Method for preparing CdTe quantum dots in aqueous phase and at low temperature

A technology in quantum dots and water phase, which is applied in the field of nanomaterial preparation, can solve the problems of reducing the fluorescence yield of quantum dots, demanding the preparation process, and the high price of reagent toxicity, and achieves low requirements for reaction equipment, good dispersion, and high preparation efficiency. convenient effect

Inactive Publication Date: 2011-09-21
FUDAN UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

However, the reaction requires high-temperature devices, inert gas protection, high toxicity of reagents, high price, and low yield. The surface of the obtained quantum dots is a hydrophobic alkyl chain, which requires ligand exchange in many fields of applications, and will also reduce the qua

Method used

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  • Method for preparing CdTe quantum dots in aqueous phase and at low temperature
  • Method for preparing CdTe quantum dots in aqueous phase and at low temperature

Examples

Experimental program
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Effect test

Embodiment 1

[0028] (a) Ligand Preparation

[0029] Add 5g proline, 3.47g NaOH, 50ml deionized water into a 100ml flask, stir for 30min, and dissolve 2.76mlCS 2 Dissolve it in 25ml of ethanol, slowly drop it into the flask, and finish adding in 50 minutes. After 24 h of reaction, the solvent was removed under reduced pressure.

[0030] (b) Preparation of cadmium source

[0031] Add CdCl to the 2L flask 2 229mg, 1L of ultrapure water, 440mg of proline dithiocarbamate sodium salt, adding NaOH solution to adjust the pH of the solution to 8 to obtain a cadmium source of 1.25mmol / L.

[0032] (c) Preparation of tellurium source

[0033] Add 95.7mg Te powder, 73mg NaBH4, 3ml ultrapure water into a vial with an air outlet, and react at 0°C for 24 hours to obtain a 250mmol / L tellurium source. .

[0034] (d) Growth of CdTe

[0035] Pass high-purity nitrogen gas through 1L of 1.25mmol / L cadmium source solution for 30min, inject 1ml of freshly prepared tellurium source, and react in a water ba...

Embodiment 2

[0037] (a) Ligand Preparation

[0038] Add 5g proline, 3.47g NaOH, 50ml deionized water into a 100ml flask, stir for 30min, and dissolve 3.3ml CS 2 Dissolve it in 40ml of ethanol, slowly drop it into the flask, and finish adding in 30 minutes. After 24 h of reaction, the solvent was removed under reduced pressure.

[0039] (b) Preparation of cadmium source

[0040] Add CdCl to 1L flask 2 229mg, 500ml of ultrapure water, 586mg of proline dithiocarbamate sodium salt, adding NaOH solution to adjust the pH of the solution to 9 to obtain a cadmium source of 2.5mmol / L. .

[0041] (c) Preparation of tellurium source

[0042] Add 95.7mg of Te powder, 73mg of NaBH4, 3ml of ultrapure water into a vial with an air outlet, and react at 10°C for 15 hours to obtain a 250mmol / L tellurium source.

[0043] (d) Growth of CdTe

[0044] Pass high-purity nitrogen gas through 1L of 2.5mmol / L cadmium source solution for 30min, inject 3ml of freshly prepared tellurium source, and react in a w...

Embodiment 3

[0046] (a) Ligand Preparation

[0047] Add 5g of proline, 3.47g of NaOH, and 50ml of deionized water into a 100ml flask, stir for 30min, dissolve 5.52ml of CS2 in 25ml of ethanol, slowly drop it into the flask, and complete the addition within 20min. After 24 h of reaction, the solvent was removed under reduced pressure.

[0048] (b) Preparation of cadmium source

[0049] Add CdCl to 1L flask 2 229mg, 1L of ultrapure water, 440mg of proline dithiocarbamate sodium salt, adding NaOH solution to adjust the pH of the solution to 10 to obtain a cadmium source of 1.25mmol / L.

[0050] (c) Preparation of tellurium source

[0051] Add 95.7mg Te powder, 110.5mg KBH4, and 3ml ultrapure water into a vial with an air outlet, and react at 0°C for 20 hours to obtain a 250mmol / L tellurium source.

[0052] (d) Growth of CdTe

[0053] Pass high-purity nitrogen gas through 1L of 1.25mmol / L cadmium source solution for 30min, inject 1ml of freshly prepared tellurium source, and react in a 50°C...

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Abstract

The invention belongs to the field of preparation of nano materials and relates to a method for preparing CdTe quantum dots in an aqueous phase and at a low temperature. The method comprises the following steps of: preparing solution from dithioamino formate serving as a stabilizing agent, water serving as a solvent, cadmium salt and a ligand according to a certain ratio; injecting sodium hydrogen telluride or potassium hydrogen telluride aqueous solution; and reacting in water bath at the low temperature for a certain time to obtain the water dispersible CdTe quantum dots. The preparation method has the advantages of low reaction temperature, readily available raw materials, convenience of preparation, easiness in operation, low requirement on reaction equipment, low price, energy conservation, environmental friendliness, preparation on a large scale and suitability for industrialization because the CdTe quantum dots are prepared in the aqueous phase completely. The prepared CdTe quantum dots have uniform grain size and high dispersibility, and can serve as solar battery dye sensitive materials or photocatalytic materials.

Description

Technical field: [0001] The invention belongs to the field of nano material preparation and relates to a method for preparing CdTe quantum dots at low temperature in water phase. It specifically relates to the synthesis of dithiocarbamate and the method for large-scale preparation of CdTe quantum dots under low temperature conditions under the regulation of the ligand. Background technique: [0002] When the size of semiconductor nanocrystals reaches or is smaller than its Bohr excitonic radius, it exhibits size-dependent optoelectronic properties, which are called quantum dots. Studies have shown that due to the wide spectral absorption of II-VI quantum dots such as CdTe, the range is adjustable, and they have high carrier transport rates, they are a class of excellent photoelectric conversion materials, which can be used in light-emitting diodes, solar cells, Photodetectors and other fields. Alivisatos et al. reported in 2005 the use of quantum dots such as CdTe to prepa...

Claims

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Application Information

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IPC IPC(8): C09K11/06H01G9/20
CPCY02E10/542Y02P70/50
Inventor 汪联辉宇文力辉陈利琴朱兴荣陆昊婷
Owner FUDAN UNIV
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