Molten Salt Synthesis Of Ti₃C₂T_x MXene And The Performance In Radionnuclides Adsorption By Its Composites

The rapid development of nuclear energy brings us convenience and inevitably produces radioactive nuclear waste.Properly disposing of uranium waste is vital to the ecological environment and human health.Therefore,higher requirements are put forward for the preparation and performance of nanomaterials used to remove radionuclides in environmental applications.Benefiting from unique layer structures,large specific surface area,excellent physical and chemical properties and good radiation resistance,two-dimensional MXene materials haves shown broad application prospects in the field of radionuclide wastewater treatment.In view of the non-environmental friendliness of the traditional preparation method of MXene,the macro-preparation and practical application of MXene are limited.In the second chapter,this article attempts to synthesize Ti₃C₂T_xMXene by electrochemically etching the ternary ceramic Ti₃Al C₂using the fluorine-free molten salt Li Cl-KCl system.Based on the cyclic voltammetry curve（CV）and electrolytic behavior,the synthesis conditions of Ti₃C₂T_x MXene are explored and optimized.The materials before and after electrolytic etching were characterized by powder ray diffractometer（XRD）,Raman spectrometer（Raman）and scanning electron microscope（SEM）.The synthesis method is expected to be extended to the preparation of other two-dimensional MXene materials.It provides new research ideas for the development of a green,environmentally friendly and efficient general synthesis strategy.In Chapter 3,this article uses the traditional fluoride salt preparation method to synthesize single-layer Ti₃C₂T_x MXene nanosheets,and then through the self-polymerization of dopamine monomer on the surface of Ti₃C₂T_xMXene nanosheets,Ti₃C₂@PDA nanocomposites were prepared,which effectively improved the specific surface area utilization rate of MXene materials and the removal performance of radionuclides.XRD,SEM,Raman Fourier Transform Infrared Spectrometer（FT-IR）,Malvern Zeta Potentiometer and Thermogravimetric Analyzer（TGA）were used to characterize the morphology and structure of the material before and after composite.The effects of contact time,p H,temperature,initial concentration of U（VI）,ionic strength,and competing ions on the adsorption behavior of Ti₃C₂@PDA composites to remove U（VI）were discussed.The adsorption isotherm model and the results of thermodynamic studies show that adsorption is a spontaneous endothermic process,and the maximum adsorption capacity of this material for U（VI）is 343.6 mg/g at T=298.15K.Finally,the synthesis and adsorption mechanism of Ti₃C₂@PDA were explored,and it was found that the–NH–,–NH2 and C–O functional groups on the surface of Ti₃C₂@PDA were complexed and adsorbed with U（VI）in the solution.These research results provide a reference for promoting the better application of MXene materials in the field of radionuclide wastewater treatment.