Fluorescence-Enhanced Covalent Organic Frameworks\nvia Hydrogen Bonding Interactions for Bisphenol a Detection and Removal

Covalent\norganic frameworks (COFs) are a class of porous organic\nmaterials with exceptional crystallinity, porosity, and well-defined\nstructure, which are crucial for detection and removal applications.\nIn this study, we report the synthesis of emissive and stable COFs\nvia a Schiff base condensation reaction. The exceptional porosity,\nstability, and emission properties of TT-COFs are attributed to intramolecular\nhydrogen bonding between the OH units and imine bonds. Through π–π\nstacking and hydrogen bonding interactions between adsorbed bisphenol\nmolecules and the COF host, TT-COFs demonstrate sensitivity and selectivity\ntoward bisphenol A (BPA) in water, achieving a lower detection limit\nthrough emission quenching in water, placing them among the best-reported\nsensor systems. Additionally, TT-COFs exhibit rapid adsorption of\nBPA with high performance (548 mg g<sup>–1</sup>) at room temperature,\nalong with efficient sustained cyclic adsorption capability without\nsignificant efficiency loss. This research represents a significant\nadvancement in COF-based approaches for substance adsorption and detection\nin water treatment.