构建高通量石墨烯毛细管阵列微反应器及类芬顿反应强化行为

Heterogeneous Fenton-like catalytic degradation is one of the most important technologies for eliminating persistence organic contaminants contained water with low concentration. However, the problems of enriching concentration and low efficiency exist. To solve them, we strategically design monolithic graphene capillary array microreactor with high flux using fir wood with abundant capillary microstructure as framework, and the reaction process is strengthened owing to micro-size effect and adsorption/loading characteristics of graphene. On this basis, organic contaminants can be absorbed effectively due to high surface area of graphene, and catalytic performance is able to enhance remarkably on account of high dispersion/anchoring to nanoparticles from graphene and transfer process enhancement in graphene constructed micro channels. Mussel-inspired polydopamine (PDA) is used to modify wood framework via in-situ polymerization. Graphene can be uniformly and firmly deposited on the modified wood by hydrogen and π-π bond self-assembly method. The deposition regulation is obtained, and graphene capillary array is formed using fir wood as framework. The effect of capillary array structure and adsorption/loading characteristics of graphene on intensified reaction will be investigated. Therefore the reinforcement mechanism of Fenton-like catalysis will be clarified. The development on graphene capillary array microreactor lays scientific foundation for the design high-performance microscale reactor and is of great significance to resolve the intractable issue for persistence organic contaminants treatment in a high-efficiency and economic way.

本研究以非均相类芬顿催化处理低浓度难降解有机污染物为应用背景，针对污染物的浓度富集和反应效率低的问题，以具有丰富毛细管微结构的杉木为骨架，构建整体式高通量石墨烯毛细管阵列微反应器，基于微尺寸效应与石墨烯吸附/负载特性协同强化反应过程。利用石墨烯的高比表面积有效吸附富集污染物，同时通过微通道内的传递过程强化以及石墨烯对纳米粒子的高分散/锚定功能等优势，显著提高催化反应性能。借助多巴胺仿生材料对杉木骨架进行表面修饰，进而利用氢键和π-π键自组装技术牢固沉积石墨烯，研究石墨烯均匀沉积规律，搭建杉木骨架的石墨烯毛细管阵列；重点研究石墨烯毛细管微结构及其吸附/负载特性与反应性能之间的联系，揭示所构筑微反应器的类芬顿催化增强机制，为高性能微尺度反应器的开发奠定科学基础，对于高效、经济解决低浓度难降解有机污染物的处理难题具有重要意义。

本项目系统研究了杉木骨架直长/互联的毛细管束微结构、毛细微结构调控过程与木材特性，揭示天然木材毛细管互穿网络结构与流体传输特点；研究了石墨烯在三维木材骨架内的负载过程与均匀沉积规律，获得了杉木毛细骨架表面负载均匀的石墨烯涂层，揭示其固载机制，并探究了多种非均相类Fenton催化剂在有机染料废水处理中的催化降解性能；成功构建了高质量单原子催化剂负载的毛细微通道阵列反应器，研究了其在有机染料废水处理中的类芬顿催化性能，结合Fluent流体仿真软件揭示了木骨架毛细管微结构内催化反应机理与增强机制。结果表明，所构建的微反应器在有机染料废水处理中兼具优异的类芬顿催化降解性能与高通量处理效率。以杉木为原料开发的兼具高通量和高截留率的生态环境处理材料，有望在生态环境治理中实现绿色、低成本与规模化应用，而且该研究成果还能为高性能微反应器的设计提供重要参考，并为木材资源高值化利用提供了一条重要思路。