亚10纳米Fe(III)氧化物复合材料的制备及其高效除砷特性研究

Fe(III)氧化物纳米颗粒（NPs）可通过配体交换实现对砷（As）的选择性吸附，当其尺寸降低到亚10 nm常表现出显著的表面效应，并大幅提升材料的深度净污性能。将NPs分散到聚合物中可有效克服其易团聚、操作困难等不足。然而，受常用聚合物载体宽孔分布的影响，制备亚10 nm Fe(III)氧化物复合材料仍面临挑战。本项目拟基于“闪速冷冻法”制备介孔聚合物，探讨载体孔结构（5-30 nm）对NPs生长过程与粒径的影响规律，开发并优化亚10 nm Fe(III)氧化物复合材料的制备方法；深入研究限域条件下亚10 nm Fe(III)氧化物形貌、晶体结构及表面化学特性的演变规律，系统评价所制复合材料的除As性能，阐明新材料吸附除As过程的表面效应；此外，还将探究溶液化学性质对新材料除As性能的影响与新材料的再生方法。本项目有望为高性能环境纳米复合材料的研制及应用提供理论与技术参考。

Iron oxide nanoparticles (NPs) are very promising for decontamination of water from arsenic (As) via ligand-exchange reactions. Accompanying with decreasing NPs size below 10 nm, their decontamination reactivity could be enhanced greatly. By dispersing inside polymer matrix, the defects of NPs, such as tendency of aggregation and difficult operation, could be partially or even completely remedied without compromising their high reactivity. However, polymer-supported NPs are commonly with size from dozens of nanometers to even >100 nm arising from the wide pore size distribution of the hosts. In this project, we intend to prepare millimeter-scale mesoporous polystyrene (MesoPS) through flash-freezing method to assemble iron oxide NPs. By varying the pore size of MesoPS from 5 to 30 nm, we will investigate the effect of host pore size on growth of the confined iron oxide NPs, and thereby realizing the preparation of polymer-supported sub-10 nm iron oxides. We will focus on surface chemistry of the confined NPs and their removal efficiencies toward As. Moreover, the mechanism of As(III)/(V) adsorption onto iron oxide NPs, the effect of solution chemistry on As removal, and regeneration of the newly developed nanocomposites will be studied. We anticipate that this work could stimulate more studies towards the rational design of highly efficient environmental nanocomposites.