Prepartation And Adsorption Properties On Iodine Of Different Morphology CuBTC And Its Derivatives

As the trend of economic globalization spreads,my country has become a majorindustrial country.In the process of economic development,energy consumption is increasing.Nuclear power,as an efficient and clean energy source,has high efficiency and low pollution compared with traditional thermal power generation.However,during the operation of a nuclear power plant,if it is not handled properly,nuclear leakage will cause great harm.Radioactive iodine is one of the main products of nuclear fission,and entering the water body will cause various diseases to the human body.In order to find an effective response to radioactive iodine in this paper,the three main metals copper,silver,and bismuth that can chemically react with iodide ions are used as the main direction,and a series of different copper-based MOFs—HKUST-1（Cu-BTC）with high specific surface area are prepared as the carrier.A new material for processing radioactive iodine with high performance.（1）Three copper-based MOFs precursors（O-Cu BTC,R-Cu BTC,W-Cu BTC）with different morphologies were prepared by simple stirring synthesis method and hydrothermal synthesis method,and then prepared porous material by pyrolysising at different temperatures and atmospheresby according to TGA results that can interact with iodide ions and retain their skeleton structure.Firstly,according to the results of TG-DTG and SEM analysis the changes in the structure of the copper-based MOFs at different calcination temperatures and their different adsorption effects on iodide ions were discovered,and the ones with the temperature and atmosphere that can produce the appropriate pore size and achieve the best adsorption effect were found.Then through XRD and EDS,the specific composition and substance content inside the material are determined and the adsorption mechanism is studied.The results show that it is mainly through the formation of Cu I by the monovalent copper and iodide ions in the Cu/Cu₂O porous materials of the retention structure formed after pyrolysis to achieve the effect of removing iodide ions,and the maximum adsorption capacity is95.8mg/g and 119.6 mg/g,63.8mg/g.（2）As a green metal used in the wastewater treatment industry,bismuth has a wide range of applications in the fields of adsorption,catalysis,and membrane separation.In order to increase the adsorption capacity of Cu/Cu₂O porous materials,the process of stirring synthesis by means of R-Cu BTC is simple,and the adsorption capacity after pyrolysis is highest.First,bismuth salt is introduced in the preparation process,and the bismuth salt is reduced to metallic bismuth by a strong reducing agent to prepare a new Bi@Cu BTC modified material on the surface of the precursor material.The precursor material is pyrolyzed at the previously determined calcination temperature to prepare a new Bi₂O₃@Cu/Cu₂O derived composites,with the help of SEM,XRD,EDS analysis of the internal composition of the material structure and adsorption mechanism,it is mainly through the combined effect of Bi₂O₃and Cu₂O on I^-to produce a mixed materials Bi-I-O with Bi IO,Bi₄I₂O₅,Bi₅IO₇and Cu I to remove iodine ions.By changing the content of bismuth salt,it is found that the equilibrium adsorption capacity of 230.0mg/g can be reached when the mass fraction of Bi is30%.（3）As a precious metal with stable chemical properties,silver has a wide range of applications in the fields of photocatalysis and advanced oxidation.The main advantages are fast reaction speed and stable performance.In order to further solve the slow adsorption speed of bismuth modified materials,we tried to add Ag that can react with I^-quickly into the precursor material.With the help of O-Cu BTC hydrothermal synthesis method,the particles are uniform.We adopted simple impregnation,the method firstly fixes Ag on the surface of O-Cu BTC to synthesize a new Ag₂O@Cu BTC modified material.The precursor material is pyrolyzed at the previously determined calcination temperature to prepare a new Ag@Cu O derived composites.With the help of SEM,XRD and EDS,the internal composition and adsorption mechanism of the material are analyzed.It is mainly generated by the reversible reaction of silver and divalent copper in Ag@Cu O to produce monovalent silver and monovalent copper and iodide ions.The chemical adsorption of Cu and Ag as well as physical adsorption of Cu O itself remove iodide ions,which can achieve a high adsorption capacity,and the time to reach equilibrium is greatly shortened,reaching half of the maximum adsorption capacity in about 15 minutes.By changing the doping ratio of silver ions,it is found that Ag@Cu O doped with 20%Ag can reach the equilibrium adsorption capacity of 225mg/g in about 90 minutes.