High-entropy oxide material rich in oxygen vacancies and preparation method and application thereof

Abstract

The application belongs to the technical field of high-entropy oxides, and relates to a high-entropy oxide material rich in oxygen vacancies and a preparation method and application thereof. The preparation method of the high-entropy oxide (Ce / D-HEOs) rich in oxygen vacancies is as follows: taking nitrate salts of cobalt, chromium, iron, manganese, nickel and cerium as raw materials in an equimolar ratio, forming a uniform wet gel under the assistance of polyethylene glycol and citric acid, obtaining a high-entropy oxide precursor through combustion and air calcination, and finally obtaining the high-entropy oxide material rich in oxygen vacancies through inert atmosphere calcination treatment. Based on the synergistic effect of the photo-thermal effect and multi-enzyme catalytic activity, the Ce / D-HEOs can continuously kill bacteria, ablate biofilms and effectively inhibit the adhesion of algae on the surface of the material through photo-thermal and ROS. The composite antifouling coating prepared by using the Ce / D-HEOs exhibits long-acting antifouling performance superior to mainstream copper-based coatings, and provides a new method for solving the sustainability and biological toxicity problems of traditional antifouling technologies.

Description

Technical Field

[0001] This invention belongs to the field of high-entropy oxide technology, specifically relating to a high-entropy oxide material rich in oxygen vacancies, its preparation method, and its application. Background Technology

[0002] Marine biofouling refers to the biological communities that adhere to the surfaces of underwater facilities such as ships, offshore platforms, and aquaculture equipment. It can lead to increased drag, higher fuel consumption, accelerated structural corrosion, and increased safety hazards. Antifouling coatings are a widely used marine antifouling technology. They inhibit biofouling by releasing biotoxic antifouling active substances and act as a physical barrier to protect the substrate material. They also offer advantages such as easy construction and maintenance and low cost.

[0003] However, current marine antifouling coating technologies primarily rely on the continuous release of metallic compounds such as cuprous oxide and cuprous thiocyanate, or organic antifouling agents such as diuron and chlorothalonil, to kill and inhibit fouling organisms. However, this method suffers from several problems: firstly, the released toxic substances accumulate in the marine environment, causing persistent harm to non-target organisms and the marine ecosystem, failing to meet increasingly stringent environmental protection requirements; secondly, the antifouling effect diminishes as the antifouling agent is gradually consumed, making long-term stable protection difficult to achieve. Furthermore, with the strengthening of environmental regulations, the application of such antifouling agents faces increasing restrictions. Summary of the Invention

[0004] The purpose of this invention is to provide a high-entropy oxide material rich in oxygen vacancies, its preparation method, application, and marine antifouling coating, thereby overcoming the shortcomings of the prior art. A high-entropy oxide material (Ce / D-HEOs) with both multi-enzyme catalytic activity and photothermal properties was prepared, and a functional composite antifouling coating was prepared, exhibiting excellent antifouling performance and broad application prospects.

[0005] To achieve the above objectives, the technical solution of the present invention is as follows: In a first aspect, the present invention provides a method for preparing a high-entropy oxide rich in oxygen vacancies, comprising the following steps: (1) Cobalt salt, chromium salt, iron salt, manganese salt, nickel salt and cerium salt are added to water and mixed. Polyethylene glycol and citric acid are added in sequence and stirred and mixed. The pH is adjusted to neutral and the wet gel is obtained by evaporation and concentration. The molar ratio of cobalt salt, chromium salt, iron salt, manganese salt, nickel salt, and cerium salt is (0.8-1.2):(0.8-1.2):(0.8-1.2):(0.8-1.2):(0.8-1.2):(0.5-2). (2) The wet gel is subjected to a combustion reaction, followed by calcination in an air atmosphere to obtain a high-entropy oxide; (3) After pulverizing the high-entropy oxide, it is calcined under an inert atmosphere to obtain a high-entropy oxide rich in oxygen vacancies.

[0006] This preparation method achieves uniform complexation and dispersion of multi-metal ions at the molecular level through wet gel combustion synthesis combined with a two-step calcination process, and directionally introduces oxygen vacancies into the crystal lattice using controlled atmosphere heat treatment. The prepared high-entropy oxide possesses both the structural stability of a high-entropy system and the surface activity conferred by oxygen vacancies. It is not only uniform in composition and highly crystallized, but also has a tunable electronic structure, thus providing an effective preparation route for obtaining long-lasting, environmentally friendly antifouling functional materials.

[0007] Secondly, the present invention provides a high-entropy oxide rich in oxygen vacancies.

[0008] This oxygen-vacancy-rich high-entropy oxide (Ce / D-HEOs) is composed of multiple metallic elements such as cobalt, chromium, iron, manganese, nickel, and cerium in a high-entropy configuration. The synergistic effect of these multiple elements forms a stable single-phase structure, and the introduced oxygen vacancies further optimize the electronic structure and surface activity of the material. This structure not only enhances lattice distortion and thermal stability through the high-entropy effect, but also improves the adsorption and migration capacity of oxygen species by leveraging the variable valence properties of cerium and the redox synergy with other transition metals. As a result, it exhibits significantly enhanced functionality in photothermal conversion, multi-enzyme catalysis, and reactive oxygen species generation.

[0009] Thirdly, this invention provides the application of high-entropy oxides rich in oxygen vacancies in marine antifouling.

[0010] The abundant oxygen vacancies on the surface of high-entropy oxides can modulate the hydrophilicity and hydrophobicity of the material and promote the continuous generation of reactive oxygen species (ROS), achieving highly efficient inhibition and elimination of fouling organisms such as bacteria and algae. Simultaneously, the synergistic effect between the high-entropy components endows the material with excellent photothermal conversion capabilities and multi-enzyme catalytic activity, further enhancing antifouling efficiency under light irradiation. This material is environmentally friendly, does not release toxic substances, and is structurally stable and resistant to seawater corrosion, maintaining its antifouling performance for a long time, providing a new path for developing green, efficient, and durable marine antifouling coatings.

[0011] The beneficial effects of this invention are: (1) The preparation method has the advantages of simple process, uniform composition and controllable structure. By adding polyethylene glycol and citric acid, a variety of metal ions are uniformly complexed and dispersed, which effectively avoids component segregation; the wet gel can form a high-entropy oxide with a single phase structure by low-temperature combustion and subsequent calcination; finally, heat treatment under an inert atmosphere can introduce oxygen vacancies in the crystal in an orderly manner, thereby improving the catalytic and surface activity of the material.

[0012] (2) The Ce / D-HEOs prepared by introducing oxygen vacancies through cerium doping and oxygen-deficient calcination in this invention effectively reduces the band gap of the material, enhances light absorption and photothermal conversion efficiency, and thus improves photothermal sterilization performance. At the same time, its oxidase (OXD) activity can catalyze the generation of ROS, inhibiting biofilm adhesion; while its catalase (CAT) properties can catalyze the generation of O2 from H2O2 in seawater, further promoting OXD activity and achieving continuous ROS generation. This synergistic mechanism of photothermal and multi-enzyme catalysis enables Ce / D-HEOs to efficiently and continuously kill bacteria, remove biofilms and inhibit algal adhesion, demonstrating long-lasting and environmentally friendly marine antifouling potential.

