Metal organic coordination polymer anti-corrosion slurry based on photo-magnetic coordinated regulation and application

Abstract

The invention discloses metal organic coordination polymer anti-corrosion slurry based on photo-magnetic coordinated regulation and application, and belongs to the technical field of metal corrosion prevention. The core active component of the anticorrosive slurry is a metal organic coordination polymer with the chemical formula of Co (bpy) (dhbq) (bq). The preparation method comprises the following steps: dispersing the metal organic coordination polymer Co (bpy) (dhbq) (bq), conductive carbon black and epoxy resin in a xylene solvent to form the slurry. The slurry is applied to a metal matrix to prepare a coating, photo-induced electron directional enrichment is achieved through the illumination-induced ligand-ligand charge transfer (LLCT) effect, carrier recombination is inhibited by combining the spin polarization effect regulated and controlled by a magnetic field, the interface charge transfer resistance is remarkably reduced through the photo-magnetic synergistic effect, and the charge transfer efficiency is improved. The invention solves the problem of low carrier utilization rate of the existing photo-assisted cathode protection technology, has the advantages of greenness, energy conservation, excellent protection effect, good stability and the like, and can be widely applied to metal corrosion prevention of engineering facilities such as ships, ocean platforms and the like.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of material science and engineering technology, specifically to the sub-field of metal corrosion protection materials, and particularly relates to a metal-organic coordination polymer coating material for realizing efficient cathodic protection function by utilizing light field and magnetic field to cooperatively regulate carrier behavior, a preparation method thereof, and application thereof in metal substrate corrosion protection. BACKGROUND

[0002] Metal materials are widely used in major engineering fields such as ships, offshore platforms, bridges, and petroleum and chemical equipment due to their excellent mechanical properties. However, metal corrosion problems can lead to material performance degradation and structural failure, resulting in not only huge economic losses but also serious safety accidents. According to statistics, the economic losses caused by metal corrosion each year account for 2% - 4% of the global GDP, so developing efficient, long-acting, and green corrosion protection technology has important practical significance and economic value.

[0003] Traditional metal corrosion protection technologies mainly include sacrificial anode cathodic protection method, impressed current cathodic protection method, and coating isolation method. Among them, the sacrificial anode method consumes a large amount of active metal (such as zinc, aluminum, magnesium, and their alloys), which has the problems of resource waste and high replacement and maintenance cost; the impressed current method needs to continuously consume electric energy, and has safety hazards in flammable and explosive environments, which limits its application scenarios; traditional coatings (such as epoxy resin coatings and polyurethane coatings) mainly rely on physical isolation to achieve corrosion protection, and are prone to cracking, peeling, and other problems after long-term use, with limited protection life.

[0004] In recent years, the "light-assisted cathodic protection technology" based on photoelectrochemical effect has become a research hotspot in the field of corrosion protection due to its advantages of green and sustainability by utilizing solar energy to drive cathodic protection reactions. The core principle of this technology is to generate photo-generated electron-hole pairs by absorbing light energy through photoactive materials, and then transfer the photo-generated electrons to the surface of the metal substrate, so that the electrode potential of the metal substrate is negatively shifted below the corrosion potential, thereby inhibiting the anodic dissolution reaction of the metal. However, the existing light-assisted cathodic protection technology generally has the key bottleneck of low photo-generated carrier separation efficiency and high recombination rate, which leads to insufficient utilization of photo-generated electrons and makes it difficult to achieve efficient and long-acting cathodic protection effect.

[0005] To address these issues, researchers have proposed improvement strategies such as constructing heterojunctions and introducing hole transport layers to promote the separation of photogenerated carriers. However, these strategies have significant drawbacks: on the one hand, the heterojunction interface and hole transport layer are prone to charge accumulation, leading to local electric field distortion, which in turn hinders the dynamic processes of ion migration and charge transport; on the other hand, the disordered spin arrangement within photoactive materials causes a large number of high-energy excitons to dissipate energy through non-radiative recombination, further reducing the effective utilization rate of photogenerated electrons. Therefore, how to achieve efficient separation and directional migration of photogenerated carriers from the two dimensions of charge transfer path regulation and spin state regulation is the core key to overcoming the bottleneck of existing photo-assisted cathodic protection technology.

