Composite material with halogenated peroxide mimic enzyme catalytic activity as well as preparation and application of composite material

Abstract

The invention belongs to the field of marine antifouling, and particularly relates to a composite material (CeO2-MOF / C) with halogenated peroxide mimic enzyme catalytic activity and preparation and application thereof. The specific method comprises the following steps: adding activated carbon black into a CeO2-MOF precursor, and calcining an obtained sample in a muffle furnace at 350 DEG C for 2 hours to prepare a CeO2-MOF / C composite material; wherein the precursor of the CeO2-MOF is 4, 4-diphenyldicarboxylic acid and ceric ammonium nitrate; the mass ratio of the precursor 4, 4-diphenyldicarboxylic acid to the ceric ammonium nitrate is 1: (1-1.5). The antifouling coating is constructed on the basis of cerium-based halogenated peroxide bionic enzyme, the prepared antifouling coating is used for antifouling application in real sea environments, and the real sea environments comprise a sea total immersion zone and a tidal range zone. The antifouling coating has no pollution to the marine environment, is green and environment-friendly, and has a wide application prospect in marine fouling protection.

Description

Technical Field

[0001] This invention belongs to the field of marine antifouling, specifically relating to a composite material (CeO2-MOF / C) with halogenated peroxide biomimetic enzyme catalytic activity, its preparation and application. Background Technology

[0002] Marine algae (such as *Corallina officinalis* and *Delisea pulchra*) achieve a dual antifouling effect by secreting vanadium halide peroxidases to catalyze the production of hypohalous acids: hypohalous acids can oxidize and modify bacterial quorum sensing signaling molecules, blocking their signal transduction networks, and degrade the extracellular polymeric backbone, thus disintegrating biofilm structures. However, natural vanadium halide peroxidases suffer from high extraction costs and poor environmental adaptability. While these natural halogen peroxidases possess biocatalytic activity and environmentally friendly properties, potentially leading to the development of novel environmentally friendly enzyme-based antifouling technologies, they are prone to inactivation, have limited content, and are expensive. Applying these enzymes as additives to antifouling paints not only lacks long-term stability but also requires mild reaction conditions, hindering large-scale use. Furthermore, vanadium complexes can induce cancer and birth defects, and many countries classify them as prohibited chemicals. Therefore, developing a vanadium-free inorganic metal material as a hypohalide-mimicking enzyme catalyst to replace natural enzymes in antifouling coatings is a feasible and environmentally friendly new antifouling technology.

[0003] Cerium-based oxides (such as CeO2) are due to their unique Ce... 3+ / Ce 4+ The redox cycle and controllable oxygen vacancy characteristics stand out. Studies have shown that the oxygen vacancy density on the CeO2 surface is positively correlated with haloperoxidase activity, and nano-sizing strategies can improve its catalytic activity.

[0004] However, the slow progress in research on halogenated peroxide biomimetic enzymes, the limited variety of types, and the scarcity of cerium reserves restrict their widespread application. Summary of the Invention

[0005] In order to overcome the shortcomings of the prior art, the present invention aims to provide a composite material (CeO2-MOF / C) with halogenated peroxide biomimetic enzyme catalytic activity, as well as its preparation and application.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: A method for preparing a composite material with halogenated peroxide biomimetic enzyme catalytic activity: Activated carbon black is added to the precursor of CeO2-MOF, and the resulting sample is calcined in a muffle furnace at 350 °C for 2 h to prepare CeO2-MOF / C composite material; wherein, the precursor of CeO2-MOF is 4,4-biphenyldicarboxylic acid and cerium ammonium nitrate; the mass ratio of the precursor 4,4-biphenyldicarboxylic acid to cerium ammonium nitrate is 1:1-1.5.

[0007] The mass ratio of activated carbon black to CeO2-MOF precursor is 1:8.3.

[0008] The activated carbon black is obtained by activating commercial carbon black (Vulcan XC-72) with concentrated nitric acid and is ready for use.

[0009] A composite material prepared by the method described herein, wherein a uniform and regular porous CeO2-MOF / C composite material is prepared by the method described herein.

[0010] An application of the composite material: the application of the composite material as an additive in antifouling coatings for the marine field.

[0011] A biomimetic enzyme antifouling coating based on cerium-based halide peroxides is formed by coating a composite material containing the cerium-based halide peroxides.

