CN112408365A - Method for preparing graphene quantum dots by using soybean meal as raw material - Google Patents

Abstract

The invention discloses a method for preparing graphene quantum dots by taking soybean meal as a raw material. Uniformly dispersing 0.1-5.0 g of soybean meal in 0.1-2.0 mol/L sodium hydroxide solution, ultrasonically dispersing for 30-60 min, transferring the obtained dispersion liquid into a reaction kettle with a polytetrafluoroethylene lining, placing the reaction kettle in an oven, reacting for 1-3 h at 150-250 ℃, pouring out the obtained mixed liquid, centrifuging at 10000-20000 rpm, dialyzing and filtering to obtain the graphene quantum dots. The method is simple to operate, and the prepared graphene quantum dots are uniform in size, good in water solubility and stable in fluorescence performance.

Description

Method for preparing graphene quantum dots by using soybean meal as raw material

Technical Field

The invention belongs to the technical field of new graphene materials, and particularly relates to a method for preparing graphene quantum dots by taking soybean meal as a raw material.

Background

The graphene quantum dots are carbon-based zero-dimensional materials. The graphene quantum dots have the advantages of good optical properties, good water solubility, low toxicity, low cost, environmental friendliness, wide raw material source, good biocompatibility and the like. Since the first discovery of graphene quantum dots, many synthetic methods have been developed, including arc discharge methods, laser ablation methods, electrochemical synthesis methods, chemical oxidation methods, combustion methods, hydrothermal synthesis methods, microwave synthesis methods, template methods, and the like. The application of the graphene quantum dots is wide, and the graphene quantum dots have good application prospects in various fields such as medical imaging technology, environmental monitoring, chemical analysis, catalyst preparation, energy development and the like.

Zero-dimensional carbon nanomaterial fullerenes were prepared by british chemists Kroto doctor and american scientist Smalley at rice university in 1985. One-dimensional carbon nanotubes were discovered by doctor of electronic company (NEC) in japan in 1991. In 2004, geom and Novoselov, two scientists at manchester university, uk, discovered that graphene with a two-dimensional structure was fabricated. Xu et al in the same year reported a method for preparing single-walled carbon nanotubes (SWCNTs) using arc discharge, and discovered for the first time graphene quantum dots that can emit bright fluorescence during the process of electrophoretic purification of the product.

With the more intensive research on graphene quantum dots, people make great progress on the synthesis, performance and application aspects of the graphene quantum dots. Meanwhile, the graphene quantum dots are wide in raw material source and low in preparation cost, have great advantages in the field of material preparation, and have good application prospects in wide fields of medical imaging equipment, tiny light-emitting diodes, chemical sensors, photocatalytic reactions and the like. But its greatest limitation is the low autofluorescence quantum yield (< 10%). In addition, an effective functional modification, purification means and fluorescence regulation and control mode are lacked, the light-emitting mechanism is still unclear so far, and the factors limit the development of the graphene quantum dots to different degrees. Therefore, how to obtain graphene quantum dots with high quality, high fluorescence efficiency and adjustable fluorescence, and simultaneously reveal the fluorescence emission mechanism thereof, remains an important and urgent subject for the scientists of chemistry and materials.

The method takes the soybean meal as the carbon source, and the graphene quantum dots prepared by the hydrothermal method have the advantages of low cost, convenience in operation, simple equipment, easiness in industrial production and the like. The influence of factors such as alkali proportion, heating time and reaction temperature on various performances of the graphene quantum dots is intensively researched. The graphene quantum dots prepared by the method have uniform size, good water solubility and stable fluorescence property, and a simple method is provided for preparing high-quality graphene quantum dots by taking soybean meal as a raw material.

Disclosure of Invention

The invention aims to provide a method for preparing graphene quantum dots by taking soybean meal as a raw material.

The method comprises the following specific steps:

uniformly dispersing 0.1-5.0 g of soybean meal in 0.1-2.0 mol/L sodium hydroxide solution, ultrasonically dispersing for 30-60 min, transferring the obtained dispersion liquid into a reaction kettle with a polytetrafluoroethylene lining, placing the reaction kettle in an oven, reacting for 1-3 h at 150-250 ℃, pouring out the obtained mixed liquid, centrifuging at 10000-20000 rpm, dialyzing and filtering to obtain the graphene quantum dots.

The method is simple to operate, and the prepared graphene quantum dots are uniform in size, good in water solubility and stable in fluorescence performance.

Drawings

Fig. 1 is a TEM image of the graphene quantum dot prepared in example 2 of the present invention.

FIG. 2 is a fluorescence spectrum of 310-470 nm of the graphene quantum dot prepared in example 2 of the present invention.

