Application of cobalt single-atom doped strontium titanate composite catalytic material in catalytic degradation of organic pollutants by activated peroxyacetic acid

Abstract

The application discloses a preparation method and application of a cobalt monatomic doped strontium titanate composite material, and belongs to the field of water treatment. The cobalt doped strontium titanate composite catalytic material is composed of a cobalt metal doped strontium titanate material. A preparation process uses tetrabutyl titanate and a nitrate as reactants, ethylene glycol and water as solvents, and prepares strontium titanate (SrTiO3: STO) through a hydrothermal method. Then, cobalt monatomic atoms are doped into the strontium titanate through cobalt chloride (a cobalt source) by using an electrostatic adsorption method, so as to form cobalt doped strontium titanate (Co-STO). The material can efficiently activate an oxidant peracetic acid and rapidly degrade various antibiotic pollutants, and especially performs well in degrading quinolone, tetracycline and macrolide antibiotics. The catalytic material has the advantages of low cost, renewability and environmental protection, and is very suitable for being applied to a deep treatment process of pharmaceutical wastewater.

Description

Technical Field

[0001] This invention relates to the field of water treatment technology, and in particular to the application of a cobalt single-atom-doped strontium titanate composite catalytic material in the catalytic degradation of organic pollutants by activated peracetic acid. Background Technology

[0002] In recent years, Fenton-like catalytic reactions have attracted widespread attention due to their excellent performance in degrading organic pollutants. The Fenton reaction relies on iron ions to catalyze the decomposition of hydrogen peroxide (H₂O₂) to generate hydroxyl radicals (·OH). These radicals possess extremely strong oxidizing power and can rapidly and effectively degrade organic pollutants in water. However, traditional Fenton reactions have some prominent drawbacks in practical applications, such as rapid catalyst deactivation, harsh reaction conditions, and potential secondary pollution caused by iron sources. These issues limit their wider application and use in broader scenarios.

[0003] To overcome these challenges, researchers have gradually turned their attention to Fenton-like reaction systems, exploring different metal ions or metal-based catalysts to activate peroxides, such as hydrogen peroxide (H₂O₂), persulfate (PMS), and peracetic acid (PAA). Among these, peracetic acid, due to its high oxidizing power and excellent stability, exhibits good adaptability in treating a variety of organic pollutants. By designing and synthesizing novel catalytic materials, it is possible to achieve efficient activation of peracetic acid, thereby generating active species for the rapid degradation of various antibiotics and other organic pollutants in water.

[0004] Among numerous catalytic materials, strontium titanate oxide (ABO3) has attracted significant attention in materials science and heterogeneous catalysis in recent years due to its flexible chemical composition, elemental abundance, rich electronic structure, and high thermal stability. In particular, the B-site cation in this type of material is typically a transition metal with incompletely filled 3d orbitals; therefore, the B site can not only participate in catalytic reactions but also serve as the active site for redox reactions. Thus, strontium titanate materials possess immense potential as catalytic substrate materials. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention provides an application of a cobalt single-atom-doped strontium titanate composite catalytic material in the catalytic degradation of organic pollutants using activated peracetic acid. The cobalt-doped strontium titanate composite material proposed in this invention, based on the above concepts, provides a novel and effective solution for removing organic pollutants by efficiently activating peracetic acid. This research achievement provides new ideas and perspectives for the further development and optimization of water treatment technologies, and helps to address current environmental protection challenges.

[0006] The purpose of this invention is to provide an application of a cobalt single-atom-doped strontium titanate composite catalytic material in the catalytic degradation of organic pollutants by activated peracetic acid; the cobalt single-atom-doped strontium titanate composite catalytic material includes strontium titanate crystals and cobalt single atoms embedded in the strontium titanate crystal structure.