[0006] Metal-organic coordination polymers (MOFs), a class of crystalline materials assembled from metal ions / metal clusters and organic ligands through coordination bonds, possess characteristics such as tunable pore size, large specific surface area, controllable structure, and excellent photochemical properties, and have been extensively studied in photocatalysis, energy storage, and sensors. Applying MOFs to photo-assisted cathodic protection coatings allows for the regulation of light absorption performance and carrier behavior by controlling the type and structure of the metal center and organic ligands. However, there are currently no reports on incorporating the synergistic regulation mechanism of light and magnetic fields into the design of MOF anti-corrosion coatings, and there is a lack of MOF material systems capable of simultaneously achieving directional migration and spin polarization regulation of photogenerated carriers. Summary of the Invention

[0007] The technical problem to be solved by this invention is as follows: In existing photo-assisted cathodic protection technologies, there are issues such as high recombination rate of photogenerated carriers, low separation efficiency, insufficient electron utilization, and the tendency of existing improvement strategies to induce charge accumulation and hinder ion migration dynamics. This invention provides a metal-organic coordination polymer anti-corrosion coating material and its application based on photomagnetic synergistic regulation. By designing a metal-organic coordination polymer with a specific structure, and combining the synergistic effect of light and magnetic fields, the directional migration and efficient separation of photogenerated carriers are achieved, significantly improving the cathodic protection effect. Simultaneously, the invention provides a method for preparing this material and its applications to meet the engineering field's demand for efficient, green, and long-lasting anti-corrosion technology.

[0008] To achieve the above-mentioned technical effects, the technical solution adopted by the present invention is as follows: A metal-organic coordination polymer (MOC) anticorrosive slurry based on photomagnetic synergistic regulation is disclosed. The slurry comprises a solid component, a MOC, conductive carbon black, and epoxy resin. The slurry is formed by dispersing the solid component in xylene solvent. The mass percentages of the solid components are as follows: MOC 20-30%, conductive carbon black 20-30%, and epoxy resin 40-50%. The mass-to-volume ratio of the solid component to the xylene solvent is 1 g:5 mL, and the viscosity of the slurry is 500-1500 mPa·s.

[0009] The metal-organic coordination polymer material is Co(bpy)(dhbq)(bq), where Co represents cobalt ions (Co). 2+ ), bpy is 2,2'-bipyridine, dhbq is 2,5-dihydroxy-1,4-benzoquinone, and bq is 1,4-benzoquinone. In this organometallic coordination polymer, Co 2+ As the central metal ion, it forms stable coordination bonds with the nitrogen atom of 2,2'-bipyridine, the oxygen atoms of 2,5-dihydroxy-1,4-benzoquinone, and 1,4-benzoquinone, constructing a three-dimensional crystalline structure with specific electronic structure and spin characteristics. This metal-organic coordination polymer material has a crystal grain size of 50-200 nm and a specific surface area of ​​150-300 m². 2 / g.

[0010] The preparation method of this metal-organic coordination polymer includes the following specific steps: 1. Raw material pretreatment: Cobalt nitrate (Co(NO3)2·6H2O), 2,2'-bipyridine, 2,5-dihydroxy-1,4-benzoquinone and 1,4-benzoquinone were placed in a vacuum drying oven and dried at 60°C for 4 hours to remove moisture and impurities from the raw materials; 2. Solution preparation: Accurately weigh the pretreated cobalt nitrate, 2,2'-bipyridine, 2,5-dihydroxy-1,4-benzoquinone and 1,4-benzoquinone in a molar ratio of 1:1:1:1, add them to a round-bottom flask, and then add anhydrous methanol as the solvent. The solvent volume is 40 mL of anhydrous methanol for every 1 mmol of cobalt nitrate. 3. Isothermal reaction: Place the round-bottom flask in a constant temperature water bath, set the temperature to 50°C, turn on the magnetic stirrer, and stir at a rate of 300 r / min for 2 hours to allow the raw materials to dissolve completely and undergo a coordination reaction. 4. Product Separation: After the reaction was completed, the reaction solution was transferred to a centrifuge tube and evaporated at 50°C and 0.08 MPa using a rotary evaporator to remove 2 / 3 of the volume of solvent, obtaining a concentrated solution. 30 mL of anhydrous diethyl ether was slowly added dropwise to the concentrated solution while stirring. After the addition was completed, the solution was allowed to stand for 20 minutes to allow the product to fully separate. The centrifuge tube was then placed in a high-speed centrifuge and centrifuged at 8000 r / min for 10 minutes, and the bottom precipitate was collected. 5. Purification and drying: The collected precipitate was washed with anhydrous diethyl ether, and the washing was repeated 3 times, with a washing volume of 10 mL each time, to remove unreacted raw materials and impurities; the washed precipitate was placed in a vacuum drying oven and dried at 80°C for 12 hours to finally obtain a black-brown powdery Co(bpy)(dhbq)(bq) metal-organic coordination polymer product.

