等离子体诱导环糊精修饰石墨烯/铁氧化物对放射性核素吸附及其机理研究

Graphene, as a novel kind of carbon material with a 2D structure, has unique physicochemical properties and extra high surface areas, which indicate that some functionalized materials based on graphene can be used as superabsorbent with high sorption capacity. The plasma induced grafting technique, as an environment friendly and effective material surface functionalization method, is applied in the surface modification of materials. In this project, graphene oxide is synthesized from graphite using the Hummers method and combined with iron oxides to form graphene oxide/iron oxides magnetic composites. The magnetic composite of β-cyclodextrin grafted onto graphene oxide/iron oxides (denoted as GO/Iron oxides/CD) is synthesized using the plasma-induced grafting technique.The composites are used as a sorbent for the removel of radionuclides due to high surface eara, abundant of founctional groups and magnetite. The sorption behavior of radionuclides by GO/Iron oxides/CD is studied as a function of contact time, pH, ionic strength under ambient conditions. The sorption capacity and meachemism of radionuclides in the composites are studied by static sorption and microstructural analysis. This study will illustrate the relations between the sorption capacity and composition, reveal the connection between the microstructure and sorption machenism, and develop a new kind of material and technique in the field of nuclear waste water treatment.

石墨烯是全新的二维有序碳材料，具有独特的物理化学特性和极高的表面积，在吸附方面有重要应用价值。本项目利用高效、环境友好的低温等离子体技术在石墨烯/铁氧化物表面可控接枝环糊精，制备一种具有磁分离及高吸附性能的石墨烯/铁氧化物/环糊精磁性纳米复合材料。并对该材料进行物理、化学特性表征。利用该材料高比表面积、表面富含官能基团、具有磁性等特点，吸附放射性Cs(I)、Sr(II)和U(VI)。通过静态吸附实验，研究反应时间、溶液环境条件对磁性纳米复合材料吸附放射性核素的影响。通过对比石墨烯/铁氧化物接枝环糊精前后对放射性核素的吸附性能，揭示环糊精在放射性核素去除中的作用和机理。采用宏观静态吸附法和微观表征相结合的方法，研究复合材料对放射性核素吸附性能和机理，揭示吸附微观结构与吸附机理的规律，探索一种高效、安全、稳定的放射性废液处理的新材料和新技术。

本项目主要以氧化石墨烯（GO）为载体，通过材料的设计、优化和合成，优化制备方法，制备基于石墨烯/ Fe3O4复合材料（EDTA-mGO、AMGO、FGC）、基于石墨烯/ 零价铁复合材料（Fe-PANI-GA）、基于石墨烯复合材料（PAS-GO、GO-SH）。获得了上述材料去除水中U(VI)和Eu(III)的优异性能，研究不同实验条件（pH值、 离子强度、 反应温度、 反应时间）下，纳米复合材料对U(VI)和Eu(III)去除性能的影响，阐明材料的吸附性能与上述因素的关系，揭示材料结构表面化学特性与放射性核素（U(VI)、 Eu(III)）吸附之间的内在关联规律。阐述复合材料与目标污染物间的相互作用机理，期望藉此为研究新型高效石墨烯复合材料去除核素提供可靠的科学依据和理论基础。