Platinum nanoparticle antifouling oxidation reduction metal electrode based on MOF material modification and preparation method and application thereof

Abstract

The invention provides a platinum nanoparticle antifouling oxidation reduction metal electrode based on MOF material modification and a preparation method and application thereof, and belongs to the technical field of marine pollution detection. The preparation method comprises the following steps: carrying out electrodeposition on a platinum-based electrode by using K2PtCl4 and CTAB to form a platinum nanoparticle substrate, then mixing BDC-F4 and ZrO (NO3) 22H2O by using a hydrothermal reaction to form a UiO-66-F4 MOF material, and finally putting the electrode into a solution to obtain Pt NPs at UiO-66-F4. The prepared electrode can inhibit adhesion of organic macromolecules in seawater, and has excellent stability.

Description

Technical Field

[0001] This invention belongs to the field of marine water body detection technology, and particularly relates to a platinum nanoparticle antifouling redox metal electrode based on MOF material modification, its preparation method and application. Background Technology

[0002] Redox conditions are one of the main determinants and indicators of chemical processes in natural water and sediments. The redox environment in water bodies determines the valence state of substances. For example, the forms of iron and manganese are mainly regulated by redox conditions; under oxidizing conditions, they can change from soluble to solid forms, and under reducing conditions, they dissolve back into the water. Research on marine redox conditions can not only help us understand the evolution of marine ecosystems and the succession of biological communities, but also help us find scarce resources such as high-quality source rocks and sedimentary manganese carbonate deposits. Therefore, conducting research on redox conditions is of great significance for clarifying the evolutionary environment of organisms and analyzing the spatiotemporal distribution of sedimentary mineral deposits in basins.

[0003] Currently, redox potential methods, using inert metals as working electrodes and saturated calomel electrodes as reference electrodes, are mainly used to assess redox conditions in seawater and other water bodies. Platinum is widely used for redox potential measurement, and its response depends primarily on the characteristics of the platinum surface, especially the thin layer that forms on the platinum surface. However, platinum is easily biofouled in solutions with high biomass, affecting the electrode response and leading to a series of problems such as potential drift and slow response time. Therefore, effectively addressing the biofouling problem is key to improving the stability of redox electrodes. Summary of the Invention

[0004] To address the aforementioned issues, this invention develops a platinum nanoparticle antifouling redox metal electrode based on MOF material modification, along with its preparation method and applications.

[0005] According to a first aspect of the present invention, the present invention provides a method for preparing a platinum nanoparticle antifouling redox metal electrode based on MOF material modification, comprising the following steps: S1: The platinum-based electrode is polished and pretreated, then immersed in a mixture of sulfuric acid and hydrogen peroxide. After being removed, washed and dried, it is then encapsulated with heat shrink tubing. S2: Dissolve K2PtCl4 and CTAB in dilute sulfuric acid solution and stir to prepare electroplating solution; S3: Place the platinum-based electrode obtained in S1 into the electroplating solution obtained in S2, and electroplat the platinum nanoparticles onto the platinum-based electrode at room temperature using the chronoelectric method to obtain an electrode with a platinum nanoparticle substrate. S4: Dissolve BDC-F4 and ZrO(NO3)2∙2H2O in acetic acid solution, heat in a water bath and stir to allow the MOF material to complete self-assembly in the solution. Then, place the electrode obtained in S3 into the above solution to load the generated MOF material onto the surface of platinum nanoparticles, thereby obtaining the platinum nanoparticle anti-fouling redox metal electrode based on MOF material modification.

[0006] According to some preferred embodiments of the present invention, in step S1, the platinum-based electrode is a platinum wire or a composite electrode made by welding platinum wire and gold wire.

[0007] According to some preferred embodiments of the present invention, in step S1, the platinum-based electrode is pre-treated by polishing, specifically by using aluminum oxide polishing powder with a radius of 1.5~0.05 μm to polish the platinum-based electrode, then rinsing the surface with deionized water, and wiping or drying it.

