Highly Polarizable Embedded Interfaces Toward Superior Organic Heterojunction Photocatalysts

Organic photovoltaic catalysts (OPCs) hold great potential for energy conversion and environmental purification yet often suffer from inefficient exciton dissociation and rapid charge recombination, particularly at disordered donor/acceptor (D/A) interfaces, limiting their photocatalytic performance. Herein, we propose an embedded interface strategy that involves a highly polarizable molecule named Y6CO-S at the D/A interface within OPC bulk heterojunction (BHJ) to amplify the local electric field and enhance molecular ordering, improving hole transfer efficiency and prolonging hole polaron lifetime, and thereby boosting photocatalytic activity. Specifically, the optimized PM6:PYF-T-o:Y6CO-S nanoparticles (NPs) achieve remarkable photocatalytic sacrificial average mass-united/area-united hydrogen evolution rates of 263.8-1974.7 mmol h^{- 1} g^{- 1} and 42.7-182.4 mmol h^-1 m^-2 at varied NP concentrations under simulated sunlight (AM 1.5G, 100 mW cm^-2) for 10 h along with high external quantum efficiencies of >10% across the visible to near-infrared region, 36%-47% exceeding those of the binary PM6:PYF-T-o system without Y6CO-S embedded interface and representing one of the highest performances reported to date for photocatalysts. This work demonstrates the significant potential of embedded interface strategy in developing high‑performance heterojunction OPCs as well as other optoelectronic applications.