N- and S-rich covalent organic framework for highly efficient removal of indigo carmine and reversible iodine capture

Organic dye containing wastewater and nuclear waste have received more worldwide attention because of the significant environmental problems and the effects of radiation on health. Adsorption is considered to be an efficient, low-cost, and environmentally friendly method for pollutant removal. In this paper, we developed a novel covalent organic framework (BTT-TAPT-COF) adsorbent which contains abundant S and N active sites as well as extended π-conjugated structure. This COF shows high crystallinity, large surface area, and thermal stability. Due to the porous feature, existence of electron-rich heteroatoms as well as the large π-conjugated network structure, BTT-TAPT-COF exhibits excellent adsorptive performance for the removal of hazardous dye indigo carmine with an adsorption capacity of 547.33 mg g−1 and rapid reversible volatile iodine uptake with an adsorption capacity of 276 wt%. After five cycles, BTT-TAPT-COF almost retains the same iodine adsorption capacity with the original adsorbent.