A rare earth material with high efficient scavenging active oxygen and a preparation method and application thereof

Abstract

This invention provides a rare earth material with high efficiency in scavenging reactive oxygen species, its preparation method, and its application. The rare earth material comprises a rare earth cerium salt, a pH adjuster, a copper salt, zinc oxide (ZnO), and boron nitride (BN) in a molar ratio of (5-7):(8-12):(4-6):(1-3):(0.5-1.5). In this invention, zinc oxide can regulate the electron distribution on the material surface, and boron nitride can optimize the crystal structure arrangement. The two, together with the copper salt, further enhance the number and stability of oxygen vacancies. Its free radical scavenging rate constant is more than 15 times higher than that of traditional materials, and it can significantly inhibit the inflammatory response during the inflammatory phase of wound healing.

Description

Technical Field

[0001] This invention belongs to the field of new materials, and in particular relates to a rare earth material with high efficiency in scavenging reactive oxygen species, its preparation method and application. Background Technology

[0002] Wound healing is a complex and dynamic process that results in the restoration of normal anatomy and function of damaged tissue. Typically, the wound healing process comprises three temporarily overlapping phases: inflammation, proliferation, and remodeling. The inflammatory phase clears damaged cells, pathogens, and other debris through phagocytosis, paving the way for the proliferative phase. However, abnormally prolonged inflammation leads to the excessive release of cytotoxic enzymes, inflammatory mediators, free radicals, and cytokines, causing widespread cellular damage to surrounding tissues. Excessive free radical production also induces oxidative stress, leading to harmful cytotoxic effects and delayed wound healing. Therefore, introducing anti-inflammatory and antioxidant agents to reduce persistent inflammation and excess free radicals may be an important strategy for improving wound healing.

[0003] Oxidative stress caused by excessive accumulation of reactive oxygen species (ROS) around ulcer wounds can lead to excessive inflammatory responses and slow down healing. This is because cerium dioxide nanoparticles (CeO2 NPs) have abundant oxygen vacancies on their surface. 3+ and Ce 4+ The ability to reversibly transfer CeO2 NPs has led to their widespread application in both traditional catalysis and photocatalysis. As a good free radical scavenger, CeO2 NPs also have excellent antioxidant activity and have great potential in the treatment of atherosclerosis, arthritis, and neurodegenerative diseases. In addition, studies have shown that CeO2 can promote the proliferation and migration of cells around chronic ulcer wounds, eliminate ROS, and accelerate wound healing. Summary of the Invention

[0004] In view of this, the present invention aims to overcome the defects in the prior art and propose a rare earth material with high efficiency in scavenging reactive oxygen species, its preparation method and application.

[0005] To achieve the above objectives, the technical solution of the present invention is implemented as follows: In a first aspect, the present invention provides a rare earth material with high efficiency in scavenging reactive oxygen species, the rare earth material comprising rare earth cerium salt, pH adjuster, copper salt, zinc oxide (ZnO) and boron nitride (BN) in a molar ratio of (5-7):(8-12):(4-6):(1-3):(0.5-1.5).

[0006] Preferably, the rare earth cerium salt is one or more of cerium sulfate, cerium nitrate, and cerium carbonate.

[0007] Preferably, the copper salt is copper sulfate and / or copper nitrate.

[0008] Preferably, the pH adjuster is one or more of citric acid, tartaric acid, oxalic acid, and ethylenediaminetetraacetic acid.

[0009] Preferably, the zinc oxide is nano-sized zinc oxide with a particle size of 20-50 nm.

[0010] Preferably, the boron nitride is hexagonal boron nitride with a particle size of 10-30 nm.

[0011] Secondly, the present invention also provides a method for preparing the above-mentioned rare earth material with high efficiency in scavenging reactive oxygen species, the preparation method comprising the following steps: S1: Dissolve the pH adjuster in water, add copper salt, zinc oxide and boron nitride to the solution, ultrasonically disperse for 30-60 minutes, and stir evenly to form a composite salt solution; S2: Add rare earth cerium salt and ethylene glycol to the composite salt solution, and stir the solution at 75℃-85℃ until a blue gel is formed. Dry the blue gel at 110℃-130℃ for 14-15 hours. Grind the dried gel and calcine the resulting powder at 750℃-850℃ for 2-4 hours. S3: Add 2%-4% polyvinyl alcohol to the calcined powder and grind it. Then sinter the ground powder at 950℃-1050℃ for 2-4 hours to obtain multi-doped CeO2 nanocrystalline material, which is a rare earth material with high efficiency in scavenging active oxygen.

