Synthesis of Silver Sulf ide Quantum Dots Via the Liquid–Liquid Interface Reaction in a Rotating Packed Bed Reactor

We developed the high-gravity coupled liquid–liquid interface reaction technique on the basis of the rotating packed bed(RPB) reactor for the continuous and ultrafast synthesis of silver sulfi de(Ag_2S) quantum dots(QDs) with near-infrared(NIR) luminescence. The formation of Ag_2S QDs occurs at the interface of microdroplets, and the average size of Ag_2S QDs was 4.5 nm with a narrow size distribution. Ag_2S QDs can disperse well in various organic solvents and exhibit NIR luminescence with a peak wavelength at 1270 nm under 980-nm laser excitation. The mechanism of the process intensifi cation was revealed by both the computational fl uid dynamics simulation and fl uorescence imaging, and the mechanism is attributed to the small and uniform droplet formation in the RPB reactor. This study provides a novel approach for the continuous and ultrafast synthesis of NIR Ag_2S QDs for potential scale-up.