超高层间氧化石墨对重金属吸附行为及其复合体γ辐照下结构演化控制

As the product obtained by exfoliation of graphite oxide, graphene has a promising prospect in the absorption recovery and reuse field of heavy metal because of its unique structure. But there are problems encountered in previous studies, such as agglomeration, high cost, difficult separation and functional group reduction of graphene. Therefore, we will modify the interlayer structure of graphite oxide by γ-ray irradiation, absorb the heavy metal ion in wastewater using the irradiated graphite oxide and then prepare graphene/metal nanoparticle composites via γ-ray irradiation of adsorption products. In this project, the absorption behavior of metal ion in interlayer of irradiated graphite oxide will be investigated, and the structure evolution law of metal-intercalated graphite oxide will be explored to reveal the regulation mechanisms of metal absorption behavior in interlayer of graphite oxide and grasp the control method of structure and morphology of graphene/metal nanoparticle composites. We will pay attention to the control of migration, combination and agglomeration behavior of metal nanoparticles on graphene surface. The theoretical basis and experimental base for the recovery and reuse of heavy metal will be enriched after the project is carried out. The project will be of significance for the improvement of environmental governance and resource recycling levels in our country.

氧化石墨在重金属治理回收领域具有诱人的应用前景，但面临如下难题：氧化石墨剥离为石墨烯后应用成本高，直接使用的效率很低，且在金属离子还原过程中石墨烯片表面含氧官能团易被同步还原。为此，申请人已借助γ辐照技术对氧化石墨进行层间改性，获得了超高层间的氧化石墨(HGO)。项目将采用“先辐照改性，后插层吸附”的氧化石墨吸附重金属路线，利用HGO吸附重金属离子，再通过γ辐照由金属离子插层HGO一步制备石墨烯负载金属纳米颗粒复合材料。分析并揭示金属离子在HGO层间的吸附行为及其调控机制，探索γ辐照下由金属离子插层HGO向石墨烯负载金属纳米颗粒复合材料演变的规律及机理，重点研究辐照过程中金属纳米颗粒在石墨烯表面迁移和生长行为及其控制，掌握基于γ辐照的石墨烯/金属纳米颗粒结构与形貌的控制方法。项目将为重金属的吸附回收及再生利用提供重要的理论依据和实验基础，对于提高我国环境治理与资源循环利用水平具有重要意义。

由于丰富的表面含氧官能团及独特的层间限域空间，氧化石墨在重金属回收及利用方面具有显著的优势。本项目首先对氧化石墨的层间结构进行优化与调控，利用氧化石墨吸附重金属离子，并通过γ辐照由金属离子插层氧化石墨一步制备石墨烯负载金属纳米颗粒复合材料。探讨了金属离子在氧化石墨层间的吸附行为及其调控机制，研究了γ辐照下由金属离子插层氧化石墨向石墨烯负载金属纳米颗粒复合材料演变的规律及机制，分析了石墨烯负载Ag、Au及Pt等贵金属纳米复合材料在Raman增强、癌细胞抗原选择性探测以及碱性电解液中燃料电池氧还原催化等领域的应用性能。重点研究辐照过程中金属纳米颗粒的生长行为及其形貌控制方法。所制备Ag NPs/石墨烯复合材料Raman信号是纯氧化石墨烯的6.3倍；所得产物修饰的电极经癌细胞抗体修饰后检测癌细胞抗原的检测极限可达15.8pg；制备的生物免疫传感器用于癌胚抗原的检测，在CEA浓度为10-108 fg•mL-1范围内，检测限为7fg/mL；所得氮掺杂石墨烯负载铂催化剂还原峰电势为0.805 V，极限电流密度为6.69 mA•cm-2，远高于商业Pt/C催化剂。项目将为重金属的吸附回收及再生利用提供重要的理论依据和实验基础，对于提高我国贵金属资源循环利用以及碳/贵金属纳米复合材料在传感及催化领域的应用具有重要意义。