Confinement‐Induced Metastable Supramolecular Assembly: Dynamic Built‐in Electric Field Driving Deep Mineralization of Organic Pollutants

Abstract Constructing built‐in electric fields (IEF) in homomeric supramolecular assembly (SA) offers an exciting research avenue. To boost dipole, the introduction of a functional side chain in the monomer is essential. Unfortunately, this disrupts the monomer planarity, inevitably increasing intermolecular distance, which is contradictory to achieving high IEF. Here, by means of the confinement of layered double hydroxide (LDH), various monomers (naphthalene and perylene diimide derivatives) successfully form metastable SA with smaller intermolecular distances than in crystals. The IEF enhancement value can reach 11.8 times, enabling a 71.52% charge separation efficiency and a 78.10% total organic carbon (TOC) removal rate in phenol degradation, presenting state‐of‐the‐art results. Mechanism elucidates LDH confinement overcomes the energy barrier associated with the ordered and close packing of monomers, moving monomer away from the thermodynamic equilibrium state. The universality of this approach will pave the way for exploring other multifunctional monomers, thereby fostering advancement in material science, chemical synthesis, and photo‐conversion.