Highly-efficient preparation method for strong-fluorescence graphene quantum dot

Abstract

The invention discloses a highly-efficient preparation method for a strong-fluorescence graphene quantum dot. The highly-efficient preparation method comprises the following steps: with pyrene as a reactant precursor and concentrated nitric acid as a nitrating agent, mixing the pyrene with the concentrated nitric acid in proportion, subjecting a mixed solution to water-bath heating to a constant low temperature of 60 to 80 DEG C under a reflux state, and carrying out a nitration reaction so as to obtain an intermediate product namely 1,3,6-trinitropyrene; and dissolving the intermediate product and an alkaline substance namely hydrazine hydrate into a solvent in a certain proportion, carrying out ultrasonic crushing so as to obtain an ultrasonically-crushed suspension, then transferring the suspension to a high-pressure-resistant reaction kettle, carrying out a hydrothermal reaction so as to synthesize a graphene quantum dot solution with high quantum efficiency, and carrying out vacuum filtering, drying and collection so as to obtain a graphene quantum dot powder. The method provided by the invention has the advantages of simple and highly-efficient preparation process, low cost,high quantum efficiency, environmental protection, no generation of harmful wastes and convenience in large-scale production, and facilitates promotion of graphene quantum dot application.

Description

technical field [0001] The invention belongs to the technical field of nano fluorescent materials, and in particular relates to a high-efficiency preparation method of strongly fluorescent graphene quantum dots. Background technique [0002] Graphene quantum dots (GQDs) are quasi-zero-dimensional materials that can reach the thickness of a single atom. Due to the remarkable quantum confinement effect and edge effect presented by its quasi-zero-dimensional characteristics, it has many unique thermal, electrical and Optical properties have attracted extensive attention of many domestic and foreign researchers in the past ten years. Compared with traditional fluorescent materials and other semiconductor quantum dots, GQDS has the advantages of abundant raw materials, low price, low toxicity, stable structure, easy surface functionalization, adjustable bandgap width range, good biocompatibility, and superior fluorescence performance. . These characteristics make GQDS have grea...

AI Technical Summary

Problems solved by technology

From top to bottom, the C=C bond is destroyed by chemical or physical means, and the large-sized carbon source precursor is cut into small-sized quantum dots. Common methods include hydrothermal method, electrochemical method, chemical exfoliation method, and acid oxidation. The advantage is that the selected raw materials are low in price and suitable for large-scale preparation. The disadvantages are harsh reaction conditions, long preparation cycle, low yield, difficult control of the surface morphology and size of the product, and great difficulty in purification.

From bottom to top, small molecular organic substances such as polycyclic aromatic hydrocarbons are used as precursors to synthesize graphene quantum dots through a series of chemical reactions. The advantage is that the shape and size of the final product can be controlled, and the size of quantum dots is uniform. The disadvantage is the synthesis mechanism. Complex, relatively low synthesis yield

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