Work

Morphology Controlled Covalent Organic Framework Nano‐Trap for Synergetic Uranium Adsorption and Photoreduction

Year: 2025

Type: article

Abstract: Covalent organic frameworks (COFs) without donor–acceptor pairs or inefficient separation of photogenerated electrons are usually considered unfavorable for photocatalysis due to electron‐hole recombination. However, the study demonstrates a nitrile (CN) functionalized covalent organic framework nano‐traps (COF‐nTs; COF‐nTS 1 , COF‐nTS 2 , and COF‐nTS 3 ), in which the CN groups act as electron‐withdrawing centers, surrounding electron and facilitating charge separation, transport, and adsorption process. To further enhance the efficiency of charge carriers, a special approach is introduced to integrate morphology control through acid regulation and defect engineering. These key strategies optimize the key structure and improve photocatalytic performance, achieving a maximum uranium extraction capacity of 3548.1 mg g −1 , which is significantly higher than previously reported COF‐based photocatalysts under visible light. A flexible 3 × 6 cm film of COF‐nTs 3 is prepared by the blade coating method, successfully extracting uranium from spiked seawater with a 7‐day capacity of 76 mg g −1 , a saturation capacity of 193 mg g −1 , and 0.2 day half saturation time. This demonstrates its potential for uranium extraction from aqueous solutions.

Source: Small

DOI: 10.1002/smll.202501578