[0007] In some embodiments of the present invention, the average diameter of the cobalt single-atom doped strontium titanate composite catalyst is 30 ~ 200 nm;

[0008] The loading of cobalt single atoms in the cobalt single-atom doped strontium titanate composite catalyst is 0.5 wt% - 6.0 wt%. For example, it can be 0.5 wt%, 1.0 wt%, 1.5 wt%, 2.0 wt%, 2.5 wt%, 3.0 wt%, 3.5 wt%, 4.0 wt%, 4.5 wt%, 5.0 wt%, 5.5 wt%, 6.0 wt%, etc., or any range between any two values.

[0009] In some embodiments of the present invention, the organic pollutants include antibiotic pollutants.

[0010] In some embodiments of the present invention, the antibiotic contaminants include one or more of macrolides, cephalosporins, sulfonamides, tetracyclines, and quinolones.

[0011] Furthermore, the macrolides include azithromycin (AZI), roxithromycin, erythromycin, clarithromycin, etc.

[0012] The cephalosporins include cefadroxil, cefradine, and ceftazidime;

[0013] The sulfonamides include sulfaacetamide (SCT), sulfisoxazole (SIZ), sulfamethoxazole, etc.

[0014] The tetracyclines include tetracycline (TC), oxytetracycline (OTC), chlortetracycline, doxycycline, etc.

[0015] The quinolones include norfloxacin (NOF), gatifloxacin (GAT), moxifloxacin (MOX), ciprofloxacin (CIP), etc.

[0016] In some embodiments of the present invention, the pH of the solution of catalytically degraded organic pollutants is 1 to 11. Exemplarily, it can be 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, or any range between any two values; furthermore, the pH can also be 3 to 9, 3 to 7, 3 to 5, 5 to 9, etc.

[0017] In some embodiments of the present invention, the cobalt single-atom-doped strontium titanate composite catalytic material is prepared by the following method:

[0018] (1) Add titanium source, nitrate and sodium hydroxide to a mixed solvent to obtain a mixed solution, heat to carry out hydrothermal reaction, and after the reaction is completed, separate the solid and liquid to obtain the solid product, namely strontium titanate composite material;

[0019] (2) Disperse the strontium titanate composite material obtained in step (1) in a water-ethylene glycol mixture, add a cobalt source solution, and obtain the cobalt single-atom doped strontium titanate composite catalyst material.

[0020] In some embodiments of the present invention, in step (1), the titanium source is selected from tetrabutyl titanate.

[0021] In some embodiments of the present invention, in step (1), the nitrate includes one or more of barium nitrate, strontium nitrate, and lead nitrate;

[0022] The mixed solvent includes ethylene glycol and water; the volume ratio of ethylene glycol to water is (1:1) to (2:1).

[0023] The concentration of sodium hydroxide is 1~10 mmol / L.

[0024] In some embodiments of the present invention, in step (1), the hydrothermal reaction conditions are: temperature of 180 ~ 210℃ and time of 12 ~ 24 h; for example, the temperature is 180℃, 190℃, 200℃, 210℃, etc., or any range between any two values; for example, the time can be 12h, 15h, 18h, 20h, 21h, 22h, 23h, 24h, etc., or any range between any two values.

[0025] In some embodiments of the present invention, in step (2), the cobalt source in the cobalt source solution is selected from one or more of cobalt chloride, cobalt nitrate, and cobalt acetylacetonate;

[0026] The volume ratio of water to ethylene glycol in the water-ethylene glycol mixture is 9:1.

[0027] The technical solution of the present invention has the following advantages compared with the prior art:

[0028] This invention enables the production of nanosheet catalytic substrates with specific morphologies by controlling reaction conditions, thereby enhancing catalytic performance. Cobalt metal ions, as a transition metal catalyst, demonstrate excellent catalytic performance and cost-effectiveness, showing great potential for application in water treatment.

