The development of organic supramolecular photocatalytic materials requires a deeper understanding of the structure-activity relationship. Herein, the effects of H/J-type stacking on the photocatalytic mechanism and activity of PDI have been investigated. As a face-to-face arrangement, H-aggregates have higher π-electron conjugation and show more semiconductor characteristics, which results in higher carrier separation and migration efficiency under irradiation. Whereas, J-aggregates exhibit more molecular properties due to its low π-electron conjugation caused by head-to-tail stacking mode. As a result, H-aggregated PDI mainly forms superoxide radicals (O₂⁻) and holes (h⁺) through electron-transfer (ET). In contrast, J-aggregated PDI mainly generates singlet oxygen species (¹O₂) via energy-transfer (EnT). Benefit from the stronger oxidizability of O₂⁻ and h⁺, H-aggregated PDI shows higher photocatalytic activity for small molecule degradation and oxygen evolution under visible light. Whereas, J-aggregated PDI exhibits potential application in photocatalytic anti-cancer treatment owing to its high ¹O₂ quantum yields (0.66) under red light radiation. Our findings may provide a guidance for the development of supramolecular organic photocatalytic materials.

有机超分子光催化材料的发展需要对结构-活性关系有更深的了解。在本文中，已经研究了H / J型堆叠对PDI的光催化机理和活性的影响。作为面对面的排列，H聚集体具有更高的π电子共轭并显示出更多的半导体特性，这导致在辐射下具有更高的载流子分离和迁移效率。然而，J-聚集体由于其从头到尾的堆积模式引起的低π电子共轭而显示出更多的分子特性。其结果是，H-聚集的PDI主要形成超氧自由基（ö ₂ ^- ）和空穴（h ⁺）通过电子转移（ET）。相反，J聚集的PDI主要通过能量转移（EnT）产生单线态氧（¹ O ₂）。受益的强氧化性Ò ₂ ^-和H ⁺，H-聚集的PDI显示出较高的光催化活性为在可见光下小分子降解和析氧。而J聚集的PDI由于在红光辐射下具有较高的¹ O ₂量子产率（0.66），因此在光催化抗癌治疗中具有潜在的应用前景。我们的发现可能为超分子有机光催化材料的开发提供指导。