功能化MIL-125异质结吸附-光催化协同去除水中酚类环境激素机理研究

Endocrine disruptors has become a global issue that needs to be addressed, because it can interfere with normal endocrine function. Photocatalytic technology is an effective way to endocrine disruptors treatment, and metal-organic frameworks(MOFs) are widely regarded as new photocatalyst materials, due to due to their high specific surface area and tunable structure. In the project, we intend to design MIL-125(Ti), make the functionalization of MIL-125(Ti), construct composite materials and study the photocatalytic degradation of typical phenolic endocrine disruptors. The different functional groups will be introduced into the organic bridging ligands of MIL-125(Ti) by modifying the organic linker before or after synthesis. The effects of functional groups on the material structure and physicochemical properties of MIL-125(Ti) will be described systemically. MoS2/MIL-125(Ti) composite materials will be constructed, the optimization of the catalyst preparation, the chemical composition, optical property, surface state of the catalysts as well as the local and electronic structure of the active sites, together with the separation and interfacial migration of the photo-generated carriers will be examined in details, and the interaction and matching between MoS2 and MIL-125(Ti) will be explored. The adsorption and diffusion behavior, photocatalysis degradation reaction kinetics and degratation mechanism of typical phenolic endocrine disruptors over functioned MIL-125(Ti) or MoS2/MIL-125(Ti) will be researched. The synergistic effect between the adsorption and the photocatalytic degradation behaviors of phenolic endocrine disruptors on the prepared photocatalysts will be illuminated. This project provides theoretical basis and reference for treatment of undegradable pollutants with low concentration but high toxicity by the integrated adsorption and decomposition technology.

环境激素干扰生物体内分泌机制，已成全球重大环境问题。光催化技术可有效降解环境激素，金属有机骨架材料具有比表面积高、结构易调等特点，正成为新型光催化材料。本课题拟开展MIL-125制备、功能化改性、复合材料构筑，光催化降解典型酚类环境激素研究。通过配体预修饰和MOFs后嫁接引入官能团，研究对MIL-125材料结构和理化特性的调控。构筑MoS2与MIL-125异质结，研究材料的优化制备、化学组成、光吸收特性、表面状态、活性中心以及光生载流子的分离和界面转移，探讨MoS2和MIL-125之间的相互作用和匹配问题。研究典型酚类环境激素在功能化MIL-125和MoS2/MIL-125材料界面的吸附扩散动力学行为和光催化反应机理，探讨材料对环境激素的吸附富集行为与光催化降解行为的协同作用机制，为“吸附-降解”一体化处理水体低浓度、高毒性、难降解污染物技术提供理论基础和技术参考。

光催化高级氧化技术在污水处理应用中，研制新型可见光光催化材料是目前研究热点，本项目主要研究内容是制备金属有机骨架材料NH2-MIL-125(Ti)、MoS2及相关复合材料，以及光催化降解性能。利用窄带隙半导体能够提高可见光利用率，构筑复合材料异质结构抑制光生载流子复合，提高量子效率，从而提高光催化能力。.研究发现，通过引入氨基制备NH2-MIL-125(Ti)，扩展MIL-125(Ti)的光学吸收性能，最大光响应波长达480nm。采用超声技术制备MoS2量子点（MoS2 QDs）溶液，并构筑MoS2 QDs/NH2-MIL-125(Ti)复合材料。通过SEM、TEM、XRD、DRS、XPS观察材料的形态结构、晶相结构、光学吸收性能、元素表面化学形态。MoS2 QDs的尺寸约为4nm，MoS2 QDs/NH2-MIL-125(Ti)复合材料具有良好的可见光吸收性能和可见光催化剂降解甲基橙性能，可见光光照2 h可以去除81%甲基橙，并具有良好的稳定性和重复利用性，循环使用5次，其光催化降解能力没有明显降低。利用超声协助沉淀技术制备BiOI及BiOI/NH2-MIL-125(Ti)复合材料，BiOI具有厚度约为50nm的纳米片结构，NH2-MIL-125(Ti)均匀分布在BiOI纳米片上。BiOI带隙为1.77 eV，扩展了NH2-MIL-125(Ti)光吸收能力，BiOI和NH2-MIL-125（Ti）形成异质结，促进电子-空穴的分离，提高光催化活性，可见光光照2 h可以去除93.1%甲基橙，循环使用4次，其光催化降解能力没有明显降低。通过添加有机配体2,5-二溴对苯二甲酸，采用溶剂热法成功制备金属有机骨架材料Br2-NH2-MIL-125(Ti)，通过原位反应-光还原技术获得新型复合材料Ag/AgBr/NH2-MIL-125(Ti)。Ag/AgBr粒子尺寸约为10nm，XPS、HRTEM和UV-DRS证明Ag/AgBr纳米粒子生成，Ag/AgBr/NH2-MIL-125(Ti)复合材料具有良好的可见光吸收性能。Ag/AgBr/NH2-MIL-125(Ti)复合材料在可见光照射下，具有优异的可见光光催化降解能力。.本项目的相关研究成果，已发表SCI收录论文6篇，申请专利4项，其中授权2项，该研究为新型可见光催化复合材料的研制及其在污水处理应用中提供科学参考。