A method for preparing a nano-high-entropy ferrite-based Fenton catalyst, the catalyst prepared therein, and its applications.

Abstract

This invention relates to organic pollutant wastewater treatment technology, specifically a method for preparing high-entropy ferrite-based Fenton catalysts and their applications. This invention utilizes a low-temperature solvothermal method in a strongly alkaline environment to prepare nano-high-entropy ferrites in a one-step growth process. The chemical composition of these nano-high-entropy ferrites is (M... x Co x Ni 0.2 Cu 0.2 Zn 0.2 )Fe₂O₄, where M is Mg and / or Mn, 0

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment technology, specifically to a method for preparing nano-high-entropy ferrite-like catalysts, the catalysts prepared therefrom, and their applications. Background Technology

[0002] With the emission of emerging organic pollutants such as endocrine disruptors and pharmaceutical and personal care products (PPCPs) far exceeding the capacity for natural degradation, the development of technologies and methods for the rapid and effective removal of these emerging organic pollutants has become a global focus. Heterogeneous Fenton-like catalytic degradation technology, combining high catalytic oxidation energy, a wider pH application window, and a faster oxidant activation process, has great application potential in the construction of catalytic systems for the treatment of PPCPs wastewater, attracting widespread academic attention and some commercial applications.

[0003] Ferrites, due to their low cost, flexible composition, and tunable properties, along with their ability to continuously change ionic valence and form stable continuous solid solutions through ion substitution or replacement, are a class of highly efficient heterogeneous catalytic materials with multifunctional applications. Spinel ferrites, exhibiting higher stability, more active sites, and synergistic effects between metal ions compared to single-metal catalysts, are gradually gaining dominance in heterogeneous Fenton-like systems based on sulfate and hydroxyl radicals. Recently, Professor Qiu Huajun's research at Harbin Institute of Technology (Shenzhen) has been working on dealloying of multi-component alloys or high-entropy alloys to obtain a series of spinel-type oxides, such as (AlMnCo)3O4 nanosheets, (AlNiCoRuMo)3O4 nanowires, and nano-hierarchical porous (AlCoFeMoCr)3O4. Due to their large specific surface area and "cocktail" effect, these materials exhibit excellent oxygen catalytic activity (Adv. Funct. Mater. 31, 2007 129 (2021); ACS Mater. Lett. 2, 1698-1706 (2020); Chem. Mater. 33, 1771-1780 (2021)). However, these materials are mainly used for the adsorption and degradation of waste gases. While high-entropy design strategies can enhance the catalytic activity of materials, there is still room for further improvement. Furthermore, traditional methods for preparing high-entropy materials include conventional solid-state sintering (CS), spark plasma sintering (SPS), and flash sintering (FS). However, these methods require high temperatures, exceeding 1000℃, thus placing high demands on the equipment and processes used.

[0004] CN116282224 discloses a high-entropy spinel catalyst with controllable oxygen vacancy concentration under mild conditions and a preparation method thereof. This catalyst is synthesized by a two-step method of solvothermal treatment combined with annealing at a relatively high temperature, which requires subsequent heat treatment to increase the complexity of the process, and the powder has an irregular shape. At the same time, CN113860911A discloses a preparation method of a high-entropy ferrite porous ceramic material. The high-entropy ferrite powder prepared by this patent needs to be obtained by high-temperature heat treatment. The prepared high-entropy powder is in the micron level and has a limited specific surface area, thus limiting the heterogeneous catalytic activity of the catalyst.

[0005] In summary, aiming at the problems of insufficient catalytic activity and complex preparation process of ferrite-based Fenton catalysts in the prior art, the present invention proposes a preparation method of a high-entropy ferrite-based Fenton catalyst. Summary of the Invention

[0006] In view of the deficiencies in the prior art, the purpose of the present invention is to provide a preparation method of a nano high-entropy ferrite-based Fenton catalyst. The provided preparation method can synthesize a high-entropy ferrite-based Fenton catalyst by a one-step method under mild conditions, greatly reducing the production cost. The high-entropy ferrite-based Fenton catalyst prepared by this method has a regular morphology and a high specific surface area, and has good catalytic activity. It has a good application prospect in the field of heterogeneous activation of persulfate or hydrogen peroxide to treat organic pollutants. Its application range is wide, and it can not only degrade traditional organic dyes, but also has a good degradation effect on emerging organic pollutants such as antibiotics.

