利用溶剂热法合成了一维的氧化钨纳米线,通过掺入适量单壁碳纳米管(SWNT)制备了基于氧化钨纳米线-SWNT复合结构的室温气敏元件并评价了其对NO_2气体的室温敏感性能.利用X射线与扫描电子显微镜表征了材料的微结构,结果表明,合成的氧化钨纳米线具有单斜的W_(18)O_(49)结构,复合材料中SWNT被包埋在氧化钨纳米线中间.气敏性能测试结果表明,氧化钨纳米线-SWNT复合结构气敏元件在室温下对NO_2气体表现出了高的灵敏度和超快的响应特性;较低的SWNT掺入量对获得好的气敏性能有利.分析了基于复合结构材料气敏元件的可能的气敏机理,认为元件良好的室温敏感性能与SWNT掺入在复合结构材料中引入大量的贯穿气孔和p-n异质结有关.
One-dimensional tungsten oxide nanowires are synthesized by the solvothermal method. The sensors based on tungsten oxide nanowires/single-wall carbon nanotubes (SWNTs) composites are fabricated by introducing SWNT, and their NO2 sensing properties are evaluated at room temperature. X-ray diffraction and field emission scanning electron microscope characterizations indicate that the as-synthesized nanowires are monoclinic WlsO49, and SWNTs are embedded within the nanowire matrix in the prepared tungsten oxide nanowires/SWNT composites. The tungsten oxide nanowires/SWNT composites-based sensors show high sensitivity, good selectivity and super fast response to NO2 gas at room temperature. The NO2 sensing properties of the sensors increase with the decrease of SWNT content. The sensing mechanism of the composites-based sensor is discussed and it is thought that the introduction of SWNT induces the formation of a large number of p-n hetero junctions and cross-linked diffusion channels in the structure of the composites, which are responsible for the good NO2 sensing properties at room temperature.