[0013] (3) The oxygen-vacancy-rich high-entropy oxide prepared by this invention has a spherical structure with a particle size of 80-120 nm; the photothermal conversion efficiency is ≥85%, and the degradation rates of methylene blue and rhodamine B are ≥95% and 93%, respectively; under light conditions, the antibacterial rate against Gram-positive methicillin-resistant Staphylococcus aureus and Gram-negative Escherichia coli is ≥99%. The marine antifouling coating prepared by this invention has a biofilm removal rate of ≥83%, a tensile strength of ≥11 MPa, and an inhibition rate of ≥99% against diatoms (Navicula sp.) and green algae (Chlorella sp.). Attached Figure Description

[0014] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0015] Figure 1 This is a schematic diagram illustrating the principle of achieving sustainable marine antifouling based on the photothermal properties of Ce / D-HEOs and a multi-enzyme catalytic synergistic strategy. Figure 2 These are representative SEM images of Ce / D-HEOs; Figure 3 The energy spectrum images of representative elements in Ce / D-HEOs; Figure 4 Representative photothermal images and corresponding photothermal heating curves for HEOs, D-HEOs, and all Ce / D-HEOs are shown, where a is a representative photothermal image and b is the photothermal heating curve corresponding to a. Figure 5The diagram shows the photothermal stability test results for Ce / D-HEOs and the photothermal cycling curves for HEOs, D-HEOs, and all Ce / D-HEOs. Specifically, a is the photothermal stability test diagram, b is the photothermal cycling curve for HEOs, c is the photothermal cycling curve for D-HEOs, d is the photothermal cycling curve for 0.5 Ce / D-HEOs, e is the photothermal cycling curve for 1 Ce / D-HEOs, and f is the photothermal cycling curve for 2 Ce / D-HEOs. Figure 6 The UV-vis absorption spectra and corresponding degradation rates of MB catalyzed by HEOs, D-HEOs, and all Ce / D-HEOs are shown below. Specifically, a represents the UV-vis absorption spectrum of MB catalyzed by HEOs, b represents the UV-vis absorption spectrum of MB catalyzed by D-HEOs, c represents the UV-vis absorption spectrum of MB catalyzed by 0.5 Ce / D-HEOs, d represents the UV-vis absorption spectrum of MB catalyzed by 1 Ce / D-HEOs, e represents the UV-vis absorption spectrum of MB catalyzed by 2 Ce / D-HEOs, and f represents the degradation rate of MB catalyzed by HEOs, D-HEOs, and all Ce / D-HEOs. Figure 7 The diagram shows the UV-vis absorption spectra and corresponding degradation rates of RhB catalyzed by HEOs, D-HEOs, and all Ce / D-HEOs. Specifically, a represents the UV-vis absorption spectrum of RhB catalyzed by HEOs, b represents the UV-vis absorption spectrum of RhB catalyzed by D-HEOs, c represents the UV-vis absorption spectrum of RhB catalyzed by 0.5 Ce / D-HEOs, d represents the UV-vis absorption spectrum of RhB catalyzed by 1 Ce / D-HEOs, e represents the UV-vis absorption spectrum of RhB catalyzed by 2 Ce / D-HEOs, and f represents the degradation rates of RhB catalyzed by HEOs, D-HEOs, and all Ce / D-HEOs. Figure 8 Michaelis-Menten kinetic analysis and Lineweaver-Burk curves for D-HEOs and Ce / D-HEOs are shown, where a is the kinetic analysis plot and b is the Lineweaver-Burk curve. Figure 9 Dissolved oxygen generation detection for HEOs, D-HEOs, and all Ce / D-HEOs; Figure 10 The graphs show the degradation rates of MB and RhB by Ce / D-HEOs under normal or H2O2 addition conditions. In the graphs, a represents the degradation rate of MB and b represents the degradation rate of RhB. Figure 11The images show representative bacterial smears and related antimicrobial rate statistics for PBS, HEOs, D-HEOs, and Ce / D-HEOs under dark conditions. In the image, a is a representative bacterial smear under dark conditions, and b is the antimicrobial rate statistics corresponding to a. Figure 12 The images show representative bacterial smears and related antibacterial rate statistics for PBS, HEOs, D-HEOs, and Ce / D-HEOs under light conditions. In the image, a is a representative bacterial smear under light conditions, and b is the antibacterial rate statistics corresponding to a. Figure 13 For different treatment conditions, MRSA and E. coli Representative SEM images, where a is a representative SEM image of MRSA, and b is... E. coli Representative SEM images; Figure 14 The images show representative CLSM images and corresponding thickness statistics of different materials for biofilm removal under dark conditions. In the image, a is a representative CLSM image under dark conditions, and b is the thickness statistics corresponding to a. Figure 15 The images show representative CLSM images and corresponding thickness statistics of different materials for biofilm removal under illumination conditions. In the image, a is a representative CLSM image under illumination conditions, and b is the thickness statistics corresponding to a. Figure 16 Stress-strain curves for PDMS, HEOs, D-HEOs, and Ce / D-HEOs coatings; Figure 17 Optical microscope images, CLSM images, and corresponding anti-algae rate diagrams of PDMS, HEOs, D-HEOs, and Ce / D-HEOs coatings after different algal cell treatments are shown. In the image, a is an optical microscope image of the coating, b is a CLSM image, and c is an anti-algae rate diagram. Figure 18 These are photographs showing the surface contamination of PDMS, HEOs, D-HEOs, and Ce / D-HEOs coatings after 90 days of immersion. Figure 19 This is a statistical chart showing the fouling rate of different substrates and PDMS, HEOs, D-HEOs and Ce / D-HEOs coatings after 90 days of immersion. Figure 20 Representative photographs of metallic paint, commercial antifouling paint RAL, HEOs and Ce / D-HEOs antifouling paint before and after 150 days of immersion in the Yellow Sea are shown. Among them, a is a representative photograph of antifouling paint after 0 days of immersion and b is a representative photograph of antifouling paint after 150 days of immersion. Figure 21A statistical chart showing the fouling coverage of metallic paint, commercial antifouling paint RAL, HEOs and Ce / D-HEOs antifouling paint before and after 150 days of immersion in the Yellow Sea; Among them, HEOs is the sample prepared in Comparative Example 2, D-HEOs is the sample prepared in Comparative Example 1, and Ce / D-HEOs is the Ce / D-HEOs sample prepared in Example 1. Detailed Implementation

[0016] Those skilled in the art will understand that the following embodiments are for illustrative purposes only and should not be construed as limiting the scope of the invention. Specific conditions are not specified in the embodiments; they are performed under conventional conditions or conditions recommended by the manufacturer. Unless otherwise specified, all components used are commercially available conventional products. Some of the materials used are as follows: Cobalt nitrate hexahydrate (Co(NO3)2·6H2O), chromium nitrate nonahydrate (Cr(NO3)3·9H2O), ferric nitrate nonahydrate (Fe(NO3)3·9H2O), manganese nitrate hexahydrate (Mn(NO3)2·6H2O), nickel nitrate hexahydrate (Ni(NO3)2·6H2O), and cerium nitrate hexahydrate (Ce(NO3)3·6H2O) were all purchased from Sigma-Aldrich. Polyethylene glycol, Rhodamine B, methylene blue, 5,5-dimethyl-1-pyrrolidine-N-oxide (DMPO), hydrogen peroxide, tryptic soy agar medium, Luria-Bertani broth medium, and Luria-Bertani nutrient agar were all purchased from Maclean's Biochemical Technology Co., Ltd. Citric acid and polydimethylsiloxane (PDMS) were purchased from Shanghai Yuanye Biotechnology Co., Ltd. Ammonia and anhydrous ethanol were purchased from Sinopharm Chemical Reagent Co., Ltd. Phosphate buffer and tryptone soybean medium were purchased from Wuhan Cell Biotechnology Co., Ltd. Glass, polyvinyl chloride, epoxy resin, and 316 stainless steel plates were purchased from Shandong Chengchuan Life Science Technology Co., Ltd. Live / dead bacterial staining reagents were purchased from Thermo Fisher Scientific. Other chemicals were from Shanghai Yuanye Biotechnology Co., Ltd., and were ready for use without further purification. All experiments used deionized (DI) water (Millipore Milli-Q grade, 18.2 MΩ).