[0007] In order to achieve the above invention purpose, the technical solution of the present invention is as follows:

[0008] On the one hand, the present invention provides a preparation method of a high-entropy ferrite-based Fenton catalyst. The chemical formula of the high-entropy ferrite catalyst is (M x Co x Ni 0.2 Cu 0.2 Zn 0.2 )Fe2O4, where M is Mg and / or Mn, 0 < x ≤ 0.2, and the preparation steps include:

[0009] S1. Weigh the salts of M, Co, Ni, Zn, Cu and Fe according to the chemical ratio, then add them to ethanol, stir and ultrasonic until the salts are completely dissolved to obtain a mixed solution;

[0010] S2. Dropwise add an alkaline solution to the mixed solution while stirring to adjust the pH value of the mixed solution to an alkaline environment;

[0011] S3. Place the mixed solution in step S2 in a reaction kettle, and carry out a solvothermal reaction at 140 - 220 °C for 18 - 36 h, and then obtain a precipitate;

[0012] S4. The precipitate is washed and dried to obtain a nano-high-entropy ferrite-based Fenton catalyst.

[0013] Furthermore, the high-entropy ferrite-based Fenton catalyst is octahedral and / or plate-shaped, with a particle size of 20–50 nm and a specific surface area of ​​50–160 m². 2 / g.

[0014] Due to its regular shape, it disperses well in wastewater and exhibits better catalytic performance. Because of its nanoscale effect and high specific surface area, it demonstrates higher catalytic activity compared to micron-sized Fenton-like catalytic materials.

[0015] With a specific surface area of ​​50–160 m² 2 Within the range of / g, the high-entropy ferrite-based Fenton catalyst can better form complexes with hydrogen peroxide or persulfate, exhibiting better adsorption of reaction substrates, and can efficiently achieve electron transfer under mild conditions, thereby improving catalytic degradation efficiency.

[0016] Furthermore, the salt in step S1 can be a nitrate or a sulfate, with a molar concentration of 0.01–0.1 mol / L.

[0017] Furthermore, the alkaline solution in step S2 is at least one of ammonia, sodium hydroxide, or potassium hydroxide solution, with a concentration of 4.0–6.0 mol / L, and the hydroxide ion concentration in the mixed solution is adjusted to 0.40–0.65 mol / L.

[0018] Furthermore, in step S4, the precipitate is washed 3 to 6 times with distilled water and ethanol respectively, and then dried in an oven at 50 to 70°C for 20 to 48 hours.

[0019] On the other hand, the present invention provides a nano-high-entropy ferrite-based Fenton catalyst prepared using the above-described preparation method.

[0020] The nano-high-entropy ferrite-based Fenton catalyst obtained by the above method is a ferrite-based solid solution compound composed of more than six elements. It has a high entropy value and high thermodynamic stability. Furthermore, the interaction between atoms causes lattice distortion, which can simultaneously couple the redox processes of multiple variable-valence metal ions. It can effectively reduce high-valence ions in the activation of hydrogen peroxide, persulfate (PDS), and permonose (PMS), exhibiting excellent catalytic activity and stability. Compared with low-entropy catalysts such as ZnFe2O4, CoFe2O4, and NiFe2O4, it shows superior catalytic degradation effect and efficiency in the catalytic degradation of organic pollutants.

[0021] On the other hand, the present invention provides an application of a nano-high-entropy ferrite-based Fenton catalyst prepared by the above preparation method in the degradation of organic pollutants in wastewater.

[0022] Furthermore, the pH value of the wastewater solution is 4–11. Compared to traditional Fenton catalysts, which require specific pH values ​​for the wastewater when using hydrogen peroxide to degrade organic matter and exhibit good degradation activity only within a narrow pH range, the high-entropy ferrite-based Fenton catalyst of this invention maintains excellent catalytic activity in a liquid phase environment with a pH value of 4–11, thus having a wider range of applications.

[0023] Furthermore, the organic pollutants include at least one of organic dyes, organophosphorus pesticides, or antibiotics. The nano-high-entropy ferrite-based Fenton catalyst can not only catalytically degrade traditional organic pollutants but also catalytically degrade emerging antibiotic pollutants, thus having a wide range of applications.

[0024] Furthermore, the organic dye includes at least one of methyl orange, rhodamine B, and methylene blue; the antibiotic contaminant includes at least one of tetracycline hydrochloride, sulfamethoxazole (SMX), or fluoroquinolone antibiotics.

