Microscopic high-curvature biomass carbon supported metal monatomic catalyst as well as preparation method and application thereof

Abstract

The invention discloses a microcosmic high-curvature biomass carbon supported metal monatomic catalyst and a preparation method and application thereof, the catalyst is composed of a carrier and a monatomic metal active component, and the catalyst is obtained by supporting the monatomic metal active component on the carrier; the preparation method comprises the following steps: grinding chestnut shells into powder, adding the powder into an etching solution for treatment, and then adding nitrate for further carbon etching to obtain powder; carrying out carbonization induction treatment on the obtained powder, and washing to obtain the high-curvature biomass-based carbon material. The preparation method comprises the following steps: grinding and mixing a high-curvature biomass-based carbon material, a Fe precursor, NaCl and KCl, uniformly mixing, roasting, washing and drying to obtain a biomass carbon-loaded metal monatomic catalyst with a high-curvature microstructure; the microcosmic high-curvature biomass carbon-loaded metal monatomic catalyst is used for degradation reaction of organic pollutants, the preparation cost is low, and an oxidizing agent does not need to be added in the degradation process.

Description

Technical Field

[0001] The present invention belongs to the technical field of catalyst preparation methods, and specifically relates to a microscopic high-curvature biomass carbon-loaded metal single-atom catalyst, a preparation method of a microscopic high-curvature biomass carbon-loaded metal single-atom catalyst, and an application of a microscopic high-curvature biomass carbon-loaded metal single-atom catalyst. Background Art

[0002] In recent years, due to the rapid development of society, the improvement of industrialization and living standards, water pollution has become increasingly prominent. Common organic pollutants in industrial wastewater include dyes, antibiotics, phenols, etc. Due to their complex macromolecular aromatic structures, they are very stubborn and difficult to degrade. In order to better improve the natural environment, the latest research shows that the use of carbon materials loaded with transition metal single atoms can efficiently catalyze the oxidative degradation of stubborn macromolecular aromatic organic pollutants in industrial wastewater, thereby alleviating the environmental pressure caused by industrial wastewater. However, the raw materials for the preparation of traditional carbon materials currently rely on fossil resources, and their preparation process consumes a lot of energy. Carbon materials such as carbon nanotubes, amorphous carbon, carbon black, etc. often lack suitable functional groups on their surfaces, so it is difficult to anchor metal single atom active centers, resulting in metal aggregation and a significant reduction in degradation ability. In order to obtain efficient organic pollution degradation performance, researchers currently generally use two-dimensional carbon materials with larger specific surface areas, such as graphene, but their high price limits the industrial application of traditional single-atom catalysts. At the same time, the traditional catalytic system's dependence on oxidants has multiple disadvantages. Taking H2O2 as an example, its consumption rate is 5-8 kg / ton of wastewater, which not only requires continuous addition, but also directly leads to an increase in treatment costs of 50-70 yuan / ton; high-concentration H2O2 is highly corrosive and can easily cause equipment aging, and residual H2O2 will react with organic matter to form toxic intermediates (such as quinones). Summary of the Invention

[0003] The first purpose of the present invention is to provide a microscopic high-curvature biomass carbon-supported metal single-atom catalyst to solve the problems of high cost and strong dependence on oxidants of existing catalysts.

[0004] The second object of the present invention is to provide a method for preparing a microscopic high-curvature biomass carbon-supported metal single-atom catalyst.

[0005] The third object of the present invention is to provide an application of a microscopic high-curvature biomass carbon-supported metal single-atom catalyst.

[0006] The first technical solution adopted by the present invention is that the microscopic high-curvature biomass carbon-loaded metal single-atom catalyst is composed of a biomass carbon carrier with a high-curvature microstructure and a single-atom metal active component, and is obtained by loading the single-atom metal active component on a biomass carbon carrier with a high-curvature microstructure. The present invention is also characterized in that: The single-atom active component is the transition metal Fe.

[0007] The loading amount of single-atom metal active components is 0.01%~5%.

