Synthesis method of near infrared silver sulfide quantum dots

Abstract

The invention discloses a synthesis method of near infrared silver sulfide quantum dots, belonging to the technical field of functional nanomaterials. The synthesis method comprises the following steps: (1) dissolving silver nitrate crystals into a polar solvent ethylene glycol, stirring at a dark place being 3 DEG C-5 DEG C until dissolving is achieved, so as to obtain a solution A; (2) under the stirring state, adding a mercaptan carboxylic acid solution to obtain a solution B; (3) placing the solution B under the condition of 70 DEG C to 80 DEG C and stirring at a dark place, reacting for 2min to 8min, so as to lead the solution B to gradually become milk white from colorless and gradually form silver sulfide crystal nucleus; (4) increasing the reaction temperature to 140 DEG C to 150 DEG C from 70 DEG C to 80 DEG C, continuously reacting, to gradually transform the milk white solution B into clear brown solution B, and form stable silver sulfide crystal nucleus; (5) rapidly cooling to room temperature and stopping reaction; and (6) ultrafiltering to remove the solvent and reaction side products, adding water for washing and dispersing, to obtain silver sulfide quantum dots. The method is simple and highly efficient, and can conduct mass production, the synthesized quantum dots are good in water phase dispersity, scattered and uniform in particle size and stable in optical property.

Description

technical field [0001] The invention belongs to the technical field of functional nanometer materials, and relates to a method for synthesizing carboxyl water-soluble silver sulfide quantum dots with near-infrared fluorescence properties. Background technique [0002] Quantum dots are microcrystalline particles with a particle size distribution of 1-100nm, because of their unique physical and chemical properties, such as quantum size effects, dielectric confinement effects, etc., which make the energy band of quantum dots become molecular or The separated energy level structure of atomic characteristics shows many characteristics superior to those of bulk materials, so it has great application value in the fields of biomedicine and molecular imaging. [0003] Silver sulfide quantum dots, as a nano-semiconductor material with high biocompatibility, have attracted much attention in recent years. Its optical properties are stable, the fluorescence spectrum can be adjusted, and ...

AI Technical Summary

Problems solved by technology

In aqueous phase synthesis, the nucleation process of silver sulfide is affected by many factors, such as the concentration of reactants, the temperature and time of nucleation, the speed of reactant addition, etc. These precise and complex adjustments increase the quantum of silver sulfide. The synthesis difficulty of points does not conform to the principle of "simple, green, high-yield, and efficient", which is not conducive to the promotion in practical applications

The traditional method of synthesizing near-infrared silver sulfide quantum dots in the organic phase is often accompanied by high-temperature and high-heat reactions, and it needs to be converted into the aqueous phase through ligand exchange after the synthesis. However, incomplete ligand exchange often occurs during the conversion process. , the surface structure of quantum dots changes, the aggregation of quantum dots precipitates or the particle size increases, resulting in changes in the original properties of quantum dots

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