[0025] Compared with the prior art, the technical effects of this invention are as follows:

[0026] (1) The nano high-entropy ferrite (M) provided by this invention x Co x Ni 0.2 Cu 0.2 Zn 0.2 The preparation method of Fe2O4-based Fenton catalysts requires inexpensive raw materials, is easy to control, and does not require high-temperature heat treatment. Under mild conditions without the addition of surfactants, it can prepare nano-high-entropy ferrite particles with regular shape, high crystallinity, high specific surface area, and high catalytic activity. It has the advantages of low production cost, high versatility, simplicity, and simple equipment, providing a new approach and new ideas for the application of high-entropy ferrite materials in catalysis, energy conversion and other fields.

[0027] (2) The nano high-entropy ferrite (M) provided by this invention x Co x Ni 0.2 Cu 0.2 Zn 0.2Fe2O4-based Fenton catalysts have significant application value in activating hydrogen peroxide and persulfate to degrade typical and emerging organic pollutants, exhibiting excellent catalytic activity and stability. The degradation rates for traditional organic pollutants such as methyl orange, rhodamine B, and methylene blue reach over 87%, and for methyl orange, even exceeding 93%. For emerging organic pollutants such as tetracycline hydrochloride, sulfamethoxazole (SMX), or fluoroquinolone antibiotics, the degradation rates generally reach over 86%, and for tetracycline hydrochloride, the degradation rate can even exceed 95%.

[0028] (3) The high-entropy ferrite-type Fenton catalyst provided by the present invention has a high specific surface area and can form complexes with hydrogen peroxide or persulfate. It has good adsorption properties for reaction substrates and can efficiently achieve electron transfer under mild conditions, showing excellent degradation effect on emerging organic pollutants.

[0029] (4) The nano high-entropy ferrite Fenton catalyst provided by the present invention has a pH range of 4 to 11 in the liquid phase environment, which is a wide range of applications. It is easy to disperse uniformly in solution and has a stronger catalytic degradation effect and efficiency in degrading organic pollutants than low-entropy catalysts with single phase composition such as ZnFe2O4, CoFe2O4 and NiFe2O4. Attached Figure Description

[0030] Figure 1 High entropy (Mg) was prepared by solvothermal method after holding at 180℃ for 20 hours. 0.2 Co 0.2 Ni 0.2 Zn 0.2 Cu 0.2 TEM image of Fe2O4.

[0031] Figure 2 High entropy (Mg) was prepared by solvothermal method after holding at 180℃ for 20 hours. 0.2 Co 0.2 Ni 0.2 Zn 0.2 Cu 0.2 XRD pattern of Fe2O4.

[0032] Figure 3 High entropy (Mg) was prepared by solvothermal method after holding at 180℃ for 20 hours. 0.2 Co 0.2 Ni 0.2 Zn 0.2 Cu 0.2 Particle size distribution diagram of Fe2O4.

[0033] Figure 4 High entropy (Mn) was prepared by a solvothermal method after holding at 200℃ for 30 hours. 0.2 Co0.2 Ni 0.2 Zn 0.2 Cu 0.2 TEM image of Fe2O4.

[0034] Figure 5 High entropy (Mg) 0.2 Co 0.2 Ni 0.2 Zn 0.2 Cu 0.2 Kinetics of the degradation of tetracycline hydrochloride (TCH) by Fe2O4-activated hydrogen peroxide (H2O2), persulfate (PDS), and permonosulfate (PMS).

[0035] Figure 6 High entropy (Mg) at different initial pH values 0.2 Co 0.2 Ni 0.2 Zn 0.2 Cu 0.2 Kinetics of Fe2O4-activated persulfate (PMS) degradation of tetracycline hydrochloride (TCH).

[0036] Figure 7 High entropy nanoparticles (Mn) were prepared under different sodium hydroxide concentrations. 0.2 Co 0.2 Ni 0.2 Zn 0.2 Cu 0.2 Fe2O4-based Fenton catalysts. Detailed Implementation

[0037] The following non-limiting embodiments are intended to enable those skilled in the art to gain a more comprehensive understanding of the invention, but do not limit the invention in any way. The following content is merely an exemplary description of the scope of protection claimed in this application. Those skilled in the art can make various changes and modifications to the invention based on the disclosed content, and such changes should also fall within the scope of protection claimed in this application. The term "about" refers to a range of 10% above or below a certain value, for example, about 20 nanometers, i.e., 20 ± 2 nanometers.

[0038] The present invention will be further described below by way of specific embodiments. Unless otherwise specified, all chemical reagents used in the embodiments of the present invention are obtained through conventional commercial means.