[0008] The second technical solution adopted by the present invention is a method for preparing a microscopic high-curvature biomass carbon-supported metal single-atom catalyst, which is specifically implemented according to the following steps: Step 1: Wash and dry the chestnut shells with water and grind them into powder, add the powder into an etching solution for treatment, then add nitrate for further carbon etching, wash with boiling water after carbon etching, and dry to obtain a powder; Step 2, subjecting the powder obtained in step 1 to carbonization induction treatment, and then washing it to obtain a high-curvature biomass-based carbon material; Step 3: Grind and mix the high-curvature biomass-based carbon material, Fe precursor, NaCl, and KCl obtained in step 2, mix them evenly, then roast, wash, and dry them to obtain a biomass carbon-loaded metal single-atom catalyst with a high-curvature microstructure.

[0009] The present invention is also characterized in that: In step 1, the etching solution consists of NaOH, Na2SO3 and water, and the concentration of NaOH in the etching solution is 2.5 mol / L, and the concentration of Na2SO3 is 0.4 mol / L.

[0010] The temperature of the etching solution is 65° C. to 75° C., and the processing time is 295 min to 305 min.

[0011] The specific process of step 2 is as follows: the powder obtained in step 1 is heated to 495°C~505°C under an N2 atmosphere for carbonization to obtain carbonized powder, the carbonized powder is mixed with an inducer, and then the temperature is raised to 745°C~755°C under an H2 and N2 mixed gas atmosphere for activation to obtain activated carbonized powder, and the activated carbonized powder is washed with HCl solution and deionized water in turn, and dried to obtain a high-curvature biomass-based carbon material.

[0012] The mass ratio of carbonized powder to inducer is 1:4~1; the inducer is one of KOH and KHCO3 or a combination of the two; the volume ratio of H2 and N2 in the mixed gas is 1:3.

[0013] In step 3, the calcination temperature is 495°C to 505°C and the time is 1 hour; The Fe precursor is any one of Fe(OH)(CH3COO)2, FeCl2, and Fe(NO3)2.

[0014] The third technical solution adopted by the present invention is the application of a microscopic high-curvature biomass carbon-supported metal single-atom catalyst in the degradation reaction of organic pollutants. The organic pollutants can be degraded by stirring an aqueous solution of the organic pollutants with the microscopic high-curvature biomass carbon-supported metal single-atom catalyst at room temperature. The organic pollutants are any one of dyes, antibiotics, and phenolic compounds. The beneficial effects of the present invention are: (1) A method for preparing microscopic high-curvature biomass carbon-supported metal single-atom catalysts, using agricultural waste chestnut shells as carbon-based carrier raw materials, converting them into biomass carbon materials with microscopic high-curvature structures, realizing the conversion of renewable waste biomass into high-value-added catalytic materials, and treating waste with waste; (2) Microscopic high-curvature biomass carbon-loaded metal single-atom catalysts use high-curvature biomass-based carbon materials synthesized from chestnut shells as carriers. They have rich functional groups and can increase the single-atom metal loading, which not only greatly improves the metal utilization rate and reduces the cost of the catalyst, but also the metal single-atom catalysts with high-curvature microstructures show excellent catalytic degradation performance. There is no need to add additional oxidants such as H2O2 and PMS, and they can directly activate oxygen in the air to continuously degrade organic pollutants, thereby realizing in-situ dynamic pollutant treatment. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 The efficiency diagram of tetracycline degradation by catalyst prepared in Example 1 and Comparative Examples 1 to 3 of the present invention; Figure 2 This is a graph showing the degradation efficiency of the catalyst obtained in Example 1 of the present invention for different pollutants; Figure 3 This is a graph showing the efficiency of tetracycline degradation by single-atom catalysts with different active component loadings in Example 6 of the present invention; Figure 4 This is a cyclic stability test chart of the catalyst of Example 7 of the present invention.

