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.