Ferrocene-based porous organic polymers for high-affinity iodine capture

The effective removal of radioactive vapor wastes in fission is of significant importance and numerous porous solids have been developed to control volatile iodine emissions. However, most of porous matrixes fail to trap radioiodine reliably due to the weak binding interaction between scavenger and radioiodine, causing unexpected serious consequences. Herein, we report a facile pore engineering strategy to overcome this challenge by developing metal-polymer hybrids with high binding ability, inspired by the Ag-loaded activated carbon (Ag-AC). While unlike the Ag-AC, the ferrocene-containing porous organic polymer (FcTz-POP) via Schiff base reaction is rather stable and cost-effective, and gives a significantly promoted iodine vapor capacity which is 1.8 times that of a reference ferrocene-free one (BpTz-POP). Bearing abundant ferrocene blocks with high electron density, FcTz-POP demonstrates a fast adsorption rate and a rather high affinity towards I-2. In addition, high content of polyiodide (I-3(-), I-5(-)) was detected, implying the crucial role of polyiodide for capture efficiency of adsorbent. This study may provide a useful guidance for further design of novel Fc-linked POPs to achieve effective capture of I-2.