Detailed Description

Example 1:

(1) 0.1 g of soy flour was uniformly dispersed in 0.1mol/L sodium hydroxide solution.

(2) And (2) ultrasonically dispersing the dispersion liquid obtained in the step (1) for 30 min, and then transferring the dispersion liquid into a reaction kettle with a polytetrafluoroethylene lining.

(3) The reaction kettle is placed in an oven and reacts for 1.0 h at 150 ℃.

(4) Pouring out the mixed solution after the reaction in the step (3), and centrifuging, dialyzing and filtering at 10000 rpm to obtain the graphene quantum dots.

Example 2:

(1) 5.0 g of soy flour was uniformly dispersed in 1.0mol/L sodium hydroxide solution.

(2) And (2) ultrasonically dispersing the dispersion liquid obtained in the step (1) for 45 min, and then transferring the dispersion liquid into a reaction kettle with a polytetrafluoroethylene lining.

(3) The reaction kettle is placed in an oven and reacts for 3 hours at 180 ℃.

(4) Pouring out the mixed solution after the reaction in the step (3), and centrifuging at 15000 rpm, dialyzing and filtering to obtain the graphene quantum dots.

Example 3:

(1) 2.5 g of soy flour was uniformly dispersed in 2.0mol/L sodium hydroxide solution.

(2) And (2) ultrasonically dispersing the dispersion liquid obtained in the step (1) for 60min, and then transferring the dispersion liquid into a reaction kettle with a polytetrafluoroethylene lining.

(3) The reaction kettle is placed in an oven and reacts for 1.5 h at the temperature of 250 ℃.

(4) Pouring out the mixed liquid after the reaction in the step (3), and centrifuging, dialyzing and filtering at 20000rpm to obtain the graphene quantum dots.

Example 4:

(1) 3.0 g of soy flour was uniformly dispersed in 1.0mol/L sodium hydroxide solution.

(2) And (2) ultrasonically dispersing the dispersion liquid obtained in the step (1) for 30 min, and then transferring the dispersion liquid into a reaction kettle with a polytetrafluoroethylene lining.

(3) The reaction kettle is placed in an oven and reacts for 2 hours at the temperature of 200 ℃.

(4) Pouring out the mixed solution after the reaction in the step (3), and centrifuging at 15000 rpm, dialyzing and filtering to obtain the graphene quantum dots.

Example 5:

(1) 2.0 g of soy flour was uniformly dispersed in 1.5 mol/L sodium hydroxide solution.

(2) And (2) ultrasonically dispersing the dispersion liquid obtained in the step (1) for 40 min, and then transferring the dispersion liquid into a reaction kettle with a polytetrafluoroethylene lining.

(3) The reaction kettle is placed in an oven and reacts for 2.5 hours at the temperature of 170 ℃.

(4) Pouring out the mixed solution after the reaction in the step (3), and centrifuging at 15000 rpm, dialyzing and filtering to obtain the graphene quantum dots.

Example 6:

(1) 0.5 g of soy flour was uniformly dispersed in 2.0mol/L sodium hydroxide solution.

(2) And (2) ultrasonically dispersing the dispersion liquid obtained in the step (1) for 30 min, and then transferring the dispersion liquid into a reaction kettle with a polytetrafluoroethylene lining.

(3) The reaction kettle is placed in an oven and reacts for 3 hours at the temperature of 200 ℃.

(4) Pouring out the mixed liquid after the reaction in the step (3), and centrifuging at 18000 rpm, dialyzing and filtering to obtain the graphene quantum dots.

Example 7:

(1) 4.0 g of soy flour was uniformly dispersed in 0.8 mol/L sodium hydroxide solution.

(2) And (2) ultrasonically dispersing the dispersion liquid obtained in the step (1) for 40 min, and then transferring the dispersion liquid into a reaction kettle with a polytetrafluoroethylene lining.

(3) The reaction kettle is placed in an oven and reacts for 1.5 h at the temperature of 250 ℃.

(4) Pouring out the mixed solution after the reaction in the step (3), and centrifuging, dialyzing and filtering at 10000 rpm to obtain the graphene quantum dots.

Claims (1)

1. A method for preparing graphene quantum dots by taking soybean meal as a raw material is characterized by comprising the following specific steps:

uniformly dispersing 0.1-5.0 g of soybean meal in 0.1-2.0 mol/L sodium hydroxide solution, ultrasonically dispersing for 30-60 min, transferring the obtained dispersion liquid into a reaction kettle with a polytetrafluoroethylene lining, placing the reaction kettle in an oven, reacting for 1-3 h at 150-250 ℃, pouring out the obtained mixed liquid, centrifuging at 10000-20000 rpm, dialyzing and filtering to obtain the graphene quantum dots.

Images