CN111792638A - Method for improving yield of biomass carbon quantum dots through dilute acid pretreatment - Google Patents
Method for improving yield of biomass carbon quantum dots through dilute acid pretreatment Download PDFInfo
- Publication number
- CN111792638A CN111792638A CN202010599343.XA CN202010599343A CN111792638A CN 111792638 A CN111792638 A CN 111792638A CN 202010599343 A CN202010599343 A CN 202010599343A CN 111792638 A CN111792638 A CN 111792638A
- Authority
- CN
- China
- Prior art keywords
- carbon quantum
- dilute acid
- quantum dots
- biomass
- powder
- 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.)
- Pending
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
- C01B32/15—Nano-sized carbon materials
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B82—NANOTECHNOLOGY
- B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
- B82Y20/00—Nanooptics, e.g. quantum optics or photonic crystals
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B82—NANOTECHNOLOGY
- B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
- B82Y40/00—Manufacture or treatment of nanostructures
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- C09K11/00—Luminescent, e.g. electroluminescent, chemiluminescent materials
- C09K11/08—Luminescent, e.g. electroluminescent, chemiluminescent materials containing inorganic luminescent materials
- C09K11/65—Luminescent, e.g. electroluminescent, chemiluminescent materials containing inorganic luminescent materials containing carbon
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Nanotechnology (AREA)
- Organic Chemistry (AREA)
- Inorganic Chemistry (AREA)
- Crystallography & Structural Chemistry (AREA)
- Materials Engineering (AREA)
- Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Biophysics (AREA)
- Condensed Matter Physics & Semiconductors (AREA)
- General Physics & Mathematics (AREA)
- Manufacturing & Machinery (AREA)
- Life Sciences & Earth Sciences (AREA)
- Carbon And Carbon Compounds (AREA)
- Preparation Of Compounds By Using Micro-Organisms (AREA)
Abstract
A method for improving the yield of biomass carbon quantum dots through dilute acid pretreatment comprises the following steps: drying the biomass material, grinding the biomass material into powder, soaking the powder in dilute acid pretreatment solution at the temperature of 25-75 ℃ for 30-120min, then heating the powder in a closed reaction kettle to the temperature of 160-240 ℃ for reaction for 3-12h, naturally cooling the solution to room temperature, centrifuging the solution, collecting supernatant, filtering the supernatant, collecting filtrate, and drying the filtrate to obtain carbon quantum dot powder; according to the invention, biomass is used as a carbon source, and the carbon quantum dots are prepared by a dilute acid pretreatment and a hydrothermal method, and the prepared carbon quantum dots have high yield, good water solubility and strong fluorescence; the method does not relate to a high-concentration acid reagent, has low requirement on equipment, mild reaction conditions, simple process and easy operation.
Description
Technical Field
The invention relates to a method for improving the yield of biomass carbon quantum dots through dilute acid pretreatment.
Background
The carbon quantum dot has an average particle size of less than 10nm, contains abundant hydroxyl, carbonyl and other groups on the surface, and has the characteristics of nano-size distribution, good biocompatibility and water solubility, stable fluorescence and the like. These properties make Carbon quantum dots potentially useful in the medical field, optical field, detection and analysis, etc. (Carbon,2018(140): 77-99). Different carbon sources can prepare the carbon quantum dots by different synthesis methods. The biomass material can be used as a carbon source to prepare carbon quantum dots due to the large amount of biomass material existing in nature. In the process of preparing the carbon quantum dots, the carbon quantum dots are prepared by taking natural biomass as a raw material, so that the cost of the raw material can be reduced, and the reasonable utilization of resources can be improved (RSC advances,2014,4(52): 27184-27200.). Compared with other organic synthetic carbon quantum dots, the biomass carbon quantum dots have the problem of low fluorescence quantum yield and yield, and the yield reported by a hydrothermal method and a pyrolysis carbonization method is between 5 and 10.6 percent (Journal of Materials Chemistry B,2015,3(33): 6783-. The biomass carbon quantum dots are mainly composed of C, H, O, N four elements. The four elements enable the surface of the carbon quantum dot to contain hydrophilic functional groups such as hydroxyl, carboxyl and the like, and the hydrophilic groups enable the carbon quantum dot to have better water solubility and provide possibility for further pretreatment.