[0017] Current marine antifouling coatings generally rely on the release of toxic substances (such as copper-containing compounds and organic antifouling agents), which result in a gradual weakening of the antifouling effect as the agent is released, making it difficult to maintain its effectiveness. Toxic substances accumulate in the ocean, polluting the environment and being subject to strict regulations. The coatings are also prone to aging and failure in harsh marine environments, affecting long-term protection.

[0018] like Figure 1As shown, this invention prepares a high-entropy oxide material (Ce / D-HEOs) possessing both multi-enzyme catalytic activity and photothermal properties, and proposes an efficient and sustainable marine antifouling coating strategy. Ce doping and the oxygen vacancies introduced during the anoxic calcination process effectively reduce the band gap of the material, enhancing its light absorption capacity and thus effectively strengthening the photothermal properties of Ce / D-HEOs. Simultaneously, Ce / D-HEOs exhibit oxidase (OXD) catalytic activity, continuously generating reactive oxygen species (ROS) to achieve antifouling. Furthermore, the catalase (CAT) activity of Ce / D-HEOs catalyzes the generation of O2 from naturally occurring H2O2 in seawater. The generated O2 further promotes the OXD catalytic performance of Ce / D-HEOs, thereby achieving continuous ROS generation. Based on the synergistic effect of photothermal effect and multi-enzyme catalytic activity, Ce / D-HEOs can continuously kill bacteria and eliminate biofilms through photothermal effect and ROS, and effectively inhibit algae adhesion to the material surface. Furthermore, this study successfully prepared a series of functional composite antifouling coatings by mixing Ce / D-HEOs with a polydimethylsiloxane (PDMS) matrix, demonstrating excellent antifouling performance and broad application prospects. In actual marine siding experiments, the coatings containing Ce / D-HEOs exhibited superior long-term antifouling performance compared to mainstream copper-based (Cu2O) coatings. The photothermal and multi-enzyme catalytic synergistic strategy proposed in this study provides a new approach to addressing the sustainability and biotoxicity issues of traditional antifouling technologies, and is expected to promote the development of marine antifouling technologies towards a more stable, efficient, and widely applicable direction.

[0019] In a first aspect, the present invention provides a method for preparing a high-entropy oxide rich in oxygen vacancies, comprising the following steps: (1) Cobalt salt, chromium salt, iron salt, manganese salt, nickel salt and cerium salt are added to water and mixed. Polyethylene glycol and citric acid are added in sequence and stirred and mixed. The pH is adjusted to neutral and the wet gel is obtained by evaporation and concentration. The molar ratio of cobalt salt, chromium salt, iron salt, manganese salt, nickel salt, and cerium salt is (0.8-1.2):(0.8-1.2):(0.8-1.2):(0.8-1.2):(0.8-1.2):(0.5-2). (2) The wet gel is subjected to a combustion reaction, followed by calcination in an air atmosphere to obtain a high-entropy oxide; (3) After pulverizing the high-entropy oxide, it is calcined under an inert atmosphere to obtain a high-entropy oxide rich in oxygen vacancies.

[0020] This preparation method has the advantages of simple process, uniform composition and controllable structure. By adding polyethylene glycol and citric acid, the uniform complexation and dispersion of various metal ions are achieved, effectively avoiding component segregation; the wet gel can form a high-entropy oxide with a single-phase structure through low-temperature combustion and subsequent calcination; finally, heat treatment under an inert atmosphere can introduce oxygen vacancies into the crystal in an orderly manner, thereby improving the catalytic and surface activity of the material.

[0021] In some other embodiments, in step (1), the molar ratio of cobalt salt, chromium salt, iron salt, manganese salt, nickel salt and cerium salt is 1:1:1:1:1:(0.5-2). Cobalt salts are one or both of cobalt nitrate and cobalt chloride; Chromium salts are one or both of chromium nitrate and chromium chloride; Iron salts are one or both of ferric nitrate and ferric chloride; Manganese salts are one or both of manganese nitrate and manganese chloride; Nickel salts are one or both of nickel nitrate and nickel chloride; Cerium salts are one or both of cerium nitrate and cerium chloride.

[0022] Preferably, the molar ratio of cobalt salt, chromium salt, iron salt, manganese salt, nickel salt, and cerium salt is 1:1:1:1:1:1; the cobalt salt is cobalt nitrate, the chromium salt is chromium nitrate, the iron salt is ferric nitrate, the manganese salt is manganese nitrate, the nickel salt is nickel nitrate, and the cerium salt is cerium nitrate. This combination of six elements has significant advantages compared to other combinations of metallic elements. First, Co, Ni, and Fe are recognized as highly reactive elements in the oxygen evolution reaction, and the introduction of Cr can further promote the formation of higher oxidation states at active sites such as Co, Ni, and Fe, thereby optimizing the adsorption of oxygen-containing species on the surface and enhancing their structural stability. Furthermore, Mn possesses multiple variable valence states and can participate in electron transfer during the catalytic cycle, enriching the electronic structure of the material. In addition, due to its unique Ce... 4+ / Ce 3+ In redox pairs, Ce acts as a buffer in catalytic reactions, effectively enhancing the redox capacity of the material. Simultaneously, its large ionic radius exacerbates lattice distortion, generating more active defects such as oxygen vacancies, thereby further strengthening the material's catalytic performance. It is worth noting that these six metals are relatively abundant and do not rely on precious metals, giving the material significant advantages in cost and sustainability. In summary, we selected this combination of six metals to construct the high-entropy material.

[0023] This method employs six equimolar amounts of nitrates (Co, Cr, Fe, Mn, Ni, Ce): through the high-entropy effect and the synergistic effect of multiple variable-valence metal ions, a uniform polynuclear complex precursor is formed in the citric acid-polyethylene glycol system, achieving atomic-level dispersion and compositional homogeneity, effectively avoiding phase separation. During heat treatment, redox coupling between different metals promotes the formation of a single stable phase, and by utilizing the oxygen storage capacity of cerium and the differential affinity of other metals for oxygen, oxygen vacancies are controllably introduced under a reducing atmosphere, thereby optimizing the electronic structure, surface activity, and stability of the material. This lays the compositional and structural foundation for the controllable preparation of high-performance high-entropy oxides.

[0024] In some other embodiments, in step (1), the molecular weight of polyethylene glycol is 200-600, preferably 400. The mass ratio of polyethylene glycol to citric acid is (4-5):(11.5-14). The molar ratio of cobalt salt to citric acid is 1:(5.8-7.5). The evaporation and concentration are carried out at a temperature of 75-85°C for 10-15 hours.

[0025] A stable complex-dispersion network was constructed by compounding polyethylene glycol and citric acid, ensuring the uniform distribution of multi-metal ions and the stability of the gel structure. Controlling the molar ratio of cobalt salt to citric acid provided sufficient carboxyl coordination sites for effective metal ion integration while avoiding the adverse effects of excessive ligands on subsequent heat treatment processes, thus guaranteeing the uniformity of the high-entropy oxide precursor in terms of composition, structure, and particle size.

[0026] In step (2), the combustion reaction temperature is 120-140℃. Preferably, the combustion reaction temperature is 130℃. Directly initiating combustion of the wet gel enables low-temperature, rapid self-propagating combustion synthesis. This fully utilizes the large amount of heat released by the redox reaction of the organic components (polyethylene glycol, citric acid) in the precursor, completing the initial crystallization of high-entropy oxides in a short time. This avoids the component segregation or particle coarsening caused by traditional high-temperature, long-term calcination, and is beneficial for forming intermediate products with uniform composition, fine particles, and abundant defects.