[0039] Example 1 High Entropy (Mg) 0.2 Co 0.2 Ni 0.2 Zn 0.2 Cu 0.2 Preparation of Fe2O4

[0040] According to (Mg 0.2 Co0.2 Ni 0.2 Zn 0.2 Cu 0.2 The stoichiometric ratio of Fe₂O₄ was used to prepare the mixture, specifically by weighing magnesium nitrate, cobalt nitrate, nickel nitrate, zinc nitrate, copper nitrate, and ferric nitrate sequentially in a metal molar ratio of 0.2:0.2:0.2:0.2:0.2:2. The nitrates were then added sequentially to an ethanol solution, stirred until completely dissolved, and sonicated for 20 minutes. The pH of the mixture was then adjusted using sodium hydroxide solution to maintain a hydroxide ion concentration of 0.5 mol / L. The mixture was reacted at 180°C for 20 hours as a solvothermal reaction to obtain a heat-treated mixture. After cooling the heat-treated mixture obtained in the above steps, the product was centrifuged and washed, and then dried in an oven at 70°C to obtain the final product. Figure 1 To prepare high entropy (Mg) 0.2 Co 0.2 Ni 0.2 Zn 0.2 Cu 0.2 TEM image of Fe2O4. Figure 2 To prepare high entropy (Mg) 0.2 Co 0.2 Ni 0.2 Zn 0.2 Cu 0.2 XRD pattern of Fe2O4. Figure 3 To prepare high entropy (Mg) 0.2 Co 0.2 Ni 0.2 Zn 0.2 Cu 0.2 Particle size distribution diagram of Fe2O4.

[0041] Example 2 High Entropy (Mn) 0.2 Co 0.2 Ni 0.2 Zn 0.2 Cu 0.2 Preparation of Fe2O4

[0042] According to (Mn) 0.2 Co 0.2 Ni 0.2 Zn 0.2 Cu 0.2The stoichiometric ratio of Fe₂O₄ was used to prepare the mixture, specifically by weighing manganese nitrate, cobalt nitrate, nickel nitrate, zinc nitrate, copper nitrate, and ferric nitrate in a metal molar ratio of 0.2:0.2:0.2:0.2:2. The nitrates were then added sequentially to an ethanol solution, stirred until completely dissolved, and sonicated for 20 minutes. The pH of the mixture was then adjusted using sodium hydroxide solution, with the hydroxide ion concentration controlled at 0.65 mol / L. The mixture was reacted at 200°C for 30 hours as a solvothermal reaction to obtain a heat-treated mixture. After cooling the heat-treated mixture obtained in the above steps, the product was centrifuged and washed, and then dried in an oven at 70°C to obtain the final product. Figure 4 To prepare high entropy (Mn) 0.2 Co 0.2 Ni 0.2 Zn 0.2 Cu 0.2 TEM image of Fe2O4.

[0043] Example 3: Preparation of high-entropy (Mn) under different strongly alkaline environments 0.2 Co 0.2 Ni 0.2 Zn 0.2 Cu 0.2 Fe2O4

[0044] According to (Mn) 0.2 Co 0.2 Ni 0.2 Zn 0.2 Cu 0.2 The stoichiometric ratio of Fe₂O₄ was used for batching, specifically by weighing manganese nitrate, cobalt nitrate, nickel nitrate, zinc nitrate, copper nitrate, and ferric nitrate in a metal molar ratio of 0.2:0.2:0.2:0.2:2. The nitrates were then added sequentially to an ethanol solution, stirred until completely dissolved, and sonicated for 20 minutes. The pH of the mixture was then adjusted using sodium hydroxide solution, maintaining a hydroxide ion concentration between 0.41 and 0.50 mol / L. The mixture was then reacted at 180°C for 20 hours as a solvothermal reaction to obtain a heat-treated mixture. After cooling the heat-treated mixture obtained in the above steps, the product was centrifuged and washed, and then dried in a 70°C oven to obtain a series of powders. The results are as follows: Figure 7 As shown, from Figure 7 It is known that when the hydroxide ion concentration is greater than or equal to 0.50 mol / L, a one-step solvothermal method can prepare single-phase high-entropy nanoparticles (Mn). 0.2 Co 0.2 Ni 0.2 Zn 0.2 Cu 0.2 )Fe2O4.

