Iodine is one of the key elements that must be removed from the off-gas systems of nuclear fuel reprocessing. This study systematically investigates the iodine vapor adsorption performance of the metal–organic framework (MOF) material HKUST-1(1-(2-methyl-4-(2-oxopyrrolidin-1-yl)phenyl)-3-morpholino-5,6-dihydropyridin-2(1H)-one), with particle sizes of 100 nm and 20 μm. HKUST-1 samples with varying particle sizes were synthesized via a hydrothermal method. The experimental results show that the 20 μm HKUST-1 exhibits superior crystallinity, a more intact pore structure, and a higher iodine adsorption capacity, reaching 700 mg/g, which is significantly greater than the 300 mg/g capacity of the 100 nm HKUST-1. Kinetic analysis reveals that the adsorption process follows the pseudo-second-order model, with physical adsorption as the predominant mechanism, where iodine molecules are accommodated within the pores. FTIR and XRD further confirm the structural stability of the HKUST-1 framework after iodine adsorption. However, desorption experiments show that iodine molecules are easily volatilized into the air, with a 20% weight loss observed within 10 h and a color change from black to green. The results provide experimental evidence for optimizing the application of HKUST-1 materials in iodine capture and suggest that material modification could enhance the long-term stability of iodine fixation.
Low adsorption efficiency and secondary pollution release pose a bottleneck for the efficient capture of radioactive iodine vapor during nuclear utilization via adsorption. In addition, the simultaneous adsorption of iodine vapor alongside other harmful vapors in complex systems has been rarely reported. In this work, an electron/H-donating defective pore construction strategy involving MIL-101 modification via amino acids (AAs) was proposed to enhance its simultaneous adsorption efficiency for iodine and formaldehyde vapors. These defective microenvironments possessed microporous property with 11.3 Å, which not only formed strong affinity for I 2 molecules itself but also enhanced its adsorption interaction towards polyiodide anion (I 3 - and I 5 - ) through electron donation of AAs. Moreover, these adsorbed polyiodide anions and AAs-SL within the MOFs, resulting in multisite capture of FA via NH…O-H…I hydrogen bonding. The results revealed that AAs coordinated MIL-101 exhibited superior removal rate ( k 80% = 0.61–1.15 g g −1 h −1 ) for iodine vapor than that of the original MIL-101, which was 3.6–30.8 times higher that of state-of-the-art adsorbents under similar conditions. Notably, a high-capacity superior retention rate of 94.8 % was achieved for its I 2 adsorption after exposure to air for 7 days. After adsorption of iodine, AAs coordinated MIL-101 retained high FA adsorption capacity up to 9.7–12.9 mg/g, representing 75.1 %–87.7 % of the original AAs@MIL adsorption capacity for FA. This defective engineering strategy in MOFs supplied an efficient method for removing multiple harmful gases from the surrounding nuclear waste atmosphere.
危险品化学品经营许可证（带存储）