[0016] Figure 5 This is a diagram of the degradation efficiency of tetracycline at different pH values in Example 5 of the present invention. DETAILED DESCRIPTION

[0017] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0018] The microscopic high-curvature biomass carbon-loaded metal single-atom catalyst of the present invention is composed of a biomass carbon carrier with a high-curvature microstructure and a single-atom metal active component. It is obtained by loading the single-atom metal active component on the biomass carbon carrier with a high-curvature microstructure, and the loading amount of the metal single atom is 0.01%~5%.

[0019] Among them, the single-atom active component is the transition metal Fe.

[0020] The preparation method of the microscopic high-curvature biomass carbon-supported metal single-atom catalyst of the present invention is specifically implemented according to the following steps: Step 1: The chestnut shells are washed, dried, and then ground into powder. The powder is added to an etching solution at 65°C to 75°C for 295 minutes to 305 minutes, and then further carbon-etched with nitrate. After carbon etching, the shells are washed with boiling water and dried to remove impurities in the raw materials, thereby obtaining a powder having high nitrogen and oxygen content functional groups. The etching solution consists of NaOH, Na2SO3 and water, with the concentration of NaOH being 2.5 mol / L and the concentration of Na2SO3 being 0.4 mol / L. Step 2, subjecting the powder obtained in step 1 to carbonization induction treatment, and then washing it to obtain a high-curvature biomass-based carbon material; The specific process is: The powder obtained in step 1 was heated at 1.5 °C·min under N2 atmosphere. -1 ~2.5℃·min -1 The temperature was raised to 495°C~505°C at a rate of 1:1 and carbonized for 115min~125min to obtain carbonized powder. The carbonized powder was mixed with an inducer at a mass ratio of 1:4~1, and then heated at 1.5°C·min in a mixed gas atmosphere composed of H2 and N2 at a volume ratio of 1:3. -1 ~2.5℃·min -1 The temperature was raised to 745°C~755°C at a rate of 10000 ℃ and activated for 115min~125min to obtain activated carbonized powder, which was washed with 2 mol / L HCl solution and deionized water in sequence and dried at 105°C to obtain a high-curvature biomass-based carbon material; Wherein, the inducer is one of KOH and KHCO3 or a combination of the two; This process is an in-situ carbonization induction technology that uses a modifier to induce self-assembly during thermal depolymerization to controllably synthesize high-curvature biomass-based carbon materials. Step 3: Grind and mix the high curvature biomass-based carbon material obtained in step 2, Fe precursor, NaCl, and KCl in a mass ratio of 1: (0.02~1): 5: 5 for 20 minutes, mix well, and heat at 1.5 ° C min -1 ~2.5℃·min -1 The temperature was raised to 495°C~505°C at a rate of 1000 ℃ and calcined for 1 hour, washed with deionized water, and dried at 110°C to obtain a biomass carbon-supported metal single atom catalyst with a high-curvature microstructure. Wherein, the Fe precursor is any one of Fe(OH)(CH3COO)2, FeCl2, and Fe(NO3)2.

[0021] The present invention discloses an application of a microscopic high-curvature biomass carbon-supported metal single-atom catalyst in an organic pollutant degradation reaction; the organic pollutant is any one of a dye, an antibiotic, and a phenolic compound; and a method for degrading the organic pollutant using the biomass carbon-supported metal single-atom catalyst of the present invention comprises the following steps: 50 mL of an organic pollutant having a concentration of 15 mg / L is stirred with 3 mg of the microscopic high-curvature biomass carbon-supported metal single-atom catalyst to degrade the organic pollutant; the pH of the mixed solution of the two is 1-14, and the stirring rate is 300 rpm-800 rpm.

