氧等离子体处理ZnO纳米纤维材料的制备及其对丙酮气敏性能的研究

采用静电纺丝法制备了ZnO纳米纤维材料并使用氧等离子体对其进行表面处理.通过X射线衍射(XRD),扫描电子显微镜(SEM),BET比表面积测试以及X射线光电子能谱分析(XPS)等手段对样品的结构与形貌进行了表征分析.将氧等离子体处理前后的ZnO纳米纤维分别制成气体传感器,对浓度为1×10-6~100×10-6(体积分数)丙酮气体的敏感特性进行了测试分析.测试结果表明,氧等离子体处理后的ZnO纳米纤维响应值较未处理的ZnO纳米纤维有大幅度的提升,最佳工作温度也有所降低,且对甲醛、苯、甲苯、二甲苯等几种干扰气体表现出更好的选择性.从晶粒间势垒和耗尽层厚度等角度初步分析了氧等离子体处理改善ZnO气敏特性的机理.

The preparation and acetone gas sensing properties of ZnO nanofibers treated by oxygen plasma

ZnO nanofibers were synthesized by an electrospinning method and subsequently treated by oxygen plas-ma. The structure and morphology of the samples were characterized using X-ray diffraction( XRD) ,scanning elec-tron microscopy(SEM),Brunner-Emmet-Teller(BET)measurements and X-ray photoelectron spectroscopy(XPS). The sensitivity of the plasma treated and untreated ZnO nanofibers towards acetone from 1 × 10-6 to 100 × 10-6 ( volume fraction) was investigated. It was found that the gas sensing properties of ZnO nanofibers to acetone vapor obviously improved after it treated by oxygen plasma,such as decreasing the operating temperature and enhancing the response value. Meanwhile,the responses of the treated ZnO nanofibers sensor to formaldehyde,benzene,xylene and methylbenzene decrease,indicating an improved selectivityand anti-disturbance from interference to acetone va-por. The improvement mechanism of ZnO nanofibers treated by oxygen plasma is analyzed briefly by means of deple-tion layer thickness and potential barriers between grains.