氧化铟纳米纤维的制备及其甲醛气敏性能

采用静电纺丝法和随后的热处理过程制备了新颖的氧化铟纳米纤维材料. 利用扫描电子显微镜，透射电子显微镜，X射线衍射等表征手段对该材料形貌和晶体结构进行表征. 结果表明，所得到的纳米纤维材料的直径约为250 nm~300 nm. 这些纳米纤维由氧化铟纳米颗粒组成，而且其颗粒尺寸均一. 将这种纳米纤维材料制备成气敏传感器，研究表明基于该敏感材料的传感器对甲醛具有优异的气敏性能. 氧化铟纳米纤维传感器具有较低的最佳工作温度 200 ℃，并且对低体积浓度为百万分之五的甲醛气体具有2.1的灵敏度响应值. 在探讨甲醛的气敏机理的过程中，认为氧化铟纳米纤维的一维结构、甲醛的高还原性及敏感材料表面吸附氧促使了该材料对甲醛的优异的气敏性能. 此外，通过对传感器的选择性及稳定性测试，传感器对甲醛具有非常好的选择性和稳定性，这为制备高性能的甲醛传感器开拓了一种优异的气敏材料.

Fabrication of In2O3 Nanofibers and Their Formaldehyde Sensing Properties

The novel In₂O₃ nanofibers were prepared via electrospinning method combined with a subsequent thermal process. The morphology and crystalline of the as-prepared products were characterized by scanning electron microscopy， transmission electron microscopy and X-ray diffraction. The results indicate that these nanofibers have diameters in the ranges of 250 nm-300 nm and are composed of numerous tiny In2O3 nanoparticles with good uniform size. The In₂O₃ nanofibers-based sensor has excellent sensing properties towards formaldehyde. The results demonstrate that the optimum working temperature of In₂O₃ nanofibers-based sensor is 200 ℃ and it exhibits a response of 2.1 to 5 percent per million formaldehyde. After investigating the sensing mechanism of the sensor， the great sensing properties of the sensor can be attributed to the one-dimensional structure of nanofiber， the reduction properties of formaldehyde and the surface adsorption oxygen of the material. Moreover， the sensor based on In₂O₃ nanofibers displays good stability and selectivity to formaldehyde， which brings a promising future for designing superior formaldehyde gas sensors.