[0012] Thirdly, this invention also provides the application of the aforementioned rare earth materials in the preparation of anti-inflammatory wound dressing films. Compared with the prior art, this invention has the following advantages: (1) This invention successfully prepared multi-element doped CeO2 nanocrystalline materials with an oxygen vacancy concentration of over 20% through the synergistic effect of rare earth cerium salts, pH adjusters, copper salts, zinc oxide, and boron nitride. Zinc oxide can regulate the electron distribution on the material surface, and boron nitride can optimize the crystal structure arrangement. The two, together with copper salts, further enhance the number and stability of oxygen vacancies. Its free radical scavenging rate constant is more than 15 times higher than that of traditional materials, and it can significantly inhibit the inflammatory response during the inflammatory phase of wound healing. (2) The rare earth anti-inflammatory wound dressing film prepared by the present invention exhibits excellent inhibitory effect on Escherichia coli, with an antibacterial rate of over 99.9%; (3) The present invention uses a green process combining sol-gel method and high-temperature calcination to prepare nanocrystalline materials. During the calcination and sintering process in air atmosphere, high-density oxygen vacancies and uniform multi-element doped structure are formed. At the same time, large-scale production can be achieved without additional carrier, which significantly reduces the process cost of material preparation. (4) The rare earth material of this invention possesses dual enzyme-like activities mimicking superoxide dismutase (SOD) and catalase (CAT). Ce on the material surface... 3+ / Ce 4+ The redox pair, through synergistic interfacial interactions with zinc oxide and boron nitride, can catalyze the formation of superoxide anions (O₂O₃). 2- The oxygen undergoes a disproportionation reaction to produce hydrogen peroxide (H2O2) and oxygen (O2), which further catalyzes the decomposition of H2O2 into water and oxygen. Through this cyclic catalytic process, various reactive oxygen species (ROS) in the wound microenvironment can be efficiently and continuously removed, thereby effectively alleviating oxidative stress. Attached Figure Description

[0013] Figure 1 SEM images of the CuO / CeO2 composite material prepared in Example 1 at different resolutions; Figure 2 To test the active oxygen scavenging efficiency of CeO2 nanocrystals prepared in Example 1 at different concentrations; Figure 3 A statistical chart of agar-coated plate data for Test Example 2; Figure 4 The survival rate of Escherichia coli prepared in Example 1 of Test Example 2 was compared with that of the blank control group. Detailed Implementation

[0014] The embodiments of the present invention are described in detail below. The embodiments described below are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0015] In this document, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0016] In this document, when values ​​are described as ranges, it should be understood that such disclosure includes disclosure of all possible subranges within that range, as well as the specific numerical values ​​falling within that range, regardless of whether the specific numerical value or specific subrange is explicitly specified.

[0017] In this article, the terms "multiple" or "more than" are used unless otherwise specified, referring to a quantity greater than or equal to 2. For example, "one or more" means one or more types.

[0018] In this document, the terms "preferred" and "more preferred" are used only to describe implementation methods or embodiments with better effects, and should be understood as not constituting a limitation on the scope of protection of this invention.

[0019] In this document, terms such as "further" are used for descriptive purposes to indicate differences in content, but should not be construed as limiting the scope of protection of this invention.

[0020] In this article, the term "and / or" describes an association between objects, indicating that three relationships can exist. For example, A and / or B means: A or B, or A and B.

[0021] In this document, the term "about" means a specified value of + / - 10%, preferably + / - 5%, and more preferably + / - 1%.

[0022] In this article, the terms “include,” “including,” “have,” “contain,” etc., are all open-ended terms, meaning that they include but are not limited to.

[0023] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar to or equivalent to those described herein may be used in the implementation or testing of this invention.