[0027] In some other embodiments, in step (2) or step (3), the calcination temperature is 850-950℃, the time is 1-3h, and the heating rate is 2-5℃ / min. Preferably, in step (2) or step (3), the calcination temperature is 900℃, the time is 2h, and the heating rate is 3℃ / min. Slow heating can reduce material cracking or component segregation caused by thermal stress, and this calcination temperature range ensures that the material has sufficient crystallinity and thermal stability.

[0028] Secondly, the present invention provides a high-entropy oxide rich in oxygen vacancies.

[0029] The high-entropy oxide rich in oxygen vacancies prepared by this invention achieves a comprehensive improvement in surface activity, stability and environmental adaptability through the synergy of defect engineering and high-entropy effect, and also possesses photothermal and multiple enzyme-like activities.

[0030] Specifically, the high-entropy oxide rich in oxygen vacancies has a spherical structure with a particle size of 80-120 nm; the photothermal conversion efficiency is ≥85%; the degradation rates of methylene blue and rhodamine B are ≥95% and 93%, respectively; and the antibacterial rate against Gram-positive methicillin-resistant Staphylococcus aureus and Gram-negative Escherichia coli is ≥99% under light conditions.

[0031] Thirdly, this invention provides the application of high-entropy oxides rich in oxygen vacancies in marine antifouling.

[0032] High-entropy oxides rich in oxygen vacancies combine the synergistic effects of multiple elements in high-entropy materials with the advantages of defect engineering. Their oxygen vacancies not only modulate the electronic structure and surface energy of the material, enhancing photocatalytic / electrocatalytic activity and carrier transport efficiency, but also induce the generation of reactive oxygen species to achieve efficient and environmentally friendly antifouling and anti-corrosion functions. Simultaneously, the inherent lattice distortion and slow diffusion effects of the high-entropy system ensure the structural stability and compositional durability of the material under harsh environments, giving it a comprehensive advantage of environmental friendliness, tunable performance, and long-term reliability, making it a promising candidate for marine protection applications.

[0033] In some other embodiments, the marine antifouling coating used includes a high-entropy oxide rich in oxygen vacancies, an organic polymer matrix, and a curing agent.

[0034] In some other embodiments, the mass ratio of the oxygen-vacancy-rich high-entropy oxide, the organic polymer matrix, and the curing agent is 1:(18-22):(1.8-2.2); The organic polymer matrix is ​​polydimethylsiloxane; The curing agent is tetraethoxysilane.

[0035] High-entropy oxides utilize their oxygen vacancies and surface functions to avoid agglomeration or degradation of coating mechanical properties caused by excessive fillers; the PDMS matrix provides good adhesion, flexibility, and environmental aging resistance while ensuring that the coating has suitable application viscosity and film-forming properties; the curing agent can achieve full cross-linking of PDMS without affecting the dispersion stability of fillers and the surface characteristics of the coating, ultimately giving the coating the advantages of long-lasting antifouling, environmental tolerance, and convenient application.

[0036] In some other embodiments, the preparation method of the marine antifouling coating is as follows: a high-entropy oxide rich in oxygen vacancies is added to an organic polymer matrix, stirred and mixed, and then a curing agent is added and mixed. After vacuum degassing and curing reaction, the marine antifouling coating is obtained; the curing reaction temperature is 75-85℃ and the time is 1-3h.

[0037] The preparation method is simple, mild, and easy to scale up: by directly incorporating high-entropy oxides rich in oxygen vacancies into an organic polymer matrix (such as PDMS), uniform dispersion of high-entropy oxides and effective cross-linking of PDMS can be achieved at a lower temperature, avoiding the destruction of oxygen vacancy structure by high temperature; the vacuum degassing step significantly reduces defects and bubbles inside the coating, improving its density and adhesion.

[0038] The solution of the present invention will be further described below with reference to specific embodiments and comparative examples: Example 1 A high-entropy oxide material rich in oxygen vacancies and its preparation method include the following steps: (1) Synthesis of high-entropy oxides Ce / HEOs: 2.91 g Co(NO3)2·6H2O, 4 g Cr(NO3)3·9H2O, 4.04 g Fe(NO3)3·9H2O, 2.87 g Mn(NO3)2·6H2O, 2.91 g Ni(NO3)2·6H2O, and 4.34 g Ce(NO3)3·6H2O were dissolved together in 30 mL of deionized water and sonicated for 10 minutes to ensure complete dissolution. Then, 4.8 g of polyethylene glycol (M...) was added sequentially. n =400) and 13.82 g of citric acid were mixed and stirred vigorously for 30 minutes. The pH of the solution was then adjusted to neutral with ammonia. The mixed solution was obtained by adjusting the pH of the solution to neutral with ammonia.

[0039] The mixed solution was transferred to a beaker and vigorously stirred at 80 °C for 12 hours to evaporate most of the solvent, forming a wet gel. The beaker containing the wet gel was transferred to a fume hood and placed on a 130 °C hot plate to initiate a combustion reaction. After complete combustion, the product was collected. The combustion product was thoroughly ground and transferred to a crucible, which was then placed in a tube furnace and calcined at 900 °C for 2 hours at a heating rate of 3 °C / min. After the sample was allowed to cool naturally to room temperature, it was removed and thoroughly ground again to obtain the high-entropy oxide Ce / HEOs.

[0040] (2) Synthesis of high-entropy oxides Ce-D / HEOs rich in oxygen vacancies: After homogenizing the high-entropy oxide Ce / HEOs, the samples were transferred to a crucible and placed in a tube furnace. Under an argon (Ar) atmosphere, the samples were heated to 900 °C for 2 hours at a heating rate of 3 °C / min to introduce oxygen vacancies into the material. After the samples cooled naturally to room temperature, they were removed and thoroughly ground again to obtain cerium-doped high-entropy oxide Ce / D-HEOs (labeled as 1Ce / D-HEOs).

[0041] In addition, following the above synthesis method, high-entropy oxides with different cerium doping contents (labeled as 0.5Ce / D-HEOs and 2Ce / D-HEOs) were synthesized by changing the mass of Ce(NO3)3·6H2O (adding 2.17 g or 6.51 g).

[0042] Comparative Example 1 A high-entropy oxide material rich in oxygen vacancies and its preparation method, which differs from Example 1 in that the addition of Ce(NO3)3·6H2O is omitted in step (1), and specifically includes the following steps: (1) Synthesis of high-entropy oxides (HEOs): 2.91 g Co(NO3)2·6H2O, 4 g Cr(NO3)3·9H2O, 4.04 g Fe(NO3)3·9H2O, 2.87 g Mn(NO3)2·6H2O, and 2.91 g Ni(NO3)2·6H2O were dissolved together in 20 mL of deionized water and sonicated for 10 minutes until completely dissolved. Then, 4 g of polyethylene glycol (M...) was added sequentially. n =400) and 11.52 g of citric acid were stirred vigorously for 30 minutes to ensure uniform mixing. The pH of the solution was then adjusted to neutral using ammonia water to obtain a mixed solution.

[0043] The mixed solution was transferred to a beaker and vigorously stirred at 80 °C for 12 hours to evaporate most of the solvent, forming a wet gel. The beaker containing the wet gel was transferred to a fume hood and placed on a 130 °C hot plate to initiate a combustion reaction. After complete combustion, the product was collected. The combustion product was thoroughly ground and transferred to a crucible, which was then placed in a tube furnace and heated to 900 °C for 2 hours at a heating rate of 3 °C / min. After the sample was allowed to cool naturally to room temperature, it was removed and thoroughly ground again to obtain high-entropy oxides (HEOs).

