High Photocatalytic Oxygen Evolution via Strong Built-In Electric Field Induced by High Crystallinity of Perylene Imide Supramolecule.

A highly crystalline perylene imide supramolecular photocatalyst (PDI-NH) is synthesized via imidazole solvent method. The catalyst shows a breakthrough oxygen evolution rate (40.6 mmol g -1 h -1 ) with apparent quantum yield of 10.4% at 400 nm, which is 1353 times higher than the low crystalline PDI-NH. The highly crystalline structure comes from the ordered self-assembly process in molten imidazole solvent via π-π stacking and hydrogen bonding. Further, the excellent performance ascribes to the robust built-in electric field induced by its high crystallinity, which greatly accelerates the charge separation and transfer. What is more, the PDI-NH is quite stable and can be reused over 50 h without performance attenuation. Briefly, the crystalline PDI-NH with strong built-in electric field throws light on photocatalytic oxygen evolution, showing a new perspective for the design of organic photocatalysts.