Synchronous construction of high sulfonic acid grafting degree and large surface area in conjugated microporous polymer adsorbents for efficient removal of uranium (VI)

Functionalization and specific surface area (BET) are two decisive factors for conjugated microporous polymers (CMPs) as an effective uranium adsorbent, but it remains challenging to simultaneously achieve high degree of functionalization and large BET in a CMP. Herein, we innovatively adopt an ingenious molecular engineering strategy to synchronously construct high sulfonic acid grafting degree and large BET in an adsorbent. The PePy containing the pyrene-based monomer with extended π-conjugation degree and high rigidity has narrow energy band and rigid skeleton, which leads to PePy-SO3H holding a higher degree of sulfonic acid grafting while maintaining a satisfactory BET. Astonishedly, the PePy-SO3H adsorben exhibits strong affinity toward uranium with the distribution coefficient of 2.3 × 104 mL g−1 and an exceptionally high adsorption capacity of 579.0 mg g−1. This work highlights the advantages of molecular engineering strategies in optimizing the purification performance of CMPs adsorbents for uranium-containing wastewater.