CN109354014B - Graphitized carbon quantum dot and preparation method thereof - Google Patents
Graphitized carbon quantum dot and preparation method thereof Download PDFInfo
- Publication number
- CN109354014B CN109354014B CN201811453167.8A CN201811453167A CN109354014B CN 109354014 B CN109354014 B CN 109354014B CN 201811453167 A CN201811453167 A CN 201811453167A CN 109354014 B CN109354014 B CN 109354014B
- Authority
- CN
- China
- Prior art keywords
- carbon quantum
- graphitized carbon
- quantum dot
- quantum dots
- drying
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B32/00—Carbon; Compounds thereof
- C01B32/20—Graphite
- C01B32/205—Preparation
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B82—NANOTECHNOLOGY
- B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
- B82Y30/00—Nanotechnology for materials or surface science, e.g. nanocomposites
Abstract
The invention discloses a graphitized carbon quantum dot and a preparation method thereof. The method is simple to operate, the yield of the carbon quantum dots is high, the cost is low, large-scale production is easy to realize, and the prepared carbon quantum dots are uniform in size (less than 10nm) and good in conductivity and are expected to be used as a conductive agent of an industrial energy storage electrode material.
Description
Technical Field
The invention relates to a carbon quantum dot, in particular to a graphitized carbon quantum dot, and also relates to a method for preparing the graphitized carbon quantum dot with high yield by using Super P, belonging to the technical field of carbon quantum dot preparation.
Background
Carbon quantum dots (generally less than 10nm in size) have recently received wide attention worldwide as a new class of zero-dimensional carbon materials, and due to their unique properties such as quantum size effect and dielectric confinement effect, they have shown attractive prospects in the fields of fluorescence, biomedicine, bioimaging, sensing, photocatalysis, optical devices, and energy conversion and storage. In 2013, a composite material constructed by compounding carbon quantum dots and ruthenium dioxide is reported to be used as a supercapacitor electrode material [ Energy environ.Sci.,2013,6,3665-3675], and compared with pure ruthenium dioxide, the composite material achieves enhanced capacitance performance. Since then, reports of carbon quantum dots for super capacitors, lithium (sodium) ion batteries, fuel cells, and solar cells have been increasing. However, the currently prepared carbon quantum dots for energy storage mainly have the problems of low yield, low conductivity and the like, and the practical application of the carbon quantum dots is limited.
At present, graphitized carbon quantum dots with excellent conductivity are prepared by adopting a chemical oxidation method in the prior art, but the yield of the graphitized carbon quantum dots is less than 20% [ Energy environ.sci.,2013,6, 3665-3675; j. Mater. chem.A,2015,3,866-877 ]; for another example, organic aldehydes are reacted with strong alkali to obtain carbon quantum dots with high yield, but the conductivity is not high [ adv.mater.2015,27,7861-7866], which limits the practical application in the field of energy storage.
Disclosure of Invention
Aiming at the problems of low yield, low conductivity and the like of carbon quantum dots prepared by a chemical method in the prior art, the invention aims to provide a method for preparing graphitized carbon quantum dots with excellent conductivity at high yield, wherein the method is simple, low in cost and beneficial to large-scale production.
The second purpose of the invention is to provide a graphitized carbon quantum dot with good conductivity, and the graphitized carbon quantum dot is expected to be used as a conductive agent in industrial-grade energy storage electrode materials.
The invention provides a method for preparing graphitized carbon quantum dots with high yield, which comprises the steps of dispersing Super P powder into a concentrated nitric acid/concentrated sulfuric acid mixed acid for reflux reaction, and sequentially carrying out purification treatment and reduction treatment on reaction products to obtain the graphitized carbon quantum dots.
Preferably, the mixed acid of the concentrated nitric acid and the concentrated sulfuric acid is composed of the concentrated nitric acid and the concentrated sulfuric acid according to the volume ratio of (0.1-1): 1. The concentrated nitric acid and the concentrated nitric acid of the invention are common industrial grade commercial raw materials. Compared with the single acid, the mixed acid has stronger etching capability on the Super P powder due to stronger oxidizability, thereby leading to higher graphitized carbon quantum dot yield.
In a preferable scheme, the temperature of the reflux reaction is 60-140 ℃, and the time is 6-48 h.