[0045] Example 4: Preparation of high-entropy (Mn) under ultra-high alkalinity environment 0.2 Co0.2 Ni 0.2 Zn 0.2 Cu 0.2 Fe2O4

[0046] According to (Mn) 0.2 Co 0.2 Ni 0.2 Zn 0.2 Cu 0.2 The stoichiometric ratio of Fe₂O₄ was used for batching, specifically, manganese sulfate, cobalt sulfate, nickel sulfate, zinc sulfate, copper sulfate, and ferric sulfate were weighed sequentially according to a metal molar ratio of 0.2:0.2:0.2:0.2:0.2:2. The sulfates were then added sequentially to an ethanol solution, stirred until completely dissolved, and sonicated for 20 minutes. The pH of the mixture was then adjusted using sodium hydroxide solution, with the hydroxide ion concentration controlled at 0.62 mol / L. The mixture was then reacted at 180℃ for 20 hours as a solvothermal reaction to obtain a heat-treated mixture. After cooling the heat-treated mixture obtained in the above steps, the product was centrifuged and washed, and then dried in a 70℃ oven to obtain a series of powders. The results are as follows: Figure 7 As shown, from Figure 7 It is known that at a hydroxide ion concentration of 0.62 mol / L, a one-step solvothermal method can prepare single-phase high-entropy nanoparticles (Mn). 0.2 Co 0.2 Ni 0.2 Zn 0.2 Cu 0.2 )Fe2O4.

[0047] Comparative Example 1: Preparation of a single component ZnFe2O4

[0048] The ingredients were prepared according to the stoichiometric ratio of ZnFe₂O₄. Zinc nitrate and ferric nitrate were weighed and added sequentially to the ethanol solution, and the mixture was magnetically stirred until completely dissolved, followed by sonication for 20 minutes. The pH of the mixture was then adjusted using sodium hydroxide solution, with the hydroxide ion concentration controlled at 0.50 mol / L. The mixture was reacted at 180°C for 20 hours as a solvothermal reaction to obtain a heat-treated mixture. After cooling the heat-treated mixture obtained in the above steps, the product was centrifuged and washed, and then dried in an oven at 70°C to obtain the final product.

[0049] Comparative Example 2: Preparation of a single component CoFe2O4

[0050] The ingredients were prepared according to the stoichiometric ratio of ZnFe₂O₄. Cobalt nitrate and ferric nitrate were weighed and added sequentially to the ethanol solution, and the mixture was magnetically stirred until completely dissolved, followed by sonication for 20 minutes. The pH of the mixture was then adjusted using sodium hydroxide solution, with the hydroxide ion concentration controlled at 0.50 mol / L. The mixture was reacted at 180°C for 20 hours as a solvothermal reaction to obtain a heat-treated mixture. After cooling the heat-treated mixture obtained in the above steps, the product was centrifuged and washed, and then dried in an oven at 70°C to obtain the final product.

[0051] Comparative Example 3: Preparation of Single-Component NiFe2O4

[0052] The ingredients were prepared according to the stoichiometric ratio of NiFe₂O₄. Nickel sulfate and ferric nitrate were weighed and added sequentially to the ethanol solution, and the mixture was magnetically stirred until completely dissolved, followed by sonication for 20 minutes. The pH of the mixture was then adjusted using sodium hydroxide solution, with the hydroxide ion concentration controlled at 0.60 mol / L. The mixture was reacted at 220℃ for 36 hours as a solvothermal reaction to obtain a heat-treated mixture. After cooling the heat-treated mixture obtained in the above steps, the product was centrifuged and washed, and then dried in an oven at 70℃ to obtain the final product.

[0053] Experimental Example 1: Comparison of Performance in Degrading Typical Organic Pollutants

[0054] 1. Experimental materials: Nano-high entropy ferrite-based Fenton catalysts prepared in Examples 1-4 and single-component ZnFe2O4, CoFe2O4 and NiFe2O4-based Fenton catalysts prepared in Comparative Examples 1-3.

