In Situ Synthesis of Lead-Free Halide Perovskite–COF Nanocomposites as Photocatalysts for Photoinduced Polymerization in Both Organic and Aqueous Phases

A critical challenge that hinders the application of perovskite materials is their instability toward water and light. Herein, we report lead-free bismuth halide perovskite nanocrystals encapsulated by the covalent organic frameworks (PNCs–COFs) via an in situ growth approach. The PNCs–COFs nanocomposites demonstrated good water processability that originates from the hydrophobic COFs shell. Furthermore, the COFs coating enables the formation of PNCs–COFs heterojunction, which facilitates the generation and transportation of photoinduced charge carriers. The PNCs–COFs were further applied as photocatalysts for free-radical polymerizations, photoactivating different coinitiators via both hole and electron transfer mechanisms in aqueous and organic phases. The excellent photocatalytic performance of PNCs–COFs was confirmed by high monomer conversion (up to 97.5%), diverse functional group tolerance and recyclability.