CN-121975517-A - Metal-loaded phosphorus-doped carbon quantum dot and preparation method and application thereof

Abstract

The invention belongs to the technical field of agricultural nano materials, and particularly relates to a metal-loaded phosphorus-doped carbon quantum dot, and a preparation method and application thereof. The preparation method comprises the steps of mixing citric acid, phytic acid aqueous solution, amine substances, water and soluble metal salt, performing chelating adsorption to obtain polymer quantum dot mixed solution containing metal ions, and performing hydrothermal reaction on the polymer quantum dot mixed solution to obtain the phosphorus-doped carbon quantum dot loaded with metal. The metal-loaded phosphorus-doped carbon quantum dots prepared by the preparation method provided by the invention have the advantages of high metal load, high coordination stability, excellent stability in soil with different pH values and environmental friendliness.

Inventors

• LV GUOHUA
• HUO QIUYAN
• ZHANG MAOLIN
• MEI XURONG
• HE JUAN
• HAN WEI

Assignees

• 中国农业科学院农业环境与可持续发展研究所

Dates

Publication Date

20260505

Application Date

20260128

Claims (10)

1. 1. The preparation method of the metal-loaded phosphorus-doped carbon quantum dot is characterized by comprising the following steps of: Mixing citric acid, phytic acid aqueous solution, amine substances, water and soluble metal salt, and performing chelating adsorption to obtain polymer quantum dot mixed solution containing metal ions; and carrying out hydrothermal reaction on the polymer quantum dot mixed solution to obtain the metal-loaded phosphorus-doped carbon quantum dot.
2. 2. The method of claim 1, wherein the amine species comprise one or more of ethylenediamine, o-phenylenediamine, alcohol amine, and polyethyleneimine.
3. 3. The preparation method of the water-based paint according to claim 1 or 2, wherein the concentration of the phytic acid aqueous solution is 50-90 wt%, and the dosage ratio of the citric acid, the phytic acid aqueous solution and the amine substances is (1-1.5) g (0.55-1.10) mL (1-2) mL.
4. 4. The preparation method according to claim 1, wherein the soluble metal salt is used in the form of a solution of the soluble metal salt, and the concentration of the solution of the soluble metal salt is 0.5-2 mmol/mL.
5. 5. The method of claim 1, wherein the metal ions in the soluble metal salt are one or more of Fe 3+ 、Zn 2+ 、Mn 2+ 、Cu 2+ 、Mg 2+ and Ca 2+ .
6. 6. The method according to claim 1, wherein the mixing is carried out by dissolving citric acid, an aqueous solution of phytic acid, and an amine substance in water, and adding a salt solution containing metal ions dropwise to the obtained solution.
7. 7. The method according to claim 1, wherein the dissolution time is 10 to 30min, and the chelate adsorption time is 10 to 30min.
8. 8. The method according to claim 1, wherein the hydrothermal reaction is carried out at a temperature of 160 to 200 ℃ for a reaction time of 4 to 8 hours.
9. 9. The metal-loaded phosphorus-doped carbon quantum dot prepared by the preparation method of any one of claims 1 to 8, wherein the metal loading amount in the metal-loaded phosphorus-doped carbon quantum dot is 10 to 35wt%.
10. 10. The application of the metal-loaded phosphorus-doped carbon quantum dots prepared by the preparation method of any one of claims 1-8 or the metal-loaded phosphorus-doped carbon quantum dots of claim 9 in seed germination promoters or crop foliar fertilizers.

Description

Metal-loaded phosphorus-doped carbon quantum dot and preparation method and application thereof Technical Field The invention belongs to the technical field of agricultural nano materials, and particularly relates to a metal-loaded phosphorus-doped carbon quantum dot, and a preparation method and application thereof. Background In agricultural production, medium trace elements (such as iron, zinc, copper, manganese and the like) are essential nutritional ingredients for crop growth and development, and participate in key physiological processes of photosynthesis, enzyme activity regulation, nutrient metabolism and the like to directly influence the yield formation and quality improvement of crops. The demand of the crops for the medium trace elements is lower than that of the major elements such as nitrogen, phosphorus, potassium and the like, but the shortage of the trace elements is easy to cause 'element deficiency' (such as crop yellowing disease caused by iron deficiency and small disease caused by zinc deficiency) so as to cause serious yield loss, and the trace element supply technology in the prior art is difficult to balance 'effectiveness' and 'environmental friendliness', so that the technical bottleneck needs to be broken through. Most of traditional fertilizers are inorganic acid salts (such as zinc sulfate, ferrous chloride, boric acid and magnesium sulfate) or simple chelates (such as EDTA-Zn), the fertilizer application mode is mainly broadcast application and ditch application, and part of the fertilizer is matched with foliar application or water-soluble fertilizer flushing application. The method has obvious disadvantages that inorganic acid salts are easy to combine with other ions in soil with different pH values to form precipitates (for example, zn 2+ in alkaline soil generates zinc hydroxide, ca 2+ in acid soil forms calcium phosphate with phosphate radical or Ca 2+ in alkaline soil forms calcium carbonate with carbonate radical), so that the crop absorptivity is low, soil salinity accumulation and aggregate structure damage can be caused by long-term broadcasting, soil hardening is caused, unabsorbed elements are lost through surface runoff or leaching, and further, the environmental problems such as water eutrophication, soil heavy metal potential accumulation and the like are caused. The carbon quantum dots (CDs) are used as novel carbon-based nano materials, and show irreplaceable advantages in the agricultural field by virtue of unique physical and chemical properties of the novel carbon-based nano materials (1) hydrophilic functional groups such as hydroxyl groups (-OH), amino groups (-NH 2) and carboxyl groups (-COOH) are densely distributed on the surfaces of the novel carbon quantum dots, the water solubility can reach more than 100mg/mL, the colloid stability can be kept in a broad-spectrum soil environment with the pH value of 2-11, the problem that the traditional nano materials are easy to agglomerate is avoided, the particle size of the novel carbon quantum dots (2) is distributed in the range of 2-10 nm, the novel carbon quantum dots can directly enter the inside of cells through the aperture (about 5-20 nm) of crop cell membranes and root ion channels, the passive absorption path of the traditional fertilizer which is needed to rely on soil ion exchange is avoided, the absorption efficiency is improved by 3-5 times, the biocompatibility of the carbon quantum dots is good, the environment residual period is short, and the safety standard of the traditional chemical fertilizer is far exceeded. Based on the advantages, the scientific research community has developed the relevant research of 'micro elements in carbon quantum dot load', such as patent CN113201330A mentions the carbon quantum dot loaded with Mg, the content of Mg is 5.58 wt%, after the fertilizer is applied to rice, the chlorophyll content and photosynthetic rate of the rice are obviously improved, eggshell powder is used as raw materials in patent CN 118479938A, biomass carbon dots rich in calcium are prepared through acidolysis and hydrothermal steps, the content of calcium is more than or equal to 10 wt%, so that the fertilizer is practically applied to agriculture, blue algae is used as a carbon source in patent CN115259957A, and blue algae-based carbon quantum dot nano selenium fertilizer is obtained through hydrothermal reaction at 200-300 ℃ after being mixed with selenium-containing solution, and is used as a foliar fertilizer of tomatoes. Although metal-loaded carbon quantum dots have many advantages, the prior art still has a core bottleneck. Generally, the existing technical path for synthesizing metal element-containing carbon quantum dots (M-CDs) is mainly prepared by taking simple organic matters such as citric acid, amine matters (such as ethylenediamine, o-phenylenediamine, alcohol amine, polyethyleneimine, urea and the like) and the like as precursors through a hydrothermal method, a microwa