In a preferred embodiment, the purification treatment comprises steps of neutralization, filtration, dialysis and drying. Wherein the neutralization process is a conventional alkali neutralization process, and the neutralization is carried out until the pH is neutral.
Preferably, the dialysis adopts a dialysis bag with the molecular weight cutoff of 500 Da-14000 Da, and the dialysis time is 12 h-120 h.
In a preferred scheme, the drying adopts normal-temperature drying, vacuum drying or freeze drying.
In a preferred embodiment, the reduction treatment conditions are as follows: reducing for 1-10 h in the mixed gas of hydrogen and inert gas at the temperature of 200-1000 ℃. An inert atmosphere such as argon. Generally, the volume ratio of hydrogen is controlled to be less than 20%. The main purpose of the reduction treatment using a mixed gas of hydrogen and an inert gas is to further reduce the oxygen-containing functional groups of the generated carbon quantum dots and to increase the graphitization degree thereof.
The Super P powder of the invention is common industrial Super P powder, and the average grain size is 50 nm.
The Super P powder is dispersed in mixed acid of concentrated nitric acid and concentrated sulfuric acid by ultrasonic. The frequency of ultrasonic dispersion is 30-50 kHz, the power is 80-120W, and the ultrasonic time is 0.5-5 h. The ultrasonic dispersion is beneficial to the full mixing of the Super P powder raw material and the mixed acid, and the reaction efficiency is improved.
The invention also provides a graphitized carbon quantum dot which is prepared by the method.
In a preferable scheme, the size of the graphitized carbon quantum dot is within the range of 1-10 nm.
Compared with the prior art, the technical scheme of the invention has the following beneficial effects:
The technical scheme of the invention adopts industrial Super P powder to prepare the carbon quantum dots by an acid etching method for the first time, the prepared graphitized carbon quantum dots have good conductivity, and the yield of the carbon quantum dots prepared by the method is far higher than that of the carbon quantum dots prepared by other methods, thereby being beneficial to industrial production and application of the carbon quantum dots.
The preparation method has the advantages of simple preparation process, mild reaction conditions and contribution to industrial production, and the raw materials are conventional raw materials sold in the market.
Drawings
FIG. 1 is a photograph of a solid powder of carbon quantum dots obtained in example 1 of the present invention;
FIG. 2 is a photograph of an aqueous solution of carbon quantum dots obtained in example 1 of the present invention;
FIG. 3 is an XRD pattern of carbon quantum dots obtained in example 1 of the present invention;
FIG. 4 is a Raman diagram of carbon quantum dots obtained in example 1 of the present invention;
FIG. 5 is an XPS chart of carbon quantum dots obtained in example 1 of the present invention;
FIG. 6 is a transmission electron micrograph of the carbon quantum dots obtained in example 1 of the present invention.
Detailed Description
The following examples are intended to illustrate the present invention in further detail, but are not intended to limit the scope of the claims of the present invention.
Example 1:
1g of industrial grade Super P conductive agent powder with the particle size of 50nm is mixed with concentrated nitric acid and concentrated sulfuric acid (v/v,1:3), ultrasonic treatment is carried out for 1h (100W, 40kHz), and then reflux is carried out for 24h at the temperature of 110 ℃; after natural cooling, neutralizing the obtained mixed solution with anhydrous sodium carbonate, controlling the pH value to be about 7.0, then filtering to obtain a carbon quantum dot solution, and dialyzing for 72 hours by adopting a dialysis bag with the molecular weight cutoff of 1000 Da; and finally, carrying out freeze drying on the solution obtained after dialysis to obtain graphitized carbon quantum dot powder, and further carrying out thermal reduction on the graphitized carbon quantum dot powder for 2 hours in hydrogen/argon mixed gas at 500 ℃ to obtain carbon quantum dot solid powder. FIG. 1 is a photograph of a solid powder of carbon quantum dots, and 0.51g of a blackish brown powder was obtained by freeze-drying the obtained carbon quantum dots. FIG. 2 is a photograph of an aqueous solution of carbon quantum dots, which are readily soluble in water and remain free of precipitates after being left for several months. Fig. 3 is an XRD pattern of the carbon quantum dot, and it can be seen that the obtained carbon quantum dot has an amorphous structure. FIG. 4 is a Raman plot of carbon quantum dots, which are shown at 1349 and 1572cm -1The D peak and the G peak are two characteristic peaks of the carbon quantum dots. Fig. 5 is an XPS graph of the carbon quantum dot, in which it is known that the peak at 284.8eV corresponds to graphitized C — C bond, and the peaks at 286.5, 288.4, and 289.2eV correspond to C-O, C ═ O and O-C ═ O bond, respectively, indicating that the surface of the prepared carbon quantum dot contains a certain number of oxygen-containing functional groups. Fig. 6 is a transmission electron microscope image of the carbon quantum dot, and it can be seen that the prepared carbon quantum dot has a uniform size, a diameter of 5-8 nm, and a lattice fringe spacing of 0.215nm observed from the inset, and belongs to a (100) crystal plane of graphite, which indicates that the prepared graphitized carbon quantum dot is obtained.