[0022] Example 1 Step 1: Wash and dry the chestnut shells with water and grind them into powder. The powder is added to a mixed aqueous solution at 70° C. and treated for 300 minutes. Nitrate is then added for carbon etching. After carbon etching, the shells are washed with boiling water and dried to obtain a powder. The etching solution consists of NaOH, Na2SO3 and water, with the concentration of NaOH being 2.5 mol / L and the concentration of Na2SO3 being 0.4 mol / L. Step 2, subjecting the powder obtained in step 1 to carbonization induction treatment, and then washing it to obtain a high-curvature biomass-based carbon material; The specific process is: The powder obtained in step 1 was heated at 2 °C·min under N2 atmosphere. -1 The temperature was raised to 500 °C at a rate of 1:3 for carbonization for 120 min to obtain carbonized powder, which was then mixed with KOH at a mass ratio of 1:3 and then heated at 2 °C min in a mixed gas atmosphere consisting of H2 and N2 at a volume ratio of 1:3. -1 The temperature was raised to 750°C at a rate of 1000 nm and activated for 120 min to obtain activated carbonized powder, which was then washed with 2 mol / L HCl solution and deionized water in sequence and dried at 105°C to obtain a high-curvature biomass-based carbon material. Step 3: Grind and mix 1g of the high curvature biomass-based carbon material obtained in step 2, 1g of Fe(OH)(CH3COO)2, 5g of NaCl, and 5g of KCl for 20min. After mixing evenly, heat the mixture at 2℃·min in a N2 atmosphere. -1 The temperature was raised to 500°C at a rate of 1000 ℃ and calcined for 1 hour, washed with deionized water, and dried at 110°C to obtain a biomass carbon-supported metal single atom catalyst with a high curvature microstructure.

[0023] The actual loading amount of iron single atoms tested by ICP was 5%, recorded as 5%-Fe1-NC.

[0024] Example 2 Step 1: Wash and dry the chestnut shells with water and grind them into powder. Add the powder into an etching solution at 65° C. and treat for 305 minutes. Then, add nitrate to perform carbon etching. After carbon etching, wash with boiling water and dry to obtain a powder. The etching solution consists of NaOH, Na2SO3 and water, with the concentration of NaOH being 2.5 mol / L and the concentration of Na2SO3 being 0.4 mol / L. Step 2, subjecting the powder obtained in step 1 to carbonization induction treatment, and then washing it to obtain a high-curvature biomass-based carbon material; The specific process is: The powder obtained in step 1 was heated at 1.5 °C·min under N2 atmosphere. -1 The temperature was raised to 495 °C at a rate of 1:1 and carbonized for 125 min to obtain carbonized powder. The carbonized powder was mixed with KHCO3 at a mass ratio of 1:4 and then heated at 1.5 °C·min in a mixed gas atmosphere consisting of H2 and N2 at a volume ratio of 1:3. -1 The temperature was raised to 745°C at a rate of 1000 ℃ for activation for 125 min to obtain activated carbonized powder, which was washed with 2 mol / L HCl solution and deionized water in sequence and dried at 105°C to obtain a high-curvature biomass-based carbon material; Step 3: Grind and mix 1g of the high curvature biomass-based carbon material obtained in step 2, 1g of FeCl2, 5g of NaCl, and 5g of KCl for 20min. After mixing evenly, heat the mixture at 1.5℃·min in a N2 atmosphere. -1 The temperature was raised to 495°C at a rate of 1000 ℃ and calcined for 1 hour, washed with deionized water, and dried at 110°C to obtain a biomass carbon-loaded metal single atom catalyst with a high curvature microstructure. The actual loading amount of iron single atoms was 5% by ICP testing.