[0029] The synthesis methods of the composite materials in this invention are all completed via hydrothermal methods, which have the advantages of low cost, no pollution, and simple operation, making them suitable for large-scale production. Compared with traditional catalysts, the cobalt single-atom strontium titanate catalyst material uses strontium titanate as a supporting material and loads cobalt single atoms on its surface. The resulting material has higher Fenton-like catalytic activity and avoids the disadvantage of single-atom agglomeration. The prepared composite catalyst has more active sites and stronger mechanical strength, and can be widely used in industries such as wastewater treatment. Attached Figure Description

[0030] To make the content of this invention easier to understand, the invention will be further described in detail below with reference to specific embodiments and accompanying drawings, wherein...

[0031] Figure 1 The image shows a SEM image of the cobalt single-atom-doped strontium titanate composite catalyst prepared in Example 1.

[0032] Figure 2 This is a TEM image of the cobalt single-atom doped strontium titanate composite catalyst prepared in Example 1.

[0033] Figure 3 The graph shows the activity data of the strontium titanate catalyst in Experiment Example 1 for the degradation of ciprofloxacin (CIP).

[0034] Figure 4 The kinetic constant for the activation reaction of PAA with ciprofloxacin by the cobalt single-atom doped strontium titanate composite catalyst in Experiment Example 1 is given.

[0035] Figure 5 The image shows the degradation data of ciprofloxacin by the cobalt single-atom doped strontium titanate composite catalyst under different catalytic conditions in Experiment Example 3.

[0036] Figure 6 This is a graph showing the degradation data of the cobalt single-atom doped strontium titanate composite catalyst activated at different pH values ​​in Experiment Example 3.

[0037] Figure 7 This is an activity diagram of the cobalt single-atom doped strontium titanate composite catalyst in Experiment Example 4, which activates PAA to degrade ciprofloxacin under different ion coexistence conditions.

[0038] Figure 8 The image shows the catalytic removal effect of PAA activated by the cobalt single-atom doped strontium titanate composite catalyst in Experiment Example 5 on different organic pollutants. Detailed Implementation

[0039] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments described are not intended to limit the present invention.

[0040] Example 1

[0041] This embodiment provides a method for preparing and applying a cobalt single-atom-doped strontium titanate composite catalytic material.

[0042] I. Material Preparation:

[0043] (1) Taking strontium titanate nanosheets as an example: 10 mM tetrabutyl titanate (CH3CH2CH2CH2O)4Ti) was added to 40 ml of ethylene glycol and stirred at room temperature for 60 min to obtain a tetrabutyl titanate solution.

[0044] (2) Add 20 mL of 0.5 M strontium nitrate (Sr(NO3)2) solution to the tetrabutyl titanate solution in step (1) under stirring to obtain mixed solution 1.

[0045] (3) Add 10 mL of 5 M NaOH solution to the mixed solution in step (2), stir until clear, stir for 40 min to obtain mixed solution 2.

[0046] (4) The resulting mixed solution 2 was transferred to a 100 mL polytetrafluoroethylene-lined stainless steel autoclave and hydrothermally heated at 200 °C for 24 h. The resulting product was washed with deionized water (DI) multiple times until neutral, and then washed with ethanol multiple times. After vacuum drying, the strontium titanate substrate material (STO-OV) was obtained.

[0047] (5) Place the 0.2 g strontium titanate substrate material obtained in step (4) into an ethylene glycol-water mixture (volume ratio 9:1), sonicate for 40 min, then add 4.0 wt% (relative to 0.2 g strontium titanate) of cobalt chloride solution containing Co ions, and stir at 60 ℃ for 10 h. Separate the reaction solution into solid and liquid phases, wash and dry the obtained solid product to obtain a green sample, which is the synthesized cobalt single-atom doped strontium titanate (4.0 wt% Co-STO) composite nanomaterial.

[0048] Comparison Group 1

[0049] This comparative group provides a strontium titanate material STO-OV containing internal oxygen vacancies.

[0050] Comparison Group 2

[0051] This comparative group provides a strontium titanate material for removing internal oxygen defects.