[0011] The present invention also provides an anti-corrosion coating formed by coating the above-mentioned anti-corrosion slurry onto the surface of a metal substrate and drying it. The preparation method of the coating includes the following steps: a) Metal substrate pretreatment: The metal substrate (such as objects made of low carbon steel, stainless steel, aluminum alloy, etc.) is polished step by step with 400 grit, 800 grit, and 1200 grit sandpaper until the surface is smooth. Then, it is ultrasonically cleaned with anhydrous ethanol for 15 minutes to remove surface oil and grinding debris. Finally, it is dried with nitrogen and placed in a desiccator for later use. b) Preparation of anti-corrosion slurry: Solid components metal-organic coordination polymer material, conductive carbon black, magnetic powder, and epoxy resin were mixed in a mass ratio of 3:3:4. Xylene solvent was added, and the mixture was then ultrasonically dispersed in an ultrasonic cleaner for 30 minutes, followed by stirring with a magnetic stirrer for 2 hours to obtain a uniformly dispersed slurry. The mass-volume ratio of solid powder (Co(bpy)(dhbq)(bq) + conductive carbon black + epoxy resin) to xylene solvent was 1 g: 5 mL. c) Coating: The slurry is uniformly coated onto the pretreated metal substrate surface to be protected using a doctor blade coating method, and the wet film thickness is controlled to be 100-150 μm. d) Drying: Place the coated metal substrate in an 80°C vacuum drying oven for 12 hours to remove the solvent and form a dense, functional anti-corrosion coating.

[0012] When the aforementioned anti-corrosion coating is applied to the cathodic protection of the metal substrate, the metal substrate includes a shell-like structure made of materials such as low-carbon steel, stainless steel, or aluminum alloy, or a solid metal component made of the aforementioned materials. The application environment includes corrosive environments such as marine, petrochemical, and bridge construction. During use, the coating is irradiated with 365 nm wavelength light (either natural sunlight or artificially created light) and subjected to a 200 mT external static magnetic field (an artificially created magnetic field outside the metal substrate to be protected) for photomagnetic synergistic modulation. After modulation, the open-circuit potential of the metal substrate is stabilized below -0.85V (vs SCE). The light intensity of the irradiation is 100-150 mW·cm. -2 The magnetic field is either a static magnetic field or a low-frequency alternating magnetic field, with the frequency of the alternating magnetic field being 50-100 Hz.

[0013] The specific mechanism by which the anti-corrosion coating of the present invention achieves efficient cathodic protection through the synergistic control mechanism of optical and magnetic dual fields is as follows: Light-induced ligand-ligand charge transfer (LLCT) effect: Under specific wavelength illumination (365 nm ultraviolet light) excitation, strong ligand-ligand electronic transitions (LLCT) occur within the Co(bpy)(dhbq)(bq) metal-organic coordination polymer system. Since the highest occupied molecular orbital (HOMO) energy of 1,4-benzoquinone (BQ) is higher than that of 2,5-dihydroxy-1,4-benzoquinone (DHBQ), photogenerated electrons migrate directionally from the 1,4-benzoquinone (BQ) ligand to the 2,5-dihydroxy-1,4-benzoquinone (DHBQ) ligand. This enriches the photogenerated electrons at the more electrochemically active DHBQ ligand sites, providing a sufficient electron source for subsequent electron transfer to the metal matrix and achieving cathodic protection. Simultaneously, photogenerated holes remain on the BQ ligand, preventing direct recombination between holes and electrons.

[0014] Magnetic field-controlled spin polarization and carrier lifetime extension effect: After introducing an external static magnetic field (200 mT), the central metal Co in Co(bpy)(dhbq)(bq) 2+ The high-spin state (S = 3 / 2) with unpaired electrons can act as a "spin filter." Under the influence of a magnetic field, Co undergoes a Zeeman splitting effect. 2+ The d-orbital energy level splits, increasing spin polarization; simultaneously, the magnetic field strengthens Co. 2+ The spin-orbit coupling (SOC) effect between the d orbitals and the π orbitals of the organic ligands effectively suppresses the nonradiative recombination of photogenerated electron-hole pairs, significantly prolongs the carrier lifetime, and provides a sufficient time window for the directional migration of photogenerated electrons from the DHBQ ligand to the metal matrix.

[0015] Photomagnetic synergistic enhancement mechanism: The synergistic effect of light field and magnetic field achieves directional enrichment of photogenerated electrons through the LLCT effect on the one hand, and efficient suppression of carrier recombination through magnetic field modulation on the other hand. The combined effect of the two significantly reduces the charge transfer resistance (Rct) at the interface between the coating and the metal substrate, optimizes the dynamic process of interface charge transport and ion migration, and ultimately achieves efficient spin-selective separation and directional migration of photogenerated electrons to the surface of the metal substrate, so that the electrode potential of the metal substrate is stably shifted negatively to below the corrosion potential, achieving the effect of efficient cathodic protection.