[0025] Example 3 Step 1: Wash and dry the chestnut shells with water and grind them into powder. The powder is added to a mixed aqueous solution at 75° C. and treated for 295 minutes. Nitrate is then added for carbon etching. After carbon etching, the shells are washed with boiling water and dried to obtain a powder. The etching solution consists of NaOH, Na2SO3 and water, with the concentration of NaOH being 2.5 mol / L and the concentration of Na2SO3 being 0.4 mol / L. Step 2, subjecting the powder obtained in step 1 to carbonization induction treatment, and then washing it to obtain a high-curvature biomass-based carbon material; The specific process is: The powder obtained in step 1 was heated at 2.5 °C·min under N2 atmosphere. -1The temperature was raised to 505 °C at a rate of 1:1 and carbonized for 115 min to obtain carbonized powder. The carbonized powder was mixed with a mixture of KOH and KHCO3 at a mass ratio of 1:1, and then heated at 2.5 °C·min in a mixed gas atmosphere composed of H2 and N2 at a volume ratio of 1:3. -1 The temperature was raised to 755°C at a rate of 1000 ℃ for activation for 115 min to obtain activated carbonized powder, which was washed with 2 mol / L HCl solution and deionized water in sequence and dried at 105°C to obtain a high-curvature biomass-based carbon material; Step 3: Grind and mix 1g of the high curvature biomass-based carbon material obtained in step 2, 1g of Fe(NO3)2, 5g of NaCl, and 5g of KCl for 20min. After mixing evenly, heat the mixture at 2.5℃·min in a N2 atmosphere. -1 The temperature was raised to 505°C at a rate of 1000 ℃ and calcined for 1 hour, washed with deionized water, and dried at 110°C to obtain a biomass carbon-loaded metal single atom catalyst with a high curvature microstructure. The actual loading amount of iron single atoms was 5% by ICP testing.

[0026] Comparative Example 1 The difference from Example 1 is that the chestnut shells are replaced with sugarcane peels.

[0027] Comparative Example 2 The difference from Example 1 is that the chestnut shells are replaced by coconut shells.

[0028] Comparative Example 3 The difference from Example 1 is that the chestnut shells are replaced by walnut shells.

[0029] In the biomass carbon-supported metal single atom catalysts obtained in Comparative Examples 1 to 3, the actual loading amount of iron single atoms was 5%.

[0030] Example 4 The degradation rate of the biomass carbon-supported metal single atom catalyst obtained in Example 1, Comparative Example 1, Comparative Example 2, and Comparative Example 3 was tested. Specifically, 50 mL of 4 tetracycline solutions with a concentration of 15 mg / L were used for the degradation experiment. At this time, the absorbance of the 4 tetracycline solutions was recorded as A0, and the time was recorded as t0. 3 mg of the catalyst obtained in Example 1, 3 mg of the catalyst obtained in Comparative Example 1, 3 mg of the catalyst obtained in Comparative Example 2, and 3 mg of the catalyst obtained in Comparative Example 3 were added to the 4 tetracycline solutions, respectively. The 4 solutions were continuously stirred at room temperature, and samples were taken for analysis and detection every 5 min. The absorbance was recorded as A t , time is t, 80min later, if Figure 1 As shown, different catalysts were used to degrade tetracycline solution, among which the catalyst obtained in Example 1 had the best degradation performance, with a degradation rate of 99.21%.

[0031] The present invention uses waste chestnut shells as carbon carrier raw materials and achieves efficient oxidative degradation of tetracycline without adding oxidants. After 80 minutes, the tetracycline solution is oxidatively degraded to 99.21%. The degradation rates of catalysts made from carbon carriers of different raw materials are chestnut shells > walnut shells > sugarcane peels > coconut shells. Therefore, waste chestnut shells are currently the best carbon carrier raw material.

[0032] Example 5 Prepare 50 mL of 15 mg / L phenol solution and salicylic acid solution. The absorbance of each solution is recorded as A0 and the time is recorded as t0. Add 3 mg of 5%-Fe1-NC catalyst prepared in Example 1 to each solution. Stir continuously at room temperature. Sampling and analysis are performed every 5 minutes. The absorbance of each solution is recorded as A0. t , time is t, 80min later, if Figure 2 The catalyst degradation efficiency diagram obtained in Example 1 for different pollutants shows that the catalyst has universal applicability in the degradation of tetracycline solution, phenol solution, and salicylic acid solution.

[0033] Example 6 The difference from Example 1 is that the mass of the Fe precursor (Fe(OH)(CH3COO)2) is 2 mg.

[0034] Example 7 The difference from Example 1 is that the mass of the Fe precursor (Fe(OH)(CH3COO)2) is 200 mg.

