Bioinspired Face‐to‐Face Supramolecular Co‐Assembled Arrays Enabled by Cation‐π Interaction With Programmed Electron Transport for Efficient Hydrogen Peroxide Photosynthesis

ABSTRACT Photocatalytic hydrogen peroxide (H 2 O 2 ) production has emerged as a sustainable alternative to the energy‐intensive anthraquinone process, yet its efficiency remains fundamentally limited by inefficient charge transport and electron‐hole recombination. Here, we report a bioinspired strategy for constructing face‐to‐face supramolecular co‐assembled arrays (FF‐SCAAs), in which periodic co‐facial organization serves as a structural platform for programming electron transport pathways toward enhanced photocatalytic H 2 O 2 production. Inspired by the signal‐transport arrays of natural compound eyes, cationic trioxatriangulenium ( TOTA + ) and electron‐rich benzophenanthrene derivatives are integrated into highly ordered FF‐SCAAs through directional cation‐π interaction. The resulting FF‐SCAAs feature enhanced dipole moments and favorable orbital alignment, enabling extended charge transport channels while intrinsically suppressing electron‐hole recombination. On this basis, FF‐SCAAs achieve a H 2 O 2 photosynthesis rate up to 6.46 mmol g −1 h −1 with a solar‐to‐chemical conversion efficiency of 0.84%. Ultrafast spectroscopic and mechanistic studies demonstrate that the periodic co‐facial arrays promote directional excited‐state electron migration and selective two‐electron oxygen reduction pathways for H 2 O 2 generation. Furthermore, the in situ generated H 2 O 2 is fed into a cascade wastewater treatment system and consumed in a downstream Fenton process for efficient degradation of phenolic pollutants.