CN112520725A - Preparation method of carbon quantum dots with controllable fluorescence wavelength - Google Patents
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Abstract
The invention discloses a preparation method of a carbon quantum dot with controllable fluorescence wavelength, and relates to the field of catalytic nano materials. The preparation method comprises the following steps: preparing fruit juice dispersion liquid and amino acid dispersion liquid, and preparing the carbon quantum dots by using the fruit juice and the amino acid as raw materials through a microchannel reaction technology. The obtained carbon quantum dots have controllable fluorescence wavelength, and can be used in the fields of organic pollutant degradation, electrochemical sensors, luminescent materials, photoelectric devices and the like. In addition, as no chemical reagent is introduced in the source and preparation process, the obtained carbon quantum dots have no cytotoxicity and have great application potential in the field of biological imaging; the microchannel reaction technology is adopted, the preparation condition is mild, the reaction is efficient, the parameters are controllable, the continuous production can be realized, and the advantage is obvious compared with the advantage of preparing the carbon quantum dots by the traditional high-temperature high-pressure reaction kettle hydrothermal method.
Description
Technical Field
The invention belongs to the technical field of catalytic nano materials, relates to a preparation method of a carbon quantum dot with controllable fluorescence wavelength, and particularly relates to a green and efficient preparation method of the carbon quantum dot with controllable fluorescence wavelength.
Background
Carbon Quantum Dots (CQDs) are a quasi-spherical but dispersed novel fluorescent carbon nano material with the diameter less than 10nm, have the remarkable characteristics of high stability, good conductivity, low toxicity, environmental protection, simple synthetic route, optical performance comparable to quantum dots and the like, and are widely applied to the fields of biomedicine, photoelectron, catalysis and sensing.
In the past, CQDs are mostly obtained by adopting a complex preparation method with high energy consumption and severe reaction conditions. Such as decomposing larger carbon structures such as graphite, carbon nanotubes and nanodiamonds into CQDs from top to bottom using laser ablation, arc discharge, electrochemical techniques, etc.; or synthesizing CQDs from micro precursors such as carbohydrate, citrate and polymer-silicon dioxide nano composite materials from bottom to top by a chemical oxidation method, a template method, a microwave synthesis method and the like. Compared with the method, the CQDs prepared by the hydrothermal carbonization method not only has simple process, wide material sources and environmental protection, but also can synthesize the CQDs with specific structures by selecting precursors and preparation conditions.
An example of preparing CQDs by hydrothermal carbonization is reported in the literature (hydrothermal route to water-stable luminescence carbon dots as biosensors for pH and temperature. carbon 82(2015):87-95) based on the principle that a mixture of glucose and glutathione forms GQDs while surface passivation occurs during hydrothermal treatment. The method is novel, but has high energy consumption, long reaction time and single reaction condition, thereby influencing the subsequent application thereof.
CN 104059644A discloses a preparation method of nitrogen-doped carbon quantum dots; according to the method, an alcohol amine organic matter or a mixture of the alcohol amine organic matter and an oxidant is subjected to high-temperature treatment, so that the nitrogen-doped carbon quantum dot is obtained. However, the method has high energy consumption, and the surface oxidation damage of the prepared nitrogen-doped carbon quantum dot is serious, so that the quantum yield and the catalytic activity of the nitrogen-doped carbon quantum dot are influenced.
Therefore, how to prepare the CQDs with controllable fluorescence wavelength in one step and mildly is a work with double meanings of scientific research and development and industrial application.
Disclosure of Invention
Aiming at the problems of serious surface oxidation damage, high energy consumption, low product purity, complex preparation process and the like of quantum dots in the prior art for preparing the quantum dots, the invention provides a green and efficient preparation method of carbon quantum dots with controllable fluorescence wavelength. The method is a high-efficiency hydrothermal carbonization method utilizing a microchannel technology, the prepared carbon quantum dots with controllable fluorescence wavelength are low in cost, mild in reaction condition, controllable in preparation process, low in energy consumption, free of secondary pollution, excellent in quantum dot dispersibility and easy to separate, and can be compounded with other photosensitive and electro-sensitive materials, so that the pollutant degradation efficiency, the electrochemical sensor sensitivity, the super capacitor capacity, the performances of materials such as luminescent materials or photoelectric devices and the like can be improved. In addition, the raw material sources are purely natural and pollution-free, so that the obtained carbon quantum dots have no cytotoxicity, and have great application potential in the field of biological imaging.
