Carbon dots catalyzed efficient near infrared light induced atom transfer radical polymerization in aqueous media

The development of efficient and environmentally benign strategies for controlled radical polymerization remains a critical challenge in polymer chemistry. Herein, we report a novel approach utilizing phosphorus and nitrogen codoped carbon dots (PN-CDs) as catalysts for near-infrared (NIR) light-induced atom transfer radical polymerization (ATRP) in aqueous media. Owing to the absorption in the near-infrared (NIR) region, PN-CDs can generate electrons under excitation by an 808 nm laser, thereby initiating aqueous-phase atom transfer radical polymerization (ATRP) through electron transfer with Cu(II) ions. The aqueous-based NIR-ATRP process demonstrates remarkable versatility, producing well-defined polymers with narrow molecular weight distributions ( Đ <1.25). And ∼ 90 % monomer conversion could be achieved within 30 min, illustrating the high polymerization efficient of NIR-ATRP in aqueous media. Excellent temporal control of the polymerization and the chain fidelity of polymers were illustrated by light-switching experiment and chain extension, separately. The polymerization was also performed in the presence of opaque barrier (i.e. pork skin) to show the penetration advantage of NIR-ATRP. Moreover, the penetrating NIR-ATRP was further applied for deep-layered healing. This work establishes a sustainable platform for precision polymer synthesis, with potential applications in functional hydrogels and functional coatings, while advancing the design of carbon-based nanomaterials for photo-polymerization technologies.