The invention provides a pretreatment method for improving biomass carbon quantum dots by taking a biomass material (sargassum horneri) as an example as a raw material. The sargassum horneri has large productivity and rapid growth, does not occupy land resources and fresh water resources, and has important significance for saving resources and protecting the environment by selecting the sargassum horneri as a preparation raw material of a carbon material. The Sargassum horneri contains abundant cellulose and lignin, has high carbon content, and is an ideal raw material for preparing carbon materials. In order to improve the yield of the biomass carbon quantum dots, the invention provides a method which can carry out proper pretreatment operation on biomass materials, and the fluorescence intensity and the yield of the biomass carbon quantum are greatly influenced before and after the pretreatment. The appropriate pretreatment method can destroy the cellulose of the natural plant structure, and increase the specific surface area and the porosity of the raw material (environmental science research, 2014, 27 (7): 804-. Since dilute acid can hydrolyze cellulose by 80-90%, compared with the traditional concentrated acid method, the dilute acid method has relatively low requirements on corrosion resistance of equipment, and compared with the emerging ultralow acid method, the dilute acid method has low requirements on reaction temperature and pressure (Biofuels Bioproducts & Biorefining,2008,2: 26-40.). Therefore, before the carbon quantum dots are prepared, the biomass material is subjected to dilute acid pretreatment, so that the yield of the biomass carbon quantum dots can be effectively improved and increased from 2.3% to 18.9%.
Disclosure of Invention
The invention provides a processing method for improving the yield of biomass carbon quantum dots. According to the method, the large-scale seaweed with high lignocellulose is used as a carbon source material, and the carbon quantum dots are prepared by a hydrothermal synthesis method. And the yield of the biomass carbon quantum dots is improved by carrying out dilute acid pretreatment on the biomass material.
The technical scheme of the invention is as follows:
a method for improving biomass carbon quantum dot yield through dilute acid pretreatment, which comprises the following steps:
drying the biomass material, grinding the biomass material into powder, soaking the powder in dilute acid pretreatment solution at the temperature of 25-75 ℃ for 30-120min, then heating the powder in a closed reaction kettle to the temperature of 160-240 ℃ for reaction for 3-12h, naturally cooling the powder to room temperature (20-30 ℃), centrifuging the reaction product, collecting supernatant, filtering the supernatant, collecting filtrate, and drying the filtrate to obtain carbon quantum dot powder;
the biomass material is terrestrial or aquatic plants with high lignocellulose content, such as Sargassum horneri (Sargassum horneri);
the dilute acid pretreatment solution is obtained by dissolving inorganic acid in deionized water, wherein the inorganic acid is selected from sulfuric acid or nitric acid, and the mass fraction of the dilute acid pretreatment solution is 1-10%; the volume dosage of the dilute acid pretreatment solution is 10-30mL/g based on the mass of the biomass material powder;
the speed of the centrifugation is 8000-12000 r/min;
the filtration is to filter the supernatant using a 0.22 μm pore size microfiltration membrane to remove large particles;
the drying method can be freeze drying, vacuum drying or air drying;
the obtained product is placed in a closed container and stored in the dark or is dispersed in deionized water and stored in the dark.
The invention has the beneficial effects that: the invention takes biomass as a carbon source, and prepares the carbon quantum dots by a hydrothermal method through dilute acid pretreatment. The prepared carbon quantum dots have high yield, good water solubility and strong fluorescence. The method does not relate to a high-concentration acid reagent, has low requirement on equipment, mild reaction conditions, simple process and easy operation.
Drawings
FIG. 1 is a fluorescence spectrum of carbon quantum dots prepared by biomass at different temperatures in example 1.