[0024] Cerium nitrate (Ce(NO3)3), citric acid (CA), copper acetate (Cu(CH3COO)2), nano zinc oxide (particle size 20-50 nm), and hexagonal boron nitride (particle size 10-30 nm) were purchased from Aladdin Chemicals Ltd. All chemicals were used without further treatment. Distilled water (ρ=18.2 MΩ·cm, 25℃) was obtained from the Millipore Milli-Q water purification system. Gram-negative bacteria. E. coli All reagents are from Beijing Sihuan Biopharmaceutical Co., Ltd. Unless otherwise specified, all reagents are standard biochemical reagents; all experimental methods, unless otherwise specified, are standard methods.

[0025] The present invention will be described in detail below with reference to the embodiments.

[0026] Example 1 4.80 g of citric acid (CA, 0.025 mol) was dissolved in 100 mL of distilled water. 2.5 g of copper acetate (Cu(CH3COO)2·H2O, 0.0125 mol), 0.41 g of nano zinc oxide (0.005 mol), and 0.062 g of hexagonal boron nitride (0.0025 mol) were added to the solution. After ultrasonic dispersion for 45 minutes, the mixture was stirred until homogeneous to form a composite salt solution.

[0027] 6.51 g of cerium nitrate (Ce(NO3)3·6H2O, 0.015 mol) and 20 mL of ethylene glycol were added to the above solution, and the solution was stirred at 80 °C with a magnetic stirrer until a blue gel remained in the container. The gel was dried at 120 °C for 15 hours. The dried gel was ground in a mortar. The resulting powder was poured into an alumina crucible and calcined in air at 800 °C for 2 hours. The calcined powder was then ground again by adding 2% polyvinyl alcohol (PVA). Finally, the prepared powder was sintered at 1000 °C for 3 hours in atmospheric air at room temperature to obtain multi-component doped CeO2 nanocrystalline materials.

[0028] Example 2 This embodiment illustrates that high-performance materials can still be prepared when the molar ratio of each component is at the lower limit of the claim range.

[0029] 3.69 g of citric acid (CA, 0.0192 mol) was dissolved in 100 mL of distilled water. 1.92 g of copper acetate (Cu(CH3COO)2·H2O, 0.0096 mol), 0.20 g of nano zinc oxide (0.0024 mol), and 0.030 g of hexagonal boron nitride (0.0012 mol) were added to the solution. After ultrasonic dispersion for 30 minutes, the mixture was stirred until homogeneous to form a composite salt solution.

[0030] 5.21 g of cerium nitrate (Ce(NO3)3·6H2O, 0.012 mol) and 20 mL of ethylene glycol were added to the above solution, and the solution was stirred with a magnetic stirrer at 75 °C until a blue gel was formed. The gel was dried at 110 °C for 15 hours. The dried gel was ground in a mortar. The resulting powder was poured into an alumina crucible and calcined in air at 750 °C for 4 hours. The calcined powder was then ground again by adding 2% polyvinyl alcohol (PVA). Finally, the prepared powder was sintered at 950 °C for 4 hours in air at room temperature to obtain multi-component doped CeO2 nanocrystalline materials.

[0031] Example 3 This embodiment illustrates that excellent performance can still be obtained when the molar ratio of each component is at the upper limit of the claim range.

[0032] 5.93 g of citric acid (CA, 0.0309 mol) was dissolved in 100 mL of distilled water. 3.08 g of copper acetate (Cu(CH3COO)2·H2O, 0.0154 mol), 0.63 g of nano zinc oxide (0.0077 mol), and 0.096 g of hexagonal boron nitride (0.0039 mol) were added to the solution. After ultrasonic dispersion for 60 minutes, the mixture was stirred until homogeneous to form a composite salt solution.

[0033] 7.82 g of cerium nitrate (Ce(NO3)3·6H2O, 0.018 mol) and 20 mL of ethylene glycol were added to the above solution, and the solution was stirred with a magnetic stirrer at 85 °C until a blue gel was formed. The gel was dried at 130 °C for 14 hours. The dried gel was ground in a mortar. The resulting powder was poured into an alumina crucible and calcined in air at 850 °C for 2 hours. The calcined powder was then ground again by adding 4% polyvinyl alcohol (PVA). Finally, the prepared powder was sintered at 1050 °C for 2 hours in atmospheric air at room temperature to obtain multi-component doped CeO2 nanocrystalline materials.

[0034] Example 4 This example illustrates that high-performance materials can also be prepared using other pH adjusters.

