Batch Preparation of Tungsten Disulfide Quantum Dots

Quantum dots are zero-dimensional nanomaterials consisting of a small number of atoms. In recent years, quantum dots (QDs), as a new type of nanomaterials with unique physical properties, have attracted extensive interest of researchers at home and abroad. Their research contents involve physics, chemistry, materials and other disciplines, and have become a new interdisciplinary subject.

Tungsten disulfide is stable in air, insoluble in water, alcohol and grease, does not produce chemical reaction and is not affected by radiation. Tungsten disulfide can withstand the corrosion of sulfuric acid and nitric acid. It has good adsorption characteristics on metal surface and does not react with metal surface. It is usually used as lubricating material. Tungsten disulfide quantum dots have smaller size, higher specific surface area, more active sites, good dispersion in solvents, stronger fluorescence emission. Tungsten disulfide quantum dots can be used in hydrogen evolution reaction, catalysis, photoelectric devices, energy storage and medical bioimaging, etc. They have broad application prospects.

However, how to prepare tungsten disulfide quantum dots in batches is a difficult problem in its practical application, which is the main reason for its high price. In view of the existing shortcomings, some researchers proposed a simple batch preparation method of tungsten disulfide quantum dots, which mainly uses ball milling ultrasonic method to prepare tungsten disulfide quantum dots. The powder was mixed with N-methyl pyrrolidone, dimethylmethylamine or absolute ethanol, then milled by a high-energy planetary ball mill, then ultrasonically and centrifugally to prepare tungsten disulfide quantum dot dispersions. Specific steps include:

1)Disperse tungsten disulfide into N-methyl pyrrolidone, dimethylmethylamine or anhydrous ethanol, mix well, and then grind for 5-50 hours at a speed of 100-900 rpm.

2)The ball-milled solution was ultrasonic for 0.5-10 hours in the rod-type ultrasonic instrument, and then ultrasonic for 0.5-20 hours in the box-type ultrasonic instrument. The mixed solution containing lamellar tungsten disulfide and tungsten disulfide quantum dots was obtained.

3)The mixed liquid is centrifuged in step 2, and the supernatant is taken to obtain a high purity tungsten disulfide quantum dot dispersion solution.

The microstructure of the prepared tungsten disulfide quantum dots was observed by transmission electron microscopy (TEM). It can be found that the tungsten disulfide quantum dots prepared in the above steps have the characteristics of uniform scale and excellent luminescence performance, simple process, uniform product particle size, high yield and easy operation, and the prepared tungsten disulfide quantum dots can be widely applied to biological fluorescein. New optoelectronic devices such as light marking, solar cells, light-emitting diodes, and detectors.

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