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

Photocatalytic hydrogen peroxide (H2O2) 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 H2O2 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 H2O2 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 H2O2 generation. Furthermore, the in situ generated H2O2 is fed into a cascade wastewater treatment system and consumed in a downstream Fenton process for efficient degradation of phenolic pollutants.