[0052] Preparation method: 0.2 g of STO-Ov was placed in a muffle furnace and heated at 400 °C for 4 h. Subsequently, it was washed three or more times with deionized water and anhydrous ethanol, and dried under vacuum to obtain the product, which was named STO.

[0053] II. Material Application: A study on the activation of PAA to degrade ciprofloxacin (CIP) using STO-OV obtained in Comparative Group 1, STO titanate obtained in Comparative Group 2, and cobalt single-atom doped STO titanate Co-STO composite nanomaterials obtained in Example 1. Specific steps are as follows:

[0054] 1. A ciprofloxacin concentration of 0.05 mM was used. 100 mL of the solution was placed in a beaker, and 0.1 mM peracetic acid (PAA) solution was added. The pH was adjusted to 5.0 using HCl or NaOH. The reactor containing the beaker was placed at room temperature, and the reaction temperature was 25 °C. 10 mg of STO material, STO-OV material, and Co-STO nanomaterial were added separately and mixed thoroughly. Subsequently, 1 mL of the reaction solution was taken at regular intervals. After the reaction was complete, the reaction system was separated using a 0.22 μm filter membrane. The concentration of ciprofloxacin in the solution was determined using high-performance liquid chromatography (HPLC), and the removal rate of ciprofloxacin by different catalysts was calculated. The experimental results are shown below. Figure 3-4 .

[0055] This invention first selected quinolone antibiotic contaminants as model contaminants, with a primary focus on their application in removing the antibiotic ciprofloxacin (CIP). Ciprofloxacin is a widely used antibiotic, and its residues in the environment can lead to antibiotic resistance; therefore, efficient removal of this contaminant is of great significance. This invention successfully synthesized three different strontium titanate-based catalytic materials: strontium titanate (STO material) in Comparative Group 1, oxygen-deficient strontium titanate (STO-Ov material) in Comparative Group 2, and cobalt-doped strontium titanate composite nanomaterials (Co-STO nanomaterials) in Example 1.

[0056] Depend on Figure 3 As can be seen, after a 5-minute reaction, the Co-STO nanomaterials exhibited extremely high removal efficiency, with a removal rate exceeding 98%. This contrasts sharply with STO materials and STO-Ov materials, both of which had removal rates of less than 20%, demonstrating a significant performance difference.

[0057] From the perspective of reaction kinetics ( Figure 4The reaction kinetic constant k of the Co-STO nanomaterial reached 0.59 min⁻¹, indicating a rapid reaction rate, 21.07 times that of STO material (0.028 min⁻¹) and 9.08 times that of STO-Ov material (0.065 min⁻¹). These differences in reaction rate constants clearly demonstrate the significant effect of cobalt doping, greatly enhancing catalytic activity, especially in the activation of peracetic acid. This undoubtedly strengthens the overall performance and practical value of the catalyst. The presence of cobalt not only improves the electronic structure and surface properties of the material, increasing the number and types of active sites, but may also enhance catalytic efficiency by introducing new reaction mechanisms. This also highlights its enormous potential in practical water treatment applications, promoting the development of environmentally friendly catalytic technologies.

[0058] Experiment Example 2

[0059] Material Application: Degradation of Ciprofloxacin by Cobalt Single-Atom Doped Strontium Titanate Composite Catalyst under Different Reaction Conditions

[0060] Reaction conditions 1: Ciprofloxacin concentration is 5 μM. Take 100 mL of the solution and place it in a beaker. Add PAA solution (final concentration is 0.1 mM). Adjust the pH to 5.0 using HCl or NaOH. Place the reactor at room temperature and the reaction temperature is 25 ℃.

[0061] Reaction conditions 2: Ciprofloxacin concentration is 10 μM. Take 100 mL of the solution and place it in a beaker. Add PAA solution (concentration is 0.1 mM). Adjust the pH to 5.0 using HCl or NaOH. Place the reactor at room temperature and the reaction temperature is 25 ℃.

