Thermally Activated Delayed Fluorescence (TADF) Carbonized Polymer Dots for Efficient Red-Light-Induced Reversible Deactivation Radical Polymerization

Thermally activated delayed fluorescence (TADF) carbon dots (CDs) have generated interest due to their ability to capture singlet and triplet excitons for efficient emission. However, there are still challenges in achieving high photocatalytic efficiency for traditional TADF CDs prepared by matrix-confinement strategies. Herein, we propose a facile one-pot solvothermal synthesis strategy of matrix-free TADF carbonized polymer dots (CPDs) with an absorption wavelength up to the red-light region and a long delayed fluorescence lifetime of 7.66 μs in DMSO. The unprecedented high-efficiency photocatalytic ability of TADF CPDs as a photocatalyst in both organic and aqueous solvents has been demonstrated for the first time in red-light-triggered photoinduced electron/energy transfer–reversible addition–fragmentation chain transfer (PET-RAFT) polymerization and photoinduced atom transfer radical polymerization (photo-ATRP), with high monomer conversion (>90%) and narrow polymer dispersity (Mw/Mn < 1.20). In addition, the designed CPDs are also successfully utilized in the inverse miniemulsion PET-RAFT polymerization system, expanding the application scope of CDs in photoinduced reversible deactivation radical polymerization (photo-RDRP). This work offers a unique avenue for designing and regulating the intersystem crossing (ISC) and reverse intersystem crossing (RISC) processes to achieve matrix-free TADF CD photocatalysts with long-lived excited states for effectively photocatalyzed RDRP.