[0044] (2) Synthesis of high-entropy oxides D-HEOs rich in oxygen vacancies: After homogenizing the high-entropy oxides (HEOs), the samples were transferred to a crucible and placed in a tube furnace. Under an argon (Ar) atmosphere, the crucible was heated to 900 °C for 2 hours at a heating rate of 3 °C / min to introduce oxygen vacancies into the material. After the samples cooled naturally to room temperature, they were removed and thoroughly ground again to obtain oxygen-vacancy-rich high-entropy oxides (D-HEOs).

[0045] Comparative Example 2 A high-entropy oxide material and its preparation method, which differs from Comparative Example 1 in that step (2) of adding oxygen vacancies by calcination in an argon (Ar) environment is omitted. Specifically, it includes the following steps: Synthesis of high-entropy oxides (HEOs): 2.91 g Co(NO3)2·6H2O, 4 g Cr(NO3)3·9H2O, 4.04 g Fe(NO3)3·9H2O, 2.87 g Mn(NO3)2·6H2O, and 2.91 g Ni(NO3)2·6H2O were dissolved together in 20 mL of deionized water and sonicated for 10 minutes until completely dissolved. Then, 4 g of polyethylene glycol (M...) was added sequentially. n =400) and 11.52 g of citric acid were stirred vigorously for 30 minutes to ensure uniform mixing. The pH of the solution was then adjusted to neutral using ammonia water to obtain a mixed solution.

[0046] The mixed solution was transferred to a beaker and vigorously stirred at 80 °C for 12 hours to evaporate most of the solvent, forming a wet gel. The beaker containing the wet gel was transferred to a fume hood and placed on a 130 °C hot plate to initiate a combustion reaction. After complete combustion, the product was collected. The combustion product was thoroughly ground and transferred to a crucible, which was then placed in a tube furnace and heated to 900 °C for 2 hours at a heating rate of 3 °C / min. After the sample was allowed to cool naturally to room temperature, it was removed and thoroughly ground again to obtain high-entropy oxides (HEOs).

[0047] Example 2 A method for preparing a Ce / D-HEOs coating includes the following steps: 100 mg of Ce / D-HEOs was added to 1.9 g of polydimethylsiloxane (PDMS) and mixed thoroughly. Then, 0.19 g of curing agent tetraethoxysilane was added. After thorough mixing, the mixture was placed in a vacuum drying oven for degassing for 2 h. After degassing, the drying oven was heated to 80 °C under vacuum for 2 h to obtain the Ce / D-HEOs coating.

[0048] Following the steps described above, D-HEOs coatings (D-HEOs in Comparative Example 1) and... HEOs coating (HEOs in Comparative Example 2).

[0049] Performance testing: 1. Morphological characteristics and elemental distribution of Ce / D-HEOs: like Figure 2 As shown, the synthesized 1Ce / D-HEOs particles are spherical with a particle size of approximately 100 nm. Figure 3 As shown, elemental scanning results indicate that 1Ce / D-HEOs are mainly composed of Co, Cr, Mn, Fe, Ni, Ce, and O, and these elements are uniformly distributed within the particles. These results confirm that Ce has been successfully incorporated into the high-entropy oxide.

[0050] 2. Photothermal performance testing of Ce-D / HEOs: The photothermal properties of HEOs, D-HEOs, and all Ce / D-HEOs were systematically evaluated by monitoring the heating behavior of different high-entropy materials in aqueous solution. The specific experimental procedures are as follows: 2 mg of samples (including HEOs, D-HEOs, 0.5Ce / D-HEOs, 1Ce / D-HEOs, and 2Ce / D-HEOs) were weighed and dispersed in 2 mL of deionized water, and sonicated for 5 minutes to ensure uniform dispersion. Subsequently, the dispersions were irradiated under a 300W xenon lamp (operating current 18A), and the solution temperature was recorded every 5 minutes using a thermal imaging camera to obtain their photothermal response curves.

[0051] Under xenon lamp irradiation, the aqueous solution temperatures of all samples increased significantly. The highest temperatures for HEOs and D-HEOs reached 48.37 °C and 51.43 °C, respectively. In contrast, all Ce-doped samples exhibited significantly higher equilibrium temperatures (0.5Ce-D / HEOs: 57.5 °C, 1Ce-D / HEOs: 65.57 °C, and 2Ce-D / HEOs: 53.2 °C) (e.g., ...). Figure 4 As shown in a), its heating rate is also significantly better than that of HEOs and D-HEOs. Among all Ce-doped samples, 1Ce / D-HEOs exhibits the best photothermal performance, with a photothermal conversion efficiency as high as 89.60%, which is approximately 1.95 times that of pure HEOs (as shown in a diagram). Figure 4 (as shown in b in the text).

[0052] 3. Photothermal stability testing of Ce-D / HEOs: To evaluate the photothermal stability of different high-entropy materials, five rounds of thermal cycling tests were conducted on aqueous solutions of different high-entropy materials, and their temperature changes were monitored in real time using a thermal imager. Specifically, a 1 mg / mL sample solution was continuously irradiated under a 300W xenon lamp (operating current of 18A) for 10 minutes, then the xenon lamp was turned off, and the solution was allowed to cool naturally for 10 minutes. This operation was repeated five times. During the cycling process, the solution temperature was recorded every 2 minutes using a thermal imager to obtain its thermal cycling response curve.

[0053] Through five consecutive light-dark cycle experiments ( Figure 5 (a) for HEOs ( Figure 5 (b) D-HEOs ( Figure 5 c) and 0.5Ce / D-HEOs ( Figure 5 d) 1Ce / D-HEOs ( Figure 5 e) and 2Ce / D-HEOs ( Figure 5 The photothermal stability of f) was systematically evaluated. All samples exhibited excellent photothermal stability in 5 light-dark cycles, and their maximum heating temperature did not change significantly, indicating that all photothermal materials have good stability and durability.

[0054] 4. Detection of Ce-D / HEOs oxidase (OXD) activity: The OXD activity of Ce-D / HEOs was evaluated by detecting the degradation of methylene blue (MB) and rhodamine B (RhB). Specifically, 3 mg of Ce-D / HEOs were dispersed in 3 mL of MB (1 mM) or RhB (0.1 mM) aqueous solution, and the intensity of the characteristic absorption peaks of MB (664 nm) or RhB (554 nm) was measured every 2 minutes to assess the degree of degradation. Furthermore, the degradation rates of MB or RhB by HEOs, D-HEOs, 0.5Ce-D-HEOs, and 2Ce-D-HEOs were quantified using the aforementioned quantitative methods to screen for high-entropy materials with optimal OXD activity for subsequent studies.

[0055] By selecting methylene blue (MB) and rhodamine B (RhB) as model pollutants, the degradation rates of MB and RhB were monitored using ultraviolet-visible (UV-vis) absorption spectroscopy to systematically evaluate the OXD activity of the material. Compared to other experimental groups, specifically HEOs ( Figure 6 a in Figure 7 a) D-HEOs ( Figure 6 b in Figure 7 (b) 0.5Ce-D-HEOs Figure 6 c in Figure 7 c) and 2Ce-D-HEOs ( Figure 6 e in Figure 7 In the group e), the dyes of the 1Ce / D-HEOs group underwent significant degradation, which affected MB ( Figure 6 d) and RhB ( Figure 7 The degradation rates of d) in 1Ce / D-HEOs reached 97.09% and 93.63%, respectively, indicating that 1Ce / D-HEOs possessed the strongest OXD activity. Figure 6 f in Figure 7 f in the middle.