[0035] Example 8 The difference from Example 1 is that the mass of the Fe precursor (Fe(OH)(CH3COO)2) is 300 mg.

[0036] Example 9 The difference from Example 1 is that the mass of the Fe precursor (Fe(OH)(CH3COO)2) is 400 mg.

[0037] Example 10 The difference from Example 1 is that the mass of the Fe precursor (Fe(OH)(CH3COO)2) is 550 mg.

[0038] Example 11 The difference from Example 1 is that the mass of the Fe precursor (Fe(OH)(CH3COO)2) is 650 mg.

[0039] Example 12 The difference from Example 1 is that the mass of the Fe precursor (Fe(OH)(CH3COO)2) is 800 mg.

[0040] In Example 1 and Examples 6 to 11, the theoretical iron loadings obtained were 0.03% (Example 6), 3% (Example 7), 5% (Example 8), 7% (Example 9), 9% (Example 10), 11% (Example 11), 13% (Example 12) and 17% (Example 1), respectively, and the actual loadings of the iron single atoms tested by ICP were 0.01% (Example 6), 0.9% (Example 7), 1.5% (Example 8), 2.1% (Example 9), 2.7% (Example 10), 3.3% (Example 11), 3.9% (Example 12) and 5% (Example 1).

[0041] The experiment was conducted using 8 groups of 50 mL tetracycline solutions with a concentration of 15 mg / L. The absorbance of the solution at this time was recorded as A0 and the time was recorded as t0. 3 mg of biomass-based single-atom catalyst with different loadings was added to each solution. The solution was stirred continuously at room temperature and samples were taken every 5 minutes for analysis and detection. The absorbance was recorded as A t , time is t. After 80min, if Figure 3 As shown in the figure, catalytic activity gradually increases with increasing Fe loading. The 5%-Fe1-NC catalyst exhibits the best catalytic degradation performance for tetracycline solution, with a degradation rate of 99.21%. This indicates that metallic Fe atoms are catalytically active centers, and increasing Fe single-atom loading improves catalytic performance.

[0042] Example 13 The experiment was conducted using 50 mL of a 15 mg / L tetracycline solution. The absorbance of the solution was recorded as A0 and the time was recorded as t0. 3 mg of the 5%-Fe1-NC catalyst prepared in Example 1 was added to the solution and stirred continuously at room temperature. Samples were taken every 5 minutes for analysis and detection. The absorbance was recorded as A0. t After the experiment, the catalyst was recovered and the experimental steps were repeated to determine the cyclic stability of the catalyst. The experimental results are shown in the figure. Figure 4 As shown, the degradation efficiency of the catalyst for tetracycline solution remained basically unchanged within five cycles, indicating that the catalyst achieved chemical degradation of organic pollutants rather than simple adsorption, and had good stability.

[0043] Example 14 The experiment was conducted using 7 groups of 50 mL tetracycline solutions with a concentration of 15 mg / L. The absorbance of the solution at this time was recorded as A0, and the time was recorded as t0. The pH values of the 7 groups of tetracycline solutions were 1, 3, 5, 7, 9, 11, and 14, respectively. 3 mg of the 5%-Fe1-NC catalyst prepared in Example 1 was added to each of the 7 solutions. The solution was stirred continuously at room temperature, and samples were taken every 5 minutes for analysis and detection. The absorbance was recorded as A t , time is t. The degradation efficiency at different pH was tested respectively, and the experimental results are as follows Figure 5 As shown in the figure, the degradation efficiency of tetracycline solution at different pH values is basically the same, indicating that the catalyst has good acid and alkali resistance and a wide range of applications.

[0044] The present invention utilizes chestnut shells to prepare high-curvature biomass carbon-loaded metal single-atom catalysts. This is achieved through a unique preparation method that changes the micromorphology of biomass-based carbon materials to form a high-curvature surface, which can directly activate oxygen in the air. Simultaneously, the large specific surface area and nitrogen- and oxygen-rich surface functional groups of biomass-based carbon materials are utilized to solve the problem of single atoms easily aggregating on the surface of carbon materials and having low loading. By applying it to the degradation of organic pollutants, a highly efficient and continuous degradation effect is achieved, and excellent stability is exhibited, which can realize waste utilization and reduce production and application costs. It effectively solves the pollution problem of organic pollutants in industrial wastewater and realizes a green and environmentally friendly catalytic process.

