Supramolecular Donor-Acceptor Engineering Enables Efficient Intermolecular Charge Separation for Enhanced Photocatalytic Hydrogen Production

Abstract

Organic semiconductors are promising candidates for solar-driven hydrogen production due to their structural and functional versatility. However, their photocatalytic performance remains limited by insufficient charge separation arising from the formation of strongly bound electron-hole pairs. To this end, we here report a supramolecular D-A engineering strategy for enhancing charge separation in organic photocatalysts through intermolecular electronic coupling. By co-assembling an electron-deficient perylene diimide derivative and electron-rich 1-pyrenebutanoic acid via π-π interactions, a heterostacked D-A architecture with pronounced interfacial dipoles and spatially separated frontier orbitals is constructed, which effectively reduces electron-hole overlap and facilitates intermolecular charge separation. As a result, the optimal sample achieves an exceptional photocatalytic hydrogen production rate of 71.9 mmol g-1 h-1 under visible light irradiation, with a high apparent quantum efficiency of 15.6% at 500 nm, outperforming those of most reported organic systems.