[0035] Dissolve 3.75 g tartaric acid (TA, 0.025 mol) in 100 mL distilled water. Add 3.12 g copper sulfate (CuSO4·5H2O, 0.0125 mol), 0.41 g nano zinc oxide (0.005 mol), and 0.062 g hexagonal boron nitride (0.0025 mol) to the solution. After ultrasonic dispersion for 60 minutes, stir until homogeneous to form a composite salt solution.

[0036] 6.06 g of cerium sulfate (Ce(SO4)2·4H2O, 0.015 mol) and 20 mL of ethylene glycol were added to the above solution, and the solution was stirred at 85 °C with a magnetic stirrer until a blue gel was formed. The gel was dried at 130 °C for 14 hours. The dried gel was ground in a mortar. The resulting powder was poured into an alumina crucible and calcined in air at 850 °C for 2 hours. The calcined powder was then ground again by adding 4% polyvinyl alcohol (PVA). Finally, the prepared powder was sintered at 1050 °C for 2 hours in atmospheric air at room temperature to obtain multi-component doped CeO2 nanocrystalline materials.

[0037] Comparative Example 1 This comparative example uses commercially available cerium dioxide nanoparticles (CeO2 NPs) with a particle size of approximately 50 nm and a low oxygen vacancy concentration (approximately 5%).

[0038] Comparative Example 2 4.80 g of citric acid was dissolved in 100 mL of distilled water. Without adding copper salts, zinc oxide, or boron nitride, 6.51 g of cerium nitrate (Ce(NO3)3·6H2O) and 20 mL of ethylene glycol were added directly to the solution. The solution was stirred at 80 °C with a magnetic stirrer until a blue gel remained in the container. The gel was dried at 120 °C for 15 hours. The dried gel was then ground in a mortar. The resulting powder was poured into an alumina crucible and calcined in air at 800 °C for 2 hours. The calcined powder was then ground again by adding 2% polyvinyl alcohol (PVA). Finally, the prepared powder was sintered at 1000 °C for 3 hours in atmospheric air at room temperature to obtain undoped pure CeO2 material.

[0039] Comparative Example 3 15.0 g of citric acid (CA, 0.079 mol) was dissolved in 100 mL of distilled water. 3.0 g of copper acetate (Cu(CH3COO)2, 0.017 mol), 0.3 g of nano-zinc oxide (0.004 mol), and 0.2 g of hexagonal boron nitride (0.002 mol) were added to the solution, and the mixture was stirred until homogeneous to form a metal salt solution. 4.0 g of cerium nitrate (Ce(NO3)3·6H2O, 0.009 mol) and 20 mL of ethylene glycol were added to the above solution, and the solution was stirred at 80°C with a magnetic stirrer until a blue gel formed. Subsequent drying (120°C, 15 h), calcination (800°C, 2 h), grinding, and sintering (1000°C, 3 h) were performed as in Example 1.

[0040] Comparative Example 4 4.80 g of citric acid was dissolved in 100 mL of distilled water. 2.5 g of copper acetate was added to the solution, without adding zinc oxide or boron nitride. The solution was ultrasonically dispersed for 45 minutes and then stirred until homogeneous to form a salt solution. 6.51 g of cerium nitrate (Ce(NO3)3·6H2O) and 20 mL of ethylene glycol were added to the above solution, and the solution was stirred at 80°C with a magnetic stirrer until a blue gel remained in the container. Subsequent drying (120°C, 15 h), calcination (800°C, 2 h), grinding (with the addition of 2% PVA), and sintering (1000°C, 3 h) were performed as in Example 1 to obtain a copper-doped CeO2 material.

[0041] Test Example 1: Reactive Oxygen Species (ROS) Scavenging Efficiency Escherichia coli was incubated with different concentrations (0 mg / mL, 5 mg / mL, 10 mg / mL, 15 mg / mL, 20 mg / mL, 25 mg / mL, 30 mg / mL) of the multi-doped CeO2 nanocrystals prepared in Examples 1 and 30 mg / mL in Examples 2-4. After 9 hours, E. coli were collected and intracellular reactive oxygen species (ROS) levels were measured using a reactive oxygen species detection kit (DCFH-DA method). Specific procedures: Take 1 mL of bacterial suspension, add 30 μL × 1.0 mM 2',7'-dichlorofluorescein diacetate (DCFH-DA) probe, incubate at 37°C in the dark for 30 minutes, wash 3 times with phosphate-buffered saline (PBS) to remove unloaded probe, and measure the fluorescence intensity using a Shimadzu RF-5301PC fluorescence spectrophotometer (λex=488nm; λem=525nm). The fluorescence intensity indirectly reflects the ROS content, and the reactive oxygen species scavenging efficiency is calculated (scavenging efficiency % = (fluorescence intensity of blank group - fluorescence intensity of experimental group) / fluorescence intensity of blank group × 100%).