In order to achieve the purpose, the invention adopts the following technical scheme:
a preparation method of a carbon quantum dot with controllable fluorescence wavelength comprises the following steps:
(1) preparing a fruit juice dispersion;
(2) preparing an amino acid dispersion;
(3) connecting the fruit juice dispersion liquid obtained in the step (1) and the amino acid dispersion liquid obtained in the step (2) through a three-way valve, mixing, and reacting in a microchannel to obtain a carbon quantum dot dispersion liquid with controllable fluorescence wavelength;
optionally, (4) purifying the fluorescent wavelength controllable carbon quantum dot dispersion liquid prepared in the step (3) to obtain a purified fluorescent wavelength controllable carbon quantum dot dispersion liquid;
optionally, (5) performing vacuum freeze drying on the fluorescence wavelength controllable carbon quantum dot dispersion liquid prepared in the step (3) or the purified fluorescence wavelength controllable carbon quantum dot dispersion liquid prepared in the step (4) to obtain fluorescence wavelength controllable carbon quantum dot powder or purified fluorescence wavelength controllable carbon quantum dot powder.
Wherein the fruit juice dispersion liquid in the step (1) is obtained by juicing, filtering, performing ultrasonic treatment, adding a proper amount of deionized water, and standing.
In the invention, the prepared carbon quantum dot dispersion liquid with controllable fluorescence wavelength or purified carbon quantum dot dispersion liquid is subjected to vacuum freeze drying in the step (5), so that the carbon quantum dots are convenient to store and transport while the original properties are maintained.
The invention provides a method for preparing a carbon quantum dot with controllable fluorescence wavelength, which has the following theoretical basis: polymerizing glucose and other carbon sources in fruit juice at high temperature and high pressure to form a network structure containing irregular carbocycles and partial complete carbocycles, then nucleating, growing and bursting, carbonizing macromolecular intermediate through intermolecular dehydration-induced crosslinking to form carbon cores, and simultaneously converting the irregular carbocycles into complete hexagonal carbocycles and forming sp (sp) carbon rings2And carbon clustering to form the carbon quantum dots. By utilizing the characteristic of ultra-high specific surface area of the microchannel technology, the reaction activity is greatly improved, thereby reducing the reaction temperature and the reaction time. Finally, considering the stable and controllable microchannel reaction and the nitrogen and sulfur containing characteristics of amino acid, the particle size of the prepared nitrogen-doped and sulfur-doped quantum dot is controllable, and the fluorescence wavelength of the quantum dot is controllable.
The following are preferred embodiments of the present invention, but not limiting the embodiments provided by the present invention
The technical purpose and the beneficial effects of the invention can be better achieved and realized by the following technical scheme.
As a preferable technical scheme of the invention, the preparation method of the fruit juice dispersion liquid in the step (1) comprises the following steps: juicing, filtering, ultrasonically treating and standing.
Preferably, the fruit is any one of orange, apple, watermelon, pear, banana, strawberry, kiwi or a combination of at least two of these, typical but non-limiting examples being: orange and apple combinations, watermelon, pear and banana combinations, strawberry and kiwi combinations, orange, apple, watermelon and pear combinations, banana, strawberry and kiwi combinations, and the like.
Preferably, the solvent is water.
Preferably, the juice extractor has a rotation speed of 7000rpm to 15000rpm, such as 7000rpm, 8000rpm, 9000rpm, 10000rpm, 11000rpm, 12000rpm, 13000rpm, 14000rpm or 15000rpm, etc., but is not limited to the recited values, and other non-recited values within this range are equally applicable, preferably 8000rpm to 10000 rpm.
Preferably, the pore size of the filtering membrane is 0.01-0.5 μm; for example, 0.01. mu.m, 0.02. mu.m, 0.05. mu.m, 0.1. mu.m, 0.15. mu.m, 0.2. mu.m, 0.3. mu.m, 0.4. mu.m or 0.5. mu.m, etc., but the numerical values are not limited to the above-mentioned values, and other numerical values not mentioned in the above-mentioned numerical value range are also applicable, and 0.01. mu.m to 0.2. mu.m are preferable.
Preferably, the power of the ultrasonic dispersion is 30W to 250W, such as 31W, 35W, 40W, 50W, 60W, 70W, 75W, 80W, 100W, 120W, 150W, 180W, 190W, 200W, 230W, or 250W, but is not limited to the recited values, and other non-recited values within this range of values are equally applicable, preferably 50W to 80W.
Preferably, the time for ultrasonic dispersion is 0.5h to 24h, such as 0.5h, 1h, 2h, 5h, 8h, 10h, 12h, 15h, 20h, 22h or 24h, but is not limited to the recited values, and other values not recited in the numerical range are equally applicable, preferably 1h to 5 h.
Preferably, the concentration of glucose in the fruit juice dispersion is from 0.001mg/mL to 20mg/mL, such as 0.001mg/mL, 0.005mg/mL, 0.01mg/mL, 0.02mg/mL, 0.05mg/mL, 0.1mg/mL, 0.5mg/mL, 1mg/mL, 1.5mg/mL, 2mg/mL, 3mg/mL, 5mg/mL, 8mg/mL, 10mg/mL, or 20mg/mL, but is not limited to the recited values, and other values within this range of values are equally applicable, preferably from 0.01mg/mL to 10 mg/mL.