[0008] According to some preferred embodiments of the present invention, in step S1, the mixture is formulated as a mixture of 98% concentrated sulfuric acid and 30wt% hydrogen peroxide in a volume ratio of 3:1, and the electrode is immersed in the mixture for 20 to 40 minutes.

[0009] According to some preferred embodiments of the present invention, in step S1, the washing process uses deionized water and anhydrous ethanol.

[0010] According to some preferred embodiments of the present invention, in the electroplating solution of step S2, the concentration of K2PtCl4 is 0.5~1 mmol / L, the concentration of CTAB is 0.05~0.4 g / L, and the concentration of sulfuric acid is 0.25~1 mol / L. Preferably, the stirring speed in S2 is 200~500 rpm.

[0011] According to some preferred embodiments of the present invention, step S3 is as follows: using the platinum-based electrode obtained in S1 as the working electrode to be plated, placing the working electrode, platinum counter electrode, and silver / silver chloride reference electrode into the electroplating solution obtained in S2, and performing electroplating at room temperature using the chronoamperometry method, with the following electroplating parameters: maximum voltage of 0~0.2 V, minimum voltage of -0.3~-0.1 V, during the electroplating process, the voltage jumps between the maximum and minimum voltages, with periodic abrupt changes occurring at a frequency of 0.1~0.4 Hz, and the electroplating time is 100~400 s.

[0012] According to some preferred embodiments of the present invention, in the solution of step S4, the concentration of BDC-F4 is 0.05~0.2 mol / L, the concentration of ZrO(NO3)2∙2H2O is 0.05~0.2 mol / L, and the concentration of acetic acid is 5~10 mol / L.

[0013] According to some preferred embodiments of the present invention, the solution preparation method in step S4 is as follows: first, BDC-F4 and ZrO(NO3)2∙2H2O are dissolved in acetic acid solution respectively, then heated in a water bath at 40~60 °C for 3~10 minutes, the two solutions are mixed, and then heated at 100~300 rpm for 1~5 minutes.

[0014] According to some preferred embodiments of the present invention, the step S4 of placing the electrode obtained in S3 into the above solution specifically involves: after the electrode is placed into the solution, stirring is continued for 1 to 5 minutes, then stirring is stopped, and the electrode is left to stand in the solution for 5 to 20 minutes, while maintaining the water bath temperature during the standing process.

[0015] Secondly, the present invention provides a platinum nanoparticle antifouling redox metal electrode based on MOF material modification prepared by the aforementioned method.

[0016] According to some preferred embodiments of the present invention, the antifouling redox metal electrode of the present invention can be used as a redox solid electrode to detect redox potential in situ in water. The water body can be a natural water body such as an ocean, lake, or river, or it can be industrial or domestic water, industrial or domestic wastewater, etc.

[0017] According to some preferred embodiments of the present invention, the anti-fouling redox metal electrode of the present invention achieves stable and accurate detection of the environmental redox potential while preventing fouling.

[0018] According to some preferred embodiments of the present invention, the anti-fouling redox metal electrode of the present invention comprises a platinum-based electrode and a sensitive layer encapsulating the platinum-based electrode. The sensitive layer is composed of an outer UiO-66-F4MOF material and an inner platinum nanoparticle metal layer; the UiO-66-F4MOF material is prepared by BDC-F4 and ZrO(NO3)2∙2H2O, and the platinum nanoparticles in the platinum nanoparticle metal layer are sensitive materials that respond to redox potential.

[0019] Platinum nanoparticles possess high specific surface area and active sites, enabling the construction of superhydrophobic surfaces, inhibiting biofilm formation, and reducing contaminant adhesion. Compared to conventional metal electrodes, the high specific surface area of ​​the nanoparticles in this invention's antifouling redox metal electrode significantly increases the effective active area of ​​the electrode, providing more reaction sites and enhancing the adsorption capacity of target analytes, thereby improving the detection signal intensity. Furthermore, the high catalytic efficiency of nanomaterials can promote electrochemical reaction kinetics, enabling even trace amounts of target analytes to produce significant responses.

