Preparation method of nitrogenous graphene quantum dot composite particles with controlled structure and fluorescence

A technology of graphene quantum dots and composite particles, which is applied in the field of nanomaterial preparation technology, can solve problems such as limitation, low yield of quantum dots, narrow fluorescence half-width, etc., and achieves excellent fluorescence controllability and unique morphology , Good dispersion in aqueous solution, wide range of raw material sources

Inactive Publication Date: 2013-05-22
FUDAN UNIV
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Problems solved by technology

[0003] "Journal of the American Chemical Society" (Journal of the American Chemical Society, 2011, 134, 15-18) first reported a kind of nitrogen-doped graphene quantum dots prepared by electrochemical method, the graphene quantum dots in aqueous solution at 365 nm Under the irradiation of ultraviolet light, it emits blue light, while the aqueous solution of nitrogen-free graphene quantum dots prepared by the same method emits green light, and because nitrogen atoms can change the chemical active sites well, the nitrogen-doped graphene quantum dots have good oxidation resistance. Reduction catalytic activity, but the method used to prepare quantum dots has a low yield, and it is difficult to meet the requirements of large-scale preparation
[0004] "Advanced Materials" (Advanced Materials, 2012, 24, 5333-5338) reported the preparation of nitrogen-doped graphene quantum dots by hydrothermal method under the condition of high concentration ammonia water. Due to the introduction of primary ammonia, graphene quantum dots have strong fluorescence Quantum yield (~29–19%) and very narrow fluorescence half-maximum width (~65–80nm), but the yield of the prepared quantum dots is also not high
[0005] "Journal of Materials Chemistry: B Series" (Journal of Materials Chemistry B, 2013, 1, 39–42) reported that nitrogen-containing graphene quantum dots were prepared by one-step hydrothermal oxidation of graphene fragments, with a yield of 8.7%. But its fluorescence is only a single blue light, and the same yield is still low
[0006] Although the above method can effectively adjust the fluorescence and dope nitrogen atoms, the yield is very low, which is greatly limited in practical applications. regulation reports

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  • Preparation method of nitrogenous graphene quantum dot composite particles with controlled structure and fluorescence
  • Preparation method of nitrogenous graphene quantum dot composite particles with controlled structure and fluorescence
  • Preparation method of nitrogenous graphene quantum dot composite particles with controlled structure and fluorescence

Examples

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Embodiment 1

[0029] Example 1. Preparation of nitrogen-containing graphene quantum dot composite particles with unique morphology and controllable fluorescence.

[0030] (1) Raw material pretreatment:

[0031] Place polyacrylonitrile-based carbon fibers in a muffle furnace under the protection of argon atmosphere, 350~500 o C for 0.5-2 h, then lowered to room temperature and taken out to obtain polyacrylonitrile-based carbon fibers with sizing agent removed.

[0032] (2) Preparation of nitrogen-containing graphene quantum dots:

[0033] Disperse 1 g of the treated polyacrylonitrile carbon fiber in 100 mL of 65-68% concentrated nitric acid, ultrasonically treat it for 1-5 h, and then in 100-150 o Reflux at C for 24~72 h, after cooling to room temperature, distill the concentrated nitric acid solution under reduced pressure to recover, add 30~100 mL of water and 1~10 mL of ammonia water to the product to adjust the pH value to 7, and then After centrifuging for 10-30 min, the mixed soluti...

Embodiment 2

[0036] Example 2. Preparation of nitrogen-containing graphene quantum dot composite particles with unique morphology and controllable fluorescence.

[0037]In Example 1, "1g of treated polyacrylonitrile carbon fiber" was changed to "2g of treated polyacrylonitrile carbon fiber", and the other preparation conditions were the same as in Example 1 to obtain a product similar to Example 1.

Embodiment 3

[0038] Example 3. Preparation of nitrogen-containing graphene quantum dot composite particles with unique morphology and controllable fluorescence.

[0039] In Example 1, "100 mL of 65-68% concentrated nitric acid" was changed to "200 mL of 65-68% concentrated nitric acid", and the other preparation conditions were the same as in Example 1 to obtain a product similar to that of Example 1.

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Abstract

The invention belongs to the technical field of nanometer material preparation, and particularly relates to a preparation method of nitrogenous graphene quantum dot composite particles with controlled structure and fluorescence. The preparation method comprises the following specific steps that: ammonia-water reacts with and cut epoxy groups on the surfaces of graphene quantum dots by taking a low-concentration ammonia-water solution as an etching agent and controlling reaction conditions under mild conditions so that lots of graphene quantum dot flakes are generated, the graphene quantum dot flakes gather and are assembled into spherical graphene quantum dots under a hydrothermal condition, so that the surfaces of the formed flaky graphene quantum dots are loaded with the lots of the spherical graphene quantum dots. The structure and appearance of the composite particles can be simply controlled by changing correspondingly experimental parameters; and the products have controlled fluorescence, good water-solubility, uniform and stable property and potential application prospect in fields of electronics, catalysis and bio-imaging. The raw materials in the method are wide in source, and the preparation method is simple, easy in operation and beneficial to batching and large-scale production and has good industrial production basis and wide application prospect.

Description

technical field [0001] The invention belongs to the technical field of nanomaterial preparation, and specifically relates to a nitrogen-containing graphene quantum dot composite particle with controllable structure and fluorescence and a preparation method thereof. More specifically, a low-concentration ammonia solution is used as an etchant, and the reaction conditions are controlled to obtain A series of fluorescent flake graphene quantum dots between yellow light and blue light are loaded with nitrogen-containing graphene quantum dot composite particles in the shape of a large number of spherical graphene quantum dots. Background technique [0002] In recent years, graphene has received more and more attention due to its excellent properties, such as large specific surface area, good electrical and thermal conductivity, excellent mechanical properties and environmental friendliness, etc. Graphene quantum dots, as a member of the graphene family, have attractive prospects ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C09K11/65
Inventor 刘勇武培怡
Owner FUDAN UNIV
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