Carbon dots based on cotton straws, preparation method of carbon dots and application of carbon dots in plant growth promotion and salt stress resistance
By preparing nanoscale carbon dots from waste cotton stalks, the problem of carbon dots failing to improve plant salt tolerance in agriculture in existing technologies has been solved. This has enabled carbon dots to promote plant growth and alleviate salt stress, thus promoting sustainable agricultural development.
Patent Information
- Application Number
- CN202510833951.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-20
- Publication Date
- 2025-10-17
AI Technical Summary
There is a lack of research in the existing technology on the preparation of carbon dots from agricultural waste for improving plant salt tolerance, and the existing application of carbon dots in agriculture mainly focuses on photocatalysis or drug delivery, and does not involve salt stress alleviation function.
Nanoscale carbon dots were prepared from waste cotton straw using hydrothermal and ultrasonic methods. Carbon dots with unique structures were formed through pyrolysis and ultrasonic treatment. They were used to promote plant growth and tolerate salt stress. The carbon dot solution was applied to plants at a concentration of 50-200 mg/L.
The prepared carbon dots significantly promote plant growth and development, improve plant stress resistance, effectively alleviate salt stress damage, and provide innovative solutions for saline-alkali land restoration and sustainable agricultural development.
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Figure CN120793900A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The application belongs to the technical field of nanomaterials, and particularly relates to a carbon dot based on cotton stalks, a preparation method thereof and application thereof in plant growth promotion and salt stress tolerance. BACKGROUND
[0002] Under the background of global climate change and land salinization, the cultivation of saline-alkali land has become an important factor restricting the sustainable development of agriculture. The improvement of plant salt tolerance has become an important research direction. As a new type of nanomaterial, carbon dots have attracted widespread attention in the field of agriculture in recent years. Carbon dots have good biocompatibility, low toxicity, strong antioxidant capacity and are easily absorbed by plants, and can promote the growth and development of plants and improve the stress resistance of plants.
[0003] Cotton stalks are common waste in agricultural production, and their biomass content is rich. By being converted into carbon dots, the problem of agricultural waste disposal can be effectively solved, and a new idea for improving plant salt tolerance can be provided. The use of agricultural waste to prepare carbon dots to address these environmental problems is the most economical and efficient, has no pollution, no public nuisance, long-term performance, and is suitable for a variety of environmental problems, and has broad development prospects. It is an important guarantee for realizing ecological agricultural production, ecological environment repair and protection.
[0004] Carbon dots are a new type of functional fluorescent carbon-based nanomaterial. Because of its fluorescence emission, it is also called fluorescent carbon dots. Due to its diverse physical and chemical properties, wide raw material sources, low toxicity, good biocompatibility, good water solubility, easy functionalization, and environmental friendliness, carbon dots have important application prospects in the fields of biomedicine, photocatalysis, and ion detection. However, there is a lack of research on the use of carbon dots prepared from agricultural waste straw to improve plant salt tolerance. Existing research shows that the application of carbon dots in agriculture is mainly focused on photocatalysis or drug delivery, and the use of agricultural waste to prepare carbon dots for plant stress resistance is still a blank. For example, patent CN112456876A discloses a method for preparing fluorescent carbon dots using rice husks as a carbon source, but it does not involve salt stress relief function. SUMMARY
[0005] This section aims to summarize some aspects of the embodiments of the application and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the abstract and title of the specification to avoid obscuring the purpose of this section, the abstract and the title, and such simplifications or omissions cannot be used to limit the scope of the application.
[0006] In view of the above and / or problems existing in the prior art, the present application is proposed.
[0007] Therefore, the present application aims at overcoming the deficiencies in the prior art and providing a preparation method of carbon dots based on cotton stalks.
[0008] To solve the above technical problems, the present application provides the following technical scheme: comprising,
[0009] The waste cotton stalks are dried, ground, and sieved to obtain cotton stalk powder;
[0010] The cotton stalk powder is uniformly mixed with deionized water and then subjected to pyrolysis reaction, and a carbonized liquid is obtained after cooling;
[0011] The carbonized liquid is mixed with ammonium acetate and then subjected to ultrasonic treatment to obtain a nanoscale mixed liquid by dispersion;
[0012] The nanoscale mixed liquid is centrifuged to obtain supernatant, which is filtered through a 0.22 mu m filter membrane to obtain a solution containing carbon dots.