[0056] 5. Enzymatic reaction kinetics of Ce-D / HEOs: To investigate the OXD catalytic performance of D-HEOs and Ce-D / HEOs, the concentration of the substrate TMB was varied, and relevant parameters of the enzyme-catalyzed reaction kinetics (maximum reaction rate V) were analyzed. max and Mi constant K m The TMB concentration was measured. Specifically, 1 mg / mL D-HEOs or Ce-D / HEOs were added to TMB solutions of different concentrations (0.2, 0.5, 1, 1.2, 1.5, and 2 mM). The TMB concentration in each mixed solution was then measured. ox The characteristic absorption peak at 652 nm was used to quantitatively calculate the OXD reaction rates of D-HEOs and Ce-D / HEOs according to the Lambert-Beer law. Subsequently, the Vg of the reaction was determined by fitting the calculated reaction rates to the substrate concentration using the Michaelis-Menten equation. max and Mi constant K m .

[0057] The classic chromogenic substrate TMB was selected as the research object. Steady-state kinetic analysis of D-HEOs and Ce / D-HEOs was conducted by continuously changing its concentration. Figure 8 As shown, the maximum reaction rates (V1) of D-HEOs and Ce / D-HEOs with TMB substrates are... max The values ​​were 0.1724 mM / s and 0.277 mM / s, respectively. This result indicates that Ce / D-HEOs exhibit a significantly enhanced catalytic rate for TMB compared to D-HEOs, thereby effectively accelerating the OXD catalytic reaction. Figure 8 (a) Furthermore, through Lineweaver-Burk curve analysis, the Michaelis constants of D-HEOs and Ce / D-HEOs for the TMB reaction substrate ( K m The concentrations were 0.441 mM and 0.329 mM, respectively. Figure 8 (b) The above results indicate that Ce / D-HEOs have a higher affinity for TMB reaction substrates, enabling them to capture and bind TMB molecules more quickly, thus promoting the initiation and execution of the catalytic reaction.

[0058] 6. Catalase (CAT) Activity Assay of Ce-D / HEOs: The degradation of H2O2 by HEOs, D-HEOs, and all Ce / D-HEOs was measured using a dissolved oxygen analyzer to evaluate their CAT activity. Specifically, 3 mg of HEOs, D-HEOs, and all Ce / D-HEOs were uniformly dispersed in 3 mL of 10 mM H2O2 solution. The dissolved oxygen analyzer probe was quickly inserted into the solution, and the generation rate and accumulation of dissolved oxygen in the solution were analyzed to evaluate the ability of HEOs, D-HEOs, and all Ce / D-HEOs to catalyze the decomposition of H2O2, thus reflecting their CAT catalytic performance.

[0059] The CAT activity of Ce / D-HEOs was further detected using a dissolved oxygen analyzer. Figure 9 As shown, no dissolved oxygen was detected in the HEOs solution in 10 mM H₂O₂ solution, indicating that it lacks CAT activity. In stark contrast, a large amount of dissolved oxygen was detected in the D-HEOs solution, confirming its CAT activity. Notably, all Ce-doped samples exhibited superior CAT activity compared to D-HEOs, with significantly higher dissolved oxygen generation rates. Furthermore, among all Ce-doped high-entropy oxides, the 1Ce / D-HEOs solution showed the fastest dissolved oxygen generation rate, exhibiting the highest CAT performance.

[0060] 7. Synergistic effect of Ce-D / HEOs on multiple enzymes: To investigate the promoting effect of Ce / D-HEOs' CAT activity on its OXD activity, the degradation of MB and RhB by Ce / D-HEOs with and without H2O2 was evaluated. Specifically, 3 mg of Ce / D-HEOs samples were dispersed in aqueous solutions of MB (1 mM) and RhB (0.1 mM) containing 50 μM H2O2, respectively. The characteristic peak changes of MB at 664 nm and RhB at 554 nm were measured at time intervals to assess the degree of degradation. Simultaneously, MB or RhB solutions without H2O2 were used as control groups, and their degradation curves were measured under the same conditions. By comparing the degradation rates of MB and RhB in the two groups, the enhancing effect of H2O2 introduction on the OXD activity of Ce / D-HEOs was analyzed.

[0061] MB and RhB were selected as indicators of OXD enzyme activity in the experiment. By adding an additional 1 mM H2O2, UV-Vis absorption spectroscopy was used to monitor changes in dye degradation rate, thus evaluating the promoting effect of CAT on OXD activity. Figure 10 As shown, compared with the control group containing only Ce / D-HEOs, the addition of H2O2 resulted in a significant increase in MB ( Figure 10 a) and RhB ( Figure 10 The degradation rates in (b) were significantly enhanced. At 6 minutes into the reaction, the degradation rates of MB and RhB by the H2O2-containing Ce / D-HEOs reached 96.98% and 93.17%, respectively, comparable to the final degradation rates of MB and RhB by the control group (MB: 97.20% and RhB: 93.65%). This result indicates that the CAT activity of Ce / D-HEOs can effectively enhance its OXD activity and accelerate the catalytic reaction process.

[0062] 8. Broad-spectrum antibacterial properties of Ce-D / HEOs: The broad-spectrum antibacterial activity of Ce / D-HEOs was evaluated using a bacterial plate count method. The experiment used methicillin-resistant Staphylococcus aureus (MRSA, ATCC6538) and Escherichia coli (E. coli) as targets. E. coli The antibacterial effect of Ce / D-HEOs under dark and light conditions was studied using MRSA (ATCC8739) as the test strain. First, MRSA and... E. coli The bacterial suspension was tested for its OD value using a UV-Vis spectrophotometer. 600 The value was adjusted to approximately 1.0. Then, 30 μL of the bacterial suspension was added to 2.97 mL of sterilized PBS buffer. Subsequently, 3 mg of HEOs, D-HEOs, and Ce / D-HEOs were added, and a blank control group (PBS group) was set up for comparative analysis. The prepared mixed solutions were incubated in a dark environment for 4 h to test the antibacterial properties of different samples under dark conditions. After the experiment, the solutions were serially diluted and evenly spread on agar plates using a spreader, and incubated at 37 °C for 18 h. After incubation, the colonies on the bacterial agar plates were counted, and the antibacterial ability of different materials was calculated. Furthermore, the prepared solutions were transferred outdoors and exposed to sunlight for 4 hours. After the experiment, the solutions were appropriately diluted and evenly spread on agar plates, and incubated in a 37 °C biochemical incubator for 18 hours. Subsequently, the colonies on each plate were counted, and the antibacterial rate of each group was calculated.

[0063] Classic Gram-positive methicillin-resistant Staphylococcus aureus (MRSA) and Gram-negative Escherichia coli (E. coli) were selected. E. coliAs the research subject, the broad-spectrum antibacterial properties of four groups of samples—phosphate-buffered saline (PBS, control group), HEOs, D-HEOs, and Ce / D-HEOs—were compared under both dark and light conditions. Figure 11 and 12 As shown, Ce / D-HEOs exhibited the highest antibacterial activity under dark conditions, against MRSA ( Figure 11 a) and E. coli ( Figure 12 The antibacterial rates of (a) and (b) reached 77.19% and 67.03%, respectively. Furthermore, under light conditions, Ce / D-HEOs also exhibited the highest antibacterial performance against MRSA (…). Figure 11 b) and E. coli ( Figure 12 The antibacterial rates of b) in the study reached 99.64% and 99.24% respectively, demonstrating excellent broad-spectrum antibacterial properties.