[0055] 2. Experimental Methods: Typical organic pollutants such as methyl orange, rhodamine B, methylene blue, and methyl parathion were used as target pollutants in the Fenton-like catalytic reaction. Fenton-like catalytic reaction experiments were conducted to characterize the performance differences between the nano-high-entropy ferrite Fenton-like catalysts prepared in Examples 1-4 and the single-component ZnFe₂O₄, CoFe₂O₄, and NiFe₂O₄ Fenton-like catalysts prepared in Comparative Examples 1-3. The initial concentration of the typical organic pollutants used was 100 mg / L, the amount of the test sample added was 1 g / L, and 150 mM persulfate (PMS) was added. Before the Fenton-like degradation reaction, 80 mL of a typical organic pollutant solution was taken, and the test sample was added to the solution. The mixture was stirred in a dark room for 60 min to reach adsorption-desorption equilibrium before the Fenton-like catalytic degradation experiment. After 90 min of catalytic degradation, centrifugation was performed to separate the residual catalyst from the solution. The absorbance of the supernatant was then measured using a UV-Vis spectrophotometer. The change in absorbance of the solution is measured to analyze the concentration change of organic pollutants in the solution, thereby characterizing the catalytic activity of Fenton-like catalysts.

[0056] 3. Test results: The test results are shown in Table 1.

[0057] As shown in Table 1, the nano-high-entropy ferrite Fenton-like catalysts prepared in Examples 1-4 exhibit Fenton-like catalytic degradation efficiencies greater than 87% for methyl orange, rhodamine B, methylene blue, and methyl parathion, demonstrating excellent catalytic degradation performance. Among these, the high-entropy (Mn) catalyst prepared in Example 2... 0.2 Co 0.2 Ni 0.2 Zn 0.2 Cu 0.2 The Fe2O4-based Fenton-like catalyst exhibited the highest overall degradation efficiency. In contrast, the single-component ZnFe2O4, CoFe2O4, and NiFe2O4-based Fenton catalysts prepared in Comparative Examples 1-3 showed overall degradation efficiencies below 81%, indicating lower overall degradation efficiency. The results demonstrate that the nano-high-entropy ferrite-based Fenton catalyst provided by this invention exhibits significant Fenton-like catalytic degradation effects on typical organic pollutants such as methyl orange, rhodamine B, methylene blue, and methyl parathion, demonstrating excellent overall catalytic degradation activity.

[0058] Table 1. Test results of Fenton reaction degradation of typical organic pollutants.

[0059]

[0060] Experiment Example 2: Explanation of Experimental Data

[0061] Figure 1 The high-entropy (Mg) prepared in Example 1 0.2 Co 0.2 Ni 0.2 Zn 0.2 Cu 0.2 TEM image of Fe2O4 shows that the synthesized high-entropy powder has a regular octahedral shape and is in the nanoscale range.

[0062] Figure 2 The high-entropy nanoparticles (Mg) prepared in Example 1 0.2 Co 0.2 Ni 0.2 Zn 0.2 Cu 0.2 The XRD pattern of Fe2O4 shows that the diffraction peaks of the synthesized powder are located between the five single components, indicating that the five elements are well dissolved in the crystal lattice. The high entropy of the equimolar ratio promotes the inter-element compatibility and the formation of the solid solution. No other impurity peaks or second phases appear, indicating the successful synthesis of a high-entropy material (Mg2O4) with a single phase. 0.2 Co 0.2 Ni 0.2 Zn 0.2 Cu 0.2 )Fe2O4.

[0063] Figure 3 The high-entropy nanoparticles (Mg) prepared in Example 1 0.2 Co 0.2 Ni 0.2 Zn 0.2 Cu 0.2 The particle size distribution of Fe2O4 shows that the average size of the grains is 20.4 nm.

[0064] Figure 4 The (Mn) prepared in Example 2 0.2 Co 0.2 Ni 0.2 Zn 0.2 Cu 0.2 TEM images of Fe2O4 show that the synthesized high-entropy powder has a regular flake shape and is in the nanoscale range.

[0065] Figure 5 The high-entropy nanoparticles (Mg) prepared in Example 1 0.2 Co 0.2 Ni 0.2 Zn 0.2 Cu 0.2 A comparative study of the kinetics of tetracycline hydrochloride (TCH) degradation by Fe2O4 activated hydrogen peroxide (H2O2), persulfate (PDS), and permonosulfate (PMS) is presented in the figure. Figure 5 It can be seen that high entropy (Mg) 0.2 Co 0.2 Ni 0.2 Zn 0.2 Cu 0.2 Fe2O4 exhibits good adsorption properties for tetracycline hydrochloride and shows significant catalytic degradation effects when activated with hydrogen peroxide, persulfate (PDS), and persulfate (PMS). Among these, the effect is best when activated with persulfate, and complete degradation of high-concentration tetracycline hydrochloride can be achieved in about 90 minutes.

