阅读说明：本技术 一种水溶性ZnCuInX量子点的一步水相合成方法 (One-step aqueous phase synthesis method of water-soluble ZnCuInX quantum dots ) 是由 王荣芳 韦星明 梁春杰 陶萍芳 董积有 于 2020-08-11 设计创作，主要内容包括：本发明公开了一种水溶性ZnCuInX量子点的一步水相合成方法,属于纳米材料制备技术领域。其包括步骤：在巯基乙酸中加入可溶性的锌盐、铜盐和铟盐,配制成前驱体混合溶液；将前驱体混合溶液的pH值调节至7.0-11.0；然后加入硼氢化物、硒源或硫源；在80-120℃下反应加热回流0.5-9h得水溶性ZnCuInX量子点。本发明制备的ZnCuInX量子点克服了传统有机法制备量子点疏水性的缺陷,在应用前无需通过配体交换。本发明具有反应条件温和可控,操作步骤简单,安全环保等特点。ZnCuInX量子点的最大荧光发射峰在610nm左右,近似球型形貌,颗粒大小约为5nm。(The invention discloses a one-step aqueous phase synthesis method of water-soluble ZnCuInX quantum dots, belonging to the technical field of nano material preparation. Which comprises the following steps: adding soluble zinc salt, copper salt and indium salt into mercaptoacetic acid to prepare a precursor mixed solution; adjusting the pH value of the precursor mixed solution to 7.0-11.0; then adding borohydride, selenium source or sulfur source; reacting at 80-120 ℃, heating and refluxing for 0.5-9h to obtain the water-soluble ZnCuInX quantum dot. The ZnCuInX quantum dot prepared by the invention overcomes the defect of hydrophobicity of the quantum dot prepared by the traditional organic method, and ligand exchange is not needed before application. The method has the characteristics of mild and controllable reaction conditions, simple operation steps, safety, environmental protection and the like. The maximum fluorescence emission peak of the ZnCuInX quantum dot is about 610nm, the shape of the ZnCuInX quantum dot is similar to a spherical shape, and the particle size is about 5 nm.)

1. A one-step aqueous phase synthesis method of water-soluble ZnCuInX quantum dots is characterized by comprising the following steps: x in the ZnCuInX is Se or S;

the method comprises the following steps:

(1) adding soluble zinc salt, copper salt and indium salt into mercaptoacetic acid to prepare a precursor mixed solution;

(2) adjusting the pH value of the precursor mixed solution to 7.0-11.0; then adding borohydride, selenium source or sulfur source; reacting at 80-120 ℃, heating and refluxing for 0.5-9h to obtain the water-soluble ZnCuInX quantum dot.

2. The one-step aqueous synthesis method of the water-soluble ZnCuInX quantum dot according to claim 1, characterized in that: in step (1):

the mol ratio of the total amount of the soluble zinc salt, the copper salt and the indium salt to the thioglycolic acid is 1: 1.4-4.

3. The one-step aqueous synthesis method of the water-soluble ZnCuInX quantum dot according to claim 1, characterized in that: in step (1):

the volume ratio of the soluble zinc salt, the copper salt and the indium salt is 88-35: 1-5: 10-60.

4. The one-step aqueous synthesis method of the water-soluble ZnCuInX quantum dot according to claim 1, characterized in that: in the step (1), the soluble zinc salt is at least one of zinc chloride, zinc acetate, zinc nitrate or zinc sulfate; the soluble copper salt is copper sulfate and/or copper chloride; the soluble indium salt is indium chloride.

5. The one-step aqueous synthesis method of the water-soluble ZnCuInX quantum dot according to claim 1, characterized in that: in the step (2), the borohydride is sodium borohydride and/or potassium borohydride, and the selenium source is at least one of selenium dioxide, selenium powder or sodium selenite; the sulfur source is sodium sulfide.

6. The one-step aqueous synthesis method of the water-soluble ZnCuInX quantum dot according to claim 1, characterized in that: in step (2):

the mol ratio of the total amount of the soluble zinc salt, the copper salt and the indium salt to the selenium source is 1: 0.05-0.5.

7. The one-step aqueous synthesis method of the water-soluble ZnCuInX quantum dot according to claim 1, characterized in that: in step (2):

the molar ratio of the total of the soluble zinc salt, copper salt and indium salt to the sulfur source is 1: 0.2-0.8.

8. The one-step aqueous synthesis method of water-soluble ZnCuInX quantum dots according to any one of claims 1 to 7, characterized in that: in the step (2), the water-soluble ZnCuInX quantum dots are purified by absolute ethyl alcohol.

9. The one-step aqueous synthesis method of the water-soluble ZnCuInX quantum dot according to claim 8, characterized in that:

mixing water-soluble ZnCuInX quantum dots and absolute ethyl alcohol in a ratio of 1:2, centrifuging to remove supernatant, adding distilled water until precipitate obtained by centrifuging is dissolved; and obtaining the purified water-soluble ZnCuInX quantum dots.

Technical Field

The invention relates to the technical field of nano material preparation, in particular to a one-step water-phase synthesis method of water-soluble ZnCuInX quantum dots.

Background

Quantum Dots (QDs), also called semiconductor nanocrystals (semiconductor nanocrystals), are binary or ternary inorganic nanoparticles composed of elements from groups II-VI or III-V. Quantum dots as a novel nano material have attracted extensive attention from the end of the 20 th century and the 70 th era. Compared with the traditional fluorescent material, the quantum dot has wide excitation spectrum and can be excited from ultraviolet light to visible light; the fluorescence emission spectrum is narrow and distributed symmetrically; the luminescent color of the quantum dots can be adjusted by changing the particle size of the particles; and high photochemical stability. The quantum dots have unique luminescent properties, so the quantum dots have wide application prospects in the fields of light-emitting diodes, solar cells, optical biomarkers and the like.

