Method for preparing silver sulfide quantum dots under normal pressure and temperature

Abstract

The invention discloses a method for preparing silver sulfide quantum dots under normal pressure and temperature. Under the normal pressure and temperature, a simple replacement reaction method is adopted, 50-100 nm of Ag2O nanoparticles are used as a matrix and are uniformly dispersed in water; a silver sulfide water solution is added for surface vulcanization according to the S to O mole ratio of 8:1 to 2:1, and full reaction is performed to prepare the Ag2S quantum dots uniform in size and having the size range of 1 to 10 nm. The Ag2S quantum dots have better photoluminescence characteristics under ultraviolet light. Under the near-infrared light condition, the quantum dots have higher photothermal effect. The method is simple and easy to operate and low in cost, can be used for large-scale synthetic production and has a wide application prospect.

Description

technical field

[0001] The invention relates to a method for preparing silver sulfide quantum dots at normal temperature and pressure, and belongs to the field of semiconductor nanometer material preparation. Background technique

[0002] Semiconductor quantum dot (semiconductor quantum dot), also known as semiconductor nanocrystal (semiconductor nanocrystal), is a stable, water-soluble substance composed of II-VI or III-V elements, with a size between 2 and Nanocrystalline grains between 20nm and semiconductor quantum dots have very important applications in the fields of lighting, displays, lasers, and bioluminescent markers. In quantum dots, carriers are restricted by potential barriers in three dimensions and cannot move freely. According to the analysis of quantum mechanics, the energy of carriers in quantum dots in three dimensions is quantized, and its state The density distribution is a series of discrete functions, similar to the spectral properties of atoms, so pe...

Examples

Embodiment 1

[0023] ①Ag 2 Preparation of O nanoparticles: the AgNO 3 Add the powder into deionized water to make the concentration reach 5g / L, stir, and ultrasonically disperse for 30min to make the AgNO 3 Completely dissolve, and under 50W, 40kHz ultrasonic conditions, add dropwise NaOH solution with a concentration of 0.1M to make the pH of the obtained silver nitrate aqueous solution = 14; filter, collect the product, wash, and dry at 70°C for 12 hours to obtain a brown powder. Ag 2 O nanoparticles;

[0024] ② Synthesis of silver sulfide quantum dots: the prepared Ag 2 Ultrasonic dispersion of O nanoparticles in deionized water to a concentration of 0.2g / L, magnetic stirring for 10min, and then dropwise adding 0.01mol / L Na 2 The S solution was stirred for 12 hours, ultrasonically dispersed for 30 minutes, centrifuged, the product was collected, and washed to obtain silver sulfide quantum dots.

[0025] The above-prepared Ag 2 S quantum dots are identified and detected as follows:...

Embodiment 2

[0036] ①Ag 2 Preparation of O nanoparticles: the AgNO 3 Add the powder into deionized water to make the concentration reach 1g / L, stir, and ultrasonically disperse for 30min to make the AgNO 3 Completely dissolve, and under 50W, 40kHz ultrasonic conditions, dropwise add NaOH solution with a concentration of 0.05mol / L to make the pH of the obtained silver nitrate aqueous solution = 12; filter, collect the product, wash, and dry at 70°C for 10h to obtain a brown powder Ag 2 O nanoparticles;

[0037] ② Synthesis of silver sulfide quantum dots: the prepared Ag 2 Ultrasonic dispersion of O nanoparticles in deionized water to a concentration of 0.1g / L, magnetic stirring for 10min, and then dropwise adding 0.001mol / L Na 2 S solution was stirred for 18 hours, ultrasonically dispersed for 30 minutes, centrifuged, the product was collected, and washed to obtain silver sulfide quantum dots.