[0064] 9. Detection of bacterial viability using fluorescent staining: Take OD 600 MRSA with a value of 1 or E. coli Collect 3 mL of each bacterial culture solution by centrifugation at 3000 rpm for 5 min, and collect the bacterial pellet. Divide the bacterial culture into groups as before (PBS, HEOs, D-HEOs, and Ce / D-HEOs, respectively), and thoroughly mix 3 mL of the mixed solution with the bacterial pellet. Treat each group under darkness or sunlight for 4 h. After treatment, centrifuge the solution again at 3000 rpm for 5 min and collect the bacterial pellet. Resuspend the bacterial pellet in 150 μL of sterile PBS, add 50 μL of live / dead bacterial fluorescent probe (SYTO9 / PI mixture), and stain in the dark for 30 min. After staining, drop an appropriate amount of the mixture onto a glass slide, cover with a coverslip, and observe and acquire fluorescence images using a confocal laser scanning microscope. Green fluorescence (SYTO9) represents live bacteria, and red fluorescence (PI) represents dead bacteria.

[0065] 10. SEM-based bacterial morphology studies: Following the experimental procedures described above, the bacterial precipitate after treatment (4 hours of darkness or sunlight exposure) was collected, and 1 mL of 2.5% glutaraldehyde solution was added. The precipitate was fixed at room temperature in the dark for 2 hours. After fixation, the precipitate was collected again by centrifugation (3000 rpm, 5 min), and washed three times repeatedly with sterile PBS. Subsequently, the bacterial precipitate was dehydrated sequentially with 50%, 70%, 90%, and 100% ethanol solutions, with each dehydration time fixed at 10 min. The dehydrated bacterial precipitate was resuspended in 50 μL of sterile PBS, dropped onto the surface of a silicon wafer, and dried overnight in a dehumidifier. Finally, the silicon wafer samples were sputter-coated with gold, and the morphology of the bacteria was observed using field emission scanning electron microscopy (FESEM).

[0066] like Figure 13 As shown in Figure a, under dark conditions, bacteria treated with PBS and HEOs maintained their morphology and cell membrane structure well. In contrast, bacteria treated with D-HEOs and Ce / D-HEOs showed obvious cell membrane shrinkage and rupture. Figure 13 As shown in b, under light conditions, bacteria treated with HEOs also exhibited significant morphological changes, indicating that their photothermal effect can also kill bacteria by disrupting the bacterial cell membrane. Notably, the morphological changes were most pronounced after Ce / D-HEOs treatment, showing severe deformation and distortion. These results demonstrate that Ce / D-HEOs can effectively disrupt the bacterial cell membrane structure through the synergistic effect of its photothermal effect and enzyme-like catalytic activity, thereby achieving excellent antibacterial effects.

[0067] 11. Testing of Ce / D-HEOs' anti-biofilm properties: Take OD 600200 μL of MRSA bacterial suspension with a pH of 1 was inoculated into 1.8 mL of TSB medium and thoroughly mixed. The mixture was then transferred to confocal culture dishes and incubated at 37°C for 48 h to allow bacterial biofilm formation. After incubation, the supernatant was discarded, and 1 mL of sterile PBS was added. Following the previous experimental groupings, 1 mg of HEOs, D-HEOs, or Ce / D-HEOs were added to the culture dishes, with the PBS treatment group serving as a blank control. Subsequently, each culture dish was treated under either darkness or sunlight for 4 h. After treatment, 50 μL of live / dead bacterial fluorescent probe (SYTO9 / PI mixture) was added to each culture dish and gently mixed. The dishes were then stained at room temperature in the dark for 30 min. After staining, the bacterial biofilm in the culture dishes was fluorescently imaged using a confocal laser scanning microscope, and its thickness changes were analyzed. In addition, the survival status of bacteria in the biofilm can be assessed based on the fluorescent staining results of bacteria, where green fluorescence (SYTO9) indicates live bacteria and red fluorescence (PI) indicates dead bacteria.

[0068] In the darkness ( Figure 14 a) and sunlight exposure ( Figure 15 Under the conditions described in (a), biofilms were co-incubated with PBS, HEOs, D-HEOs, and Ce / D-HEOs for 4 h, and the biofilm removal capabilities of different materials were evaluated using laser confocal scanning microscopy (CLSM). Figure 14 As shown in b, under dark conditions, the biofilm thickness after Ce / D-HEOs treatment was significantly reduced to 21.77 μm, indicating that it has a certain biofilm removal capacity. Figure 15 As shown in b, Ce / D-HEOs almost completely disrupted the biofilm structure, achieving a biofilm removal rate as high as 83.10%. Notably, CLSM images further revealed that the biofilm treated with Ce / D-HEOs exhibited significant red fluorescence, indicating that almost all bacteria within the biofilm were also dead. These results demonstrate that Ce / D-HEOs can achieve highly efficient removal of bacterial biofilms through the synergistic effect of its excellent photothermal effect and enzyme-like catalytic activity.

[0069] like Figure 16 As shown, the stress-strain curves demonstrate that the Ce / D-HEOs coating exhibits excellent mechanical tensile properties, with a tensile strength reaching 11.97 MPa, significantly superior to the PDMS coating (PDMS: 7.44 MPa). These results indicate that, compared to the PDMS coating, the Ce / D-HEOs coating possesses stronger mechanical properties, ensuring its structural integrity and operational stability in marine environments and demonstrating its long-term operational potential.

[0070] 12. Algae resistance of Ce / D-HEOs coating: 20 mL of well-grown Navicula ( Navicula sp. ) or Chlorella ( Chlorella sp. Algal solution (cell density approximately 10) 6 Algal cells (cells / mL) were inoculated into beakers containing 60 mL of CSI and BG11 medium, respectively, and mixed thoroughly by pipetting to ensure even distribution. Subsequently, the pre-prepared PDMS, HEOs, D-HEOs, and Ce / D-HEOs coatings were completely immersed in the algal culture media and cultured outdoors in full sunlight for 21 days. After culture, the coatings were carefully removed from the algal culture media with tweezers and gently rinsed three times with PBS buffer. The adhesion density and distribution of algal cells on the different coating surfaces were then observed using an optical microscope. For further quantitative analysis, the fluorescence intensity of algal cells attached to the different coating surfaces was measured using a confocal laser scanning microscope, and the anti-algae properties of each coating were calculated.

[0071] 13. Suitability Assessment of Ce / D-HEOs Coatings: To evaluate the suitability and antifouling performance of Ce / D-HEOs coatings on different substrate materials, this study selected four representative substrate materials: glass, epoxy resin (ER), polyvinyl chloride (PVC), and stainless steel (316SS), and coated their surfaces with PDMS, HEOs, D-HEOs, and Ce / D-HEOs coatings, respectively. Furthermore, this study constructed a test system simulating a marine environment. First, 28L of natural seawater collected from the Yellow Sea was used as the aquatic environment for the test system after simple sedimentation to remove large particulate impurities. Subsequently, 10mL of MRSA (10 8 CFU / mL), 10mL E. coli (10) 8 CFU / mL), 1 L Navicula sp. (10) 6 cells / mL) and 1L Chlorella sp. (10) 6 (cells / mL) to construct complex fouling biological communities.

[0072] The experiment selected diatoms with strong adhesion (Navicula, navicula, ...). Navicula sp. ) and green algae (Chlorella, which are widely distributed in marine environments) Chlorella sp. Using these as the research subject, the inhibitory effect of the coating on these algae was evaluated. Figure 17As shown in Figure a, the optical microscope image reveals only a small number of scattered algal cells on the Ce / D-HEOs coating surface, and no obvious fouling layer structure was observed. CLSM observations further confirm this. Figure 17 (b) In the Ce / D-HEOs coating, almost no obvious algal cell adhesion was observed on the surface, which is beneficial to... Navicula sp. and Chlorella sp. The inhibition rates reached 99.45% and 99.08%, respectively. Figure 17 (c) essentially achieved complete removal of algal cells. These results fully demonstrate that, thanks to its excellent photothermal properties and enzyme-like catalytic activity, the Ce / D-HEOs coating exhibits superior anti-algal adhesion performance.