Comparative example 1
mixing industrial Super P powder with concentrated nitric acid (6mol L) -1) And (3) mixing, refluxing at the temperature of 110 ℃ for 48h, and purifying, dialyzing and drying the product to obtain the graphitized carbon quantum dot with the yield of 10%.
Comparative example 2
Will be of technical grade Super P powder of (2) with concentrated nitric acid (12mol L) -1) And (3) mixing, refluxing at the temperature of 110 ℃ for 48h, and purifying, dialyzing and drying the product to obtain the graphitized carbon quantum dot with the yield of 18%.
Example 2:
1g of industrial grade Super P conductive agent powder with the particle size of 50nm is mixed with concentrated nitric acid and concentrated sulfuric acid (v/v,1:3), ultrasonic treatment is carried out for 1h (100W, 40kHz), and then reflux is carried out for 24h at the temperature of 60 ℃; after natural cooling, neutralizing the obtained mixed solution with anhydrous sodium carbonate, controlling the pH value to be about 7.0, then filtering to obtain a carbon quantum dot solution, and dialyzing for 72 hours by adopting a dialysis bag with the molecular weight cutoff of 1000 Da; and finally, freeze-drying the solution obtained after dialysis to obtain 0.32g of graphitized carbon quantum dot powder, and further carrying out thermal reduction for 2h in hydrogen/argon mixed gas at 500 ℃ to obtain carbon quantum dot solid powder.
Example 3:
1g of industrial grade Super P conductive agent powder with the particle size of 50nm is mixed with concentrated nitric acid and concentrated sulfuric acid (v/v,1:3), ultrasonic treatment is carried out for 1h (100W, 40kHz), and then reflux is carried out for 24h at the temperature of 80 ℃; after natural cooling, neutralizing the obtained mixed solution with anhydrous sodium carbonate, controlling the pH value to be about 7.0, then filtering to obtain a carbon quantum dot solution, and dialyzing for 72 hours by adopting a dialysis bag with the molecular weight cutoff of 1000 Da; and finally, freeze-drying the solution obtained after dialysis to obtain 0.41g of graphitized carbon quantum dot powder, and further carrying out thermal reduction for 2h in hydrogen/argon mixed gas at 500 ℃ to obtain carbon quantum dot solid powder.
Example 4:
1g of industrial grade Super P conductive agent powder with the particle size of 50nm is mixed with concentrated nitric acid and concentrated sulfuric acid (v/v,1:3), ultrasonic treatment is carried out for 1h (100W, 40kHz), and then reflux is carried out for 48h at the temperature of 110 ℃; after natural cooling, neutralizing the obtained mixed solution with anhydrous sodium carbonate, controlling the pH value to be about 7.0, then filtering to obtain a carbon quantum dot solution, and dialyzing for 72 hours by adopting a dialysis bag with the molecular weight cutoff of 1000 Da; and finally, freeze-drying the solution obtained after dialysis to obtain 0.51g of graphitized carbon quantum dot powder, and further carrying out thermal reduction for 2h in hydrogen/argon mixed gas at 500 ℃ to obtain carbon quantum dot solid powder.