As a preferred embodiment of the present invention, the amino acid dispersion in step (2) is any one or a combination of at least two of cysteine, glutamic acid, glutamine, glycine, alanine, valine, leucine, isoleucine, and methionine (methionine), and typical but non-limiting examples of the combination are: cysteine and glutamic acid, glutamine and glycine, alanine and valine, leucine, isoleucine and methionine (methionine) combination.
Preferably, the concentration of the amino acid in the amino acid dispersion in step (2) is 0.001mg/mL to 1mg/mL, for example, 0.01mg/mL, 0.05mg/mL, 0.08 mg/mL, 0.1mg/mL, etc., but is not limited to the recited values, and other values within the range are also applicable, preferably 0.001mg/mL to 0.01 mg/mL.
Preferably, the ratio of the mass concentration of the amino acid dispersion in step (2) to the mass concentration of the fruit juice dispersion in step (1) is 0.1 to 30, for example 0.1, 0.5, 0.8, 1, 2, 3, 5, 10, 13, 15, 17, 20, 23, 25, 27 or 30, but not limited to the recited values, and other values not recited within this range of values are equally applicable, preferably 0.1 to 5.
In the invention, the ratio of the mass concentration of the fruit juice dispersion liquid to the mass concentration of the amino acid dispersion liquid needs to be controlled within a certain range, and if the dosage of the amino acid dispersion liquid is too much, the yield of quantum dots is reduced; if the amount of the amino acid dispersion is too small, the degree of functionalization of the quantum dots is not good.
Preferably, the volume of the solvent of the amino acid dispersion of step (2) is 1% to 50% of the total solvent volume of the two dispersions, such as 1%, 2%, 5%, 8%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, or 50%, but not limited to the recited values, and other non-recited values within this range are equally applicable, preferably 2% to 10%.
As a preferable technical scheme of the invention, the sample injection modes of the fruit juice dispersion liquid obtained in the step (1) and the amino acid dispersion liquid obtained in the step (2) in the step (3) are as follows:
both are continuously injected at the same time.
When the sample is continuously fed, the sample rate of the fruit juice dispersion obtained in step (1) in step (3) is preferably 0.01mL/min to 10mL/min, such as 0.1L/min, 0.5mL/min, 1mL/min, 1.5mL/min, 2mL/min, 2.5mL/min, 3mL/min, 3.5mL/min, 4mL/min, 4.5mL/min, or 5mL/min, but not limited to the values listed, and other values not listed in the range of the values are also applicable, and preferably 0.1mL/min to 5 mL/min.
When continuous sample injection is performed simultaneously, the sample injection rate of the amino acid dispersion obtained in step (2) in step (3) is preferably 0.01mL/min to 10mL/min, such as 0.1mL/min, 0.2mL/min, 0.5mL/min, 1mL/min, 2.5mL/min, 3mL/min, 3.5mL/min, 4mL/min, 4.5mL/min, or 5mL/min, but not limited to the values listed, and other values in the range of the values are also applicable, and preferably 0.1mL/min to 1 mL/min.
As a preferable technical scheme of the invention, the fruit juice dispersion liquid obtained in the step (1) in the step (3) and the amino acid dispersion liquid obtained in the step (2) are subjected to a microchannel reaction to obtain a carbon quantum dot dispersion liquid with controllable fluorescence wavelength;
preferably, the microchannel pore size is from 0.1mm to 2mm, such as 0.1mm, 0.2mm, 0.5mm, 1mm, 1.2mm, 1.5mm, 2mm, and the like, but is not limited to the recited values, and other non-recited values within this range of values are equally applicable, preferably from 0.3mm to 1 mm;
preferably, the length of the microchannel is 1m to 20m, such as 1m, 2m, 5m, 10m, 12m, 15m, 20m, etc., but not limited to the recited values, and other values not recited in the numerical range are equally applicable, preferably 2m to 10 m;
preferably, the microchannel reaction temperature is 80 ℃ to 200 ℃, such as 80 ℃, 90 ℃, 100 ℃, 110 ℃, 120 ℃, 130 ℃, 140 ℃, 150 ℃, 160 ℃, 170 ℃, 180 ℃, etc., but not limited to the recited values, and other values not recited in the numerical range are equally applicable, preferably 100 ℃ to 180 ℃;
preferably, the microchannel reaction time is 5min to 120min, such as 5min, 10min, 20min, 30min, 60min, 90min, 120min, etc., but not limited to the recited values, and other values not recited in the range of values are equally applicable, preferably 10min to 60 min;
as a preferred embodiment of the present invention, the purification method in step (4) is dialysis.
Preferably, the dialysis is performed under stirring conditions.
Preferably, the stirring rate is 10rpm to 150rpm, such as 10rpm, 30rpm, 50rpm, 70rpm, 100rpm, 130rpm, 150rpm, and the like, but is not limited to the recited values, and other values not recited in the range of values are equally applicable, preferably 50 rpm.
