化学学报 ›› 2012, Vol. 70 ›› Issue (13): 1477-1482.DOI: 10.6023/A12030002 上一篇    下一篇

研究论文

热稳定体相还原态对二氧化钛气敏应用重要性的实验证实

邹晓新a,b, 李国栋b, 邹永存b, 王培培b, 苏娟a,b, 赵君b, 王宇宁b, 陈接胜a   

  1. a 上海交通大学化学化工学院 上海 200240;
    b 吉林大学无机合成与制备化学国家重点实验室 长春 130012
  • 收稿日期:2012-02-28 出版日期:2012-07-14 发布日期:2012-03-30
  • 通讯作者: 陈接胜 E-mail:chemcj@sjtu.edu.cn
  • 基金资助:

    项目受国家自然科学基金(No. 91022019)和国家重点基础研究计划(No. 2011CB808703)资助.

Experimental Validation of the Importance of Thermally Stable Bulk Reduction States in TiO2 for Gas Sensor Applications

Zou Xiaoxina,b, Li Guodongb, Zou Yongcunb, Wang Peipeib, Su Juana,b, Zhao Junb, Wang Yuningb, Chen Jieshenga   

  1. a School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China;
    b State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, Jilin University, Changchun 130012, China
  • Received:2012-02-28 Online:2012-07-14 Published:2012-03-30
  • Supported by:

    Project supported by the National Natural Science Foundation of China (91022019) and the National Basic Research Program of China (2011CB808703).

TiO2 中体相还原态与气敏性质之间的关系已有理论预测但一直未得到实验验证. 在此, 我们报道一种利用多孔无定型二氧化钛作前驱体制备含热稳定体相还原态TiO2 的化学方法. 紫外-可见漫反射光谱, 电子顺磁共振波谱(EPR)以及X-射线光电子能谱(XPS)证明所获材料中含有的体相还原态为热稳定的Ti3+离子以及捕获电子的氧缺位. O2-程序升温脱附测量结果表明, 体相还原态的存在可以显著提升二氧化钛表面对氧分子的吸附作用. 所获得的体相还原纳米材料不仅表现出优越的对有机分子(乙醇、甲醇及丙酮)的传感性和快速响应性, 而且具有对CO 传感的良好选择性(相对于CH4 和H2). 测试结果证实了TiO2 传感材料中体相还原态的重要性, 材料的气体传感性能与TiO2 表面氧气分子吸附作用密切相关.

关键词: 二氧化钛, 气体传感器, 体相还原态, 氧气吸附, 纳米材料

The relationship between bulk-reduction states and gas-sensing properties of TiO2 was predicted previously, but has not been validated yet experimentally. Herein, we present a chemical approach for the preparation of TiO2 nanoparticles with thermally stable bulk reduction states using porous amorphous titania as precursor. UV/vis diffuse reflectance, electron paramagnetic resonance (EPR) and X-ray photoelectron spectroscopy (XPS) confirm that the stable bulk reduction states are the thermally stable Ti3+ ions and electron-trapped oxygen vacancies. O2-temperature programmed desorption (O2-TPD) measurements demonstrate that the presence of the bulk reduction states can obviously enhance the oxygen adsorption on titania surfaces. Furthermore, the bulk-reduced nanomaterial exhibits not only enhanced sensitivity and ultrafast response/ recovery (<3 s) for the detection of organic vapors (ethanol, methanol and acetone), but also excellent selectivity to CO against CH4 and H2. The sensing performance testing results confirm the importance of bulk reduction states in TiO2 sensors for the first time, and the enhanced gas-sensing performances for bulk-reduced TiO2 materials can be related to the enhanced oxygen absorption on TiO2 surfaces.

Key words: titanium dioxide, gas sensor, bulk reduction states, oxygen adsorption, nanomaterial