[0020] Furthermore, this invention utilizes MOF materials to modify nanoparticles, further enhancing the sensor's antifouling capability. The antifouling effect of MOF materials is manifested in two aspects. First, there is the pore size screening effect: the porous structure of MOFs can selectively block the adsorption or permeation of large molecular pollutants (such as proteins, organic molecules, and microorganisms), while allowing small molecules (such as electrolyte ions) to pass freely, maintaining electrode activity. Second, similar to nanoparticles, MOF materials can regulate surface roughness, reducing the contact area between pollutants and the electrode surface and inhibiting biofilm formation.

[0021] The beneficial effects of this invention are as follows: This invention provides a platinum nanoparticle-based antifouling redox metal electrode modified with MOF material and its preparation method. This electrode is used to detect redox potentials in seawater. The platinum nanoparticles in the electrode exhibit small particle size and large specific surface area. The extremely high specific surface area provides a large number of catalytic active sites, significantly improving the electrode reaction kinetics and ensuring a faster and more stable response to redox pairs in seawater, which is the foundation for obtaining accurate redox potential readings. Simultaneously, under weak operating potentials, the platinum nanoparticles can efficiently catalyze the generation of reactive oxygen species such as hydroxyl radicals. These strong oxidants can directly disrupt the cell structure of nearby microorganisms, eliminating biofilms that locally alter pH and oxygen concentrations at their source.

[0022] Furthermore, this invention modifies platinum nanoparticles with a layer of UiO-66-F4 MOF material. This material has regular nanoscale pores that allow water molecules and ions to pass freely to maintain electrochemical sensing, while effectively preventing bacteria and organic macromolecules from directly contacting the electrode surface. At the same time, the surface-enriched CF bonds form a low surface energy superhydrophobic interface, making it difficult for contaminants to adhere firmly, and even if they do, they are easily washed away by water flow.

[0023] Finally, the Pt NPs@UiO-66-F4 composite structure achieves excellent antifouling while maximizing the retention of the electrode's ion transport capacity and electrochemical activity due to its porosity and conductive network, thus achieving a balance between antifouling and functionality. Attached Figure Description

[0024] Figure 1 Scanning electron microscope (SEM) image of platinum nanoparticles on the surface of the electrode prepared in Example 1.

[0025] Figure 2 Scanning electron microscope (SEM) image of the surface Pt NPs@UiO-66-F4 composite structure of the electrode prepared in Example 1.

[0026] Figure 3 The measurement results of the electrode prepared in Example 1 in redox standard solutions at different standard potentials.

[0027] Figure 4 Potential changes of the electrode prepared in Example 1 and a commercial redox electrode in *Streptomyces pseudodwarfus* algal solution over 12 hours.

[0028] Figure 5 The measurement results of the electrode prepared in Example 2 in redox standard solutions at different standard potentials.

[0029] Figure 6 Scanning electron microscope (SEM) image of the surface Pt NPs structure of the electrode prepared for Comparative Example 1.

[0030] Figure 7 Scanning electron microscope (SEM) image of the surface Pt NPs@UiO-66-F4 composite structure of the electrode prepared for Comparative Example 2.

[0031] Figure 8 Scanning electron microscope (SEM) image of the surface Pt NPs@UiO-66-F4 composite structure of the electrode prepared for Comparative Example 3. Detailed Implementation

[0032] To facilitate understanding of the present invention, a more detailed description is provided below with reference to the accompanying drawings and specific embodiments. Preferred embodiments of the invention are shown in the drawings. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the present invention.

[0033] Example 1: Preparation of a platinum nanoparticle redox electrode based on MOF material modification S1. The platinum electrode is pre-treated by polishing. The specific steps are as follows: Sprinkle a small amount of aluminum oxide polishing powder with radii of 1.5 μm, 0.5 μm and 50 nm onto the chamois leather, then add a small amount of deionized water, stir slightly with a glass rod, then place the platinum electrode horizontally and polish it 20 times, rotate it 90° and continue polishing it 20 times, then rinse the surface with deionized water and wipe or blow dry.