Preferably, the reaction in step (4) is stirred for 12h to 72h, for example 12h, 15h, 20h, 24h, 26h, 30h, 34h, 36h, 40h, 44h, 46h, 50h, 54h, 56h, 60h, 64h, 66h, 70h or 72h, but not limited to the recited values, and other values not recited in this range are equally applicable, preferably 24h to 48 h.
In a preferred embodiment of the present invention, the drying temperature of the vacuum freeze-drying is-110 ℃ to-10 ℃, for example, -10 ℃, -15 ℃, -20 ℃, -30 ℃, -40 ℃, -50 ℃, -60 ℃, -70 ℃, -80 ℃, -90 ℃, -100 ℃, or-110 ℃, but the drying temperature is not limited to the above-mentioned values, and other values not listed in the above-mentioned value range are also applicable, and preferably-70 ℃ to-50 ℃.
Preferably, the vacuum degree of the vacuum freeze-drying is 2Pa to 10Pa, for example, 2Pa, 3Pa, 4Pa, 5Pa, 6Pa, 7Pa, 8Pa, 9Pa, or 10Pa, but is not limited to the recited values, and other values not recited in the range of the values are also applicable, and preferably 5Pa to 8 Pa.
Preferably, the drying time of the vacuum freeze-drying is 0.5h to 72h, for example 0.5h, 1h, 5h, 10h, 12h, 24h, 30h, 36h, 40h, 48h, 50h, 60h, 65h, 70 or 72h, etc., but is not limited to the recited values, and other values not recited in the numerical range are equally applicable, preferably 24h to 48 h.
As a preferred technical scheme of the invention, the preparation method comprises the following steps:
(1) squeezing the selected fruits by using a juicer with the rotating speed of 8000 rpm-10000 rpm to obtain fruit juice, filtering fruit fibers by using a filter membrane with the diameter of 0.01-0.5 μm, and ultrasonically dispersing the obtained fruit juice in water at the ultrasonic dispersion power of 50-80W for 1-5 h to prepare a fruit juice dispersion liquid with the concentration of 0.01-10 mg/mL;
(2) the mass concentration of the amino acid dispersion liquid with the concentration of 0.001 mg/mL-0.01 mg/mL is prepared to be 0.1-5 of the mass concentration of the fruit juice dispersion liquid in the step (1).
(3) Connecting and mixing the fruit juice dispersion liquid obtained in the step (1) and the amino acid dispersion liquid obtained in the step (2) through a three-way valve, and allowing the mixture to enter a microchannel for reaction to obtain a fluorescence wavelength controllable carbon quantum dot dispersion liquid, wherein the sample injection rate of the fruit juice dispersion liquid obtained in the step (1) is 0.1-5 mL/min, the sample injection rate of the amino acid dispersion liquid obtained in the step (2) is 0-1 mL/min, the pore diameter of the microchannel is 0.3-1 mm, the length of the microchannel is 2-10 m, the reaction temperature of the microchannel is 100-180 ℃, and the reaction time of the microchannel is 10-60 min;
optionally, (4) purifying the fluorescence wavelength controllable carbon quantum dots prepared in the step (3) to obtain purified carbon quantum dot dispersion liquid;
optionally, (5) carrying out vacuum freeze drying on the fluorescence wavelength controllable carbon quantum dot dispersion liquid prepared in the step (3) or the purified carbon quantum dot dispersion liquid prepared in the step (4), wherein the drying temperature of the vacuum freeze drying is-50 ℃ to-70 ℃, the vacuum degree is 5Pa to 8Pa, and the drying time is 24h to 48h, so as to obtain the solid fluorescence wavelength controllable carbon quantum dot or the solid purified carbon quantum dot.
In a second aspect, the present invention provides a fluorescence wavelength controllable carbon quantum dot prepared by the above preparation method, wherein the fluorescence wavelength controllable carbon quantum dot has a diameter of 1nm to 10nm, for example, 1nm, 2nm, 3nm, 4nm, 5nm, 6nm, 7nm, 8nm, 9nm or 10nm, but not limited to the above-mentioned values, and other values not listed in the above-mentioned value range are also applicable. Here, the fluorescence wavelength controllable carbon quantum dot refers to an unpurified carbon quantum dot prepared through the step (3) in the preparation method.
Preferably, the purified fluorescence wavelength controllable carbon quantum dots are fluorescence wavelength controllable carbon quantum dots with uniform size and diameters of 1nm to 10 nm. The carbon quantum dots with controllable fluorescence wavelength have more uniform size, better dispersion performance and easy separation compared with the carbon quantum dots without purification.
As a preferable technical scheme, the carbon quantum dots with controllable fluorescence wavelength and the photosensitive material and/or the electro-sensitive material are compounded and then are used in the fields of organic pollutant degradation, electrochemical sensors, supercapacitors, luminescent materials, photoelectric devices or biological imaging.
