Synthesis And Application Of Actinide Porphyrin Mofs

Actinides are unique in the periodic table and exhibit special electronic structures and bonding properties due to their 5f electron orbitals.All actinides are radioactive,which on the one hand promotes the development and utilization of nuclear energy represented by uranium,and on the other hand undoubtedly increases the difficulties in the study of actinides chemistry.Compared with lanthanide or transition metals,actinides are relatively less studied.Metal-organic frameworks(MOFs),as a series of new materials,have emerged and attracted ample attention in recent years.MOFs provide a good platform for the study of actinides coordination chemistry,and also provide an ideal carrier for expanding the potential applications of actinide materials.The introduction of functional ligands adds more abundant application studies to actinide MOF.In this dissertation,a series of actinide porphyrin MOFs were constructed based on the coordination and connection between actinide metal uranium,thorium and porphyrin derivative ligands.The coordination model and topological structure of actinide coordination polymers were studied in detail,and the properties and potential applications of the materials were explored.The specific contents of this dissertation include:(1)The development of actinide MOFs is reviewed,the coordination modes of actinide elements are summarized,and the topology and potential applications of actinide MOFs reported in recent years are summarized.The research progress of porphyrin MOFs in many application fields in recent years is also summarized.(2)AMOF-1 with pto topology and AMOF-2 with tbo topology were constructed using cobalt porphyrin tetracarboxylic acid ligands and actinide metal uranium.These are the first time that actinide elements were introduced into porphyrin MOF system,filling the gap of porphyrin MOFs in the field of actinide chemistry.The coordination configurations of AMOF-1 and AMOF-2 were systematically characterized,and the catalytic dehydrogenation of nitrogen-containing heterocyclic compounds by AMOF-2 was systematically investigated.(3)Through the introduction of alkali metal K+,the doubly interpenetrated framework of uranyl MOF is connected together to form the framework structure AMOF-3,which realizes the improvement of thermal stability,air stability and water stability of MOF materials.At the same time,AMOF-3 was applied to photocatalytic CO2 fixation to realize efficient heterogeneous catalysis.(4)Based on a mixed ligand strategy,porphyrin tetracarboxylic acid ligands,linear dicarboxylic acid ligands and actinide metal thorium were constructed to form thorium-based porphyrin MOF AMOF-4,whose stability and photocatalytic performance were improved.The effectiveness of this strategy was verified by photocatalytic oxidation of thioether and photocatalytic CO2 fixation.(5)The temperature-induced two-dimensional(2D)thorium-based porphyrin MOF AMOF-6 gradually realizes the structural transformation from 2D to 3D,and the single-crystal-to-single-crystal transformation process is verified by a series of insitu characterizations.We explored its application in photocatalytic CO2 reduction reaction,and analyzed how the change of structure affects the photocatalytic performance.(6)Hierarchical mesoporous-microporous MOF AMOF-9 was constructed based on extended porphyrin tetracarboxylic acid ligands and actinide metal thorium,and phosphotungstic acid was introduced and fixed into the MOF through an in-situ encapsulation strategy,which greatly improved the photocatalytic performance of CO2 reduction.(7)The research work in this dissertation is summarized,and some views on the future research of actinide MOFs are put forward.