Covalent organic polymers for efficient removal of iodine from gas- and liquid-phase environments

Nuclear energy is a sustainable, low-carbon footprint, and cost-effective future energy source that might play an important role in the foreseeable energy demand. However, due to the volatility and long half-life of the released waste radioiodine from nuclear power stations, appropriate handling of radioactive waste is still a great challenge. Using covalent organic polymers (COPs) adsorbents to capture radioactive iodine compounds has gained much attention due to the simplicity of operation, low maintenance costs, and resistance to highly corrosive solutions. Herein, three as-synthesized amine-linked COP materials with heteroatoms (N, P, and O) are employed for iodine capture and obtain excellent iodine capture capacity due to the strong interactions of abundant heteroatoms with iodine compounds. The gas-phase iodine adsorption capacity of as-prepared COPs reached > 2.1 g gads−1 in 1 h, with an optimal gas-phase iodine adsorption capacity of 3.96 g gads−1 and a liquid-phase iodine adsorption capacity of 905.69 mg gads−1. This study showed the promising iodine removal capabilities of heteroatoms-containing COPs from nuclear wastewater and nuclear exhaust gases.