According to the invention, the prepared carbon quantum dots with controllable fluorescence wavelength are compounded with photosensitive materials and/or electro-sensitive materials, so that the pollutant degradation efficiency, the sensitivity of an electrochemical sensor, the capacity of a super capacitor, the performances of materials such as luminescent materials, photoelectric devices and fluorescent probes are improved.
Compared with the prior art, the invention has the following beneficial effects:
(1) the preparation method of the carbon quantum dots with controllable fluorescence wavelength provided by the invention adopts a microchannel reaction technology, the process is safe, simple and controllable, glucose can generate a macromolecular carbocyclic intermediate without using any chemical reagent, the carbonization and nitrogen-doped and sulfur-doped functionalization of the quantum dots can be synchronously realized, and the process for preparing the carbon quantum dots with controllable fluorescence wavelength is controllable, green and friendly and has low cost;
(2) compared with the existing preparation method of the carbon quantum dots, the preparation method of the carbon quantum dots with controllable fluorescence wavelength is simple and convenient to operate and can be completed in one step; the reaction condition is mild, no illumination, strong oxidation and high-temperature heating are needed, no secondary pollution is caused, no substances which are difficult to separate exist, the diameter of the quantum dot is 1-10 nm, the dispersibility is good, the separation is easy to realize, the maximum intensity of the quantum dot in an excitation spectrum of 350nm and an emission spectrum of 440nm can reach more than 500, and the quantum dot has good optical performance;
(3) the preparation method of the fluorescence wavelength controllable carbon quantum dot provided by the invention can realize one-step preparation and functionalization, can compound the prepared fluorescence wavelength controllable carbon quantum dot with other photosensitive materials and electro-sensitive materials, and is beneficial to improving the pollutant degradation efficiency, the sensitivity of an electrochemical sensor, the capacity of a super capacitor, and the performances of materials such as luminescent materials, photoelectric devices or fluorescent probes.
Drawings
FIG. 1 is a schematic diagram of the reaction of the present invention;
FIG. 2 is a transmission electron microscope image of a fluorescence wavelength controllable carbon quantum dot prepared in example 2 of the present invention; wherein (a) is a TEM image of the fluorescence wavelength controllable carbon quantum dot at 40000 times and (b) is an HRTEM image of the fluorescence wavelength controllable carbon quantum dot at 600000 times;
fig. 3 is a fluorescence emission spectrum of the solid fluorescence wavelength-controllable carbon quantum dot prepared in example 2 of the present invention.
Detailed Description
In order to better illustrate the present invention and facilitate the understanding of the technical solutions of the present invention, the present invention is further described in detail below. The following examples are merely illustrative of the present invention and do not represent or limit the scope of the claims, which are defined by the claims.
The specific embodiment of the invention partially provides a preparation method of a fluorescence wavelength controllable carbon quantum dot, which comprises the following steps:
(1) preparing a fruit juice dispersion;
(2) preparing an amino acid dispersion;
(3) connecting the fruit juice dispersion liquid obtained in the step (1) and the amino acid dispersion liquid obtained in the step (2) through a three-way valve, mixing, and reacting in a microchannel to obtain a carbon quantum dot dispersion liquid with controllable fluorescence wavelength;
optionally, (4) purifying the carbon quantum dots prepared in the step (3) to obtain purified fluorescent wavelength controllable carbon quantum dot dispersion liquid;
optionally, (5) performing vacuum freeze drying on the carbon quantum dot dispersion liquid prepared in the step (3) or the purified fluorescence wavelength controllable carbon quantum dot dispersion liquid prepared in the step (4) to obtain the solid fluorescence wavelength controllable carbon quantum dot or the solid purified fluorescence wavelength controllable carbon quantum dot.
The following are typical but non-limiting examples of the invention:
example 1:
the embodiment provides a preparation method of a fluorescence wavelength controllable carbon quantum dot, which comprises the following steps:
(1) adopting watermelon juice as a carbon source, firstly juicing at 8000rpm, filtering with a 0.1-micron filter membrane, and ultrasonically treating 10g of watermelon juice in 130mL of water for 1h with the power of 50W to form uniform and stable watermelon juice dispersion liquid with the glucose concentration of 5 mg/mL;
(2) taking methionine solution with concentration of 0.01mg/mL, performing ultrasonic treatment for 1h at power of 50W to form uniform and stable amino acid dispersion liquid;
(3) mixing the watermelon juice dispersion and the amino acid dispersion at the sampling rates of 0.2mL/min and 0.05mL/min respectively through a three-way valve, and feeding into a microchannel reaction tube with the tube diameter of 1mm and the length of 3 m. And reacting at 140 ℃ for 40min to obtain the carbon quantum dots.
