Polarity Gradient Engineering of Dual-Pore Covalent Organic Frameworks Synchronize Mass Transport and Reaction for...

An intrinsic mismatch between molecular transport and interfacial reaction within porous materials greatly limits the catalytic performance for water treatment. Here, we report dual-pore covalent organic frameworks (COFs) featuring alternating triangular micropores and hexagonal mesopores to optimize this trade-off. Through strategic pore-wall functionalization with of methyl (Btc-COF) and methoxy (Bto-COF) groups, we create a polarity gradient that established spatially separated hydrophilic-hydrophobic domains in a hierarchical pore architecture. This helps govern critical synergies between mass transport, confined reaction, and interface redox processes: specifically, mesoporous channels strengthen dipole-dipole interactions between polar water molecules and methoxy groups, thereby accelerating pollutant influx and radical efflux; the abundant micropores intensify the interspace solute turnover frequency (collision-driven reaction efficiency) via the solvent cage effect; compared with nonpolar Btc-COF, methoxy-induced electronic polarization in Bto-COF amplifies the built-in electric field by 2.4 times, resulting in a surface charge accumulation of 94 mV. These factors synchronously accelerate the radical generation-transport-utilization cascade dynamics, achieving exceptional pharmaceutical micropollutant decomposition and transformation into nontoxic mineralized products, while maintaining exceptional adaptability and stability across diverse water matrices. This study offers a gradient dual-pore engineering strategy to synchronize transport-reaction dynamics in hierarchically porous media for solar-driven sustainable water purification.