Boosting Exciton Dissociation and Charge Transfer in Fluorine-Substituted Covalent Organic Frameworks with Biomimetic Electron Pumps for Remarkable Photocatalytic Extraction of Uranium

Visible-light-driven photocatalytic uranium extraction based covalent organic frameworks (COFs) are green and sustainable, but their performance is severely restricted by a strong exciton effect. Herein, inspired by the physiology of cardiac pacing, a novel fluorine-based COF (PyF-DaS-COF) with a biomimetic electronic pump has been fabricated and used for the photocatalytic extraction of uranium. Both experimental and theoretical calculations confirm that strongly electronegative fluorine plays a crucial role in exciton dissociation and charge transfer. The enhanced electron push-pull effect increases the intrinsic separation driving force of charge separation. Furthermore, fluorine substitution thermodynamically favors the generation of the crucial *OOH intermediate in the uranium reduction reaction. As a result, the PyF-DaS-COF achieves a record <i>k</i> value (<i>T</i> = 293 K) of 0.082 min^-1 with an extraction capacity of 991.5 mg g^-1. Importantly, PyF-DaS-COF achieves a removal rate of over 99% in real uranium-containing wastewater. The current work provides unique insights into designing novel and effective COFs for controlling radioactive contamination.