The Adsorption Research Of Metal-organic Framework Coordination Compounds To Nuclides

With the vigorous development of the nuclear industry,radioactive metals pollution has become particularly serious,especially the uranium（U）and beta nuclide technetium(⁹⁹Tc),which mainly come from nuclear power and nuclear material experiments.Both are not only highly toxic but also radioactive,they exist in the form of UO₂²⁺and ⁹⁹Tc O₄^-in water solution respectively,with the characteristics of high solubility and fluidity.Therefore,how to deal with nuclear waste liquids have become a significant problem and a long-term challenge for humanity.Metal-Organic Frameworks（MOFs）complexes are crystalline materials with high crystallinity,high surface area,specific functional groups and adjustable channels.But MOFs are rarely used in the study of adsorption and capture of radionuclides.It is of great practical significance to design MOFs materials which can adsorb and capture radionuclides quickly and efficiently from nuclear waste water.This study explored the synthesis method,characterization and application of MOFs complexes,mainly focusing on the adsorption performance of radionuclides U and ⁹⁹Tc.The research contents designed metal-organic framework complexs,detected single crystal structure by X-ray Single Crystal Diffractometer and studied their adsorption of radionuclide;X-ray Photoelectron Spectroscopy（XPS）and Energy Dispersive X-ray Spectroscopy（EDS）are adopted to analyze relationship between the MOFs complexes and radionuclides and propose the synthesis strategy of how to compound metal-organic framework materials with high selectivity,large adsorption capacity and fast adsorption rate.The results are as follows:1.In this study,1,4,5,8-naphthalenetetracarboxylic dianhydride and5-aminosalicylic acid were used to synthesize the organic linker N,N-bis（3-carboxy-4-hydroxyphenyl）-1,4,5,8-naphthalenetetradicarboximide（named NDI-p OH）by amidation and then the organic framework complex（named Ca NDI-p OH）,whose metal node is alkaline earth metal ion Ca²⁺and oraganic linker is NDI-p OH,was synthesized by solvothermal method,and its adsorption performance was systematically investigated.The structure and stability of the complex were detected and characterized by X-ray Single Crystal Diffractometer and X-ray Powder Diffractometer（XRD）.The adsorption behavior of the complex against UO₂²⁺in waste water solution was studied by batch experiment.The results showed that the complex can selectively adsorb UO₂²⁺,with adsorption capacity reaching 382mg/g.It is a kind of adsorbent material with high affinity for UO₂²⁺.The mechanism of adsorption of UO₂²⁺was explained by XPS energy spectrum,Fourier Infrared Spectroscopy and EDS.It has certain guiding significance to design reasonable metal-organic framework complexes for adsorption of UO₂²⁺.2.A metal-organic complex material named B841-Mn-MOF with halogentic coordination was synthesized by Mn Cl₂.4H₂O and Tetrakis[4-（1 H-imidazol-1-yl）phenyl]ethylene（TIPE）to systematically study the adsorption performance of Re O₄^-/⁹⁹Tc O₄^-.The structure and stability of B841-Mn-MOF were characterized by Single Crystal Diffractometer and X-ray Powder Diffractometer（XRD）.Batch experiment was adopted to explore the adsorption performance of Re O₄^-,and it was found that the adsorption capacity of B841-Mn-MOF to Re O₄^-could reach 400 mg/g,and the adsorption equilibrium could be reached within 5 min.Moreover,B841-Mn-MOF had excellent adsorption removal capacity for Re O₄^-in a wide p H range（p H 3-11）.It has a degree of value and importance for reference regarding the synthesis of specific metal-organic framework material and removing oxygen containing metal anionic pollutants.