Method for continuously preparing quantum dots through microchannel reactor

Abstract

The invention discloses a method for continuously preparing quantum dots through a microchannel reactor and belongs to the field of chemical engineering. The quantum dots are cadmium selenide mononuclear quantum dots or cadmium selenide / zinc sulfide nuclear shell type quantum dots. The method comprises the steps of heating a prepared cadmium precursor solution and a selenium precursor solution to the reaction temperature, then mixing the solutions, and conducting a reaction, so that a solution of cadmium selenide quantum dots small in grain size is obtained; continuously adding the cadmium precursor solution, and making the cadmium selenide quantum dots small in grain size grow, so that a solution of cadmium selenide quantum dots large in grain size is obtained; or mixing the solution of the cadmium selenide quantum dots small in grain size with a prepared zinc sulfide precursor solution at the room temperature, and then heating the mixture to the reaction temperature for a reaction, so that a cadmium selenide / zinc sulfide nuclear shell type quantum dot solution is obtained; then conducting post-treatment on the quantum dot solution, so that the cadmium selenide nononuclear quantum dots or cadmium selenide / zinc sulfide nuclear shell type quantum dots are finally obtained. The preparation method is simple in operation and accurate to regulate, continuous production can be conducted, and the method is beneficial to industrialized production of the quantum dots.

Description

technical field [0001] The invention belongs to the field of chemical industry, and in particular relates to a method for continuously preparing quantum dots in a microchannel reactor. Background technique [0002] Compared with traditional organic fluorescent materials, quantum dots are easily excited, emit monochromatic fluorescence, and are not easy to be photobleached. Therefore, quantum dots have a wide range of potential applications in many fields such as solar cells, light-emitting diodes, and medical treatment. Among them, group II-VI quantum dots such as CdSe, CdS, and CdTe have attracted much attention because their emitted fluorescence wavelengths can cover the entire visible spectrum. [0003] The traditional synthesis of CdSe quantum dots is a one-pot method using organic thermal solvents. Due to the factors such as temperature inhomogeneity, inability to continuously produce, and difficulty in device scale-up in the one-pot process, the production cost of qua...

AI Technical Summary

Problems solved by technology

In the existing methods, whether it is a one-pot method or a microchannel synthesis method, the synthesis of CdSe quantum dots often completes the crystal nucleation and growth process under the same conditions, which leads to low monodispersity of CdSe quantum dots and poor fluorescence spectrum. The half maximum width is above 40nm

Therefore, the method for preparing CdSe quantum dots needs to be improved

[0004] In addition, because CdSe, CdS, and CdTe quantum dots have certain biological toxicity, and the surface is easily oxidized to cause light quenching, it is often necessary to prepare core-shell quantum dots by wrapping the shell layer. The existing methods for preparing core-shell quantum dots are also often It is prepared by a one-pot method, but this method cannot realize the continuous production of core-shell quantum dots

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