[0013] As a preferred scheme of the preparation method of carbon dots based on cotton stalks, the drying temperature of the waste cotton stalks is 50-70 DEG C.
[0014] As a preferred scheme of the preparation method of carbon dots based on cotton stalks, the mass-volume ratio of the cotton stalk powder to deionized water is 1 mg: 30-45 mL.
[0015] As a preferred scheme of the preparation method of carbon dots based on cotton stalks, the pyrolysis reaction temperature is 190-210 DEG C, and the reaction time is 11-13 h.
[0016] As a preferred scheme of the preparation method of carbon dots based on cotton stalks, the volume ratio of the carbonized liquid to acetic acid is 180-220: 1.
[0017] As a preferred scheme of the preparation method of carbon dots based on cotton stalks, the ultrasonic treatment time is 1-2 h.
[0018] Another object of the present application is to provide carbon dots based on cotton stalks.
[0019] Another object of the present application is to provide the application of carbon dots based on cotton stalks in plant growth promotion.
[0020] Another object of the present application is to provide the application of carbon dots based on cotton stalks in plant salt stress tolerance.
[0021] As a preferred scheme of the application of the cotton stalk-based carbon dots, the cotton stalk-based carbon dots are applied in the form of a carbon dot solution, the application concentration is 50-200 mg / L, and the plants include cotton and oat grass.
[0022] The application has the following beneficial effects:
[0023] The application uses the widely-sourced waste cotton stalk as a carbon source to prepare carbon dot materials, and converts the waste cotton stalk into nanoscale carbon dot materials through a hydrothermal method and an ultrasonic method, which is simple and efficient and conforms to the concept of circular economy.
[0024] The obtained carbon dot solution has excellent biocompatibility and low toxicity, can significantly promote the growth and development of cotton, oat grass and other plants at a concentration of 200 mg / L, and can effectively alleviate the damage of salt stress to plants. The carbon dots have the functions of promoting plant growth and development and salt stress tolerance, and provide an innovative solution for the repair of saline-alkali land and the sustainable development of agriculture. BRIEF DESCRIPTION OF DRAWINGS
[0025] In order to more clearly illustrate the technical solutions of the embodiments of the application, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the application, and other drawings can be obtained by those skilled in the art without creative labor. Among them:
[0026] Figure 1 Promotion of cotton stalk carbon dots prepared in Example 1 on oat grass growth.
[0027] Figure 2 The emergence rate of different cotton varieties treated by the cotton stalk carbon dots prepared in Example 1.
[0028] Figure 3 The effect of seed treatment by the cotton stalk carbon dots prepared in Example 1 on improving the salt stress tolerance of cotton. DETAILED DESCRIPTION
[0029] In order to make the above-mentioned purposes, features and advantages of the application more apparent and easy to understand, the specific embodiments of the application will be described in detail in conjunction with the description of the application.
[0030] In the following description, many specific details are set forth in order to provide a thorough understanding of the application, but the application can also be implemented in other ways different from those described herein, and those skilled in the art can make similar generalizations without departing from the concept of the application, therefore the application is not limited to the specific embodiments disclosed below.
[0031] Secondly, the "one embodiment" or "embodiment" referred to herein means a specific feature, structure, or characteristic that can be included in at least one implementation of the present application. The "in one embodiment" appearing in different places in the specification does not mean the same embodiment, nor is it an embodiment that is independent or alternative to other embodiments.
[0032] The raw materials used in the present application are commercially available in the art without special instructions.