[0066] The specific implementation process of the Fenton-like catalytic reaction is as follows: Three 80 mL cups of tetracycline hydrochloride solution (TCH, concentration 100 mg / L) are respectively placed in the reaction vessel. Then, hydrogen peroxide (H₂O₂) at a concentration of 150 mM, persulfate (PDS) at a concentration of 150 mM, permonsulfate (PMS) at a concentration of 150 mM, and high entropy (Mg²⁺) are added to each vessel. 0.2 Co 0.2 Ni 0.2 Zn 0.2 Cu 0.2 The Fe₂O₄ powder concentration is 1.0 g / L. The removal rate (Rev(%)) of the simulated target pollutant tetracycline hydrochloride can be calculated using the following formula:

[0067]

[0068] Where C t C0 represents the concentration of organic pollutants in the filtrate at a certain moment; A represents the initial concentration of organic pollutants. t A0 represents the absorbance at the maximum absorption wavelength of organic pollutants in the filtrate at a certain moment (the characteristic absorption peak of tetracycline hydrochloride is 357 nm); A0 represents the absorbance at the initial maximum absorption wavelength of organic pollutants.

[0069] Figure 6 The high entropy nanoparticles (Mn) prepared in Example 3 0.2 Co 0.2 Ni 0.2 Zn 0.2 Cu 0.2 The degradation effect of Fe2O4 on tetracycline hydrochloride under different initial pH conditions was verified. The results showed that the high entropy of nano-Mn 0.2 Co 0.2 Ni 0.2 Zn 0.2 Cu 0.2 Fe2O4 is applicable to a wide range of pH environments and has a very good activation effect on persulfate. This reaction system has an excellent effect on degrading organic pollutants.

[0070] The specific reaction process is as follows: Take several 80 mL portions of tetracycline hydrochloride solution (TCH, concentration 100 mg / L), then adjust the initial pH of the solution to the target value (3, 5, 7, 9, 11, and 12, and the control group without added acid or alkali, pH = 5.0) using sodium hydroxide solution and hydrochloric acid. Use the optimal addition amounts for hydrogen peroxide and catalyst: 150 mM persulfate (PMS) and nano-high entropy (Mn) catalysts. 0.2 Co 0.2 Ni 0.2 Zn 0.2 Cu 0.2 The Fe2O4 powder concentration is 1 g / L. The operating steps are as follows: First, the nano-high entropy (Mn) powder is... 0.2 Co 0.2 Ni 0.2 Zn 0.2 Cu 0.2 Fe₂O₄ is added to a tetracycline hydrochloride solution. After adsorption-desorption equilibrium is reached, the pH is adjusted, and hydrogen peroxide is added to allow the absorbance to stabilize again. The removal rate (Rev(%)) of the simulated target pollutant tetracycline hydrochloride can be calculated using the following formula:

[0071]

[0072] Where C tC0 represents the concentration of organic pollutants in the filtrate at a certain moment; A represents the initial concentration of organic pollutants. t A0 represents the absorbance at the maximum absorption wavelength of organic pollutants in the filtrate at a certain moment (the characteristic absorption peak of tetracycline hydrochloride is 357 nm); A0 represents the absorbance at the initial maximum absorption wavelength of organic pollutants.

[0073] Experimental Example 3: Test of the catalytic degradation performance of Fenton-like catalysts for antibiotic-like organic pollutants

[0074] 1. Experimental materials: Nano-high entropy ferrite-based Fenton catalysts prepared in Examples 1-4 and single-component ZnFe2O4, CoFe2O4 and NiFe2O4-based Fenton catalysts prepared in Comparative Examples 1-3.

[0075] 2. Experimental Methods: Tetracycline hydrochloride, sulfamethoxazole (SMX), and fluoroquinolone antibiotics were used as target pollutants in a Fenton-like catalytic reaction. The Fenton-like catalytic reaction was conducted to characterize the performance differences between the nano-high-entropy ferrite Fenton-like catalysts prepared in Examples 1-4 and the single-component ZnFe2O4, CoFe2O4, and NiFe2O4 Fenton-like catalysts prepared in Comparative Examples 1-3. The initial concentration of the typical organic pollutants used was 150 mg / L, the amount of the test sample added was 1 g / L, and the concentration of hydrogen peroxide (H2O2) added was 150 mM. Before the Fenton-like degradation reaction, 80 mL of antibiotic organic pollutant solution was taken, and the test samples were added separately to the antibiotic organic pollutant solution. The mixture was stirred in a dark room for 90 min to reach adsorption-desorption equilibrium before the Fenton-like catalytic degradation experiment. After 120 min of catalytic degradation, centrifugation was performed to separate the residual catalyst from the solution. The absorbance of the supernatant was then measured using a UV-Vis spectrophotometer. The changes in absorbance of the solution are measured to analyze the concentration changes of antibiotic-like organic pollutants in the solution, thereby characterizing the catalytic activity of Fenton-like catalysts.