[0012] The coating is formed by adding a composite material containing the cerium-based halide peroxide to the coating and then coating it onto the substrate, wherein the amount of cerium-based halide peroxide added accounts for 2% of the mass of the coating.

[0013] The coating is a water-based polyurethane waterproof coating.

[0014] An application of the aforementioned cerium-based halide peroxide-based biomimetic enzyme antifouling coating, wherein the coating is used in the preparation of antifouling coatings.

[0015] The coating is used as an antifouling coating for marine environments.

[0016] The actual marine environment refers to the fully submerged marine area and / or tidal zone.

[0017] Specifically, a coating of cerium-based halide peroxide composite material is applied to the sample to be protected, with a coating thickness of 260±10 μm, thereby protecting the sample from contamination.

[0018] The beneficial effects of this invention are as follows: This invention prepares CeO2-MOF / C composite materials by adding activated carbon black to the precursor for synthesizing CeO2-MOF, followed by calcination. The prepared CeO2-MOF / C composite material has a uniform porous structure, a large specific surface area, and exhibits higher halogenated peroxidase activity than CeO2-MOF. This method provides a biomimetic catalyst with antifouling properties while reducing the amount of rare earth element cerium used. A biomimetic enzyme antifouling coating is constructed using the antibacterial and antifouling properties of halogenated peroxidase biomimetic enzymes in CeO2-MOF and C / CeO2-MOF. Inspired by the near-perfect resistance to adhesion and fouling found in many organisms in nature, a biomimetic enzyme antifouling coating was developed and prepared based on biomimetic principles for antifouling research in marine tidal zones. This antifouling coating exhibits certain antifouling properties and is environmentally friendly. This invention not only opens up a new, efficient, and green path for the research and development of this type of material, providing a strategic approach that is both practical and innovative, but also the research on biomimetic enzyme antifouling coatings is of great significance for the protection of marine ecosystems. Attached Figure Description

[0019] Figure 1 The scanning electron microscope (SEM) images of the composite materials provided in the embodiments of the present invention are for CeO2, Ce-MOF, Ce-MOF-0.5 / C, Ce-MOF-1 / C and Ce-MOF-1.5 / C.

[0020] Figure 2 XRD (a) and Raman (b) images of the composite material provided in this embodiment of the invention, where the horizontal axis in figure a is 2 Theta (angle), and the unit is... o The vertical axis in figure b represents Intensity, in units of au; the horizontal axis in figure c represents Raman Shift, in units of cm. -1 The vertical axis represents Intensity, with units of (au). Figure 3 The specific surface area diagrams of CeO2 and Ce-MOF-1 / C provided in the embodiments of the present invention (where the horizontal axis represents relative pressure, expressed as P / P) o The vertical axis represents Quantity adsorbed, with units of cm. 3 STP / g); Figure 4The UV-Vis spectrum comparison of the solutions after 45 minutes of reaction, where different materials provided in the embodiments of the present invention are added as halogenated peroxide biomimetic enzymes (where the horizontal axis is Wavelength in nm and the vertical axis is Absorbance). Figure 5 Images showing the surface changes of the cerium-based biomimetic enzyme antifouling coating provided as an application example of the present invention during an 85-day hanging test in a seawater tidal zone. Detailed Implementation

[0021] The specific content of the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0022] In the following examples, the activated carbon black is carbon black (commercial carbon black Vulcan XC-72) activated with concentrated nitric acid in a conventional manner and then ready for use.

[0023] Example 1 Preparation of C / CeO2-MOF: Weigh 0.50 g of H2BPDC and 60 mg of activated carbon black, add 30 mL of N,N-dimethylformamide (DMF), and sonicate to obtain a homogeneous suspension. Disperse 0.5 g of cerium ammonium nitrate uniformly in 10 mL of ultrapure water. Add the cerium ammonium nitrate solution to the above suspension under vigorous stirring in a 60 ℃ constant-temperature water bath, and continue stirring the mixture at 60 ℃ for 1 h. After natural cooling to room temperature, centrifuge the solution (8000 rpm, 10 min) to obtain a black precipitate, wash three times each with DMF and anhydrous ethanol, and then dry in a vacuum drying oven at 60 ℃. Calcine the dried sample in a muffle furnace under air conditions at a rate of 1 ℃ / min to 350 ℃, maintain the temperature for 2 h, and then cool to room temperature with the furnace to obtain a gray-black powder, denoted as Ce-MOF-1 / C.