Example 5:
1g of industrial grade Super P conductive agent powder with the particle size of 50nm is mixed with concentrated nitric acid and concentrated sulfuric acid (v/v,1:3), ultrasonic treatment is carried out for 1h (100W, 40kHz), and then reflux is carried out for 48h at the temperature of 140 ℃; after natural cooling, neutralizing the obtained mixed solution with anhydrous sodium carbonate, controlling the pH value to be about 7.0, then filtering to obtain a carbon quantum dot solution, and dialyzing for 72 hours by adopting a dialysis bag with the molecular weight cutoff of 1000 Da; and finally, freeze-drying the solution obtained after dialysis to obtain 0.51g of graphitized carbon quantum dot powder, and further carrying out thermal reduction for 2h in hydrogen/argon mixed gas at 500 ℃ to obtain carbon quantum dot solid powder.
Example 6:
1g of industrial grade Super P conductive agent powder with the particle size of 50nm is mixed with concentrated nitric acid and concentrated sulfuric acid (v/v,1:1), ultrasonic treatment is carried out for 1h (100W, 40kHz), and then reflux is carried out for 72h at the temperature of 110 ℃; after natural cooling, neutralizing the obtained mixed solution with anhydrous sodium carbonate, controlling the pH value to be about 7.0, then filtering to obtain a carbon quantum dot solution, and dialyzing for 72 hours by adopting a dialysis bag with the molecular weight cutoff of 1000 Da; and finally, freeze-drying the solution obtained after dialysis to obtain 0.42g of graphitized carbon quantum dot powder, and further carrying out thermal reduction for 2h in hydrogen/argon mixed gas at 500 ℃ to obtain carbon quantum dot solid powder.
Example 7:
1g of industrial grade Super P conductive agent powder with the particle size of 50nm is mixed with concentrated nitric acid and concentrated sulfuric acid (v/v,1:10), ultrasonic treatment is carried out for 1h (100W, 40kHz), and then reflux is carried out for 24h at the temperature of 110 ℃; after natural cooling, neutralizing the obtained mixed solution with anhydrous sodium carbonate, controlling the pH value to be about 7.0, then filtering to obtain a carbon quantum dot solution, and dialyzing for 72 hours by adopting a dialysis bag with the molecular weight cutoff of 1000 Da; and finally, freeze-drying the solution obtained after dialysis to obtain 0.51g of graphitized carbon quantum dot powder, and further carrying out thermal reduction for 2h in hydrogen/argon mixed gas at 500 ℃ to obtain carbon quantum dot solid powder.
Claims (6)
1. A method for preparing graphitized carbon quantum dots with high yield is characterized in that: dispersing Super P powder into a mixed acid of concentrated nitric acid and concentrated sulfuric acid for reflux reaction, and sequentially carrying out purification treatment and reduction treatment on a reaction product to obtain the Super P powder;
The concentrated nitric acid/concentrated sulfuric acid mixed acid consists of concentrated nitric acid and concentrated sulfuric acid according to the volume ratio of (0.1-1) to 1;
The temperature of the reflux reaction is 60-140 ℃, and the time is 6-48 h;
The reduction treatment conditions are as follows: reducing for 1-10 h in the mixed gas of hydrogen and inert gas at the temperature of 200-1000 ℃.
2. The method for preparing graphitized carbon quantum dots according to claim 1, wherein the method comprises the following steps: the purification treatment comprises the steps of neutralization, filtration, dialysis and drying.
3. The method for preparing graphitized carbon quantum dots according to claim 2, wherein the graphitized carbon quantum dots are prepared by the following steps: the dialysis adopts a dialysis bag with the molecular weight cutoff of 500 Da-14000 Da, and the dialysis time is 12 h-120 h.
4. The method for preparing graphitized carbon quantum dots according to claim 2, wherein the graphitized carbon quantum dots are prepared by the following steps: the drying adopts normal temperature drying, vacuum drying or freeze drying.
