Preparetion Of Polymer Composite Molybdenum Disulfide And Its Adsorption For Uranium(?)

With the continuous development of the industry,the demand of uranium resources are increasing,at the same time of uranium resources development and utilization,will produce large quantities of radioactive uranium wastewater,if these radioactive wastewater concentration exceeds national emissions standards,emissions to the environment,will not only damage to the ecological environment,more will be hazardous to the health of human body,therefore,the effective separation and enrichment of uranium???from the radioactive waste water is very necessary.The adsorption method is widely used in the separation and enrichment of radionuclides due to the characteristics of various adsorbents and simple operation process.In order to efficiently separate and enrich uranium???in aqueous solution,economic,efficient and stable adsorption materials need to be prepared.Molybdenum disulfide is known as a new type of two-dimensional nanomaterial after graphene.It has a wide range of sources,a variety of preparation methods and excellent physical and chemical properties,such as high temperature resistance,compression resistance,radiation resistance,etc.However,there are still problems such as low MoS₂yield,complex preparation process and low adsorption capacityIn this paper,3R-MoS₂ was prepared by high-temperature electrochemical method,which effectively overcame the bottleneck problems in the traditional preparation process of molybdenum disulfide,such as the transfer of heating method from the surface to the inner layer,large temperature gradient,and hysteresis,such as long preparation time and difficult to adjust and control the morphology and size.In order to further improve the separation and enrichment effect of uranium???in aqueous solution,pyrrole,aniline and thiophene monomers were combined with molybdenum disulfide by in-situ polymerization to form Ppy/MoS₂,PANI/MoS₂ and PTh/MoS₂ composites.X-ray diffraction?XRD?to prove that the preparation of molybdenum disulfide belong to 3R type,polypyrrole,polyaniline and poly(thiophene XRD proved the existence of the characteristic diffraction peaks of the success of the composite material preparation,scanning electron microscopy and energy spectrum?SEM&EDS?results show that before,during and after the composite material of physical characteristics have not been destroyed,Fourier transform infrared spectroscopy?FT-IR?in the presence of three kinds of polymer characteristic peak means Ppy/MoS₂,PANI/MoS₂ and PTh/MoS₂ successful preparation of three composite materials,thermogravimetric analysis?TGA?showed that molybdenum disulphide has good thermal stability,A certain amount of polypyrrole,polyaniline and polythiophene were loaded on molybdenum disulfide in all three composites.Conditions by static adsorption experiments to study the different pH value,balance time,reaction temperature and initial concentration of the uranium???MoS2,Ppy/MoS2,PANI/MoS2 and PTh/MoS2 performance of adsorption of uranium???in aqueous solution,the results showed that 3R-MoS₂ and three kinds of composites for uranium???adsorption best pH is 5.5,the adsorption equilibrium time is respectively 480 min,360 min,420 min and 360 min,by adsorption dynamics model,Adsorption thermodynamics and adsorption isothermal model system to study the materials for uranium???adsorption process,the results show that the 3R-MoS2,Ppy/MoS2,PANI/MoS2 and PTh/MoS2 for uranium???adsorption kinetics of all follow the accurate dynamic model of the secondary adsorption isotherm models with the Langmuir isotherm model has good linear correlation,belong to monolayer adsorption,the maximum monolayer adsorption of 3R-MoS₂ is 58.65 mg/g,the maximum monolayer adsorption of Ppy/MoS₂ is 200.40 mg/g,the maximum monolayer adsorption of PANI/MoS₂ is 142.45 mg/g and the maximum monolayer adsorption of PTh/MoS₂ is 160.00 mg/g.The adsorption of uranium???by 3R-MoS₂,Ppy/MoS₂,PANI/MoS₂ and PTh/MoS₂ is a spontaneous heat chemical process.Studying on elution and reuse performance shows that 1.0 mol/L HCl as desorption solution has the best elution effect on uranium???.Three kinds of composite materials still have a high adsorption capacity after five desorption cycle experiments,indicating that the three kinds of composite materials have good stability and can be reused with good economy.