Highly efficient enrichment mechanism of U(VI) and Eu(III) by covalent organic frameworks with intramolecular hydrogen-bonding from solutions

In this investigation, TpPa-1 were synthesized and exploited for radionuclides ions elimination. According to Langmuir model, at pH 6.5 and 298 K, the maximum adsorption quantity of TpPa-1 were 1194.07 mg(U(VI))/g and 1107.63 mg(Eu(III))/g, respectively. The superior adsorption performance could be attributed to: (i) a great quantity of heteroatom activated sites on the pore wall could conduct as cation receptors; (ii) the forming intramolecular -C=(NHO)-H-center dot center dot center dot-O-center dot center dot center dot= hydrogen bonding in the network of TpPa-1, which was U(VI) and Eu(III) ions adsorption sites; (iii) hydrogen bonding could adjust the electron density of the complex and abate the total charge of radionuclides. The outcomes of this work suggest that TpPa-1 is a promising adsorbent, which is appropriate to enrichment and separation radionuclides from polluted wastewater.