Dynamic covalent assembly of hierarchical COF hollow fibers for selective dye remediation

The remediation of toxic dye pollutants via covalent organic frameworks (COFs) presents a promising yet challenging strategy for sustainable water purification, as conventional powdered COFs face critical limitations in recyclability and secondary contamination risks. Herein, we introduce a paradigm-shifting approach combining template-assisted electrospinning with room-temperature dynamic covalent chemistry to fabricate hierarchically porous TAPT-TFPT COF hollow fibers, which address these bottlenecks. The synthesized fibers exhibit crystallographically ordered 2.2 nm pores, a high surface area (1402 m² g⁻¹), and reliable chemical/thermal stability. These structural merits translate to unprecedented Congo red (CR) adsorption performance with a maximum capacity of 3670 mg g⁻¹ (3–15 times higher than state-of-the-art COFs), size-selective removal efficiency, and comprehensive adsorption metrics including rapid kinetics (95 % removal in 6 h), pH adaptability (50–99 % efficiency across pH 2–12), and cyclic stability (90 % retention after 5 cycles). Mechanistic analyses reveal chemisorption-dominated Langmuir monolayer adsorption governed by pseudo-second-order kinetics, with molecular recognition driven by synergistic pore-size matching, multivalent hydrogen bonding, and π-π interactions. This work establishes an ambient aqueous synthesis platform for macroscopic COF architectures while redefining performance benchmarks for industrial-scale water treatment technologies.