Electron/H-donating defective pore strategy for MIL-101 enhanced simultaneous adsorption of iodine vapor and VOCs: An experimental and theoretical study

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.