基于表面吸附氧含量调控的MOFs衍生多孔半导体金属氧化物异质气敏材料的优化设计

Rapid and effective warning of emission and leakage of toxic gases which cause serious environmental pollution is an important prerequisite to effectively control environmental pollution. The rich pore structure and large specific surface area of porous semiconductor metal oxide (pSMO) provide favorable conditions for real-time monitoring of toxic gases. However, the preparation methods of pSMO are multistep and complicated. This project will mainly focus on preparation of pSMO and its composites by using MOFs as self-sacrifice template and their application in detection of toxic gases. The uniform doping and effective integration of pSMO can be realized with the help of unique composition and structure of MOFs, leading to the enhancing of the force between different components and fully exploiting of the synergistic effect. Combine the tuning of the electronic structure of pSMO by doping and integration with activating treatment technology to increase the content of superficial adsorbed oxygen, and improve the gas-sensing performance. In addition, preparation methods of core-shell materials can be developed with the help of abundant pores of MOFs, and the effect of interface microstructure and interaction on the content of superficial adsorbed oxygen and gas-sensing performance will be studied using O2 and H2 atmosphere calcining pretreatment. Subsequently, the structure-activity relationship and gas-sensing mechanism will be investigated. The results of this work will enrich the application of pSMO derived from MOFs in gas sensor, and provide basic work for the development and practical application of new gas-sensing materials.

毒害性气体的排放和泄漏造成严重的环境污染，对其进行快速、有效地预警是有效控制环境污染的重要前提。多孔半导体金属氧化物（pSMO）的丰富孔道结构、超大比表面积为毒害性气体的实时监测提供有利条件，但其制备技术复杂、步骤繁琐。本项目拟以MOFs为自牺牲模板可控制备pSMO及复合材料，并将其应用于毒害性气体的检测中。借助MOFs组成与结构特点实现pSMO的均匀掺杂和有效复合，增加组分间结合力，充分发挥协同效应，依靠掺杂、复合等对材料电子结构的调控结合活化处理技术增加表面吸附氧含量，提高材料气敏性能。借助MOFs丰富孔道发展核壳型贵金属与pSMO复合材料的制备方法，结合O2和H2气氛煅烧处理技术探明界面微观结构、相互作用等对材料表面吸附氧含量和气敏性能的影响，建立构效关系，揭示气敏响应机制，丰富MOFs衍生pSMO及异质复合材料在气敏传感器领域的应用，为新型气敏材料的开发应用提供工作基础。

电阻式化学传感器因价廉、易携带、操作方便、可实现实时监测等优点在毒害性气体的检测方面具有广泛应用前景。气体敏感材料是决定传感器性能的关键，然而其仍然面临灵敏度（或响应值）低、工作温度高等问题，如何解决这些问题更高效地实现毒害性气体的实时监测就成为气敏传感器设计的关键。金属有机骨架（MOF，Metal-Organic Framework）作为自牺牲模板构建的多孔材料在气体传感器领域具有明显优势。本项目通过调控实验参数制备了具有多种形貌和结构的MOF微纳米粉体，并发展了Fe-MOF和In-MOF的室温普适制备方法，尤其扩展了In-MOF微纳米粉体的种类。探明了影响Fe-MOF和In-MOF微纳米粉体生长的主要因素，构建了实验参数与MOF组成、结构间的关联。该法简单、易操作，易于实现MOF微纳米粉体的宏量制备。以MOF为模板构建了多种具有丰富孔道结构的金属氧化物和金属硫化物，探究了实验参数对材料组成、结构等的影响。通过掺杂和复合调控材料改善材料电子结构，提高材料表面吸附氧含量；研究了掺杂、复合等对材料表界面微观结构、界面相互作用、电子转移等对材料气敏性能的影响；结合多种结构表征手段构建了材料结构与气敏性能之间的关联，并对其气敏机理进行了研究。此外，我们还将所研发的MOF衍生的多孔材料应用于环境污染物的去除，考察了材料组成、形貌、界面相互作用等对活性物种和污染物去除效能的影响。