Claims

1. Microscopic high-curvature biomass carbon-supported metal single-atom catalyst, characterized in that: The biomass carbon carrier comprises a biomass carbon carrier with a high-curvature microstructure and a single-atom metal active component, and is obtained by loading the single-atom metal active component on the biomass carbon carrier with a high-curvature microstructure.

2. The microscopic high-curvature biomass carbon-supported metal single-atom catalyst according to claim 1, characterized in that: The single-atom metal active component is transition metal Fe.

3. The microscopic high-curvature biomass carbon-supported metal single-atom catalyst according to claim 1, characterized in that: The loading amount of the single-atom active component is 0.01% to 5%.

4. A method for preparing a microscopic high-curvature biomass carbon-supported metal single-atom catalyst, characterized in that: Please follow the steps below to implement it: Step 1: Wash and dry the chestnut shells with water and grind them into powder, add the powder into an etching solution for treatment, then add nitrate for further carbon etching, wash with boiling water after carbon etching, and dry to obtain a powder; Step 2, subjecting the powder obtained in step 1 to carbonization induction treatment, and then washing it to obtain a high-curvature biomass-based carbon material; Step 3: Grind and mix the high-curvature biomass-based carbon material, Fe precursor, NaCl, and KCl obtained in step 2, mix them evenly, then roast, wash, and dry them to obtain a biomass carbon-loaded metal single-atom catalyst with a high-curvature microstructure.

5. The method for preparing a microscopic high-curvature biomass carbon-supported metal single-atom catalyst according to claim 4, characterized in that: In step 1, the etching solution consists of NaOH, Na2SO3 and water, and the concentration of NaOH in the etching solution is 2.5 mol / L, and the concentration of Na2SO3 is 0.4 mol / L.

6. The method for preparing a microscopic high-curvature biomass carbon-supported metal single-atom catalyst according to claim 4, characterized in that: The temperature of the etching solution is 65° C. to 75° C., and the processing time is 295 min to 305 min.

7. The method for preparing a microscopic high-curvature biomass carbon-supported metal single-atom catalyst according to claim 4, characterized in that: The specific process of step 2 is as follows: the powder obtained in step 1 is heated to 495°C~505°C under an N2 atmosphere for carbonization to obtain carbonized powder, the carbonized powder is mixed with an inducer, and then the temperature is raised to 745°C~755°C under an H2 and N2 mixed gas atmosphere for activation to obtain activated carbonized powder, and the activated carbonized powder is washed with HCl solution and deionized water in turn, and dried to obtain a high-curvature biomass-based carbon material.

8. The method for preparing a microscopic high-curvature biomass carbon-supported metal single-atom catalyst according to claim 7, characterized in that: The mass ratio of carbonized powder to inducer is 1:4~1; the inducer is one of KOH and KHCO3 or a combination of the two; the volume ratio of H2 and N2 in the mixed gas is 1:

3.

9. The method for preparing a microscopic high-curvature biomass carbon-supported metal single-atom catalyst according to claim 4, characterized in that: In step 3, the calcination temperature is 495°C to 505°C and the time is 1 hour; The Fe precursor is any one of Fe(OH)(CH3COO)2, FeCl2, and Fe(NO3)2.

10. Use of the microscopic high-curvature biomass carbon-supported metal single-atom catalyst according to any one of claims 1 to 4 in the degradation reaction of organic pollutants, characterized in that: The organic pollutants can be degraded by stirring an aqueous solution of the organic pollutants with a microscopic high-curvature biomass carbon-loaded metal single-atom catalyst at room temperature; the organic pollutants are any one of dyes, antibiotics, and phenolic compounds.

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