Interface-directed porous aromatic framework nanoflakes for ultrafast quasi-homogeneous photocatalytic aerobic oxidation <?A3B2 pi6?>in air

The development of efficient photocatalysts for crucial organic transformation, such as aerobic oxidation, remains challenging. Although powdered porous materials offer abundant accessible active sites, their application in liquid-phase catalysis is often limited by insufficient light absorption and inevitable charge recombination, which are inherent drawbacks of conventional heterogeneous catalysts. Here, through rational design and nanoscale-engineering of porous aromatic frameworks (PAFs) comprising porphyrin and porous organic cage, a quasi-homogeneous porous photocatalyst with high catalytic activity and controllable dimension was developed. The interface-directed growth in oil-in-water emulsion shaped the morphology of photoactive PAFs from powders to nanoflakes, which facilitated the light absorbance and catalyst-substrate interaction. Compared with PAF powders, PAF nanoflakes exhibited superior photocatalytic activity for aerobic oxidation. For mustard gas simulant (2-chloroethyl ethyl sulfide, CEES), PAF nanoflakes exhibited ultrafast detoxification rates in room air with a half-life (t1/2) as fast as 26 s, which even exceeded other catalysts in pure oxygen. It also completely catalyzed the aerobic oxidation of thioether within 15 min, which is almost the fastest rate among any reported organic photocatalysts. Furthermore, the efficient catalytic performance under mild conditions caused by improved light enrichment, surface charge transfer and carrier lifetime was elucidated.