[0073] To further simulate real marine environmental conditions, the entire test system was placed outdoors, subjecting it to the combined effects of day-night cycles and temperature changes to recreate the dynamic processes of the marine environment. Various substrates coated with PDMS, HEOs, D-HEOs, and Ce / D-HEOs, along with an uncoated substrate (serving as a blank control), were then immersed in the simulated system. The immersion period was three months to comprehensively evaluate the durability and antifouling performance of each coating under dynamic and complex conditions. After immersion, the substrates were carefully removed and slowly rinsed three times with PBS buffer to remove loosely attached bacteria and algae cells from the coating surfaces. Finally, the biofouling on the surfaces of each substrate was observed, and the algae coverage rate on different substrate surfaces was calculated.

[0074] This study used actual seawater (collected from the Yellow Sea) as the experimental water body and added typical marine fouling bacteria MRSA and E. coli and representative algae Navicula sp. and Chlorella sp. A complex biofouling environment was constructed. For example... Figure 18 As shown, after 90 days of continuous immersion, the various substrate surfaces modified with Ce / D-HEOs exhibited excellent antifouling performance, with only sporadic algae adhesion observed on the substrate surfaces, and the substrate surfaces maintained a high degree of smoothness. Figure 19 As shown, further quantitative results indicate that the average fouling coverage of various substrate surfaces coated with Ce / D-HEOs is only 4.09%, the surface smoothness is well maintained, and the attachment and colonization of fouling organisms are almost completely inhibited.

[0075] 14. Evaluation of the marine antifouling performance of Ce / D-HEOs: To evaluate the antifouling performance of Ce / D-HEOs in a real marine environment, it was mixed with commercial metallic paint to prepare a Ce / D-HEOs antifouling paint. The antifouling performance of the Ce / D-HEOs antifouling paint in a real marine environment was evaluated using a marine siding test system. Specifically, 0.1 g of Ce / D-HEOs powder was uniformly mixed with 1.9 g of commercial metallic paint, controlling the filler mass ratio to 5 wt%. The mixture was then stirred with a glass rod to ensure uniform dispersion of Ce / D-HEOs in the paint. After uniform dispersion, the coating was uniformly applied to the surface of a pre-prepared 316 stainless steel (316 SS) substrate. After coating, the substrate was allowed to stand at room temperature for 12 h to allow the Ce / D-HEOs antifouling paint to initially set. After fixation, the 316 SS substrates coated with Ce / D-HEOs antifouling paint were transferred to a constant temperature drying oven at 60 °C for 2 days to ensure that the antifouling paint was fully dried and firmly adhered to the substrate surface. After drying, the substrates were removed from the drying oven and allowed to cool naturally to room temperature, thus obtaining the Ce / D-HEOs antifouling paint. Using the same preparation process, commercial metallic paint, HEOs antifouling paint, and D-HEOs antifouling paint were prepared as control samples. 316 SS substrates coated with different paints were fixed on a special frame and immersed in the Yellow Sea (36°10′N, 120°51′E) at a depth of approximately 1 meter for immersion from April to September (total duration 150 days). After immersion, the 316 SS substrates were retrieved from the seawater, and the species composition and adhesion area of ​​fouling organisms on the surface of different antifouling paints were observed. The fouling coverage area of ​​different antifouling paints on the substrate surface was quantitatively evaluated using ImageJ analysis software.

[0076] The experiment used a single piece of 316 SS substrate, and its surface was evenly divided into four independent areas, with isolation strips between the areas to prevent cross-contamination. Subsequently, ordinary commercial metallic paint (control group), ordinary commercial antifouling paint RAL, HEOs antifouling paint, and Ce / D-HEOs antifouling paint were applied to the four areas respectively. After coating, the entire substrate was completely immersed in the test sea area for a 5-month marine siding test. Figure 20 and 21 As shown, the surfaces coated with commercial metal antifouling paint, commercial antifouling paint RAL, and HEOs antifouling paint all exhibited extensive biofouling, with the surfaces almost completely covered by fouling organisms such as sea anemones and algae. Figure 20 (b) In stark contrast, the surfaces treated with Ce / D-HEOs antifouling paint before and after the experiment remained relatively clean, with only some dirt appearing at the edges, while the main body remained intact. Figure 20(a) In contrast, the surface fouling coverage of the area treated with Ce / D-HEOs antifouling paint was only 18.01%, demonstrating excellent antifouling performance. Figure 21 ).

[0077] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for preparing a high-entropy oxide rich in oxygen vacancies, characterized in that, Includes the following steps: (1) Cobalt salt, chromium salt, iron salt, manganese salt, nickel salt and cerium salt are added to water and mixed well. Polyethylene glycol and citric acid are added in sequence and stirred and mixed well. The pH is adjusted to neutral and the wet gel is obtained by evaporation and concentration. The molar ratio of the cobalt salt, chromium salt, iron salt, manganese salt, nickel salt, and cerium salt is (0.8-1.2):(0.8-1.2):(0.8-1.2):(0.8-1.2):(0.8-1.2):(0.5-2). (2) The wet gel is subjected to a combustion reaction, followed by calcination in an air atmosphere to obtain a high-entropy oxide; (3) After pulverizing the high-entropy oxide, it is calcined under an inert atmosphere to obtain a high-entropy oxide rich in oxygen vacancies. In step (1), the evaporation and concentration are carried out at a temperature of 75-85°C for 10-15 hours. In step (2), the temperature of the combustion reaction is 120-140℃; In step (2) or step (3), the calcination treatment temperature is 850-950℃, the time is 1-3h, and the heating rate is 2-5℃ / min.

2. The method for preparing high-entropy oxides rich in oxygen vacancies as described in claim 1, characterized in that, In step (1), the cobalt salt is one or both of cobalt nitrate and cobalt chloride; The chromium salt is one or both of chromium nitrate and chromium chloride; The iron salt is one or both of ferric nitrate and ferric chloride; The manganese salt is one or both of manganese nitrate and manganese chloride; The nickel salt is one or both of nickel nitrate and nickel chloride; The cerium salt is one or both of cerium nitrate and cerium chloride.

3. The method for preparing high-entropy oxides rich in oxygen vacancies as described in claim 1, characterized in that, In step (1), the molecular weight of the polyethylene glycol is 200-600, and the mass ratio of the polyethylene glycol to citric acid is (4-5):(11.5-14).

4. The method for preparing high-entropy oxides rich in oxygen vacancies as described in claim 1, characterized in that, In step (1), the molar ratio of the cobalt salt to citric acid is 1:(5.8-7.5).

5. A high-entropy oxide rich in oxygen vacancies prepared by the method for preparing a high-entropy oxide rich in oxygen vacancies according to any one of claims 1-4.

6. The application of the oxygen-vacancy-rich high-entropy oxide of claim 5 in marine antifouling.

7. The application as described in claim 6, characterized in that, Marine antifouling coatings consist of high-entropy oxides rich in oxygen vacancies, an organic polymer matrix, and a curing agent.

8. The application as described in claim 7, characterized in that, The mass ratio of the oxygen-vacancy-rich high-entropy oxide, the organic polymer matrix, and the curing agent is 1:(18-22):(1.8-2.2); The organic polymer matrix is ​​polydimethylsiloxane; The curing agent is tetraethoxysilane.

9. The application as described in claim 7, characterized in that, The preparation method of marine antifouling coating is as follows: high-entropy oxide rich in oxygen vacancies is introduced into an organic polymer matrix, stirred and mixed, then a curing agent is added and mixed, and the marine antifouling coating is obtained by vacuum degassing and curing reaction. The curing reaction is carried out at a temperature of 75-85℃ for 1-3 hours.

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