Example 2:
the embodiment provides a method for preparing a fluorescence wavelength controllable carbon quantum dot, wherein steps (1) to (3) of the method are the same as those in embodiment 1, and the method further comprises the following steps:
(4) separating and purifying the carbon quantum dot dispersion liquid obtained in the step (3) in a dialysis mode to obtain a carbon quantum dot dispersion liquid with controllable fluorescence wavelength, wherein the dialysis is carried out under a stirring condition, the stirring speed is 50rpm, and the time is 30 hours;
(5) and (4) carrying out vacuum freeze drying on the fluorescent wavelength controllable carbon quantum dot dispersion liquid obtained in the step (4) at-50 ℃ for 48h, wherein the vacuum degree is 6Pa, and thus obtaining the solid fluorescent wavelength controllable carbon quantum dot.
A Transmission Electron Microscope (TEM) of the solid carbon quantum dots with controllable fluorescence wavelength prepared in this example is shown in fig. 2.
The fluorescence emission spectrum of the solid carbon quantum dot with controllable fluorescence wavelength prepared in the embodiment is shown in fig. 3, wherein the excitation wavelength is 360 nm;
the following analysis results are obtained through transmission electron microscopy analysis and fluorescence spectrum scanning analysis: the solid fluorescence wavelength-controllable carbon quantum dots prepared by the embodiment are uniform in distribution, the size is about 3-5 nm, the emission spectrum has the maximum value at 440nm when the excitation spectrum is 360nm, the intensity of the maximum value is more than 500, and the solid fluorescence wavelength-controllable carbon quantum dots have good luminescence property, so that the material is expected to be applied to luminescent devices.
Example 3:
the embodiment provides a preparation method of a fluorescence wavelength controllable carbon quantum dot, which comprises the following steps:
(1) using kiwi fruit juice as a carbon source, firstly juicing at 8000rpm, filtering with a 0.1-micron filter membrane, and ultrasonically treating 10g of kiwi fruit juice in 250mL of water for 1h with the power of 50W to form a uniform and stable kiwi fruit juice dispersion liquid with the glucose concentration of 5 mg/mL;
(2) taking cysteine solution with the concentration of 0.01mg/mL, and carrying out ultrasonic treatment for 1h at the power of 50W to form uniform and stable amino acid dispersion liquid;
(3) mixing the kiwi fruit juice dispersion liquid and the amino acid dispersion liquid through a three-way valve at the sampling rates of 0.15mL/min and 0.03mL/min respectively, and feeding into a microchannel reaction tube with the tube diameter of 1mm and the length of 3 m. And reacting for 30min at 150 ℃ to obtain the carbon quantum dots.
(4) Separating and purifying the carbon quantum dot dispersion liquid obtained in the step (3) in a dialysis mode to obtain a carbon quantum dot dispersion liquid with controllable fluorescence wavelength, wherein the dialysis is carried out under a stirring condition, the stirring speed is 60rpm, and the time is 48 hours;
(5) and (4) carrying out vacuum freeze drying on the carbon quantum dot dispersion liquid with the controllable fluorescence wavelength obtained in the step (4) at the temperature of minus 50 ℃ for 48 hours, wherein the vacuum degree is 5Pa, and thus obtaining the solid carbon quantum dot with the controllable fluorescence wavelength.
Comparative example 1:
the comparative example provides a preparation method of a fluorescence wavelength controllable carbon quantum dot, which is the same as that in example 1 except that the ratio of the mass concentration of the amino acid solution to the mass concentration of the fruit juice dispersion in step (2) is 40 (i.e., the amino acid solution is excessive).
The following analysis results are obtained through transmission electron microscopy analysis and fluorescence spectrum scanning analysis: the excess amino acid results in a decrease in the yield of quantum dots.
The following analysis results are obtained through transmission electron microscopy analysis and fluorescence spectrum scanning analysis: the reaction rate and yield decrease with a decrease in reaction temperature, and the by-products generated with the reaction increase.
It can be seen from the results of examples 1-3 and comparative example 1 that the preparation method of the fluorescence wavelength controllable carbon quantum dot provided by the invention adopts a microchannel reaction technology, the process is safe, simple and controllable, glucose can generate a macromolecular carbocyclic intermediate without using any chemical reagent, the carbonization and nitrogen-doped and sulfur-doped functionalization of the quantum dot can be synchronously realized, and the process for preparing the fluorescence wavelength controllable carbon quantum dot is controllable, green and friendly and has low cost;
compared with the existing preparation method of the carbon quantum dots, the preparation method of the carbon quantum dots with controllable fluorescence wavelength is simple and convenient to operate and can be completed in one step; the reaction condition is mild, no illumination, strong oxidation and high-temperature heating are needed, no secondary pollution is caused, no substances which are difficult to separate exist, the diameter of the quantum dot is 1-10 nm, the dispersibility is good, the separation is easy to realize, the maximum intensity of the quantum dot in an excitation spectrum of 350nm and an emission spectrum of 440nm can reach more than 500, and the quantum dot has good optical performance;
the preparation method of the fluorescence wavelength controllable carbon quantum dot provided by the invention can realize one-step preparation and functionalization, can compound the prepared fluorescence wavelength controllable carbon quantum dot with other photosensitive materials and electro-sensitive materials, and is beneficial to improving the pollutant degradation efficiency, the sensitivity of an electrochemical sensor, the capacity of a super capacitor, and the performances of materials such as luminescent materials, photoelectric devices or fluorescent probes.