[0016] Compared with the prior art, the beneficial effects of the present invention are: 1. Significantly Improved Carrier Utilization Efficiency: This invention is the first to introduce a photomagnetic synergistic control mechanism into the design of a metal-organic coordination polymer anti-corrosion coating. It achieves directional migration of photogenerated electrons through the LLCT effect and suppresses carrier recombination by combining the spin polarization effect controlled by a magnetic field. This addresses the core problem of low carrier utilization in existing photo-assisted cathodic protection technologies from two dimensions. Experimental verification shows that under dual photomagnetic field conditions, the photocurrent response intensity of the coating is increased by more than 2.5 times compared to single photofield conditions, and the charge transfer efficiency is increased by more than 3 times.

[0017] 2. Excellent and long-lasting cathodic protection performance: The synergistic effect of photomagnetism maximizes the number of photogenerated electrons that can be transferred to the metal substrate per unit time, providing a continuous and stable cathodic protection current to the metal substrate and effectively inhibiting the anodic dissolution process of the metal. In a simulated marine corrosion environment (3.5 wt% NaCl solution), the open circuit potential of the low-carbon steel sample coated with the coating of this invention can be negatively shifted to below -0.85 V (vs SCE) under the action of photomagnetic dual fields, and can be stably maintained for more than 1000 hours, with a protective effect far superior to traditional photo-assisted cathodic protection coatings.

[0018] 3. Green, environmentally friendly, energy-saving and sustainable: The anti-corrosion technology of this invention uses solar energy (light field) and magnetic field as driving force, without the need for additional power consumption or sacrificial anodes and other metal materials, and does not produce pollutant emissions, which is in line with the green and low-carbon development trend; at the same time, the preparation process of the coating material is simple and mild, and the solvents used (methanol, anhydrous ether) can be recycled, further reducing the impact on the environment.

[0019] 4. Excellent material and coating stability: The Co(bpy)(dhbq)(bq) metal-organic coordination polymer of the present invention has a stable crystalline structure, and its electrochemical redox reaction exhibits good reversibility under different conditions such as darkness, light, magnetic field, and photomagnetic dual field; the prepared coating has good density and strong adhesion to the metal substrate, and is not prone to cracking or peeling under harsh conditions such as immersion and thermal cycling, thus ensuring long-term protective performance.

[0020] 5. Wide applicability and controllable preparation cost: The anti-corrosion coating of this invention is applicable to a variety of metal substrates such as low-carbon steel, stainless steel, and aluminum alloy, and can be widely used in engineering facilities in different corrosive environments such as ships, offshore platforms, bridges, and petrochemical equipment; the raw materials used to prepare the coating (cobalt nitrate, 2,2'-bipyridine, etc.) are all commercial products, inexpensive, and the preparation process is simple and easy to scale up, with good prospects for industrial application.

[0021] As a further improvement of the present invention This invention also provides an anti-corrosion slurry and a coating. The difference between the aforementioned anti-corrosion slurry and the present invention's anti-corrosion slurry is that, based on the aforementioned anti-corrosion slurry, magnetic powder is added to its solid components. The weight of the magnetic powder is 10-15% of the total weight of the solid components composed of the metal-organic coordination polymer material, conductive carbon black, and epoxy resin. This method enables the slurry and the coating formed after drying on a metal substrate to possess magnetic properties, thereby partially or completely replacing an external magnetic field during use.

[0022] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Obviously, the described embodiments are some embodiments of the present invention, but not all embodiments. Attached Figure Description

[0023] Figure 1 is a schematic diagram of the synthetic route of Co(bpy)(dhbq)(bq) metal-organic coordination polymer; Figure 2 is a schematic diagram of the structure of the anti-corrosion coating photomagnetic synergistic cathodic protection device based on Co(bpy)(dhbq)(bq); Figure 3 shows the electrochemical impedance spectroscopy (Nyquist plot) of the Co(bpy)(dhbq)(bq) anti-corrosion coating under different conditions. Figure 4 is a schematic diagram of the mechanism of photomagnetic synergistic regulation of carrier separation and migration. Detailed Implementation

[0024] Example 1: Preparation of the metal-organic coordination polymer material Co(bpy)(dhbq)(bq) like Figure 1 As shown, the preparation of this material Co(bpy)(dhbq)(bq) includes the following steps: (1) Raw material pretreatment: Cobalt nitrate (Co(NO3)2·6H2O), 2,2'-bipyridine, 2,5-dihydroxy-1,4-benzoquinone and 1,4-benzoquinone were placed in a vacuum drying oven and dried at 60°C for 4 hours to remove moisture and impurities.