[0042] Five control groups were set up: Control group 1 used commercially available cerium dioxide nanoparticles (CeO2 NPs, particle size approximately 50 nm, oxygen vacancy concentration approximately 5%), as described in Comparative Example 1; Control group 2 used undoped pure CeO2 material prepared in Comparative Example 2; Control group 3 used doped material with an out-of-range ratio prepared in Comparative Example 3; Control group 4 used copper-doped CeO2 material prepared in Comparative Example 4; Control group 5 used traditional copper-doped CeO2 material without zinc oxide and boron nitride (same as Comparative Example 4). The experimental conditions were kept consistent with the experimental groups. The experimental results are shown in Table 1. Table 1 Results of reactive oxygen species scavenging efficiency

[0043] Test results showed that the ROS scavenging efficiency of the experimental group materials increased significantly with increasing concentration, reaching over 88% at 30 mg / mL, with Example 1 reaching 90.0%. The free radical scavenging rate constant was more than 15 times that of commercially available CeO2 NPs (Comparative Example 1) and more than 3 times that of copper-doped CeO2 materials (Comparative Example 4). The scavenging efficiency of undoped Comparative Example 2, Comparative Example 3 with an out-of-range ratio, and Comparative Example 4 without added zinc oxide and boron nitride was significantly lower than that of the experimental group, verifying the synergistic effect of zinc oxide, boron nitride, and other components, as well as the key role of reasonable ratio. Furthermore, the experimental group materials with different pH adjusters and different ratio ranges (5-7:8-12:4-6:1-3:0.5-1.5) all exhibited excellent ROS scavenging performance, demonstrating the stability and universality of the technical solution of this invention.

[0044] Test Example 2: Antibacterial Experiment (1) Bacterial culture Gram-negative *Escherichia coli* was cultured in Luria-Bertani (LB) agar at 37°C for 14–16 hours to obtain bacterial suspensions. Freshly harvested cells were used for each experiment. *E. coli* growth was assessed by optical density (OD600) measurement at 600 nm. Subsequent experiments used bacterial suspensions with OD600 = 0.4–0.6.

[0045] (2) Agar plate experiment The test sample was mixed with a fresh E. coli suspension (OD600 = 0.2). After incubation at 37°C for 3 hours, 0.2 mL of the diluted bacterial suspension was spread onto LB agar, and bacterial cell viability was determined using the standard plate count method. After culturing for 16–18 hours, the cells were photographed and colonies were counted at 37°C.

[0046] Similarly, we selected the density containing E. coli as OD. 600 LB liquid medium with a concentration of 0.1-0.2 μL was used as a blank control. We transferred 100 μL of the solution to blank culture dishes and incubated them in a constant temperature incubator following the above procedure. Three parallel experiments were conducted. The experimental results are shown in Table 2. Table 2 Results of antibacterial experiment

[0047] Test results showed that the E. coli in the blank control group grew better and were evenly distributed on the agar plate. Figure 3 After incubation with the experimental group materials, the survival rate of Escherichia coli decreased to below 0.034%, and the inhibition rate reached over 99.96%, with Example 1 achieving an inhibition rate of 99.99% against Escherichia coli. Figure 4 The antibacterial rates of Comparative Examples 2-4 were significantly lower than those of the experimental group, indicating that the synergistic effect of zinc oxide, boron nitride, rare earth cerium salts, copper salts, and pH adjusters, as well as the reasonable ratio range, are the key to the material obtaining excellent broad-spectrum antibacterial performance.