Embodiment 3

[0039] ①Ag 2 Preparation of O nanoparticles: the AgNO 3 Add the powder into deionized water to make the concentration reach 3g / L, stir, and ultrasonically disperse for 30min to make the AgNO 3 Completely dissolve, and under 50W, 40kHz ultrasonic conditions, dropwise add NaOH solution with a concentration of 0.2mol / L to make the pH of the obtained silver nitrate aqueous solution = 13; filter, collect the product, wash, and dry at 70°C for 15 hours to obtain a brown powder Ag 2 O nanoparticles;

[0040] ② Synthesis of silver sulfide quantum dots: the prepared Ag 2 O nanoparticles were ultrasonically dispersed in deionized water to a concentration of 1 g / L, magnetically stirred for 10 min, and then added dropwise to the solution with a concentration of 0.04 mol / L Na 2 S solution was stirred for 16 hours, ultrasonically dispersed for 30 minutes, centrifuged, and the product was collected and washed to obtain silver sulfide quantum dots.

technical field

[0001] The invention relates to a method for preparing silver sulfide quantum dots at normal temperature and pressure, and belongs to the field of semiconductor nanometer material preparation. Background technique

[0002] Semiconductor quantum dot (semiconductor quantum dot), also known as semiconductor nanocrystal (semiconductor nanocrystal), is a stable, water-soluble substance composed of II-VI or III-V elements, with a size between 2 and Nanocrystalline grains between 20nm and semiconductor quantum dots have very important applications in the fields of lighting, displays, lasers, and bioluminescent markers. In quantum dots, carriers are restricted by potential barriers in three dimensions and cannot move freely. According to the analysis of quantum mechanics, the energy of carriers in quantum dots in three dimensions is quantized, and its state The density distribution is a series of discrete functions, similar to the spectral properties of atoms, so pe...

Examples

Embodiment 1

[0023] ①Ag 2 Preparation of O nanoparticles: the AgNO 3 Add the powder into deionized water to make the concentration reach 5g / L, stir, and ultrasonically disperse for 30min to make the AgNO 3 Completely dissolve, and under 50W, 40kHz ultrasonic conditions, add dropwise NaOH solution with a concentration of 0.1M to make the pH of the obtained silver nitrate aqueous solution = 14; filter, collect the product, wash, and dry at 70°C for 12 hours to obtain a brown powder. Ag 2 O nanoparticles;

[0024] ② Synthesis of silver sulfide quantum dots: the prepared Ag 2 Ultrasonic dispersion of O nanoparticles in deionized water to a concentration of 0.2g / L, magnetic stirring for 10min, and then dropwise adding 0.01mol / L Na 2 The S solution was stirred for 12 hours, ultrasonically dispersed for 30 minutes, centrifuged, the product was collected, and washed to obtain silver sulfide quantum dots.

[0025] The above-prepared Ag 2 S quantum dots are identified and detected as follows:...

Embodiment 2

[0036] ①Ag 2 Preparation of O nanoparticles: the AgNO 3 Add the powder into deionized water to make the concentration reach 1g / L, stir, and ultrasonically disperse for 30min to make the AgNO 3 Completely dissolve, and under 50W, 40kHz ultrasonic conditions, dropwise add NaOH solution with a concentration of 0.05mol / L to make the pH of the obtained silver nitrate aqueous solution = 12; filter, collect the product, wash, and dry at 70°C for 10h to obtain a brown powder Ag 2 O nanoparticles;

[0037] ② Synthesis of silver sulfide quantum dots: the prepared Ag 2 Ultrasonic dispersion of O nanoparticles in deionized water to a concentration of 0.1g / L, magnetic stirring for 10min, and then dropwise adding 0.001mol / L Na 2 S solution was stirred for 18 hours, ultrasonically dispersed for 30 minutes, centrifuged, the product was collected, and washed to obtain silver sulfide quantum dots.

Embodiment 3

[0039] ①Ag 2 Preparation of O nanoparticles: the AgNO 3 Add the powder into deionized water to make the concentration reach 3g / L, stir, and ultrasonically disperse for 30min to make the AgNO 3 Completely dissolve, and under 50W, 40kHz ultrasonic conditions, dropwise add NaOH solution with a concentration of 0.2mol / L to make the pH of the obtained silver nitrate aqueous solution = 13; filter, collect the product, wash, and dry at 70°C for 15 hours to obtain a brown powder Ag 2 O nanoparticles;

[0040] ② Synthesis of silver sulfide quantum dots: the prepared Ag 2 O nanoparticles were ultrasonically dispersed in deionized water to a concentration of 1 g / L, magnetically stirred for 10 min, and then added dropwise to the solution with a concentration of 0.04 mol / L Na 2 S solution was stirred for 16 hours, ultrasonically dispersed for 30 minutes, centrifuged, and the product was collected and washed to obtain silver sulfide quantum dots.

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