Phenanthroline Derived N‐Doped Carbon Dots as Robust Metal‐Free Photocatalysts for PET‐RAFT Polymerization and Polymerization‐Induced Self‐Assembly

Abstract

AbstractMetal‐free organic photocatalysts for photo‐mediated reversible deactivation radical polymerization (photo‐RDRP) are witnessed to make increasing advancement in the precise synthesis of polymers. However, challenges still exist in the development of high‐efficiency and environmentally sustainable carbon dots (CDs)‐based organocatalysts. Herein, N‐doped CDs derived from phenanthroline derivative (Aphen) are prepared as metal‐free photocatalysts for photoinduced electron transfer reversible addition‐fragmentation chain transfer (PET‐RAFT) polymerization. The introduction of phenanthroline structure enhances the excited state lifetime of CDs and expands the conjugated length of their internal structure to enable the light‐absorption to reach green light region, thereby enhancing photocatalytic activity. The as‐designed CDs exhibit unprecedented photocatalytic capacity in photopolymerization even in large‐volume reaction (100 mL) with high monomer conversion and narrow polymer dispersity (Mw/Mn < 1.20) under green light. The photocatalytic system is compatible with PET‐RAFT polymerization of numerous monomers and the production of high molecular weight polyacrylate (Mn >250 000) with exquisite spatiotemporal control. Above results confirm the potential of CDs as photocatalyst, which has not been achieved with other CDs catalysts used in photo‐RDRP. In addition, the construction of fluorescent polymer nanoparticles using CDs as both photocatalyst and phosphor through photoinitiated polymerization‐induced self‐assembly (Photo‐PISA) technology is successfully demonstrated for the first time.