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

Abstract

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 sulfide (Ag 2 S) quantum dots (QDs) with near-infrared (NIR) luminescence. The formation of Ag 2 S QDs occurs at the interface of microdroplets, and the average size of Ag 2 S QDs was 4.5 nm with a narrow size distribution. Ag 2 S 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 intensification was revealed by both the computational fluid dynamics simulation and fluorescence 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 2 S QDs for potential scale-up.

Light Absorption and Scattering by Silver/Silver Sulfide Hybrid Nanoparticles

“…It is important to recall that there is no fundamental difference between plasmonic and dielectric resonances collectively known as Mie resonances: whereas the former occurs in the region of the negative real part of the dielectric function, e.g., silver (ε′ < 1), the latter occurs in the region of ε′ > 1, e.g., silver sulfide . The observed resonances in Ag 2 S NCs are also not due to downshifted excitonic transitions in the Ag 2 S semiconductor (1.8–2.0 eV) because the size of the NCs obtained in this work was significantly larger for the quantum regime. ,− …”

Interfacial Synthesis: Morphology, Structure, and Properties of Interfacial Formations in Liquid–Liquid Systems

“…The continuous and ultrafast method for obtaining silver sulfide quantum dots was implemented in a microdroplet version, with the reaction proceeding at the liquid-liquid interface [98]. The resulting NPs have an average size of 4.5 nm and are characterized by narrow size distribution.…”

Controllable Synthesis of Upconversion Nanophosphors toward Scale‐Up Productions

“…First reported by Ramshaw (1979), [ 119,120 ] it has been widely used in the synthesis of different nanoparticles, such as drug particles, [ 121 ] nanophosphors, [ 122 ] photocatalysts, [ 123 ] and semiconductor quantum dots. [ 124,125 ] The high‐gravity method normally is fulfilled by a rotating packed bed reactor (RPB) which intensifies the reaction process via generating a high‐gravity environment. [ 125 ] A typical structure of an RPB is illustrated in Figure , which consists of a rotator, packing reactor, pumps, valves, and outlets.…”