酞菁铜@金属有机骨架化合物核壳结构的构筑及其高氨气选择性气敏性质的研究

Ammonia as a harmful gas is a great threat to human and environment, and thus it is particularly important to prepare NH3 sensor with high sensitivity, low detection limit, fast response / recovery, excellent selectivity and room temperature operation. Aiming at the low sensitivity and low selectivity of ammonia sensor, this project combined with the efficient selective adsorption of ammonia on metal-organic framework compounds and the good response of copper phthalocyanine to ammonia, a new type of copper phthalocyanine@metal-organic framework (CuPc@MOFs) compound core-shell ammonia sensor was designed and prepared for the efficient detection of ammonia. The main studies will include in the following: (1) design, preparation and characterization of the core-shell structure of copper phthalocyanine nanowires and copper phthalocyanine@metal organic framework compounds and the optimization of the preparation process; (2) studying ammonia detection performance of copper phthalocyanine@metal organic framework compound core-shell structure sensor, in combination with quantitative calculations, the favorable reaction of copper phthalocyanine nanowires to NH3, the high gas adsorption and selectivity of metal-organic framework compounds and their synergistic mechanism are explored.

氨气（NH3）是一种对环境和人类健康具有很大危害的气体。因此利用纳米构筑途径来得到可在室温下检测，同时具有高灵敏度、低检测限、快速响应/恢复以及优良选择性的NH3传感器是一项有价值和挑战性的工作。针对当前氨气传感器普遍存在的低灵敏度，低选择性等问题，本课题结合金属有机骨架化合物(MOFs)对氨气的高效选择吸附性与酞菁铜(CuPc)对氨气的良好响应性，拟设计并制备一类新型的酞菁铜@金属有机骨架化合物核壳结构(CuPc@MOFs)氨气传感器，主要研究内容如下：（1）酞菁铜纳米线以及酞菁铜@金属有机骨架化合物核壳结构的设计、制备与表征以及制备条件的优化；（2）酞菁铜@金属有机骨架化合物核壳结构型传感器的氨气气敏性能的研究。在实验表征的同时结合量化计算，尝试弄清酞菁铜与金属有机骨架化合物两者之间的协同作用，以及该作用对NH3高吸附性和高选择性的作用机制。

氨气作为一种空气污染物、化工原料、肾病标志物和爆炸物，广泛存在于我们的日常生活中。因此，开发响应快、稳定性高、选择性优异、检测范围宽、检测限低至ppb级的氨气检测传感器是一项关键挑战并具有重要的实际意义。本课题重点合成并系统探究了一种基于酞菁铜@金属有机骨架化合物核壳结构型（CuPc@IRMOF-3）氨气传感材料。相较于其他类型的氨气传感材料，该材料具有突出的选择性。在室温、相对湿度约为60%条件下，与其他多达十种干扰性气体（包括甲醇，乙醇，丙酮，苯等）相比，具有高达34-265倍的响应性提高。同时，检出限可达52ppb,并具有优异的稳定性和再生能力。系统实验和理论计算证明，具有多孔结构的IRMOF-3的包覆有利于促进氨气的富集和吸附，是提高气敏性能（包括敏感性、稳定性和选择性等）的关键因素。DFT计算结果表明，氨分子的吸附会提高CuPc的费米能级与价带顶的距离，从而使电阻加大，电流降低。