化学学报 ›› 2014, Vol. 72 ›› Issue (4): 433-439.DOI: 10.6023/A13121212 上一篇    下一篇

研究论文

氧化锌多孔微米花的制备及其气敏性能研究

熊静芳, 肖佩, 吴强, 王喜章, 胡征   

  1. 介观化学教育部重点实验室 南京大学化学化工学院 南京 210093
  • 收稿日期:2013-12-04 出版日期:2014-04-14 发布日期:2014-02-17
  • 通讯作者: 吴强 E-mail:wqchem@nju.edu.cn; Tel.:025-83685303 E-mail:wqchem@nju.edu.cn
  • 基金资助:

    项目受国家自然科学基金(Nos.21173115,20873057)资助.

Synthesis and Gas-Sensing Properties of ZnO Porous Microflowers

Xiong Jingfang, Xiao Pei, Wu Qiang, Wang Xizhang, Hu Zheng   

  1. Key Laboratory of Mesoscopic Chemistry of MOE, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093
  • Received:2013-12-04 Online:2014-04-14 Published:2014-02-17
  • Supported by:

    Project supported by the National Natural Science Foundation of China (Nos. 21173115, 20873057).

具有大比表面积和丰富表面缺陷的三维多孔纳米材料在气体传感中极具潜力. 通过液相共沉淀法制备了三维微米花状锌基前驱物,于400 ℃热处理即转化为ZnO多孔微米花,它继承了锌基前驱物的外观形貌,但片状“花瓣”的表面形成大量无序孔洞,使得ZnO多孔微米花具有大比表面积(31.3 m2·g-1)和丰富的表面缺陷. 鉴于ZnO多孔微米花的独特微观形貌结构,用其构建的气体传感器对乙醇气体表现出最佳工作温度低、灵敏度高、响应(恢复)快速等优点,与文献报道的ZnO基乙醇气体传感器相比处于领先水平. 结合其制备过程简单、成本低等优点,ZnO多孔微米花在气体传感领域有潜在的应用价值.

关键词: 氧化锌, 多孔材料, 气敏性能, 共沉淀法, 纳米材料

Three-dimensional (3D) porous nanomaterials with large surface area and abundant surface defects have promising potential in gas sensing due to the following merits: (i) large contact area of gaseous species with the materials, and more adsorption sites on the highly defective surface, (ii) good accessibility to gaseous species of the 3D open structure, (iii) fast electron transport among the 3D network. Rational design and controlled synthesis of the 3D porous nanomaterials with specific morphology and microstructure are essential for improving the performance of gas sensing. In this work, 3D ZnO porous microflowers were prepared by directly calcining the zinc-based flowerlike precursor at 400 ℃ in air. The precursor was preformed through a simple coprecipitation method, i.e., by refluxing the aqueous solution of zinc nitrate and co-precipitators of hexamethylenetetramine and oxalic acid at 90 ℃ for 4 h. The unique ZnO porous microflowers were composed of porous nanosheets of 10~50 nanometers in thickness and 1~2 micrometers in width, which inherited from the zinc-based precursor except for the randomly distributed pores on the nanosheet "petals". The 3D porous microstructures endowed ZnO with large specific surface area of 31.3 m2·g-1 and abundant surface defects. ZnO porous microflowers were used as active materials to fabricate gas sensors, which exhibited low working temperature, high sensitivity and fast response (recovery) characteristic against ethanol vapor, at the advanced level in comparison with the reported ZnO-based gas sensors for ethanol. The superior performance of the gas sensors could be attributed to the unique microstructures of the ZnO porous nanomaterials. In addition, the sensitivity of the gas sensors showed an exponential relationship with the concentration of ethanol vapor, indicating their capability of quantitative detection within the ethanol volume ratio of 1×10-6~500×10-6. Together with the superb sensing performance, simple preparation processing and low cost, ZnO porous microflowers have promising application prospect in gas sensing area.

Key words: zinc oxide, porous materials, gas sensing properties, coprecipitation method, nanomaterials