Study On The Surface Functionalization Of Two-dimensional MXene And Its Adsorption Performance For Radioiodine

With the rapid development of social industry nowadays,people’s excessive use of energy has brought many negative effects to the environment,such as the greenhouse effect,water pollution,nuclear pollution,etc.The used nuclear fuel and radioactive iodine produced by nuclear accidents pose a serious threat to human health and the global environment.As an effective way to remove iodine,adsorption has many advantages such as convenient operation,high efficiency,and low cost.However,among the adsorbents that have been reported,the adsorption efficiency is generally low,the adsorption time is long,and the removal of iodine cannot be completed well.MXene has a high specific surface area and abundant surface functional groups,which is very suitable as an adsorbent material or an adsorption substrate material.This paper uses different methods to functionalize the surface of MXene and applies it to the field of radioactive iodine adsorption.The main results are as follows:(1)Combined with the Mussel-inspired chemistry modification method,the surface of MXene was modified with dopamine,which was used as a secondary reaction platform to load nano-silver oxide by precipitation method to adsorb radioactive iodine.It is found that the maximum adsorption capacity of the adsorbent is 80 mg/g,the removal efficiency is 80%,the best adsorption p H is 5,and the adsorption reaction is an exothermic process.(2)Combined with the two-dimensional layered MXene material after the Mussel-inspired chemistry functionalization of the mussel,the nano petal-shaped bismuth oxide was loaded by solvothermal method and used for the removal of radioactive iodine,and the adsorption performance of the sample was tested.It is found that the maximum adsorption capacity of the adsorbent is 64.65 mg/g,the adsorption equilibrium time is 30 minutes,and the adsorption thermodynamics shows that the overall adsorption process is an endothermic reaction,and as the p H increases,the adsorption performance decreases.(3)Based on the Mussel-inspired modification of the two-dimensional layered MXene as the secondary reaction platform,the ionic liquid functionalized MXene is prepared by Michael addition and used to adsorb radioactive iodine,and the surface ionic liquid is combined with iodine elemental substance and halogen bonding.Etc.to achieve effective removal of iodine elemental substance.The experimental results found that the maximum adsorption capacity was 695.4 mg/g,and the adsorption reached equilibrium in about ten minutes,and the overall adsorption process was endothermic.(4)Surface modification of MXene by silane coupling agent,and then synthesize polyionic liquid on the surface of MXene through multi-component reaction.It is found that the maximum adsorption capacity of the adsorbent is 170 mg/g.The thermodynamics of adsorption proves that the adsorption capacity increases with increasing temperature and△H~0is a positive value,which indicates that the adsorption of iodine using MXene-PIL is an endothermic process.