Anchoring of Ag into binary PBs-SOF heterostructure composite enhances selective radioactive iodine adsorption: Intrinsic affinity and interconnected framework

Abstract

Under the premise of rational use of nuclear resources such as radioactive iodine and proper disposal of water pollution in the nuclear reaction process, it is expected to achieve low-carbon goals with the help of high-energy output nuclear power. However, iodine ions are highly mobile and can easily escape into natural water, eventually posing a health hazard to humans. Thus, engineering efficient iodine adsorbents and underlying removal mechanisms have attracted widespread attention. Here we report that uniformly-dispersed Ag atoms on supramolecular organic frameworks support with Co-Fe Prussian blue analogs doped (Ag@SOF@Co-Fe PBs) on its facets show the most outstanding capability for iodine adsorption due to the strong double-substrate interaction and surface co-precipitation effect. We have carefully investigated the doping effect of PBs and the anchoring effect of Ag on SOF during the step-by-step optimization process. The nanorod framework of SOF, effective active sites of PBs, and the strong co-precipitation effect of Ag are confirmed to play a synergistic role in facilitating electron migration on the interface intersection, and improving the iodine intrinsic affinity and removal capacity. The Ag@SOF@Co-Fe PBs composite demonstrated superior iodine capture performance (388.39 mg/g), high selectivity, and excellent adsorption rate, which proves the potentially practical application of these materials. This study provides a promising strategy for optimizing iodine adsorption materials.