FIG. 2 is a graph of the fluorescence spectra of carbon quantum dots obtained from dilute acid treated solutions of different acid contents in example 2.
FIG. 3 is a fluorescence spectrum of carbon quantum dots obtained in 3% diluted acid solution at room temperature under excitation of different wavelengths in example 2.
FIG. 4 is a graph of fluorescence spectra of carbon quantum dots obtained in 3% dilute acid solution at different pretreatment temperatures in example 3.
Detailed Description
The invention is further illustrated by the following examples, without restricting its scope.
Example 1
The biomass Sargassum horneri is dried and then crushed into powder. Weighing 2g of biomass powder, adding the biomass powder into 30mL of deionized water, uniformly mixing, and transferring the mixture into a closed reaction kettle for hydrothermal reaction. 5 parts are prepared in parallel.
And (3) performing hydrothermal reaction on the 5 parts of the raw materials at 160 ℃, 180 ℃,200 ℃, 220 ℃ and 240 ℃ for 3 hours, and naturally cooling to room temperature after the reaction is finished. And taking out the product from the reaction kettle, centrifuging the product at 10000r/min for 10min, and filtering supernatant liquid by using a microporous filter membrane to obtain the carbon quantum dot solution. And placing the carbon quantum dot solution in a fluorescence spectrophotometer to detect the fluorescence spectrum of the carbon quantum dot solution.
The results show that when the hydrothermal reaction is carried out at different temperatures, the obtained products all have fluorescence, and the products are clear and transparent. The fluorescence intensity of the obtained carbon quantum dots is increased within a certain temperature range along with the increase of the reaction temperature, and the fluorescence intensity is reduced along with the increase of the temperature beyond the temperature range, as shown in the attached figure 1. FIG. 1 shows fluorescence spectra of carbon quantum dots obtained by mixing biomass powder with deionized water, and performing hydrothermal reaction at 160 deg.C, 180 deg.C, 200 deg.C, 220 deg.C, and 240 deg.C, wherein the excitation wavelength is 450 nm.
Example 2
Respectively preparing dilute acid pretreatment solutions with sulfuric acid contents of 0%, 1.5%, 3% and 4.5%, weighing 2g of biomass Sargassum horneri, placing the biomass Sargassum horneri in 30mL of dilute acid pretreatment solution, uniformly mixing, soaking for 60min at room temperature, transferring into a reaction kettle, carrying out hydrothermal reaction at 200 ℃ for 3h, and naturally cooling to room temperature. The subsequent operation was the same as in example 1.
The result shows that the obtained products have strong fluorescence, and the fluorescence intensity of the carbon quantum dots and the yield of the carbon quantum powder can be obviously improved by carrying out dilute acid pretreatment on biomass. The same carbon quantum dots are excited by different wavelengths (400nm, 450nm, 500nm, 550nm and 600nm), so that the fluorescence intensity is changed, the maximum fluorescence emission wavelength is gradually red-shifted, and the dependence of the fluorescence property of the carbon quantum dots on the excitation wavelength is shown. The fluorescence intensity is maximized under the condition that the excitation wavelength is 450nm, and the corresponding carbon quantum dot correlation values can be seen in table 1.
FIG. 2 is a fluorescence spectrum of carbon quantum dots obtained by mixing biomass powder in dilute acid pretreatment solutions with different sulfuric acid doping amounts, wherein the excitation wavelength is 450 nm.
FIG. 3 is the fluorescence spectra of carbon quantum dots obtained from diluted acid pretreatment solution with 3% sulfuric acid doping amount under excitation of different wavelengths (400nm, 450nm, 500nm, 550nm, 600 nm).
Example 3
30mL of dilute acid pretreatment solution with the doping amount of 3% sulfuric acid is prepared respectively, 2g of weighed biomass powder is added, dilute acid pretreatment is carried out at different temperatures, then the mixture is placed into a reaction kettle for hydrothermal reaction at 200 ℃ for 3 hours, and the mixture is naturally cooled to room temperature. The subsequent operation was the same as in example 1.
