【作者】 陈广；

【导师】 赵宏伟； 刘清泉；

【作者基本信息】 湖南科技大学 ， 材料科学与工程（专业学位）， 2024， 硕士

【摘要】 水体中重金属污染是当今世界范围内最严重的环境问题之一。在众多处理水体重金属离子技术中,固相吸附技术因其易于操作、成本低、无二次污染等特点而具有广阔的应用前景。近年来,利用金属有机框架（MOFs）吸附去除水中重金属离子引起人们的关注,但目前普遍研究的MOFs基吸附剂为粉末,在使用时存在回收性差和分散性不足等问题,不利于实际应用。此外,为提高吸附性能通常需要对MOFs进行功能化改性,这需要用到昂贵的试剂和繁琐的改性步骤,增加了吸附剂的制备成本。因此,本论文针对上述问题开展以下研究内容:（一）、绿色合成水稳定ZIF-8型MOF,通过非溶剂致相分离（NIPS）法将聚醚砜（PES）与ZIF-8复合制备聚合物珠PES@ZIF-8。使用BET、FT-IR、XPS、SEM、XRD和TG等表征手段对PES@ZIF-8聚合物珠的孔结构、化学结构、表面形态、结晶度和热稳定性进行分析,证明ZIF-8按比例与PES进行复合得到纳米孔结构聚合物珠。研究考察PES@ZIF-8聚合物珠在p H值、接触时间、初始浓度和离子共存等不同条件下对四种重金属离子Cu²⁺、Ag⁺、Co²⁺和Ni²⁺的吸附性能。结果表明,易于回收的聚合物珠PES@ZIF-8对Cu²⁺和Ag⁺具有优异的吸附性能,对于Cu²⁺具有高效的选择吸附性。其中,按60%质量比负载ZIF-8的聚合物珠PES@ZIF-8（60%）对Cu²⁺和Ag⁺基于Langmuir等温线拟合的最大吸附量分别为349.31mg/g和476.30mg/g。（二）、在合成水稳定UiO-66型MOF时,引入硫代水杨酸（TSA）作为调节剂,一步法合成了含有巯基官能团的缺陷型UiO-66（SH）-X。使用BET、FT-IR、XPS、SEM-EDS、XRD、TG和粒度分布等表征手段对UiO-66和UiO-66（SH）-X的孔结构、化学结构、表面形态、元素组成、结晶度、热稳定性和粒径进行分析,证明UiO-66和UiO-66（SH）-X被成功合成。此外,在UiO-66（SH）-X中含有缺陷结构并引入巯基官能团,同时缺陷结构导致UiO-66（SH）-X的晶粒尺寸减小并构建分层多孔结构。研究考察UiO-66和UiO-66（SH）-X在p H值、接触时间、初始浓度、吸附剂量、调节剂用量、温度、离子共存等不同条件下对Ag⁺的吸附性能。结果表明,含有巯基官能团的缺陷型UiO-66（SH）-X对Ag⁺的吸附性能得到显著提升,能有效的从低浓度酸性废水中选择性吸附并富集回收Ag⁺。其中UiO-66（SH）-10对Ag⁺基于Langmuir等温线拟合的最大吸附量为213.87mg/g,对于初始浓度C₀≤100mg/L的Ag⁺的去除率达到99.9%。更多还原

【Abstract】 Heavy metal pollution in water is one of the most serious environmental problems in the world today.Among the many techniques for treating heavy metal ions in water,solid-phase adsorption technology has a wide application prospect due to its simple operation,low cost and no secondary pollution.In recent years,the use of metal-organic frameworks（MOFs）adsorption to remove heavy metal ions from water has attracted attention,but the MOFs-based adsorbents commonly studied are powders,which are unfavourable for practical application due to poor recyclability and insufficient dispersion in use.In addition,functionalised modification of MOFs is usually required to improve the adsorption performance,which requires expensive reagents and cumbersome modification steps,thus increasing the preparation cost of adsorbents.Therefore,in this thesis,the following research contents are carried out to address the above problems:（i）Green synthesis of water-stabilised ZIF-8 type MOF,polymer beads PES@ZIF-8were prepared by complexing polyethersulfone（PES）with ZIF-8 by non-solvent-initiated phase separation（NIPS）method.The pore structure,chemical structure,surface morphology,crystallinity and thermal stability of the PES@ZIF-8 polymer beads were analysed using the characterisation tools of BET,FT-IR,XPS,SEM,XRD and TG to demonstrate that ZIF-8 was proportionally compounded with PES to obtain nanopore structured polymer beads.The adsorption performance of PES@ZIF-8 polymer beads on four heavy metal ions:Cu²⁺,Ag⁺,Co²⁺and Ni²⁺,was investigated under different conditions such as p H,contact time,initial concentration and ion coexistence.The results showed that the easily recyclable polymer beads PES@ZIF-8 had excellent adsorption properties for Cu²⁺and Ag⁺,and efficient selective adsorption for Cu²⁺.Among them,the maximum adsorption amounts of polymer beads PES@ZIF-8（60%）loaded with ZIF-8 at 60%mass ratio for Cu²⁺and Ag⁺based on Langmuir isotherm fitting were 349.31 mg/g and 476.30 mg/g,respectively.（ii）In the synthesis of water-stabilised UiO-66 type MOFs,thiosalicylic acid（TSA）was introduced as a modifier to synthesise defective UiO-66（SH）-X containing sulfhydryl functional groups in one step.The pore structures,chemical structure,surface morphology,elemental composition,crystallinity,thermal stability and particle size of UiO-66 and UiO-66（SH）-X were analysed using characterisation tools such as BET,FT-IR,XPS,SEM-EDS,XRD,TG and particle size distribution,which showed that UiO-66 and UiO-66（SH）-X were successfully synthesised.In addition,defect structures were included in UiO-66（SH）-X and introduced sulfhydryl functional groups,while the defect structures led to the reduction of grain size and the construction of a hierarchical porous structure of UiO-66（SH）-X.The adsorption performance of UiO-66 and UiO-66（SH）-X on Ag⁺was investigated under different conditions such as p H,contact time,initial concentration,amount of adsorbent,amount of moderator,temperature and ionic coexistence.The results showed that the adsorption performance of the defective UiO-66（SH）-X with sulfhydryl functional groups on Ag⁺was significantly improved,and it could effectively selectively adsorb and enrich and recover Ag⁺from low-concentration acidic wastewater.Among them,the maximum adsorption of Ag⁺by UiO-66（SH）-10 was 213.87 mg/g based on Langmuir isotherm fitting,and the removal rate of Ag⁺reached 99.9%for the initial concentration of C₀≤100 mg/L.更多还原