[0034] Immerse the electrode in a solution of 15 ml of 98% concentrated sulfuric acid and 5 ml of 30 wt% hydrogen peroxide for 30 minutes. After immersion, wash the electrode in an ultrasonic cleaner for 5 minutes each time with deionized water, anhydrous ethanol, and then deionized water. After drying, cover the electrode with heat-shrink tubing.

[0035] S2. Dissolve K2PtCl4 and CTAB in dilute sulfuric acid solution and stir to prepare the electroplating solution; The concentration of K2PtCl4 in the electroplating solution is 0.75 mmol / L, the concentration of CTAB is 0.1 g / L, the concentration of sulfuric acid is 0.5 mol / L, and the volume of the electroplating solution is 25 ml. Place the prepared solution on a stirrer and set the stirring speed to 300 rpm.

[0036] S3. The platinum electrode to be plated, the platinum counter electrode, and the saturated silver / silver chloride electrode were placed in the electroplating solution and electroplated at room temperature using a chronoamperometry method. The voltage transition range was set to -0.2 V to 0 V. During the electroplating process, the voltage periodically changed between the maximum and minimum voltages at a frequency of 0.2 Hz, and the electroplating time was 180 s. A nano-platinum redox electrode was thus prepared.

[0037] S4. Dissolve 1 mmol BDC-F4 and 1 mmol ZrO(NO3)2∙2H2O in 10 ml of 6 mol / L acetic acid solution and heat in a 50 ℃ water bath for 5 min. Then, pour the ZrO(NO3)2∙2H2O solution into the BDC-F4 solution and stir for 1 min. Then, place the electrode obtained in S3 into the stirred solution and continue stirring for 1 min. Let the electrode stand for 10 min to modify the MOF onto the electrode, thus obtaining a MOF-modified nano-platinum redox electrode.

[0038] The prepared MOF material-modified nanoplatinum redox electrode was used as the working electrode to measure the redox potential in seawater, which is used for antifouling measurement of redox potential in seawater.

[0039] Figure 1 This is a SEM image of the platinum nanoparticles on the surface of the MOF-modified platinum nanoparticle antifouling redox metal electrode prepared in this embodiment. The SEM image clearly shows that the platinum nanoparticles are well dispersed and uniformly distributed on the electrode surface, forming spherical shapes. Figure 1(ad in the text). The modified electrode surface forms a three-dimensional nanostructure composed of a large number of platinum nanoparticles (40-60 nm in diameter). Compared with a flat bare platinum electrode, this structure significantly increases the effective electrochemical specific surface area of ​​the electrode, with its core advantages manifested in two aspects. First, the platinum nanoparticles on the electrode surface bring extremely high surface atom utilization. The nanoscale effect exposes a large number of coordinated unsaturated platinum atoms as highly active catalytic sites, greatly improving the intrinsic utilization efficiency of the material. Second, the platinum nanoparticles also provide an optimized reaction microenvironment. The three-dimensional nanostructure shortens the ion mass transfer path, optimizes the interfacial electric field distribution, and effectively reduces the activation energy of the electrochemical reaction. Therefore, this structure not only improves the electrode performance in terms of specific surface area but also in terms of reaction kinetics, macroscopically manifesting as a faster response speed and better stability.

[0040] Figure 2 The image shows a SEM image of the surface Pt NPs@UiO-66-F4 composite structure of the MOF-modified platinum nanoparticle antifouling redox metal electrode prepared in this embodiment. The UiO-66-F4 support exhibits a highly uniform nanoparticle morphology and abundant mesoporous channels. This microstructure directly relates to and supports the superior overall performance of the modified electrode. The particulate morphology ensures high dispersion of platinum nanoparticles, maximizing the exposure of electrocatalytic active sites, which is the structural basis for the electrode to achieve high current density and excellent catalytic activity. The three-dimensional interconnected hierarchical channels formed between the particles construct an efficient mass transfer network, ensuring not only rapid transport of reactants and products and improving electrode reaction kinetics and rate performance, but also ensuring the effective diffusion of reactive oxygen species and other substances generated by the internal platinum nanoparticles to the surface, achieving a synergistic and unified "active sterilization" antifouling function and "rapid electrocatalysis" reaction function. Simultaneously, this stable, interwoven porous structure also enhances the mechanical stability of the coating, providing crucial durability assurance for the electrode to operate stably and sustainably in harsh seawater environments. Therefore, the microstructure revealed by electron microscopy directly confirms the success of this electrode design in three aspects: improving activity, optimizing mass transfer, and ensuring long-term stability.