[0024] Then, following the above-described method, while keeping the amount of activated carbon black added constant, composite materials with different proportions were prepared by adjusting the mass ratio of H2BPDC to cerium salt (1:0.5 and 1:1.5), and named CeO2-MOF-0.5 / C and CeO2-MOF-1.5 / C, respectively.

[0025] Pure CeO2 was prepared by calcining cerium nitrate under the same conditions; CeO2-MOF without carbon black was prepared as a control sample under the same conditions. The morphology of the samples prepared above is as follows. Figure 1As shown in the image, scanning electron microscopy (SEM) results indicate that pure CeO2 exhibits large bulk structures with dimensions of tens of micrometers, while CeO2-MOF consists of irregular bulk structures with dimensions of 1 to 2 micrometers. By adding carbon black and adjusting the proportion of precursors, CeO2-MOF-0.5 / C, CeO2-MOF-1 / C, and CeO2-MOF-1.5 / C were obtained, exhibiting regular and uniform porous structures.

[0026] Depend on Figure 2 As shown in figure a, the diffraction peak positions of C / CeO2-0.5 differ from those of the standard card for CeO2, exhibiting a strong characteristic peak at low angles, which is significantly different from the other two materials. This suggests that its crystal structure or phase composition differs from the other two materials. It is speculated that this is due to the formation of organic matter during the synthesis process, resulting in a complex composition. Figure 2 b shows C / CeO2-MOF-0.5 at 457 cm⁻¹ -1 There were no characteristic peaks nearby, suggesting that cerium ions were not successfully loaded onto the MOF framework during synthesis. Therefore, the calcined sample contained no cerium oxide, which corresponds to the XRD results of C / CeO2-MOF-0.5. These results indicate that the synthesized CeO2-MOF-0.5 / C does not contain CeO2; therefore, there is no CeO2-MOF-0.5 / C material for comparison in biomimetic enzyme activity control.

[0027] Example 2 The biomimetic enzyme activity of the C / CeO2-MOF-1 / C, CeO2-MOF-1.5 / C prepared in the above examples, as well as pure CeO2 and CeO2-MOF without carbon black as catalysts, was tested. Under the same temperature (25 °C) and the same reactant concentrations (28 μM phenol red, 69.4 mM NH4Br, 0.891 mM H2O2, and 0.165 mg / mL catalyst), the UV-Vis absorbance was measured after 45 min of reaction. The activity was compared with that of cerium-based materials (CeO2, CeO2-MOF, CeO2-MOF-1 / C, and CeO2-MOF-1.5 / C) for halogenated peroxide biomimetic enzymes. Figure 3 As shown in the figure. After adding the above materials and reacting the solutions for 45 min, the absorbance of the solutions showed that the absorbance of carbon-doped CeO2-MOF-1 / C and C / CeO2-MOF-1.5 / C solutions was greater than that of CeO2-MOF materials, and much greater than that of CeO2. This indicates that compared to CeO2 and CeO2-MOF materials, carbon-doped CeO2-MOF-1 / C and CeO2-MOF-1.5 / C have better halogenated peroxide biomimetic enzyme activity. This catalytic activity is related to the specific surface area of ​​the carbon-doped composite materials. The specific surface area characterization results of CeO2 and CeO2-MOF-1 / C are shown in the figure. Figure 4As shown, the specific surface area of ​​the carbon-doped CeO2-MOF-1 / C composite material is 123.3 m². 2 The specific area of ​​ / g is much larger than that of CeO2, which is 74.75 m². 2 / g. This indicates that carbon doping significantly increases the surface area of ​​the material, thus resulting in a significant increase in the activity of haloperoxide-inspired biomimetic enzymes.

[0028] Application Example 1 A cerium-based halide peroxide biomimetic enzyme antifouling coating was prepared. The test specimens were Q235 steel specimens (40×20×2 mm). Based on the biomimetic enzyme activity study of the aforementioned composite materials, CeO2-MOF and CeO2-MOF-1 / C materials were selected for antifouling coating preparation. 2% (by mass) of CeO2-MOF and CeO2-MOF-1 / C materials were added to a mixed coating (waterborne polyurethane waterproof coating (commercially available) at a mass ratio of 5:1 to anhydrous ethanol). A mixed coating without cerium-based materials served as a blank control. The prepared coating was applied to the test specimens using a soft brush, following a "thin layer, multiple coats" strategy. After each coat, approximately 30 minutes were allowed for natural surface drying before applying the next coat. The coating process was consistent across all specimens, ensuring uniform coating coverage on both sides. The coating thickness was 260±10 μm. All specimens were suspended in a cool, well-ventilated environment for 72 h for curing. The blank group consists of coating samples without cerium-based materials.

[0029] The application of cerium-based halide peroxide biomimetic enzyme antifouling coatings involved conducting marine plating experiments on the samples prepared above. The experiment was conducted in the nearshore area of ​​a wharf in Qingdao, using the tidal range. Secure all test specimens to a specially designed stainless steel frame using cable ties, ensuring that one side of each specimen always faces upwards. The frame should be firmly positioned on the shore, in an area submerged by seawater at high tide, 10 cm above the ground, to ensure the back of the specimens also has sufficient contact with seawater. During the hanging plate experiment, regularly check the surface of the specimens for dirt and damage and record the findings with photographs. Figure 5 As shown, rust and biofouling gradually appeared on the surface of the blank group test pieces, indicating that the unprotected test pieces are susceptible to both seawater corrosion and biofouling in tidal zones. The CeO2-MOF test pieces showed that the degree of fouling and rust gradually became more pronounced over time, exhibiting a certain level of antifouling ability compared to the blank group. However, rust and fouling became more obvious in the later stages, and the antifouling effect decreased over time. The CeO2-MOF-1 / C test pieces showed excellent corrosion and fouling resistance in the first ten days. As the number of days increased, a small amount of corrosion and fouling appeared on the test piece surface. Overall, compared to CeO2-MOF and the blank group, it exhibited superior antibacterial, antifouling, and corrosion resistance properties.

Claims

1. A method for preparing a composite material with halogenated peroxide biomimetic enzyme catalytic activity, characterized in that: Activated carbon black was added to the precursor of CeO2-MOF, and the resulting sample was calcined in a muffle furnace at 350 °C for 2 h to prepare CeO2-MOF / C composite material; wherein, the precursor of CeO2-MOF is 4,4-biphenyldicarboxylic acid and cerium ammonium nitrate; the mass ratio of the precursor 4,4-biphenyldicarboxylic acid to cerium ammonium nitrate is 1:1-1.

5.

2. The method for preparing the composite material with halogenated peroxide biomimetic enzyme catalytic activity according to claim 1, characterized in that: The mass ratio of 4,4-biphenyl dicarboxylic acid in the activated carbon black to the CeO2-MOF precursor is 1:8.

3.

3. The method for preparing the composite material with halogenated peroxide biomimetic enzyme catalytic activity according to claim 1 or 2, characterized in that: The activated carbon black is produced by activating carbon black with concentrated nitric acid and is ready for use.

4. The method for preparing the composite material with halogenated peroxide biomimetic enzyme catalytic activity according to claim 1 or 2, characterized in that: By adjusting the mass ratio of the precursor 4,4-biphenyldicarboxylic acid to cerium ammonium nitrate to 1:1, and reacting it with activated carbon black in a solvothermal manner, the obtained sample was calcined at a constant temperature of 350℃ to prepare CeO2-MOF-1 / C composite material.

5. A composite material prepared by the method of claim 1, characterized in that: A uniform and regular porous CeO2-MOF-1 / C composite material was prepared according to the method described in claim 1.

6. An application of the composite material according to claim 1, characterized in that: The composite material is used as an additive in antifouling coatings for marine applications.

7. A biomimetic enzyme antifouling coating based on cerium-based halide peroxides, characterized in that: The coating is formed by a coating material containing the cerium-based halide peroxide of claim 5.

8. The cerium-based halide peroxide-based biomimetic enzyme antifouling coating according to claim 7, characterized in that: The coating is formed by adding a composite material containing the cerium-based halide peroxide of claim 5 to the coating and then coating it onto the substrate, wherein the amount of cerium-based halide peroxide added accounts for 2% of the mass of the coating.

9. The cerium-based halide peroxide-based biomimetic enzyme antifouling coating according to claim 8, characterized in that: The coating is a water-based polyurethane waterproof coating.

10. An application of the cerium-based halide peroxide-based biomimetic enzyme antifouling coating as described in claim 7, characterized in that: The coating is used in the preparation of antifouling coatings.

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