Ge Wanyin, Jiao Siyi, Chang Zhe, He Xuanmeng, Li Yongxiang
School of Materials Science and Engineering, Shaanxi Key Laboratory of Green Preparation and Functionalization for Inorganic Materials, Shaanxi University of Science and Technology, Xi'an, Shaanxi 710021, China.
School of Engineering, RMIT University, Melbourne, Victoria 3000, Australia.
ACS Appl Mater Interfaces. 2020 Mar 18;12(11):13200-13207. doi: 10.1021/acsami.9b23181. Epub 2020 Mar 5.
For the development of high-performance gas sensors, ultrafast response and high selectivity are critical requirements for many practical applications. An alternative strategy is to employ hierarchical nanostructured materials in gas sensors. In this work, we report newly synthesized TiO hexagonal nanosheets with a hierarchical porous structure, which demonstrate an ultrafast gas response and high selectivity toward acetone vapor for the first time. A simple one-step annealing process to prepare hierarchical TiO nanosheets derived from layered TiSe nanosheet templates is reported. The hierarchical structure interlaced with anatase TiO nanosheets showed an open porous characteristic. The average pore size was about 20 nm examined using a high-resolution TEM. The gas sensing properties toward acetone vapor of the novel hierarchical structured TiO nanosheets were characterized in detail including optimal operation temperature, sensitivity, selectivity, response/recovery time, and long-term stability. The gas sensing response and recovery times were 0.75 s and 0.5 s, respectively. We attribute these superior response properties to its unique hierarchical pore structure with a high specific surface area. The results show great potential for acetone vapor detection, particularly in dynamic ultrafast monitoring by using the synthesized hierarchical structured TiO nanosheets.
对于高性能气体传感器的开发而言，超快响应和高选择性是许多实际应用的关键要求。一种替代策略是在气体传感器中采用分级纳米结构材料。在这项工作中，我们报告了新合成的具有分级多孔结构的TiO六角形纳米片，其首次展现出超快的气体响应以及对丙酮蒸汽的高选择性。报道了一种简单的一步退火工艺，用于制备源自层状TiSe纳米片模板的分级TiO纳米片。与锐钛矿型TiO纳米片交错的分级结构呈现出开放的多孔特性。使用高分辨率透射电子显微镜检测，平均孔径约为20nm。详细表征了新型分级结构TiO纳米片对丙酮蒸汽的气敏性能，包括最佳工作温度、灵敏度、选择性、响应/恢复时间和长期稳定性。气敏响应和恢复时间分别为0.75秒和0.5秒。我们将这些优异的响应特性归因于其具有高比表面积的独特分级孔结构。结果表明，合成的分级结构TiO纳米片在丙酮蒸汽检测方面具有巨大潜力，特别是在动态超快监测中。
