磺酸功能化纳米金属-炭氧化物@NH2-MOFs及其光芬顿催化氧化性能

Based on the unique porous structure and surface properties of amine functionalized metal-organic frameworks (NH2-MOFs), well-dispersed nano metal-carbon oxides@NH2-MOFs will be prepared through metal ions/organic acid impregnation and thermal treatment in this project. And then the supported catalysts will be modified by post-synthetic grafting of sulfonic acid groups. As noted, the visible light photocatalytic performance of heterogeneous Fenton will be efficiently enhanced and the running cost will be reduced due to the cooperative effect of carbon doping and NH2-MOFs support. Meanwhile, a large number of acid sites produced on the surface of MOFs and nanoparticles after sulfonic acid modification will make significant contributions in widening the working pH range of Fenton reaction. More special emphasis will be laid on investigating the effect of amine functionalization of node and ligand for MOFs frameworks, the composition, distribution and morphology of supported nanoparticles (NPs) and the characters of acid sites on the structure and performances of the supported catalysts. Importantly, the synergetic effect between NH2-MOFs support, metal-carbon oxides nanoparticles and sulfonic acid groups will be revealed. Moreover, the mechanism of photo-induced electron transfer and surface acid site in catalytic oxidation reaction will be clarified at microscopic level through in situ characterization and simulation calculation of density functional theory. As a result, the research progresses will make opportunities for developing of high-performance and structure controlled heterogeneous Fenton catalysts. It will play significant roles in solving the problem of environmental pollution and energy shortage, and provide technical support for ensuring the sustainable development of economy and society.

本项目基于多维金属有机骨架材料（MOFs）独特的孔道结构和表面的胺基基团，以金属-有机酸为活性组分，采用液相浸渍-热处理法合成高分散纳米金属-炭氧化物@NH2-MOFs负载型芬顿催化剂，并对其进行磺酸化改性。依靠活性组分中炭掺杂及载体的丰富表面特性，增强对可见光利用率，降低运行成本；利用磺酸化产生的酸性位，拓展芬顿反应的适用范围，克服pH对催化剂活性限制的难题。研究中重点分析MOFs节点/配体胺化、纳米颗粒组分、分布与形貌以及酸性位性质对负载型材料结构和催化性能的影响规律，揭示载体、纳米颗粒与磺酸基的协同效应；并通过原位跟踪表征和密度泛函理论模拟计算，从微观水平上深入研究光诱导电子传递和表面酸性位的催化反应机理。本项目研究可为高性能且结构可控的异相芬顿催化剂开发提供新材料和新方法，对解决环境污染和能源短缺问题具有重要科学意义和应用价值，为保障国家经济和社会的可持续发展提供技术支持。

全球性水环境恶化和水资源短缺日趋严重，对环境污染有效控制和治理已成为当今世界各国所面临和务必解决的重大问题之一。异相芬顿催化氧化作为最具实用潜力的绿色高级氧化技术，越来越受到关注和重视。本项目在材料学研究基础上，通过对多维金属有机骨架材料（MOFs）的结构调控、功能化改性以及纳米颗粒负载来制备新型MOF基负载型催化剂，为高性能异相芬顿催化剂设计开发提供了新材料、新方法。首先，采用原位组装法对MOFs金属节点和有机配体进行功能化修饰，表征分析功能性基团（如胺基、羰基等）对MOFs结构和表面特性影响；其次，以金属-有机酸为活性组分，采用液相浸渍-热处理法合成高分散纳米金属-炭氧化物@NH2-MOFs负载型芬顿催化剂；与未改性MOFs负载型催化剂相比，胺基基团的引入使催化剂在可见光条件下活性提高8-10倍（羟基自由基产率达到19.42 mg/L），并通过分析纳米颗粒在功能化MOFs材料上分布、尺寸及其负载量来揭示纳米颗粒与功能载体间协同催化效应；最后，对所制备芬顿催化剂进行酸化改性，利用改性产生的酸性位，成功将芬顿反应适用范围拓展到碱性环境（pH=10，93.9% 脱色率）；考察不同酸化方法和功能剂对表面酸性位性质的影响规律，建立酸催化反应动力学方程，并通原位表征手段从微观水平上分析了光诱导电子传递和表面酸性位的催化作用机理。本项目研究成果不仅有助于解决目前芬顿催化剂性能提高所面临的瓶颈，而且为拓展芬顿技术适用范围、增强可见光利用率以及降低运行成本进一步提供了可能，这对发展高效的绿色高级氧化技术和解决环境污染、资源短缺问题具有重要理论指导价值和研究意义。