Phase-Inversion Engineering of Covalent Organic Framework Microspheres for Advanced Water Purification.
Zhou Huina H, Zhang Ning N, Li Yingying Y, Li Dongxue D et al.
Covalent organic frameworks (COFs) are porous, crystalline polymers with broad application prospects. However, their microcrystalline powder morphology severely limits their practical implementation. Herein, a general phase-inversion spherical shaping strategy is reported, enabling the conversion of powdered COFs into robust microspheres with a radially hierarchical pore structure. This method is mild and scalable and has been validated across eight COFs with distinct topologies. The resulting microspheres retain approximately 90% of the intrinsic adsorption capacity of the pristine materials. As a representative demonstration, TAPB-DMTP-COF microspheres were employed in a fixed-bed continuous-flow water treatment system, where 1 g of the material effectively purified over 18 L of real water containing a mixture of bisphenols, with each concentration at 200 ppb, while maintaining high performance over 20 regeneration cycles. More notably, the TAPB-DMTP-COF microspheres themselves possess intrinsic catalytic activity for peroxymonosulfate activation, enabling sequential adsorption enrichment and catalytic degradation within the same fixed-bed column without metal modification. This work establishes a versatile COF shaping platform that extends the application scope of COFs from adsorption to advanced oxidation, offering a viable pathway to overcome a critical bottleneck in their industrial implementation.