[0033] Example 1
[0034] The present embodiment provides a method for preparing carbon dots using cotton stalk as a carbon source, specifically:
[0035] 1) The discarded cotton stalks were collected and placed in a 60°C oven for drying, crushed into fine powder by a pulverizer and sieved through a 40-mesh sieve to obtain cotton stalk powder;
[0036] 2) The cotton stalk powder was mixed with deionized water at a mass-volume ratio of 1 mg:30 ml by a magnetic stirrer for 30 min, and then loaded into a sealed high-pressure reaction kettle for reaction at 200°C for 12 h, and then naturally cooled to room temperature to obtain a carbonized liquid;
[0037] 3) The carbonized liquid was mixed with acetic acid at a ratio of 200:1, and ultrasonically treated for 2 hours to disperse it into a nanoscale mixed solution;
[0038] 4) The nanoscale mixed solution was centrifuged at 8000 r / min for 20 min, and the supernatant was filtered through a 0.22 μm filter membrane to obtain a solution containing carbon dots.
[0039] Example 2
[0040] The present embodiment is used to verify the promoting effect of the cotton stalk carbon dots prepared in Example 1 on plant growth, specifically:
[0041] Different concentrations (0-800 mg / L) of carbon dot solution were added to the petri dish containing filter paper and oat grass seeds, and the germination rate, root length, and shoot length of the oat grass were counted, and the corresponding concentrations and results are shown in Table 1. Figure 1
[0042] As can be seen, the 200 mg / L concentration of CDs (carbon dots) solution significantly improved the germination rate, root length, and shoot length of the oat grass (p<0.05, Figure 1 ), the germination rate increased from 40% to 60%, an increase of 50%, but when the concentration was further increased, the high concentration of carbon dots would inhibit the growth, which shows that only within a certain concentration range, the carbon dots of the present embodiment 1 can improve the germination rate and promote the growth.
[0043] Example 3
[0044] This embodiment is used to verify the effect of cotton straw carbon dots prepared in Example 1 on improving the salt stress tolerance of plants, specifically:
[0045] 1) Cotton straw carbon dots improve the emergence rate of different cotton varieties under severe salt stress conditions:
[0046] Seeds of two cotton varieties (JX1441, JX1565) soaked in water and CDs (200 mg / L) were sown on soil pretreated with 15‰ salt solution for 9 days, and the emergence rate was counted after 7 days, as shown in Figure 2 , wherein the CK group is a blank control, indicating that the seeds treated with CDs are sown on soil that is not pretreated with 15‰ salt solution; the CD group indicates that the seeds treated with CDs are sown on soil that is not pretreated with 15‰ salt solution; the CD+Salt group indicates that the seeds treated with CDs are sown on soil pretreated with 15‰ salt solution; and the Salt group indicates that the seeds not treated with CDs are sown on soil pretreated with 15‰ salt solution.
[0047] As can be seen, the emergence rates of JX1441 and JX1565 varieties treated with carbon dot solution under 15‰ salt stress are significantly higher than those under single salt stress conditions. This indicates that carbon dot solution can be used as a seed treatment agent to enable seeds to be used for plant planting in saline-alkali land.
[0048] 2) Cotton straw carbon dots improve the salt stress tolerance of cotton under severe salt stress conditions:
[0049] A 200 mg / L CDs (carbon dots) solution was used as a seed treatment agent for cotton JX1565, and the control was an equal volume of deionized water, which was sown on soil pretreated with 15‰ salt solution. After 30 days of sowing, samples were taken to detect physiological indicators such as photosynthesis, biomass, and plant height, as shown in Figure 3 , wherein the CK group is a blank control, indicating that the seeds treated with CDs are sown on soil that is not pretreated with 15‰ salt solution; the CD group indicates that the seeds treated with CDs are sown on soil that is not pretreated with 15‰ salt solution; the CD+Salt group indicates that the seeds treated with CDs are sown on soil pretreated with 15‰ salt solution; and the Salt group indicates that the seeds not treated with CDs are sown on soil pretreated with 15‰ salt solution.
[0050] As can be seen from Figure 3 , 15‰ salt stress can cause significant damage to plants, and the reduction in biomass of cotton plants treated with carbon dots is slowed down, and the net photosynthetic rate is significantly higher than that of the single salt treatment group (Salt), which further indicates that cotton straw carbon dot solution can be used as a seed pretreatment agent to respond to salt stress environment in advance.
