Preparation Of BTC-MOF Intercalated Graphene Oxide Composites And Their Application In Ion Separation

Graphene oxide(GO)has received extensive attention from researchers due to its excellent physical and chemical properties.Metal organic frameworks(MOFs)are porous materials that are self-assembled by connecting inorganic metal ions and organic ligands.Because of their pore structure,their size and morphology can be adjusted and their porosity is high,large specific surface area,simple preparation,convenient and other characteristics,has huge application potential in the fields of energy storage,separation and analysis.The MOFs and GO are composed into MOF-GO composite materials,compared with a single material,composite materials not only increase the porosity of the material,but also reduce the surface energy and enhance its stability.Based on the above research background,this work focused on the synthesis of BTC-MOF intercalated graphene oxide composite material by a simple and convenient method,and the preparation of the composite membrane for the selective separation of inorganic ions.The main contents are as follows:1.BTC-MOF intercalated GO membranes were prepared by an in-situ synthesis method,its structure,morphology and composition were characterized and evaluated.The results show that different types of BTC-MOF intercalated GO membranes have been successfully synthesized,and the BTC-MOF intercalated GO membranes have good water flux,and the materials have good pressure resistance,toughness and hydrophilicity,and high stability under acidic conditions,which is the foundation for its practical application.2.Through optimization of conditions,a BTC-MOF with m_MOFs:m_GO=1:1(n _{metal salt}:n _{organic ligand}=1:2)intercalated GO membrane was prepared,and its separation selectivity to radioactive ions(p H=2.3),the results show that metal ions can quickly and efficiently pass through Zn-BTC-MOF and Ni-BTC-MOF intercalated graphene oxide membranes,and the membrane may achieve selective separation between rare earth ions and lanthanum-actinide ions.Although the Cu-BTC-MOF intercalated graphene oxide membrane has no selective permeability to Sc³⁺and Ce³⁺,but can be used for the highly selective separation of lanthanide(Ce³⁺)and actinide(Th⁴⁺,UO₂²⁺)ions.It provides new methods and technologies for the reprocessing of spent fuel.At the same time,in the study of uranium extraction from seawater,the Zn-BTC-MOF intercalated graphene oxide membrane can successfully realize the separation and extraction of UO₂²⁺at 3 h,which provides a new method of low pollution and low energy consumption for the research in the field of uranium extraction from seawater.Further studies have found that ions can have strong electrostatic adsorption with oxygen-containing groups on the BTC-MOF intercalated graphene oxide membrane,and then through the ion exchange of protons in the driving liquid,different ions can have different mobility pass through the composite membrane to achieve high selective separation of ions.3.Using a new method of synthesizing BTC-MOF materials with graphene oxide interlayer confinement,two-dimensional BTC-MOF intercalated graphene oxide composite materials were successfully prepared.These materials were used for the selective separation of radionuclides.The results show that the material can achieve high selectivity and rapid separation of lanthanide and actinide ions.In addition,the material can also be used for the selective separation of rare earth ions.This work was successful that a new method for synthesizing MOFs materials in a two-dimensional spaced was developed,and a new technology and new idea for the selective separation of radionuclides can be provided.