不同结构 ZnO 的可控合成及其对气敏性能的影响

材料的微观形貌是影响其气敏性能的主要因素. 低维结构材料因反应时的团聚问题, 极大地限制了其应用. 因此, 通过设计合成多级结构的纳米材料来提高性能至关重要. 通过控制水热时间、阴离子表面活性剂柠檬酸钠的浓度以及 pH 值来调节形貌, 在水热条件下成功合成了多级片球状、片花状以及馒头状 3 种形貌的 ZnO 纳米材料. 通过对气敏性能进行测试, 发现多级片球状形貌具有较好的气体敏感性. 在 340 ${^\circ}$C 时, 对 100$\times10^{-6}$ 正丁醇的气敏响应达到 238, 比相同条件下的乙醇高 2.12 倍, 显示出了较好的选择性. 通过研究多级结构的生长机理及传感机制, 为设计多级体系结构 ZnO 高性能气敏材料提供了数据依据.

Controllable synthesis of ZnO with different structures and its effect on gas sensitivity

The micromorphology of a material is the main factor that influencesits gas sensitivity. Applications of low-dimensional structuralmaterials are greatly limited because of agglomeration issues duringreactions. The performance of nanomaterials can be improved bydesigning and synthesising multilevel structures. Materialmorphology was mainly adjusted by controlling the hydrothermal time,the concentration of anionic surfactant citrate ions and hydroxideions. The ZnO nanomaterial synthesised under the controlledhydrothermal conditions had three types of morphologies,pompon-like, flaky-flower-shaped, and buns-like. The pompon-like ZnOshowed good gas sensitivity. At 340 $^\circ$C, itsgas-sensitive response to 100$\times10^{-6}$ n-butanol was 238,which was 2.12 times higher than that in case of ethanol, showinggood selectivity. In addition, by investigating the growth andsensing mechanisms of the multistage structure of ZnO, insights wereprovided for designing high-performance gas sensitive materialsusing multilevelarchitecture of ZnO.