[0062] Reaction conditions 3: Ciprofloxacin concentration is 10 mM. Take 100 mL of the solution and place it in a beaker. Add PAA solution (concentration is 0.05 mM). Adjust the pH to 5.0 using HCl or NaOH. Place the reactor at room temperature and the reaction temperature is 25 ℃.

[0063] Under the three reaction conditions described above, 10 mg of 4.0 wt% Co-STO nanomaterial was added and mixed thoroughly. Subsequently, 1 ml of the reaction solution was taken at regular intervals. After the reaction was completed, the reaction system was separated using a 0.22 μm filter membrane, and the concentration of ciprofloxacin in the solution was determined by high performance liquid chromatography (HPLC). The removal rate of ciprofloxacin by different catalysts was then calculated.

[0064] Specifically, such as Figure 5As shown, the experimental results demonstrate that the 4.0 wt% Co-STO nanomaterial exhibits excellent removal capabilities under all three reaction conditions. After 10 minutes of experimentation, removal rates exceeding 80% were achieved under any of the reaction conditions. Particularly noteworthy is that under reaction condition 1, the catalyst achieved a 98.7% degradation rate of ciprofloxacin within just 5 minutes, a significant finding demonstrating its immense potential for efficient water treatment applications.

[0065] Experimental Example 3

[0066] Material Application: The degradation performance of PAA by ciprofloxacin activated by cobalt single-atom doped strontium titanate composite catalyst at different pH values.

[0067] Ciprofloxacin at a concentration of 0.05 mM was used. 100 mL of the solution was placed in a beaker, and PAA solution (0.1 mM) was added. The pH was adjusted to 1.0, 3.0, 5.0, 7.0, 9.0, and 11.0 using HCl or NaOH. The reactor was placed at room temperature, and the reaction temperature was 25 °C. 10 mg of Co-STO composite nanomaterial was added to each solution and mixed thoroughly. Subsequently, 1 mL of the reaction solution was taken at regular intervals. After the reaction was completed, the reaction system was separated using a 0.22 μm filter membrane. The concentration of ciprofloxacin in the solution was determined using high-performance liquid chromatography (HPLC), and the removal rate of ciprofloxacin by different catalysts was calculated.

[0068] As the pH value increased from 1.0 to 5.0, the degradation rate of ciprofloxacin by 4.0 wt% Co-STO nanomaterials gradually increased; notably, the degradation capacity reached 99.0% within 5 minutes at pH values ​​between 5.0 and 7.0; however, the degradation rate of ciprofloxacin began to decrease when pH > 7.0. Specifically... Figure 6 As shown, the Co-STO nanomaterials of the present invention are most suitable for sewage and wastewater treatment processes with a pH range of 3 to 9.

[0069] Experiment Example 4

[0070] Material Application: Degradation Performance of Ciprofloxacin by Cobalt Single-Atom Doped Strontium Titanate Activated PAA under Different External Ionic Strengths

[0071] Ciprofloxacin concentration is 0.05 mM. Take 100 mL of the solution and place it in a beaker. Add PAA solution (concentration 0.1 mM), then add bicarbonate ions (HCO3-). - : 1 mM), chloride ions (Cl - : 1 mM), phosphate ions (PO4) 2- 1mM), nitrate ions (NO3) -Substances such as 1 mM ciprofloxacin and humic acid (HA: 100 ppm) were added. The pH was adjusted to 5.0 using HCl or NaOH. The reactor was placed at room temperature, and the reaction temperature was 25 °C. 10 mg of Co-STO nanomaterials were added and mixed thoroughly. Subsequently, 1 ml of the reaction solution was taken at regular intervals. After the reaction was completed, the reaction system was separated using a 0.22 μm filter membrane. The concentration of ciprofloxacin in the solution was determined by high performance liquid chromatography, and the removal rate of ciprofloxacin by different catalysts was calculated. The experimental results are shown in [Figure number missing]. Figure 7 .