[0048] Test Example 3: Oxygen Vacancy Characterization Experiment (1) X-ray photoelectron spectroscopy (XPS) test O1s orbital analysis was performed on the materials of Examples 1-4 and Comparative Examples 1-4 using a Thermo Scientific K-Alpha+ X-ray photoelectron spectroscopy system. The oxygen vacancy content was calculated by peak fitting. The binding energy peak of the O1s orbital can be decomposed into lattice oxygen (O lattice, ~529.8 eV), adsorbed oxygen (O ads, ~531.2 eV), and oxygen vacancy-related oxygen (O vacancy, ~532.5 eV). The oxygen vacancy concentration was calculated as the ratio of the peak area of ​​oxygen vacancy-related oxygen to the total oxygen peak area.

[0049] (2) Electron paramagnetic resonance (EPR) test The materials of Examples 1-4 and Comparative Examples 1-4 were tested using a Bruker A300 electron paramagnetic resonance spectrometer. The test conditions were: microwave frequency 9.8 GHz, power 2 mW, modulation frequency 100 kHz, modulation amplitude 0.1 mT, and temperature 298 K. Oxygen vacancies, acting as trapping centers for unpaired electrons, exhibit characteristic signal peaks in the EPR spectrum, and the signal intensity is positively correlated with the oxygen vacancy concentration. The experimental results are shown in Table 3. Table 3. Experimental results for characterizing oxygen vacancies

[0050] Test results showed that the oxygen vacancy concentration in the experimental group materials all reached over 22%, with Example 1 having an oxygen vacancy concentration of 24.8%, which meets the technical characteristic of "oxygen vacancy concentration of over 20%" claimed in this invention. The corresponding EPR characteristic peak intensity was significantly higher than that of the comparative examples. The oxygen vacancy concentrations of Comparative Examples 1-4 were all below 16%, and the EPR characteristic peak intensities were also significantly weaker. XPS and EPR tests directly demonstrated the high oxygen vacancy concentration characteristics in the materials of this invention from different perspectives, and verified that the synergistic effect of copper salt, rare earth cerium salt, and pH adjuster can significantly increase the oxygen vacancy concentration, providing direct structural evidence for the high reactive oxygen scavenging efficiency and excellent antibacterial performance of the materials.

[0051] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A rare earth material having a high efficiency of scavenging reactive oxygen species, characterized by: The rare earth materials include rare earth cerium salts, pH adjusters, copper salts, zinc oxide, and boron nitride in a molar ratio of (5-7):(8-12):(4-6):(1-3):(0.5-1.5).

2. The rare earth material with high efficiency scavenging active oxygen according to claim 1, characterized in that: The rare earth cerium salt is one or more of cerium sulfate, cerium nitrate, and cerium carbonate.

3. The rare earth material with high efficiency in scavenging reactive oxygen species according to claim 1, characterized in that: The copper salt is copper sulfate and / or copper nitrate.

4. The rare earth material with high efficiency in scavenging reactive oxygen species according to claim 1, characterized in that: The pH adjuster is one or more of citric acid, tartaric acid, oxalic acid, and ethylenediaminetetraacetic acid.

5. The rare earth material with high efficiency in scavenging reactive oxygen species according to claim 1, characterized in that: The zinc oxide is nanoscale zinc oxide with a particle size of 20-50 nm.

6. The rare earth material with high efficiency in scavenging reactive oxygen species according to claim 1, characterized in that: The boron nitride is a hexagonal phase boron nitride with a particle size of 10-30 nm.

7. The method for preparing rare earth materials with high efficiency in scavenging reactive oxygen species as described in any one of claims 1-6, characterized in that... The preparation method includes the following steps: S1: Dissolve the pH adjuster in water, add copper salt, zinc oxide and boron nitride to the solution, ultrasonically disperse for 30-60 minutes, and then stir evenly to form a composite salt solution; S2: Add rare earth cerium salt and ethylene glycol to the composite salt solution, and stir the solution at 75-85℃ until a blue gel is formed. Dry the blue gel at 110℃-130℃ for 14-15 hours. Grind the dried gel and calcine the resulting powder at 750℃-850℃ for 2-4 hours. S3: Add 2%-4% polyvinyl alcohol to the calcined powder and grind it. Then sinter the ground powder at 950℃-1050℃ for 2-4 hours to obtain multi-doped CeO2 nanocrystalline material, which is a rare earth material with high efficiency in scavenging active oxygen.

8. The application of the rare earth material with high efficiency in scavenging reactive oxygen species as described in any one of claims 1-6 in the preparation of anti-inflammatory wound dressing membranes.

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