[0076] 3. Test results: The test results are shown in Table 2.

[0077] Table 2 shows that the nano-high-entropy ferrite Fenton-like catalysts prepared in Examples 1-4 exhibit Fenton-like catalytic degradation efficiencies greater than 86.3% for tetracycline hydrochloride, sulfamethoxazole (SMX), and fluoroquinolone antibiotics, demonstrating excellent catalytic degradation performance. Among them, the high-entropy (Mn) catalyst prepared in Example 4... 0.2 Co 0.2 Ni 0.2 Zn 0.2 Cu 0.2The Fe2O4-based Fenton catalyst exhibits the highest overall efficiency in degrading antibiotic pollutants. In contrast, the single-component ZnFe2O4, CoFe2O4, and NiFe2O4-based Fenton catalysts prepared in Comparative Examples 1-3 show overall catalytic degradation efficiencies below 82.7%, indicating lower catalytic degradation efficiency. The results demonstrate that the nano-high-entropy ferrite-based Fenton catalyst provided by this invention exhibits significant Fenton-like catalytic degradation effects on emerging organic pollutants such as tetracycline hydrochloride, sulfamethoxazole (SMX), and fluoroquinolone antibiotics, demonstrating excellent overall catalytic degradation activity.

[0078] Table 2. Test results of the catalytic degradation performance of Fenton catalysts for antibiotic-related organic pollutants.

[0079]

[0080] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and refinements can be made without departing from the principle of the present invention, and these improvements and refinements should also be considered within the scope of protection of the present invention.

Claims

1. A method for preparing a nano high-entropy ferrite catalyst, the chemical formula of the high-entropy ferrite catalyst being (M x Co x Ni 0.2 Cu 0.2 Zn 0.2 )Fe2O4, where M is Mg and / or Mn, 0 < x ≤ 0.2, characterized in that, The preparation steps include the following: S1. Weigh out the salts of M, Co, Ni, Zn, Cu and Fe according to the chemical ratio, then add them to ethanol, stir and sonicate until the salts are completely dissolved to obtain a mixed solution; S2. While adding alkaline solution dropwise to the mixed solution and stirring, adjust the pH value of the mixed solution to an alkaline environment; S3. Place the mixed solution from step S2 into a reaction vessel and carry out a solvothermal reaction at 140–220°C for 18–36 h, and then obtain the precipitate. S4. The precipitate is washed and dried to obtain a nano high-entropy ferrite-based Fenton catalyst. The alkaline solution mentioned in step S2 is at least one of sodium hydroxide or potassium hydroxide solution, with a concentration of 4.0 to 6.0 mol / L, and the hydroxide ion concentration in the mixed solution is adjusted to 0.40 to 0.65 mol / L; The specific surface area of ​​the nano-high-entropy ferrite-based Fenton catalyst is 50–160 m². 2 / g, the nano high-entropy ferrite Fenton catalyst has a particle shape of at least one of regular octahedron or plate, and an average particle size of 20-50 nm.

2. The method for preparing nano-high-entropy ferrite catalysts as described in claim 1, characterized in that, In step S1, the salt is a nitrate and / or sulfate, and its molar concentration after dissolution is 0.01 to 0.1 mol / L.

3. The method for preparing nano-high-entropy ferrite catalysts as described in claim 1, characterized in that, In step S4, the precipitate is washed 3 to 6 times with distilled water and ethanol respectively, and then dried in an oven at 50 to 70°C for 20 to 48 hours.

4. A nano-high-entropy ferrite-based Fenton catalyst prepared by the method described in any one of claims 1-3.

5. The application of the nano high-entropy ferrite-based Fenton catalyst according to claim 4 in the degradation of organic pollutants in wastewater.

6. The application as described in claim 5, characterized in that, The pH value of the wastewater solution is 4 to 11.

7. The application as described in claim 5, wherein the organic pollutant includes at least one of organic dyes, organophosphorus pesticides, or antibiotics.

8. The application as described in claim 7, wherein the organic dye comprises at least one of methyl orange, rhodamine B, and methylene blue; and the antibiotic contaminant comprises at least one of tetracycline, sulfamethoxazole, or fluoroquinolone antibiotics.

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