Amphiphilic Reactive Interfaces Enable Controlled Synthesis of Mesoscopic Covalent Organic Frameworks

Abstract Interfaces serve as powerful, versatile platforms that have significantly advanced the development of novel materials. However, bottom‐up construction of reactive interfaces for controlled synthesis of crystalline porous materials still remains a substantial challenge. Here, we constructed a stable, morphology‐tunable reactive interface by spontaneous self‐assembly of amphiphilic moiety derived from Schiff base reactions, featuring the surfactant‐free stabilization and versatile interface morphology readily adjusted by hydrophobic chain length (C4–C12) of aliphatic amines. Such interface confinement lowers nucleation barriers while the localized monomer enrichment speeds reactions, thus enabling a mild, facile, and controlled synthesis of covalent organic frameworks (COFs) with diverse mesoscopic architectures (spherical/ribbon/sheet). Further introducing colloidal SiO 2 nanospheres on the interfaces can co‐assemble and form stable nanoscale Pickering emulsions, yielding hierarchical porous COFs with tunable, large mesopores (17‐40 nm) beyond the intrinsic pore size limitation. The resulting asymmetric hemispherical hollow mCOF PEA (BET surface area of 561.9 m 2 g −1 ) as a potential iodine host (30.18 wt.% loading) delivered remarkable electrochemical performance with an initial capacity of 202.9 mAh g −1 (96.16% of theoretical value) and retained 132.8 mAh g −1 after 2500 cycles, profited from their mesoporosity and asymmetric morphology with an increased surface area, exposed more active sites and enhanced ion transport ability.