The result shows that the obtained sample has good fluorescence, and the fluorescence intensity of the obtained carbon quantum dot is correspondingly changed along with the increase of the pretreatment temperature of the dilute acid. FIG. 4 is a fluorescence spectrum of carbon quantum dots obtained by pretreatment of dilute acid with 3% sulfuric acid doping amount at different temperatures, and the excitation wavelength is 450 nm.
Compared with the comparative case (shown in table 1), the fluorescence intensity of the Sargassum horneri carbon quantum dots is weaker, so that the recombination of photon-generated carriers is less, but the Sargassum horneri carbon quantum dots are more suitable for photocatalytic application, and the carriers can survive for a longer time, so that the carriers are concentrated on the surface of the material to generate an oxidation-reduction reaction to release energy, and the photocatalytic effect is improved.
Compared with the comparative case, the invention has the advantages that: (1) after the pretreatment of dilute acid, the yield and the fluorescence intensity of the biomass carbon quantum dots are obviously enhanced; (2) although the fluorescence intensity of the cuprammonium-based carbon quantum dots is reduced compared with that of terrestrial biomass such as maple leaves and the like used as raw materials, the characteristic makes the cuprammonium-based carbon quantum dots more suitable for the field of photocatalysis.
TABLE 1 fluorescence Spectroscopy-related parameters of carbon Quantum dots
The above description is of the preferred embodiment of the invention. It should be noted that the invention is not limited to the above-mentioned embodiments, and any person skilled in the art can make many possible variations and modifications to the technical solution of the invention using the method and the technical content disclosed above, or modify equivalent embodiments with equivalent variations, without affecting the essence of the invention, without departing from the scope of the technical solution of the invention. Therefore, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention are still within the scope of the protection of the technical solution of the present invention, unless the contents of the technical solution of the present invention are departed.
Claims (4)
1. A method for improving the yield of biomass carbon quantum dots through dilute acid pretreatment is characterized by comprising the following steps:
drying the biomass material, grinding the biomass material into powder, soaking the powder in dilute acid pretreatment solution at the temperature of 25-75 ℃ for 30-120min, then heating the powder in a closed reaction kettle to the temperature of 160-240 ℃ for reaction for 3-12h, naturally cooling the solution to room temperature, centrifuging the solution, collecting supernatant, filtering the supernatant, collecting filtrate, and drying the filtrate to obtain carbon quantum dot powder;
the dilute acid pretreatment solution is obtained by dissolving inorganic acid in deionized water, wherein the inorganic acid is selected from sulfuric acid or nitric acid, and the mass fraction of the dilute acid pretreatment solution is 1-10%.
2. The method for increasing biomass carbon quantum dot yield through dilute acid pretreatment of claim 1, wherein the biomass material is Sargassum horneri.
3. The method for improving biomass carbon quantum dot yield through dilute acid pretreatment according to claim 1, wherein the volume dosage of the dilute acid pretreatment solution is 10-30mL/g based on the mass of the biomass material powder.