[0051] In addition, compared with carbon dots of different sources, the carbon dots prepared by the cotton stalk source in the application show a significant advantage over other sources of carbon source for the application effect of the homologous target crop (cotton), and compared with the carbon dots of other sources, the carbon dots of the application have a promoting effect on a variety of crops, and have a wider application range.
[0052] In the preparation process of the carbon dots of the application, pyrolysis and ultrasonic treatment are combined. In the pyrolysis process, a series of complex thermal decomposition and polymerization reactions of macromolecular organic matters such as cellulose, hemicellulose and lignin in the cotton stalk occur, forming carbon dots with unique structures. The pyrolysis temperature and time and other conditions can control the size, crystallinity and surface functional groups of the carbon dots. Suitable pyrolysis conditions can form a large number of oxygen-containing functional groups (such as hydroxyl and carboxyl) on the surface of the carbon dots, which play an important role in the growth process of plants. The high-temperature and high-pressure environment generated by the cavitation effect of ultrasonic treatment can further refine the size of the carbon dots, making them more uniform. Uniform size is conducive to the absorption and transportation of carbon dots in plants. In addition, ultrasonic treatment can also modify the surface of the carbon dots, increase the active sites on the surface of the carbon dots, and improve the interaction ability between the carbon dots and plant cells.
[0053] In summary, the application discloses a carbon dot with cotton stalk as a carbon source, a preparation method thereof and an application thereof in preparing a plant nano-fertilizer. The carbon dot material is prepared by using the widely available waste cotton stalk as a carbon source, and the waste cotton stalk is converted into a nano-sized carbon dot material by a hydrothermal method and an ultrasonic method. The process is simple and efficient, and conforms to the concept of circular economy. The obtained carbon dot solution has excellent biocompatibility and low toxicity, and can significantly promote the growth and development of cotton, oat grass and other plants at a concentration of 200 mg / L, and can effectively alleviate the damage of salt stress to plants. The carbon dot has the functions of promoting plant growth and development and salt stress tolerance, and provides an innovative solution for the remediation of saline-alkali land and the sustainable development of agriculture.
[0054] It should be noted that the above examples are only used to illustrate the technical solutions of the application and are not limiting. Although the application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the application can be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the application, which should be covered by the scope of the claims of the application.
Claims
1. A method for preparing cotton straw-based carbon dots, characterized by: include, The discarded cotton straw is dried, ground and sieved to obtain cotton straw powder; Cotton straw powder is mixed evenly with deionized water and then subjected to pyrolysis reaction, and carbonized liquid is obtained after cooling; The carbonized liquid is mixed with ammonium acetate and then ultrasonically treated to disperse the mixture to obtain a nanoscale mixed liquid; The nanoscale mixed solution was centrifuged, the supernatant was taken, and filtered through a 0.22 μm filter membrane to obtain a solution containing carbon dots.
2. The method for preparing cotton straw-based carbon dots according to claim 1, wherein: The drying temperature of the discarded cotton straw is 50-70°C.
3. The method for preparing cotton straw-based carbon dots according to claim 1, wherein: The mass volume ratio of the cotton straw powder to deionized water is 1 mg:30-45 mL.
4. The method for preparing cotton straw-based carbon dots according to claim 1, wherein: The temperature of the pyrolysis reaction is 190-210° C., and the reaction time is 11-13 hours.
5. The method for preparing cotton straw-based carbon dots according to claim 1, wherein: The volume ratio of the carbonized liquid to acetic acid is 180-220:
1.
6. The method for preparing cotton straw-based carbon dots according to claim 1, wherein: The ultrasonic treatment time is 1 to 2 hours. 7 . Cotton straw-based carbon dots prepared by the preparation method according to claim 1 .
8. Use of the cotton straw-based carbon dots as claimed in claim 7 in plant growth promotion.
9. Use of the cotton straw-based carbon dots as claimed in claim 7 in plant salt stress tolerance.
10. The use of cotton straw-based carbon dots according to any one of claims 8 or 9, characterized in that: The cotton straw-based carbon dots are applied in the form of a carbon dot solution at a concentration of 50 to 200 mg / L. The plants include cotton and oat straw.