How Luminescence Performances of Silicon-Doped Carbon Dots Contribute to Copper-Catalyzed photoATRP?

To provide some insights into the relationship between carbon dots’ optical properties and their photocatalytic ability, a series of silicon-doped carbon dots (SiCDs) featuring varying photoluminescence quantum yields (PLQYs) from 11.2 to 75.6% were synthesized, characterized, and employed in polymerization processes. The as-prepared samples exhibited varied structural and optical attributes and resulted in different reaction rates when utilized as cocatalysts for copper-catalyzed photoinduced atom transfer radical polymerization (photoATRP). Comparing the measured density of states, it was found that band gap reduction enhanced the photocatalytic capability of SiCDs. Besides, a negative correlation between the PLQY and polymerization rate was observed, while the latter saw a positive relationship with the nonradiative recombination rate. Both the doping effect and size effect account for the varied efficiency of photoreducing Cu^II to Cu^I complexes by SiCDs, thus resulting in variation in the reaction rate. The selected optimal SiCD was further investigated through kinetic study, on–off, and chain extension experiments to prove its feasibility on the aqueous photoATRP system. Remarkably, the SiCD-photocatalyzed approach exhibited an oxygen-tolerant feature and rapid reaction rate, allowing for 3D fabrication of complex structures with high precision and resolution.