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

Covalent organic frameworks (COFs) are a class of porous organic materials with exceptional crystallinity, porosity, and well-defined structure, which are crucial for detection and removal applications. In this study, we report the synthesis of emissive and stable COFs via a Schiff base condensation reaction. The exceptional porosity, stability, and emission properties of TT-COFs are attributed to intramolecular hydrogen bonding between the OH units and imine bonds. Through pi-pi stacking and hydrogen bonding interactions between adsorbed bisphenol molecules and the COF host, TT-COFs demonstrate sensitivity and selectivity toward bisphenol A (BPA) in water, achieving a lower detection limit through emission quenching in water, placing them among the best-reported sensor systems. Additionally, TT-COFs exhibit rapid adsorption of BPA with high performance (548 mg g-1) at room temperature, along with efficient sustained cyclic adsorption capability without significant efficiency loss. This research represents a significant advancement in COF-based approaches for substance adsorption and detection in water treatment.