[0041] The measurement capability of the redox electrode prepared in this embodiment was tested.

[0042] Figure 3 The open-circuit potential curves of the MOF-modified platinum nanoparticle antifouling redox metal electrode prepared in this embodiment in redox standard solutions with potential values ​​of 430 mV, 256 mV, and 86 mV show that the measurement errors of the platinum nanoparticle antifouling redox metal electrode prepared in this embodiment are 3.51 mV, 1.63 mV, and 2.55 mV, respectively, which are within the theoretical error range of ±15 mV.

[0043] The antifouling redox metal electrode prepared in this embodiment and the Thermo Scientific™ 9180BNMDORP commercial redox electrode were used to test the redox potential in a solution of *Pseudo-Dwarf Seaweed*. The results are as follows: Figure 4 As shown, the antifouling redox metal electrode reached a stable value after 30 minutes and changed by only 1 mV in the following 11 hours; while the potential of the commercial electrode was difficult to stabilize within 12 hours, gradually decreasing at a rate of 5 mV / h.

[0044] In long-term seawater testing, the stability of electrode potential is the most critical and direct macroscopic electrochemical indicator for evaluating its antifouling performance, and there is an essential causal relationship between the two. Potential drift itself is a signal of fouling: when microorganisms attach and form biofilms, this insulating layer hinders the exchange of substances between the electrode and seawater. At the same time, microbial metabolism locally alters the oxygen concentration, pH value, and ionic composition at the interface. These effects collectively cause the potential measured by the electrode to deviate significantly from its true thermodynamic equilibrium potential, manifesting as slow drift, increased noise, and hysteresis.

[0045] Therefore, the long-term stable potential readings provide strong evidence for the continued effectiveness of the antifouling coating. This indicates that the synergistic antifouling system composed of Pt NPs@UiO-66-F4 effectively inhibits the initial formation and long-term thickening of biofilms, keeping the electrochemically active interface of the electrode clean. Furthermore, this stability also demonstrates the durability of the antifouling coating itself in harsh marine environments—its porous structure remains unblocked, its mechanical bonding remains intact, and its electrochemical function does not degrade.

[0046] Example 2 S1. Same as S1 in Example 1.

[0047] S2. Same as S2 in Example 1.

[0048] S3. Same as S3 in Example 1.

[0049] S4. Dissolve 1 mmol BDC-F4 and 1 mmol ZrO(NO3)2∙2H2O in 10 ml of 6 mol / L acetic acid solution and heat in a 50 °C water bath for 5 min. Then, pour the ZrO(NO3)2∙2H2O solution into the BDC-F4 solution and stir for 1 min. Next, place the electrode obtained in S3 into the stirred solution and continue stirring for 1 min. Let the electrode stand for 15 min to modify it with MOF, obtaining a MOF-modified nano-platinum redox electrode. The electrode morphology obtained in Example 2 is similar to that in Example 1.

[0050] Figure 5The open-circuit potential curves of the MOF-modified platinum nanoparticle antifouling redox metal electrode prepared in Example 2 are shown in redox standard solutions with potential values ​​of 430 mV, 256 mV, and 86 mV. It can be seen that the measurement errors of the platinum nanoparticle antifouling redox metal electrode prepared in this example are 8.72 mV, 1.47 mV, and 2.49 mV, respectively, which are within the theoretical error range of ±15 mV, proving that the performance is good.

[0051] Example 3 S1. Same as S1 in Example 1.

