Stable and Recyclable Photocatalysts of CsPbBr₃@MSNs Nanocomposites for Photoinduced Electron Transfer RAFT Polymerization

All-inorganic metal halide perovskite CsPbX₃(X = Cl, Br, I) nanocrystals (NCs) have demonstrated attractive optoelectronic characteristics. However, their photocatalytic properties are limited by their poor stability and easy recombination of photogenerated carriers. Herein, we introduced a CsPbBr₃@MSNs nanocomposite (CsPbBr₃NCs embedded in dendritic mesoporous silica nanospheres (MSNs)) as photocatalysts for photoinduced electron transfer reversible addition-fragmentation chain transfer (PET-RAFT) polymerization. The CsPbBr₃nanocrystals (∼8.1 nm; PLQY of 62 ± 2.1%) were embedded in dendritic MSNs using a nanoconfinement strategy. PET-RAFT polymerization was successfully initiated using the CsPbBr₃@MSNs nanocomposite as the photocatalyst. Reaction variables, such as catalyst loading, monomer composition, and excitation light wavelengths, were varied to yield polymers with the desired control of molecular weight and dispersity as well as block copolymers with high chain-end fidelity. In addition, the perovskite-based photocatalysts could be readily separated and purified, which allowed effective and rapid recycling of the nanocomposites for multiple polymerization cycles.