. It lays a foundation for the further application of flexible gas sensors and has great application prospects in wearable electronic equipments.