Thermally Activated Delayed Fluorescence (TADF) Carbonized\nPolymer Dots for Efficient Red-Light-Induced Reversible Deactivation\nRadical Polymerization

Thermally\nactivated delayed fluorescence (TADF) carbon dots (CDs)\nhave generated interest due to their ability to capture singlet and\ntriplet excitons for efficient emission. However, there are still\nchallenges in achieving high photocatalytic efficiency for traditional\nTADF CDs prepared by matrix-confinement strategies. Herein, we propose\na facile one-pot solvothermal synthesis strategy of matrix-free TADF\ncarbonized polymer dots (CPDs) with an absorption wavelength up to\nthe red-light region and a long delayed fluorescence lifetime of 7.66\nμs in DMSO. The unprecedented high-efficiency photocatalytic\nability of TADF CPDs as a photocatalyst in both organic and aqueous\nsolvents has been demonstrated for the first time in red-light-triggered\nphotoinduced electron/energy transfer–reversible addition–fragmentation\nchain transfer (PET-RAFT) polymerization and photoinduced atom transfer\nradical polymerization (photo-ATRP), with high monomer conversion\n(>90%) and narrow polymer dispersity (<i>M</i><sub>w</sub>/<i>M</i><sub>n</sub> < 1.20). In addition, the designed\nCPDs are also successfully utilized in the inverse miniemulsion PET-RAFT\npolymerization system, expanding the application scope of CDs in photoinduced\nreversible deactivation radical polymerization (photo-RDRP). This\nwork offers a unique avenue for designing and regulating the intersystem\ncrossing (ISC) and reverse intersystem crossing (RISC) processes to\nachieve matrix-free TADF CD photocatalysts with long-lived excited\nstates for effectively photocatalyzed RDRP.