[0052] S2. Dissolve K2PtCl4 and CTAB in dilute sulfuric acid solution and stir to prepare electroplating solution; The concentration of K2PtCl4 in electroplating solution is 0.75 mmol / L, the concentration of CTAB is 0.1 g / L, the concentration of sulfuric acid is 0.5 mol / L, and the volume of electroplating solution is 25 ml. Place the prepared solution on a stirrer and set the stirring speed to 250 rpm.

[0053] S3. Compared with S3 of Example 1, except that the electroplating solution used is the same as that of S2 of this Example, everything else is the same.

[0054] S4. Same as S4 in Example 1. The electrode morphology obtained in Example 3 is similar to that in Example 1.

[0055] Comparative Example 1 S1. Same as S1 in Example 1.

[0056] S2. Same as S2 in Example 1.

[0057] S3. The platinum electrode to be plated, the platinum counter electrode, and the saturated silver / silver chloride electrode were placed in the electroplating solution and electroplated at room temperature using a chronoamperometry method. The voltage transition range was set to -0.4 V to 0 V. During the electroplating process, the voltage periodically changed between the maximum and minimum voltages at a frequency of 0.2 Hz, and the electroplating time was 180 s. A nano-platinum redox electrode was thus prepared.

[0058] Depend on Figure 6 As can be seen, the platinum wire surface in Comparative Example 1 showed aggregated platinum nanoparticles instead of a uniformly dispersed nanostructure. This aggregation significantly reduces the effective electrochemical active area of ​​the electrode, burying the platinum catalytic sites and resulting in sluggish electrochemical response and decreased catalytic activity. Simultaneously, the rough, irregular macroscopic surface formed by the aggregates is more prone to trapping organic matter and microorganisms through capillary action, thus promoting the initial adhesion of biofouling, completely contradicting the design intention of achieving "anti-adhesion" through nanostructuring. Therefore, the overall performance and lifespan of this nanostructured electrode will be significantly inferior to that of an electrode with a uniform nanostructure.

[0059] Comparative Example 2 S1. Same as S1 in Example 1.

[0060] S2. Same as S2 in Example 1.

[0061] S3. Same as S3 in Example 1.

[0062] S4. Dissolve 1 mmol BDC-F4 and 1 mmol ZrO(NO3)2∙2H2O in 10 ml of 6 mol / L acetic acid solution and heat in a 70 ℃ water bath for 5 min. Then, pour the ZrO(NO3)2∙2H2O solution into the BDC-F4 solution and stir for 1 min. Then, place the electrode obtained in S3 into the stirred solution and continue stirring for 1 min. After that, let the electrode stand for 10 min to modify the MOF onto the electrode.

[0063] Comparative Example 3 S1. Same as S1 in Example 1.

[0064] S2. Same as S2 in Example 1.

[0065] S3. Same as S3 in Example 1.

[0066] S4. Dissolve 1 mmol BDC-F4 and 1 mmol ZrO(NO3)2∙2H2O in 10 ml of 6 mol / L acetic acid solution and heat in a 30 ℃ water bath for 5 min. Then, pour the ZrO(NO3)2∙2H2O solution into the BDC-F4 solution and stir for 1 min. Then, place the electrode obtained in S3 into the stirred solution and continue stirring for 1 min. After that, let the electrode stand for 10 min to modify the MOF onto the electrode.

[0067] Figure 7 , Figure 8 The images show scanning electron microscope (SEM) images of Comparative Examples 2 and 3, respectively. As can be seen from the figures, at this temperature, a highly uniform MOF nanoparticle morphology failed to form on the platinum wire surface. Therefore, compared to Example 1, Comparative Examples 2 and 3 exhibit significantly reduced antifouling performance. The discontinuous and incomplete coating structure leads to direct exposure of local areas, providing sites for microbial attachment and biofilm formation, thus rendering the physical barrier function ineffective. Simultaneously, the irregular surface morphology undermines the designed superhydrophobic properties, reducing its chemical driving force for "anti-adhesion," and may actually make it easier to retain contaminants due to uneven roughness. In the long run, these structural defects also impair the mechanical stability and permeability of the coating, making it more susceptible to damage and peeling under prolonged immersion or water erosion.