The ZnCuInX (X ═ Se, S) quantum dot is a semiconductor nano material without heavy metals of Pb and Cd, and is a good light absorption material of a solar cell because the forbidden band width of the ZnCuInX quantum dot is very close to the optimal forbidden band width of a solar cell material; the fluorescence emission from visible light to near infrared is realized by changing the particle size of the quantum dots, and the quantum dots have wide application prospect in light-emitting diodes. The current method for synthesizing ZnCuInX (X ═ Se, S) quantum dots needs expensive or harmful organic reagents, and most reactions require harsh experimental conditions such as inert gas protection or high temperature. In addition, the quantum dots synthesized by the methods are all hydrophobic, and need to be converted into water-soluble quantum dots through ligand exchange before application, and the luminous intensity and stability of the synthesized quantum dots are inevitably reduced in the phase transfer process, so that the mass production and application of the quantum dots are limited. Therefore, it is important to develop a method for synthesizing water-soluble ZnCuInX (X ═ Se, S) quantum dot material with low cost, simplicity and environmental friendliness.

By combining the factors, the water-soluble ZnCuInX quantum dot is synthesized by a simple one-step aqueous phase reaction, and the method has the characteristics of mild and controllable reaction conditions, simple operation steps, safety, environmental protection and the like.

Disclosure of Invention

The invention aims to solve the problems in the prior art, and aims to provide a one-step aqueous phase synthesis method of water-soluble ZnCuInX quantum dots.

In order to realize the purpose of the invention, the method is realized by the following technical scheme:

a one-step aqueous phase synthesis method of water-soluble ZnCuInX quantum dots is characterized by comprising the following steps: x in the ZnCuInX is Se or S;

the method comprises the following steps:

(1) adding soluble zinc salt, copper salt and indium salt into mercaptoacetic acid to prepare a precursor mixed solution;

(2) adjusting the pH value of the precursor mixed solution to 7.0-11.0; then adding borohydride, selenium source or sulfur source; reacting at 80-120 ℃, heating and refluxing for 0.5-9h to obtain the water-soluble ZnCuInX quantum dot.

Preferably, in step (1):

the mol ratio of the total amount of the soluble zinc salt, the copper salt and the indium salt to the thioglycolic acid is 1: 1.4-4.

Preferably, in step (1):

the volume ratio of the soluble zinc salt, the copper salt and the indium salt is 88-35: 1-5: 10-60.

Preferably, in the step (1), the soluble zinc salt is at least one of zinc chloride, zinc acetate, zinc nitrate or zinc sulfate; the soluble copper salt is copper sulfate and/or copper chloride; the soluble indium salt is indium chloride.

Preferably, in the step (2), the borohydride is sodium borohydride and/or potassium borohydride, and the selenium source is at least one of selenium dioxide, selenium powder or sodium selenite; the sulfur source is sodium sulfide.

Preferably, in step (2):

the mol ratio of the total amount of the soluble zinc salt, the copper salt and the indium salt to the selenium source is 1: 0.05-0.5.

Preferably, in step (2):

the molar ratio of the total of the soluble zinc salt, copper salt and indium salt to the sulfur source is 1: 0.2-0.8.

Preferably, after step (2), the water-soluble ZnCuInX quantum dots are purified with anhydrous ethanol.

Further preferably, the water-soluble ZnCuInX quantum dot and the absolute ethyl alcohol are mixed in a ratio of 1:2, centrifuging to remove supernatant, adding distilled water until precipitate obtained by centrifuging is dissolved; and obtaining the purified water-soluble ZnCuInX quantum dots.

The method selects soluble zinc salt, copper salt and indium salt as a zinc source, a copper source and an indium source, selenium dioxide as a selenium source (sodium sulfide as a sulfur source), thioglycolic acid as a stabilizer, and oil bath is used as a heating mode to synthesize the water-soluble ZnCuInX (X ═ Se, S) quantum dots in a water phase system in one step.

The ZnCuInX (X ═ Se, S) quantum dot prepared by the method overcomes the defect of hydrophobicity of the quantum dot prepared by the traditional organic method, and ligand exchange is not needed before application. The method has the characteristics of mild and controllable reaction conditions, simple operation steps, safety, environmental protection and the like. The maximum fluorescence emission peak of the ZnCuInX (X ═ Se, S) quantum dot is about 610nm, the shape of the quantum dot is approximate to a spherical shape, and the particle size is about 5 nm.

Drawings

FIG. 1 is a fluorescence emission spectrum of ZnCuInSe quantum dots prepared under different reflux times in example 1;

FIG. 2 is a fluorescence emission spectrum of ZnCuInS quantum dots prepared In example 2 at different molar ratios of (Zn + Cu + In) to S;

FIG. 3 is a fluorescence emission spectrum of ZnCuInSe quantum dots prepared In example 3 at different molar ratios of (Zn + Cu + In): Se;

FIG. 4 is a high resolution TEM image of ZnCuInSe quantum dots prepared in example 4;

FIG. 5 is an X-ray diffraction pattern of ZnCuInSe quantum dots prepared in example 4.

Detailed Description

The technical solution in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. The drawings are only for purposes of illustration and are not intended to be limiting, and are merely schematic and non-limiting. For those skilled in the art to which the invention pertains, several simple deductions or substitutions can be made without departing from the spirit of the invention, and all shall be considered as belonging to the protection scope of the invention.

In the present invention, TGA refers to thioglycolic acid.