4. The method for increasing the yield of biomass carbon quantum dots by dilute acid pretreatment of claim 1, wherein the filtration is performed by filtering the supernatant by using a microporous filter membrane with a pore size of 0.22 μm.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010599343.XA CN111792638A (en) | 2020-06-28 | 2020-06-28 | Method for improving yield of biomass carbon quantum dots through dilute acid pretreatment |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010599343.XA CN111792638A (en) | 2020-06-28 | 2020-06-28 | Method for improving yield of biomass carbon quantum dots through dilute acid pretreatment |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN111792638A true CN111792638A (en) | 2020-10-20 |
Family
ID=72803928
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010599343.XA Pending CN111792638A (en) | 2020-06-28 | 2020-06-28 | Method for improving yield of biomass carbon quantum dots through dilute acid pretreatment |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111792638A (en) |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104192828A (en) * | 2014-08-26 | 2014-12-10 | 上海交通大学 | Hydrothermal synthesis method of carbon quantum dots from cotton |
| CN109292753A (en) * | 2018-12-06 | 2019-02-01 | 洛阳师范学院 | A kind of carbon quantum dot and its environment-friendly preparation method thereof and application |
-
2020
- 2020-06-28 CN CN202010599343.XA patent/CN111792638A/en active Pending
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104192828A (en) * | 2014-08-26 | 2014-12-10 | 上海交通大学 | Hydrothermal synthesis method of carbon quantum dots from cotton |
| CN109292753A (en) * | 2018-12-06 | 2019-02-01 | 洛阳师范学院 | A kind of carbon quantum dot and its environment-friendly preparation method thereof and application |
Non-Patent Citations (1)
| Title |
|---|
| 章克昌等: "《酒精工业手册》", 31 December 1989, 《轻工业出版社》 * |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US20210331149A1 (en) | Biochar-modified bismuth vanadate catalyst and preparation method and use thereof | |
| Han et al. | A graphitic‐C3N4 “seaweed” architecture for enhanced hydrogen evolution | |
| CN109095453B (en) | Preparation method of tea-based fluorescent carbon dots and fluorescent carbon dots prepared by preparation method | |
| CN109879272B (en) | Method for preparing multicolor fluorescent carbon quantum dots by using tobacco wastewater | |
| KR101048410B1 (en) | Preparation of superfine purified silica, and fibers simultaneously | |
| CN106629659A (en) | Preparation method of fluorescent carbon quantum dots employing algae as carbon sources and application | |
| Son et al. | The development of biomass-derived carbon-based photocatalysts for the visible-light-driven photodegradation of pollutants: a comprehensive review | |
| CN107955601B (en) | Nitrogen-sulfur double-doped carbon quantum dot for iron ion detection and preparation method thereof | |
| CN105295910A (en) | Method for preparing red light carbon dots by taking biomass as precursor | |
| CN109943325B (en) | Method for preparing red light carbon quantum dots by using grape vinasse | |
| CN108855033B (en) | Method for preparing porous nanosheet three-dimensional zinc oxide photocatalytic material by taking shaddock endothelium as template | |
| CN104724695A (en) | Preparation method of bamboo biochar | |
| Zhao et al. | Carbonized polymer dots/TiO 2 photonic crystal heterostructures with enhanced light harvesting and charge separation for efficient and stable photocatalysis | |
| CN107325815B (en) | Nitrogen-doped high-quantum-yield fluorescent carbon dot and preparation method and application thereof | |
| CN101693188A (en) | Agricultural waste anion adsorbent and application thereof | |
| CN111701587A (en) | Core-shell structure catalysis-photocatalysis composite material and preparation method and application thereof | |
| CN111662524B (en) | Red fluorescent carbon dot light conversion film and preparation method and application thereof | |
| CN111792638A (en) | Method for improving yield of biomass carbon quantum dots through dilute acid pretreatment | |
| CN111621292A (en) | Preparation method of large marine plant-based carbon quantum dots | |
| KR101799795B1 (en) | MANUFACTURING METHOD OF TiO2 FLOWER SPHERE-REDUCED GRAPHENE OXIDE COMPOSITES | |
| CN102239263A (en) | Use of recycled cotton for producing ethanol, and production method | |
| CN111662713B (en) | Preparation method of double-carbon-source double-nitrogen-source multicolor fluorescent carbon dots | |
| CN107651685B (en) | Method for preparing porous biomass charcoal through chemical activation | |
| CN114772578B (en) | Method for converting vinasse into carbon quantum dots and capacitance carbon | |
| CN113683077B (en) | Oil-soluble carbon quantum dot, preparation method thereof and ultraviolet-resistant master batch prepared from oil-soluble carbon quantum dot |
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 | ||
| RJ01 | Rejection of invention patent application after publication | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20201020 |