5. A graphitized carbon quantum dot, characterized in that: prepared by the method of any one of claims 1 to 4.
6. The graphitized carbon quantum dot of claim 5, wherein: the size of the graphitized carbon quantum dot is within the range of 1-10 nm.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811453167.8A CN109354014B (en) | 2018-11-30 | 2018-11-30 | Graphitized carbon quantum dot and preparation method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811453167.8A CN109354014B (en) | 2018-11-30 | 2018-11-30 | Graphitized carbon quantum dot and preparation method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN109354014A CN109354014A (en) | 2019-02-19 |
| CN109354014B true CN109354014B (en) | 2020-07-31 |
Family
ID=65330505
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201811453167.8A Active CN109354014B (en) | 2018-11-30 | 2018-11-30 | Graphitized carbon quantum dot and preparation method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN109354014B (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110534745B (en) * | 2019-08-07 | 2022-07-05 | 合肥国轩高科动力能源有限公司 | Carbon quantum dot/SP composite conductive agent and preparation method and application thereof |
| CN113181906A (en) * | 2021-04-23 | 2021-07-30 | 西安交通大学 | Pt @ CDs composite nano material and preparation method thereof |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106573778A (en) * | 2014-06-19 | 2017-04-19 | 威廉马歇莱思大学 | Bandgap engineering of carbon quantum dots |
| CN108467028A (en) * | 2018-04-26 | 2018-08-31 | 上海大学 | The preparation method and application of intelligent graphene quantum dot cluster |
-
2018
- 2018-11-30 CN CN201811453167.8A patent/CN109354014B/en active Active
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106573778A (en) * | 2014-06-19 | 2017-04-19 | 威廉马歇莱思大学 | Bandgap engineering of carbon quantum dots |
| CN108467028A (en) * | 2018-04-26 | 2018-08-31 | 上海大学 | The preparation method and application of intelligent graphene quantum dot cluster |
Also Published As
| Publication number | Publication date |
|---|---|
| CN109354014A (en) | 2019-02-19 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Zhang et al. | A review of porous carbons produced by template methods for supercapacitor applications | |
| EP3617147B1 (en) | Process for preparing titanic acid salt, titanic acid, and titanium oxide having controllable particle size and hierarchical structure | |
| EP2660199A1 (en) | Composite material of carbon-coated graphene oxide, preparation method and application thereof | |
| WO2016141706A1 (en) | Composite-coated lithium iron phosphate and preparation method therefor, and lithium ion battery | |
| US10115497B2 (en) | Compressive graphene hydrogel and preparation method therefor | |
| CN104815637A (en) | Method for hydrothermal method preparation of graphene-loaded flower-type titanium dioxide composite material | |
| EP2657191A1 (en) | Preparation method and use of manganese dioxide nano-rod | |
| CN104445163B (en) | A kind of preparation method of carboxylated Graphene | |
| CN103922328A (en) | Method for preparing nitrogenous hierarchical pore three-dimensional graphene by using chitosan | |
| Weng et al. | A review of metal-organic framework-derived carbon electrode materials for capacitive deionization | |
| CN109354014B (en) | Graphitized carbon quantum dot and preparation method thereof | |
| CN112420402B (en) | Nitrogen-doped biochar, preparation method and application thereof, electrode and preparation method | |
| Zhang et al. | Recent progress of transition metal-based biomass-derived carbon composites for supercapacitor | |
| Feng et al. | Biomass derived diverse carbon nanostructure for electrocatalysis, energy conversion and storage | |
| CN108615904B (en) | Nickel cobaltate hollow sphere/carbon nitride quantum dot composite material and preparation method and application thereof | |
| Hou et al. | Preparation of flexible composite electrode with bacterial cellulose (BC)-derived carbon aerogel supported low loaded NiS for methanol electrocatalytic oxidation | |
| Duan et al. | Elemental phosphorus for recent sustainable processes: rules and strategies in preparation and applications | |
| CN102504249A (en) | Preparation method of order meso porous manganese dioxide/ conductive polyaniline composite material | |
| Hou et al. | Application of coal-based carbon dots for photocatalysis and energy storage: a minireview | |
| CN110885069A (en) | Three-dimensional macroporous ultralight carbon nitride material and preparation method thereof | |
| CN103641101A (en) | Two-dimensional structural carbon nanomaterial and preparation method thereof | |
| JP2020504068A (en) | Graphite-like microcrystalline carbon nanomaterial, its production method and application | |
| Yang et al. | Electrochemical control of the conversion of cellulose oligosaccharides into glucose | |
| CN109433246B (en) | Carbon vacancy-containing nanosheet C3N4Photocatalyst and preparation method thereof | |
| CN113816425B (en) | MoS 2 Nitrogen-doped carbon/modified activated carbon sodium ion battery negative electrode material and preparation method thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |