A molybdenum complex nanorod and its preparation method and marine antifouling application

Abstract

The present invention relates to the field of preparation of marine biological antifouling materials, and specifically discloses a method for preparing molybdenum complex nanorods. Using molybdenum salt as the metal source, a mixed intermediate is added, and coordination polymerization is carried out by a solvothermal method to assemble into nanorod-shaped complexes. The nanorod-shaped complexes prepared by this method not only have uniform morphology, strong interaction between metal and ligand, a large number of unsaturated metal atoms and suitable active ligands, and a large specific surface area; but also can effectively catalyze the oxidation of halide ions in the presence of H2O2 oxidant, thereby generating hypohalous acid with strong antibacterial activity, and then preventing the attachment of marine organisms. Therefore, the nanorod-shaped complexes exhibit excellent anti-marine biological fouling ability and have potential application prospects in the field of preparation of marine biological antifouling materials.

Description

Technical Field

[0001] The invention relates to the field of new nano materials, and in particular to a molybdenum complex nanorod and a preparation method thereof and marine anti-fouling application thereof. Background Art

[0002] Marine biofouling is a long-term and complex problem worldwide, which seriously troubles the development of human marine activities and the development and utilization of marine resources. Early antifouling materials can cause marine pollution, the death of a large number of seaweeds and the destruction of ecological balance. Therefore, the development of environmentally friendly marine antifouling materials has attracted much attention from researchers.

[0003] Initially, researchers developed environmentally friendly materials by imitating antifouling defense mechanisms. For example, some seaweeds can resist fouling by other organisms by producing reactive oxygen species such as hydroxyl radicals, hydrogen peroxide, and hypohalous acid; or the natural vanadium haloperoxidases secreted by large algae such as brown algae and coralline algae can catalyze the oxidation of bromide ions to generate HOBr / OBr through activated peroxy intermediates in the presence of H2O2. - , thus playing an anti-biofouling role. However, such natural materials usually have inherent defects, such as easy inactivation, high cost and poor stability.

[0004] In recent years of research, there have been literature reports on metal nanomaterials used to resist marine biofouling, such as V2O5, CeO2 and CrC3N4, and the experimental results also show that the metal nanomaterials exhibit catalytic behavior similar to vanadium haloperoxidase and excellent anti-algae attachment and growth ability. Therefore, the good catalytic activity, stability, low cost and other advantages of metal nanomaterials make them the most promising new environmentally friendly and efficient anti-marine biomaterials. For example, Chinese patent CN201711209958.1 discloses a composite nanomaterial composed of MnO, CoO and TiO2, doped with transition metal elements and rare earth elements, the mass percentage of doped transition metal elements is 0.1% to 5%, and the mass percentage of doped rare earth elements is 0.1% to 3%. The composite nanomaterial of the present invention has a significant inhibitory effect on the attachment of marine microorganisms, marine soft fouling organisms seaweed and marine large fouling organisms mussels at low concentrations, but due to the physical effect between the molecular structures, it is easy to release heavy metal ions into the ocean, causing secondary pollution.

[0005] Metal complexes are widely used in enzyme catalysis, sterilization, energy storage, and medicine due to their unique physical and chemical properties, flexible molecular structure, and strong bonding between metals and intermediates. Especially in the field of enzyme catalysis, metal complex materials have the advantages of good size and shape, selectivity, and catalytic regeneration. However, there have been no reports on new metal complex materials and their application in marine biofouling prevention and control. Summary of the invention

[0006] In view of this, the present invention provides a method for preparing molybdenum complex nanorods, which solves the problems existing in the background technology.

[0007] On one hand, the present invention adopts a method for preparing molybdenum complex nanorods, comprising the following steps: uniformly dispersing a certain amount of molybdenum salt in a solvent, and adding a first intermediate and a second intermediate respectively to mix, and then using a solvent thermal method to react at a certain temperature, centrifuge and wash to obtain the molybdenum complex nanorods.

[0008] Preferably, the molybdenum source is selected from one of sodium molybdate, ammonium molybdate tetrahydrate, molybdenum acetylacetonate and molybdenum pentachloride.

[0009] Preferably, the first intermediate is selected from one of 4,4-bipyridine, 2-methylimidazole and 2,3,5,6-tetramethylpyrazine, and the second intermediate is trimesic acid or 2-propylthiophene.

[0010] Preferably, the molar mass of the metallic molybdenum source is 0.2 mmol to 1 mmol.

[0011] Preferably, the molar mass of the first intermediate is 0.05 mmol to 0.5 mmol, and the molar mass of the second intermediate is 0.5 mmol to 1.5 mmol.

[0012] Preferably, the reaction temperature is 150° C. to 200° C., and the reaction time is 40 h to 60 h.

[0013] Another aspect of the present invention provides a molybdenum complex nanorod and its application in preparing anti-marine biofouling material.

[0014] The nanorod-shaped complex prepared by the method of the present invention not only has uniform morphology, strong interaction between metal and ligand, a large number of unsaturated metal atoms and suitable active ligands, and a large specific surface area, but also can effectively catalyze the oxidation of halide ions in the presence of H2O2 oxidant, thereby generating hypohalous acid with strong antibacterial activity, thereby preventing the attachment of marine organisms. Therefore, the nanorod-shaped complex exhibits excellent anti-marine biofouling ability and has obvious advantages in the field of preparing marine biofouling anti-fouling materials.

[0015] Furthermore, compared with existing antifouling technologies, the nanomaterials of the present invention will not release heavy metal ions into the ocean during use, which can avoid the problem of damage to the marine ecosystem. Therefore, they have potential application prospects in the preparation of new green, efficient and stable marine biological antifouling agents. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a scanning electron microscope (SEM) image of the molybdenum complex nanorods of Example 1;

[0017] Figure 2 is the X-ray diffraction (XRD) pattern of the molybdenum complex nanorods of Example 1;

[0018] Figure 3 is the N2 adsorption-desorption isotherm of the molybdenum complex nanorods of Example 1;

[0019] Figure 4 The UV-visible absorption curve of the bromination process of phenol red catalyzed by the molybdenum complex nanorods of Example 1;

[0020] Figure 5 The molybdenum complex nanorods of Example 1 are in H2O2 / Br - UV-visible absorption curve of the oxidative degradation process of lapis lazuli blue in the presence of

[0021] Figure 6 This is a photo of the molybdenum complex nanorods of Example 1 hanging on a board in a real marine environment for 92 days. DETAILED DESCRIPTION

[0022] The principles and features of the present invention are described below in conjunction with the accompanying drawings. The examples given are only used to explain the present invention but not to limit the scope of the present invention.

[0023] Example 1: A method for preparing molybdenum complex nanorods, comprising the following steps: first weigh 0.60 mmol of ammonium molybdate tetrahydrate and ultrasonically disperse it in 40 mL of N,N-dimethylformamide, then add 0.08 mmol of 2-methylimidazole and 1.2 mmol of trimesic acid respectively, mix the above system into a uniform dispersion and place it at 190°C for reaction for 60 hours, finally centrifuge and wash with a mixed solution of water and ethanol (V1:V2=1:2) to obtain molybdenum complex nanorods.

[0024] (1) The molybdenum complex nanorods prepared by the method of this embodiment were tested using a scanning electron microscope. Figure 1 The results show that the material prepared by the above experiment has a typical nanorod configuration, with a length of about 2μm, uniform morphology and high dispersion, which is convenient for further preparation of uniform anti-fouling film materials as coatings.

[0025] (2) X-ray diffraction (XRD) was used to test the molybdenum complex nanorods prepared by the method of this embodiment. Figure 2 The results show that the sample prepared by the above experiment has multiple obvious diffraction peaks, indicating that the nanorod complex of this example has a polycrystalline structure and good crystallinity.

[0026] (3) The molybdenum complex nanorods prepared by the method of this embodiment were tested using the N2 adsorption-desorption isotherm curve. Figure 2 The results show that the specific surface area of ​​the nanorod complex of this embodiment is 60.4 mg -1 The larger specific surface area is beneficial to improving its catalytic effect.

[0027] (4) The molybdenum complex nanorods prepared by the method of this embodiment were studied by UV-visible absorption spectrometry in H2O2 / Br - Catalytic behavior in the environment

[0028] Molybdenum complex nanorods (50 μg mL -1 ) in H2O2 / Br - Under the condition of 490μM / 25mM, phenol red (50μM) was used as the color developer, and the reaction solution was scanned by UV-visible spectrophotometer curve with time correlation. Figure 4 The results show that as time goes by, the ultraviolet absorbance of the reaction solution at 430nm (the absorption peak of phenol red) gradually decreases, while the absorption peak at 589nm (the absorption peak of bromophenol blue generated by bromination of phenol red) gradually increases, confirming the continuous production of hypobromous acid during the catalytic process.

[0029] Molybdenum complex nanorods (50 μg mL -1 ) in H2O2 / Br - (245 μM / 25 mM) environment, with lapis lazuli blue (50 μM) as the color developer, the reaction solution was scanned by time-dependent UV-visible spectrophotometer curve, such as Figure 5 As shown in the results, the absorption peak at 640nm (Azure Blue) gradually weakens. This is because the hypobromous acid produced during the catalytic process can oxidize and degrade Azure Blue. This further shows that the molybdenum complex nanorods of this embodiment can simulate vanadium haloperoxidase and effectively catalyze the oxidation of halide ions in the presence of H2O2 oxidant to generate hypohalous acid with strong antibacterial activity and can effectively prevent the attachment of marine microorganisms.

[0030] (5) The molybdenum complex nanorods prepared by the method of this embodiment are applied in marine anti-biofouling test

[0031] The molybdenum nanorod complex (1.2 g) prepared in this example was mixed with commercial marine paint (24 g) and coated on a stainless steel plate. The same amount of commercial marine paint (24 g) was coated on a stainless steel plate as a control and then suspended in a real marine environment for 92 days. Figure 6 The results showed that compared with the blank stainless steel plate (a), the biofouling of the substrate (b) treated with the molybdenum nanorod complex coating was significantly reduced, which fully confirmed that the molybdenum complex has excellent anti-biofouling ability.

[0032] In other embodiments of the present invention, ammonium molybdate, molybdenum acetylacetonate or molybdenum pentachloride is used instead of sodium molybdate tetrahydrate as the molybdenum source to prepare molybdenum complex nanorods.

[0033] In other embodiments of the present invention, the first intermediate can be selected from one of 4,4-bipyridine and 2,3,5,6-tetramethylpyrazine, and the second intermediate is 2-propylthiophene.

[0034] In other embodiments of the present invention, the molar mass of the metal molybdenum source is 0.2 mmol to 1 mmol.

[0035] In other embodiments of the present invention, the molar mass of the first intermediate is 0.05 mmol to 0.5 mmol, and the molar mass of the second intermediate is 0.5 mmol to 1.5 mmol.

[0036] In other embodiments of the present invention, the hydrothermal reaction temperature is 150° C. to 200° C., and the reaction time is 40 h to 60 h.

[0037] In summary, the molybdenum nanorod complex for marine biofouling prevention prepared by the method of the present invention has uniform morphology, strong metal-ligand interaction, and a large number of unsaturated metal atoms and suitable active ligands, which lay the foundation for its excellent enzyme catalytic performance. Further, the molybdenum nanorod complex of the present invention uses a molybdenum complex to simulate vanadium haloperoxidase, which can effectively catalyze the oxidation of halide ions in the presence of H2O2 oxidant to generate hypohalous acid with strong antibacterial activity and can effectively prevent the attachment of marine microorganisms. Compared with existing antifouling technology, this nanomaterial will not release heavy metal ions into the ocean during use, which can avoid the problem of damage to the marine ecosystem. Therefore, it has potential application prospects in the preparation of new green, efficient and stable marine biofouling agents.

[0038] 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 in the scope of protection of the present invention.

Claims

1. A method for preparing molybdenum complex nanorods, characterized in that The following steps are involved: A certain amount of molybdenum source is uniformly dispersed in a solvent, and the first intermediate and the second intermediate are added and mixed respectively, and then a solvothermal method is used to react at a certain temperature, centrifuge and wash to obtain molybdenum complex nanorods; The molybdenum source is selected from one of sodium molybdate, ammonium molybdate tetrahydrate, molybdenum acetylacetonate and molybdenum pentachloride; the molar mass of the molybdenum source is 0.2 mmol to 1 mmol; The first intermediate is selected from one of 4,4-bipyridine, 2-methylimidazole and 2,3,5,6-tetramethylpyrazine, and the second intermediate is trimesic acid or 2-propylthiophene; The molar mass of the first intermediate is 0.05 mmol to 0.5 mmol, and the molar mass of the second intermediate is 0.5 mmol to 1.5 mmol.

2. The method for preparing a molybdenum complex nanorod according to claim 1, characterized in that: The reaction temperature is 150° C. to 200° C., and the reaction time is 40 h to 60 h.

3. The method for preparing a molybdenum complex nanorod according to claim 1, characterized in that: The following steps are involved: First, 0.6 mmol of ammonium molybdate tetrahydrate was weighed and ultrasonically dispersed in 40 mL of N,N-dimethylformamide, and then 0.08 mmol of 2-methylimidazole and 1.2 mmol of trimesic acid were added respectively. The above system was mixed into a uniform dispersion and reacted at 190°C for 60 hours. Finally, the molybdenum complex nanorods were obtained by centrifugation and washing with a mixed solution of water and ethanol, and the volume ratio of water to ethanol was 1:

2.

4. A molybdenum complex nanorod prepared by the method according to any one of claims 1 to 3.

5. Use of the molybdenum complex nanorods according to claim 4 in the preparation of anti-marine biofouling materials.

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