The applicant states that the present invention is illustrated by the above examples to show the detailed process equipment and process flow of the present invention, but the present invention is not limited to the above detailed process equipment and process flow, i.e. it does not mean that the present invention must rely on the above detailed process equipment and process flow to be implemented. It should be understood by those skilled in the art that any modification of the present invention, equivalent substitutions of the raw materials of the product of the present invention, addition of auxiliary components, selection of specific modes, etc., are within the scope and disclosure of the present invention.
Claims (10)
1. A preparation method of a carbon quantum dot with controllable fluorescence wavelength is characterized by comprising the following steps:
(1) preparing a fruit juice dispersion;
(2) preparing an amino acid dispersion;
(3) and (3) connecting the fruit juice dispersion liquid obtained in the step (1) and the amino acid dispersion liquid obtained in the step (2) through a three-way valve, mixing, and reacting in a micro-channel to obtain the carbon quantum dot dispersion liquid with controllable fluorescence wavelength.
2. The method for preparing the fluorescence wavelength controllable carbon quantum dot according to claim 1, characterized by adding a purification step: and (4) purifying the carbon quantum dot dispersion liquid with the controllable fluorescence wavelength prepared in the step (3) to obtain the purified carbon quantum dot dispersion liquid with the controllable fluorescence wavelength.
3. The method for preparing a fluorescence wavelength controllable carbon quantum dot according to claim 2, wherein the fluorescence wavelength controllable carbon quantum dot dispersion liquid prepared in the step (3) or the purified fluorescence wavelength controllable carbon quantum dot dispersion liquid prepared in the step (4) is subjected to vacuum freeze drying to obtain fluorescence wavelength controllable carbon quantum dot powder or purified fluorescence wavelength controllable carbon quantum dot powder.
4. The method for preparing the fluorescence wavelength controllable carbon quantum dot according to any one of claims 1 to 3, wherein the method for preparing the fruit juice dispersion liquid in the step (1) comprises the following steps: juicing fruits, filtering, performing ultrasonic treatment, and adding a proper amount of deionized water to obtain fruit juice dispersion solutions with different concentrations; the fruit is one or more of orange, apple, watermelon, pear, banana, strawberry and kiwi fruit; the rotating speed of the juicer is 7000 rpm-15000 rpm; the aperture of the filtering membrane is 0.01-0.5 μm; the power of the ultrasonic dispersion is 30W-250W; the ultrasonic dispersion time is 0.5-24 h; the concentration of glucose in the fruit juice dispersion liquid is 0.001 mg/mL-20 mg/mL.
5. The method for preparing the fluorescence wavelength controllable carbon quantum dot according to any one of claims 1 to 3, wherein the amino acid dispersion in the step (2) is one or a combination of two or more of cysteine, glutamic acid, glutamine, glycine, alanine, valine, leucine, isoleucine and methionine; the concentration of amino acid in the amino acid dispersion liquid is 0.001 mg/mL-1 mg/mL; the mass concentration ratio of the amino acid dispersion liquid in the step (2) to the fruit juice dispersion liquid in the step (1) is 0.1-30.
6. The method for preparing the carbon quantum dots with controllable fluorescence wavelength according to any one of claims 1 to 3, wherein when the fruit juice dispersion liquid obtained in the step (1) and the amino acid dispersion liquid obtained in the step (2) are injected simultaneously in the step (3): the sample introduction rate of the fruit juice dispersion liquid obtained in the step (1) in the step (3) is 0.01 mL/min-10 mL/min; the sample introduction rate of the amino acid dispersion liquid obtained in the step (2) in the step (3) is 0.01 mL/min-10 mL/min; the aperture of the micro-channel is 0.1 mm-2 mm; the length of the micro-channel is 1 m-20 m; the reaction temperature of the micro-channel is 80-200 ℃; the micro-channel reaction time is 5 min-120 min.
7. The method for preparing the fluorescence wavelength controllable carbon quantum dots according to any one of claim 3, wherein the purification mode is dialysis, and the dialysis is performed under stirring conditions; the stirring speed is 10-150 rpm, and the stirring time is 12-72 h; the drying temperature of the vacuum freeze drying is-110 ℃ to-10 ℃, the vacuum degree is 2Pa to 10Pa, and the drying time is 0.5h to 72 h.
