Co-adsorption performance of iodine and NOX in iodine exhaust gas by NH2-MIL-125

Ti-based MOFs exhibit ultra-high stability in radioactive waste gases containing nitrogen oxides (NOX) and are effective in capturing radioactive iodine. In this study, NH2-MIL-125 was synthesized via a one-pot solvothermal method and its adsorption performance for iodine was investigated using batch adsorption experiments, the stability of materials was tested by simulating post-processing conditions. The results indicated that NH2-MIL-125 had a maximum iodine adsorption capacity of 1.61 g/g at 75 ℃ and reached adsorption equilibrium within 60 min, and the adsorption capacity of methyl iodine reached 776.9 mg/g. The material also exhibited excellent stability and iodine adsorption performance in the presence of NOX. After soaking in NO2 for 24 h, its structure remained stable and the adsorption capacity for iodine remained at 231.5 mg/g. The excellent co-adsorption performance of NH2-MIL-125 on iodine and NOX was attributed to the synergistic effects of Ti-OH groups and amino functional groups. These findings provide a reference for the capture of radioactive iodine and also demonstrate the potential of NH2-MIL-125 for iodine capture during spent fuel reprocessing. With the utilization of nuclear fuel, a large amount of radioactive waste has been generated, such as radioactive iodine (129I and 131I), which is one of the fission products, and radioactive iodine in the environment can cause serious damage to the human body by irradiating personnel through internal and external irradiation. Therefore, how to effectively deal with radioactive iodine is of great practical significance. In this paper, a titanium-based MOFs material (NH2-MIL-125) with super stability was prepared by solvothermal method. The material is characterized by strong capture capacity, fast adsorption kinetics and high stability, which provides a feasible solution to the problem of radioactive iodine pollutants in the environment.