[0072] Figure 7 This demonstrates the ability of a cobalt single-atom-doped strontium titanate composite catalyst to activate the degradation of PAA, in which Cl... - , HA and NO3 - The effects of these on the degradation of materials are negligible, especially those related to Cl. - Under these conditions, not only did it not inhibit the activation of PAA, but it actually increased the degradation capacity, reaching 98% degradation capacity within 3 minutes. This may be due to the generation of Cl radicals. In summary, the cobalt single-atom doped strontium titanate catalytic material of this invention has good resistance to coexisting ions in water and can activate PAA to degrade more target organic pollutants under ion-containing conditions, proving that the material involved in this invention has better prospects for practical applications.

[0073] Experimental Example 5

[0074] Material Application: Performance Testing of the Co-doped Strontium titanate Composite Catalyst Prepared in Example 1 for Degrading and Removing Multiple Antibiotics

[0075] In this experiment, several common antibiotics were selected as representative contaminants for testing. These antibiotics cover several common drug classes: azithromycin (AZI) representing macrolides, cefadroxil (CFR) representing cephalosporins, sulfaacetamide (SCT) and sulfaisoxazole (SIZ) representing sulfonamides, tetracycline (TC) and oxytetracycline (OTC) representing tetracyclines, and norfloxacin (NOF), gatifloxacin (GAT), and moxifloxacin (MOX) representing quinolones.

[0076] The experiment employed the same methods as in Example 1 to ensure comparability of results; degradation tests were conducted under standardized conditions, with a uniform reaction time of 5 minutes. The results showed that the catalytic material exhibited extremely high removal efficiency for the aforementioned antibiotics within just 5 minutes. Specifically, except for cefadroxil, the removal rates for the other antibiotics all exceeded 98%. While cefadroxil performed slightly less efficiently, its removal rate still reached 80%, demonstrating that Co-STO nanomaterials retain strong catalytic capabilities even when facing more complex or difficult-to-degrade pollutants.

[0077] These results fully validate the significant potential of 4.0 wt% Co-STO nanomaterials in removing complex chemical pollutants from water. Figure 8 The fact that it achieves highly efficient degradation within such a short reaction time highlights its value in practical water treatment applications. In the future, by further optimizing the material structure and reaction conditions, this catalyst can be expected to demonstrate even greater advantages in treating a wider range of pollutants. This research provides new insights into the development of water treatment technologies and offers potential solutions to challenges in the environmental protection field.

[0078] Comparative Example 1

[0079] In step (6) of Example 1, the cobalt chloride solution containing a cobalt source was replaced with other metal solutions, including an iron-containing ferric chloride solution (FeCl3), a copper-containing copper chloride solution (CuCl2), and a nickel-containing nickel chloride solution (NiCl2). These solutions were stirred at 60 °C for 10 hours to successfully prepare iron-doped strontium titanate (Fe-STO), copper-doped strontium titanate (Cu-STO), and nickel-doped strontium titanate (Ni-STO) materials. However, their degradation efficiency was significantly lower than that of Co-STO. Specifically, their reaction kinetic constants were: 0.31 min⁻¹ for Fe-STO, 0.23 min⁻¹ for Cu-STO, and 0.35 min⁻¹ for Ni-STO. -1 This indicates that Co, as a single-atom doped material, plays an irreplaceable role in enhancing catalytic activity in Co-STO nanomaterials.

[0080] Comparative Example 2

[0081] Further experiments explored variations in solvent type and synthesis conditions. Using ethanol instead of ethylene glycol as the solvent resulted in a decrease in the catalytic performance of the Co-STO nanomaterials, with the degradation efficiency dropping to 90% within 5 minutes. Simultaneously, when the hydrothermal synthesis temperature was lowered to 100 °C, the material yield decreased by 40.2%, while the degradation efficiency dropped to 85% within 5 minutes. This may be related to a reduction in the material's crystallinity, indicating that lower synthesis temperatures may negatively impact the material's crystal structure, thereby affecting its catalytic performance.