8. The method for preparing the fluorescence wavelength controllable carbon quantum dot according to any one of claim 3, wherein in the step (1): the rotating speed of the juicer is 8000 rpm-10000 rpm; the power of the ultrasonic dispersion is 50-80W; the ultrasonic dispersion time is 1-5 h; the concentration of glucose in the fruit juice dispersion liquid is 0.01 mg/mL-10 mg/mL; in the step (2): the concentration of amino acid in the amino acid dispersion liquid is 0.001 mg/mL-0.01 mg/mL; the mass concentration ratio of the amino acid dispersion liquid in the step (2) to the fruit juice dispersion liquid in the step (1) is 0.1-5; in the step (3): when the fruit juice dispersion liquid obtained in the step (1) and the amino acid dispersion liquid obtained in the step (2) are injected simultaneously: the sample injection rate of the fruit juice dispersion liquid obtained in the step (1) in the step (3) is 0.1 mL/min-5 mL/min; the sample introduction rate of the amino acid dispersion liquid obtained in the step (2) in the step (3) is 0.1 mL/min-1 mL/min; the aperture of the micro-channel is 0.3 mm-1 mm; the length of the micro-channel is 2 m-10 m; the reaction temperature of the micro-channel is 100-180 ℃; the microchannel reaction time is 10 min-60 min; the purification mode is dialysis, and the dialysis is carried out under stirring conditions; the stirring rate was 50 rpm; the stirring time is 24-48 h; the drying temperature of the vacuum freeze drying is-70 ℃ to-50 ℃, the vacuum degree is 5Pa to 8Pa, and the drying time is 24h to 48 h.
9. The carbon quantum dot with controllable fluorescence wavelength prepared by the preparation method of any one of claims 1 to 8, wherein the diameter of the quantum dot with controllable fluorescence wavelength is 1nm to 10 nm.
10. The application of the carbon quantum dot with controllable fluorescence wavelength prepared by the preparation method of any one of claims 1 to 8 is characterized in that the carbon quantum dot with controllable fluorescence wavelength is compounded with a photosensitive material and/or an electro-sensitive material and then is used in the fields of organic pollutant degradation, electrochemical sensors, supercapacitors, luminescent materials, photoelectric devices or biological imaging.
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Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103342347A (en) * | 2013-05-09 | 2013-10-09 | 江苏大学 | Preparation method of carbon quantum dots with high fluorescence property |
| CN103693633A (en) * | 2013-12-04 | 2014-04-02 | 上海交通大学 | Method for green synthesis of fluorescent chiral carbon dots |
| WO2017077381A2 (en) * | 2016-11-17 | 2017-05-11 | Research Institute Of Petroleum Industry (Ripi) | Formulation for the synthesis of thermal nanofluid based on carbon nanodots |
| CN107758642A (en) * | 2017-10-27 | 2018-03-06 | 华南理工大学 | A kind of apparatus and method of extensive Fast back-projection algorithm carbon quantum dot |
| CN107934936A (en) * | 2018-01-04 | 2018-04-20 | 陕西科技大学 | A kind of fast preparation method of carbon quantum dot |
| CN108659834A (en) * | 2018-06-22 | 2018-10-16 | 清华大学 | A kind of method for continuously synthesizing of the carbon nano dot of nearly full spectral emissions |
-
2020
- 2020-12-01 CN CN202011387275.7A patent/CN112520725A/en active Pending
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103342347A (en) * | 2013-05-09 | 2013-10-09 | 江苏大学 | Preparation method of carbon quantum dots with high fluorescence property |
| CN103693633A (en) * | 2013-12-04 | 2014-04-02 | 上海交通大学 | Method for green synthesis of fluorescent chiral carbon dots |
| WO2017077381A2 (en) * | 2016-11-17 | 2017-05-11 | Research Institute Of Petroleum Industry (Ripi) | Formulation for the synthesis of thermal nanofluid based on carbon nanodots |
| CN107758642A (en) * | 2017-10-27 | 2018-03-06 | 华南理工大学 | A kind of apparatus and method of extensive Fast back-projection algorithm carbon quantum dot |
| CN107934936A (en) * | 2018-01-04 | 2018-04-20 | 陕西科技大学 | A kind of fast preparation method of carbon quantum dot |
| CN108659834A (en) * | 2018-06-22 | 2018-10-16 | 清华大学 | A kind of method for continuously synthesizing of the carbon nano dot of nearly full spectral emissions |
Non-Patent Citations (4)
| Title |
|---|
| AKHGARI FARHAD ET AL.: "A green one-pot synthesis of nitrogen and sulfur co-doped carbon quantum dots for sensitive and selective detection of cephalexin", 《 CANADIAN JOURNAL OF CHEMISTRY》 * |
| BIHANI OMKAR ET AL.: "Interaction of proteins with lemon-juice/glutathione-derived carbon nanodot: Interplay of induced-aggregation and co-solubilization", 《INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES》 * |
| 孙墨杰等: "碳量子点的合成研究进展与展望", 《化学通报》 * |
| 李进等: "L-鸟氨酸盐酸盐碳点的制备及其在细胞成像中的应用", 《湖北医药学院学报》 * |
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