Photogenerated singlet oxygen over zeolite-confined carbon dots for shape selective catalysis

Singlet oxygen as an activated oxygen species played an important role in organic synthesis. Suitable catalyst for converting ubiquitous oxygen molecule to singlet oxygen under mild conditions has attracted a wide range of attention. Herein, carbon dots have been confined into mesopores of silicalite-1 nanocrystals framework and acted as active sites for generation of singlet oxygen. The high oxygen-adsorption capacity of zeolite nanocrystals facilitated the photocatalytic generation rate of singlet oxygen, outpacing the free-standing carbon dots for 14-fold. The integrated carbon dot-zeolite nanocrystal hybrid also exhibited a special size-dependent selectivity for organic synthesis by using the in situ formed and confined singlet oxygen as active oxygen species.