[0068] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the appended claims.

Claims

1. A method for preparing a platinum nanoparticle antifouling redox metal electrode based on MOF material modification, characterized in that, Includes the following steps: S1: Polish the platinum-based electrode, immerse it in a mixture of sulfuric acid and hydrogen peroxide, remove it, wash and dry it, and then encapsulate it with heat shrink tubing. S2: Dissolve K2PtCl4 and CTAB in dilute sulfuric acid solution and stir to prepare electroplating solution; S3: Place the platinum-based electrode obtained in S1 into the electroplating solution obtained in S2, and electroplat the platinum nanoparticles onto the platinum-based electrode at room temperature using the chronoelectric method to obtain an electrode with a platinum nanoparticle substrate. S4: Dissolve BDC-F4 and ZrO(NO3)2∙2H2O in acetic acid solution, heat in a water bath and stir to allow the MOF material to complete self-assembly in the solution. Then, place the electrode obtained in S3 into the above solution to load the generated MOF material onto the surface of platinum nanoparticles, thereby obtaining the platinum nanoparticle anti-fouling redox metal electrode based on MOF material modification.

2. The preparation method according to claim 1, characterized in that, In step S1, the platinum-based electrode is a platinum wire or a composite electrode made by welding platinum wire and gold wire.

3. The preparation method according to claim 1, characterized in that, In step S1, the platinum-based electrode is pre-treated by polishing. The specific steps are as follows: the platinum-based electrode is polished with aluminum oxide polishing powder with a radius of 1.5~0.05 μm, and then the surface is rinsed with deionized water and wiped or dried.

4. The preparation method according to claim 1, characterized in that, In step S1, the mixture is formulated as 98% concentrated sulfuric acid and 30wt% hydrogen peroxide mixed in a volume ratio of 3:1, and the electrode is immersed in the mixture for 20 to 40 minutes.

5. The preparation method according to claim 1, characterized in that, In the electroplating solution of step S2, the concentration of K2PtCl4 is 0.5~1 mmol / L, the concentration of CTAB is 0.05~0.4 g / L, and the concentration of sulfuric acid is 0.25~1 mol / L; the stirring speed in S2 is 200~500 rpm.

6. The preparation method according to claim 1, characterized in that, Step S3 is as follows: the platinum-based electrode obtained in S1 is used as the working electrode to be plated. The working electrode, platinum counter electrode, and silver / silver chloride reference electrode are placed in the electroplating solution obtained in S2. Electroplating is performed at room temperature using the chronoamperometry method. The electroplating parameters are: maximum voltage of 0~0.2 V, minimum voltage of -0.3~-0.1 V. During the electroplating process, the voltage jumps between the maximum and minimum voltages, and periodic abrupt changes occur with a frequency of 0.1~0.4 Hz. The electroplating time is 100~400 s.

7. The preparation method according to claim 1, characterized in that, In the solution of step S4, the concentration of BDC-F4 is 0.05~0.2 mol / L, the concentration of ZrO(NO3)2∙2H2O is 0.05~0.2 mol / L, and the concentration of acetic acid is 5~10 mol / L; The solution preparation method for step S4 is as follows: first, dissolve BDC-F4 and ZrO(NO3)2∙2H2O in acetic acid solution respectively, then heat in a water bath at 40~60℃ for 3~10 minutes, mix the two solutions, and then continue heating at 100~300 rpm for 1~5 minutes.

8. The preparation method according to claim 1, characterized in that, In step S4, the electrode obtained in S3 is placed into the above solution. Specifically, after the electrode is placed into the solution, stirring is continued for 1 to 5 minutes, then stirring is stopped, and the electrode is left to stand in the solution for 5 to 20 minutes, while keeping the water bath temperature constant during the standing process.

9. The anti-fouling redox metal electrode based on MOF material modified platinum nanoparticles prepared by any one of claims 1-8.

10. The application of the antifouling redox metal electrode as described in claim 9 as a redox solid electrode in in-situ detection of redox potential in water.

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