Preparation method of carbon dot having high fluorescent quantum yield

A fluorescence quantum yield, carbon dot technology, applied in chemical instruments and methods, luminescent materials, etc., can solve the problem of quantum yield not higher than 30%, and achieve good solubility, high output and broad application prospects. Effect

Active Publication Date: 2013-04-17
JILIN UNIV
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  • Preparation method of carbon dot having high fluorescent quantum yield
  • Preparation method of carbon dot having high fluorescent quantum yield
  • Preparation method of carbon dot having high fluorescent quantum yield

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Embodiment 1

[0030] Weigh 1.051g (5mmol) of citric acid solid powder (with a crystal water, Beijing Chemical Plant) and dissolve it in 10ml of deionized water, measure 335μL (5mmol) of ethylenediamine (Xilong Chemical Co., Ltd.) and add it to the citric acid solution , stir well with a glass rod. The liquid was transferred into a 20mL polytetrafluoroethylene-lined stainless steel reaction kettle, the lid of the kettle was tightened, and the reaction was carried out at 200°C for 5 hours. The reactor was naturally cooled to room temperature to obtain an aqueous solution of carbon dots.

[0031] Put the obtained carbon dot aqueous solution into a 3500 molecular weight dialysis bag for dialysis for 48 hours. The collected dialyzate was combined, and the liquid was spin-dried using a rotary evaporator, and the solid was dried in a vacuum oven to obtain 0.89 g of brown solid powder, and the reaction yield was close to 70%.

[0032] The prepared carbon dot solid powder does not have fluorescent...

Embodiment 2

[0040] Weigh 0.420g (2mmol) of citric acid solid powder and dissolve it in 10ml of deionized water, measure 268μL (4mmol) of ethylenediamine into the citric acid solution, and stir evenly with a glass rod. (At the same time, citric acid and ethylenediamine millimoles can be configured as 1:1, 2:2, 5:5, 10:10, 1:5, 5:1, 4:2, 1:10, 10:1 10 mL of each solution) Transfer the liquid into a 20 mL stainless steel reaction kettle lined with polytetrafluoroethylene, tighten the lid of the kettle, and react at 200°C for 5 hours. The reactor was naturally cooled to room temperature to obtain an aqueous solution of carbon dots.

[0041] The fluorescent properties of carbon dot aqueous solutions prepared with different raw material ratios are similar, and the best excitation wavelength of each sample is around 370nm, and the best emission wavelength is around 445nm. We measured the solid content of each carbon dot aqueous solution and took quinine sulfate as a reference, measured the abso...

Embodiment 3

[0045] Weigh 1.051g (5mmol) of citric acid solid powder and dissolve it in 10ml of deionized water, measure 335μL of ethylamine and add it to the citric acid solution, and stir evenly with a glass rod. In addition, 335 μL of butanediamine, 600 μL of n-hexylamine, 0.303 g of urea, and 0.541 g of p-phenylenediamine were added to the citric acid solution of the same concentration. Each liquid was transferred into a 20mL polytetrafluoroethylene-lined stainless steel reaction kettle, the lid of the kettle was tightened, and the reaction was carried out at 200°C for 5 hours. The reactor was naturally cooled to room temperature to obtain an aqueous solution of carbon dots. .

[0046] The fluorescence properties of carbon dots prepared by different amine reactions are similar, and the fluorescence quantum yields are different. Among them, the fluorescence quantum yield of carbon dots using ethylenediamine as the starting material is higher than that of others (Table 3). In particula...

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Abstract

The invention belongs to the technical field of preparation of a carbon nano material, and particularly relates to a method for preparing a carbon dot having a high fluorescent quantum yield from citric acid and different nitrogen-containing molecules. The method comprises the following steps: weighing 1-10 mmol of solid citric acid, and dissolving in 10 ml of deionized water; weighing 1-10 mmol of ethylenediamine, ethylamine, propylamine, butanediamine, n-hexylamine, p-phenylene diamine or urea, adding into the citric acid solution, and uniformly stirring; transferring the solution into a hydrothermal or high-pressure microwave reaction kettle, reacting under hydrothermal or microwave conditions, and naturally cooling the reaction kettle to room temperature, thus obtaining a yellow or brown carbon dot water solution; and finally, purifying the carbon dot water solution, evaporating, and drying to obtain pure carbon dot solid powder. The carbon dot solution can send out bright blue fluorescence under the irradiation of a handheld ultraviolet lamp. The invention has wide application prospects in the fields of biological imaging, fluorescent printing and the like.

Description

technical field [0001] The invention belongs to the technical field of carbon nanomaterial preparation, in particular to a method for preparing carbon dots with high fluorescence quantum yields from citric acid and different types of nitrogen-containing molecules. Background technique [0002] Carbon dots (c-dots), were discovered unexpectedly in 2004 as a by-product isolated during the purification of single-walled carbon nanotubes. Carbon dots refer to carbon-containing spherical nanoparticles with a size of less than 10 nm, which have characteristic fluorescence excitation dependence. The surface of carbon dots often has groups such as carboxyl groups, which have good water solubility. Carbon dots also have good fluorescence properties, and they do not contain heavy metal elements, have low biological toxicity, and good biocompatibility, so they have broad application prospects in the fields of detection, sensing, and optoelectronics. [0003] The fluorescence emission ...

Claims

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Application Information

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IPC IPC(8): C09K11/65
Inventor 杨柏宋玉彬朱守俊张俊虎相思源刘洋
Owner JILIN UNIV
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