[0082] Comparative Example 3

[0083] In this comparative example, when peracetic acid (PAA) was not added during the reaction, the study observed that the Co-STO nanomaterials had almost no degradation ability for ciprofloxacin, achieving only 15.2% removal. This further emphasizes the importance of PAA as a co-catalyst, which significantly enhances the degradation ability of Co-STO nanomaterials in the reaction.

[0084] Comparative Example 4

[0085] In this set of comparative experiments, different synthetic methods were explored to prepare various morphologies of strontium titanate (STO) materials, including nanorods and nanoparticles, to evaluate the impact of material morphology on catalytic performance. In the experiments, these different STO materials were all doped with single atoms of cobalt, becoming Co-STO nanomaterials. The results showed that, regardless of whether they existed as nanorods or nanoparticles, these morphological changes did not appear to significantly affect the degradation ability of the Co-STO catalytic materials. Experimental data showed that within a 5-minute reaction time, these different Co-STO nanomaterial morphologies all achieved a removal rate of over 95% for ciprofloxacin. These results indicate that although different morphologies may possess unique physicochemical properties for specific applications, single-atom cobalt doping appears to play a more crucial role in catalytic performance, surpassing the influence of morphological differences. This finding highlights the central role of active sites in cobalt doping during catalysis, regardless of their morphology. This phenomenon not only broadens the potential synthetic routes for such materials but also provides greater flexibility in morphology selection for specific applications.

[0086] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. The application of a cobalt single-atom-doped strontium titanate composite catalytic material in the catalytic degradation of organic pollutants by activated peracetic acid; the cobalt single-atom-doped strontium titanate composite catalytic material comprises strontium titanate crystals and cobalt single atoms embedded in the strontium titanate crystal structure; when catalytically degrading organic pollutants by activated peracetic acid, chloride ions are also included; the concentration of the chloride ions is 1 mM; the organic pollutant is ciprofloxacin; The cobalt single-atom-doped strontium titanate composite catalytic material was prepared by the following method: (1) Add titanium source, strontium nitrate and sodium hydroxide to a mixed solvent to obtain a mixed solution, heat to carry out hydrothermal reaction, and after the reaction is completed, separate the solid and liquid phases to obtain the solid product, namely strontium titanate composite material; (2) Disperse the strontium titanate composite material obtained in step (1) in a water-ethylene glycol mixture, add a cobalt source solution, and obtain the cobalt single-atom doped strontium titanate composite catalyst material.

2. The application according to claim 1, characterized in that, The average diameter of the cobalt single-atom doped strontium titanate composite catalyst is 30 ~ 200 nm; The loading of cobalt single atoms in the cobalt single-atom doped strontium titanate composite catalyst is 0.5 wt%-6.0 wt%.

3. The application according to claim 1, characterized in that, The pH of the solution for catalytic degradation of organic pollutants is 3-9.

4. The application according to claim 1, characterized in that, In step (1), the titanium source is selected from tetrabutyl titanate.

5. The application according to claim 1, characterized in that, In step (1), the mixed solvent includes ethylene glycol and water; the volume ratio of ethylene glycol to water is (1:1) to (2:1). The concentration of sodium hydroxide is 1~10 mmol / L.

6. The application according to claim 1, characterized in that, In step (1), the hydrothermal reaction conditions are: temperature 180~210℃, time 12~24 h.

7. The application according to claim 1, characterized in that, In step (2), the cobalt source in the cobalt source solution is selected from one or more of cobalt chloride, cobalt nitrate, and cobalt acetylacetonate; The volume ratio of water to ethylene glycol in the water-ethylene glycol mixture is 9:1.

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