[0025] (2) Solution preparation: Accurately weigh 1.0 mmol of pretreated cobalt nitrate (0.291 g), 1.0 mmol of 2,2'-bipyridine (0.156 g), 1.0 mmol of 2,5-dihydroxy-1,4-benzoquinone (0.142 g) and 1.0 mmol of 1,4-benzoquinone (0.108 g), add them to a 100 mL round-bottom flask, add 40 mL of anhydrous methanol, and seal the round-bottom flask.

[0026] (3) Constant temperature reaction: Place the round bottom flask in a constant temperature water bath, set the temperature to 50°C, turn on the magnetic stirrer, stir at a speed of 300 r / min, and continue stirring for 2 hours.

[0027] (4) Product separation: After the reaction is completed, the reaction solution is transferred to a 50 mL centrifuge tube and evaporated at 50°C and 0.08 MPa using a rotary evaporator to remove about 27 mL of solvent (i.e., 2 / 3 volume of anhydrous methanol) to obtain a concentrated solution; 30 mL of anhydrous diethyl ether is slowly added dropwise to the concentrated solution while stirring with a magnetic stirrer. After the addition is completed, the solution is allowed to stand for 20 minutes to allow the product to fully separate; then the centrifuge tube is placed in a high-speed centrifuge and centrifuged at 8000 r / min for 10 minutes to collect the dark brown precipitate at the bottom. (5) Purification and drying: Wash the precipitate with 10 mL of anhydrous diethyl ether, repeat the washing 3 times to remove unreacted raw materials and impurities, and centrifuge after each washing; put the washed precipitate into a vacuum drying oven and dry it at 80°C for 12 hours to obtain a black brown powder product with a yield of 85%.

[0028] The product was characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and elemental analysis. The results showed that the prepared product was a Co(bpy)(dhbq)(bq) metal-organic coordination polymer with the target structure.

[0029] Example 2: Preparation of anti-corrosion slurry and anti-corrosion coating based on Co(bpy)(dhbq)(bq) (1) Pretreatment of metal matrix: Q235 low carbon steel was selected as the metal matrix to be protected and cut into 10 mm × 10 mm × 2 mm samples; the sample surface was polished step by step with 400 mesh, 800 mesh and 1200 mesh sandpaper until the surface was smooth and without scratches; the polished sample was placed in anhydrous ethanol and ultrasonically cleaned for 15 minutes; the sample was taken out, dried with nitrogen gas and placed in a desiccator for later use.

[0030] (2) Preparation of anti-corrosion slurry: Weigh 0.3 g of Co(bpy)(dhbq)(bq) powder prepared in Example 1, 0.3 g of conductive carbon black (Ketjenblack EC300J) and 0.4 g of epoxy resin, and add them to 5 mL of xylene solvent; put the mixture into an ultrasonic cleaner, ultrasonically disperse for 30 minutes, and then stir with a magnetic stirrer at a rate of 500 r / min for 2 hours to obtain a uniform coating slurry without agglomeration.

[0031] (3) Coating and drying: The prepared slurry was uniformly coated on the surface of the pretreated Q235 low carbon steel sample by the doctor blade coating method, and the wet film thickness was controlled to be 120 μm. The coated sample was placed in a vacuum drying oven and dried at 80°C for 12 hours to remove xylene solvent, and a dense anti-corrosion coating was obtained with a dry film thickness of 40-50 μm.

[0032] Example 3: Performance testing of anti-corrosion coating, like Figure 2 As shown, the Q235 low-carbon steel sample coated with an anti-corrosion coating prepared in Example 2 was used as the working electrode, a platinum sheet as the counter electrode, a saturated calomel electrode (SCE) as the reference electrode, and a 3.5 wt% NaCl solution as the electrolyte to construct a three-electrode testing system to simulate a marine corrosion environment. The open-circuit potential (OCP) and electrochemical impedance spectroscopy (EIS) of the coating were tested under the following four conditions: ① Dark conditions; ② Single illumination conditions (365 nm LED light source, light intensity 125 mW·cm). -2 ); ③ Single magnetic field condition (external static magnetic field strength 200 mT); ④ Optical and magnetic dual field condition (365 nm LED illumination + 200 mT static magnetic field).

[0033] The test results are as follows: (1) Open circuit potential (OCP) test: Under dark conditions, the OCP of the coating is -0.42 V (vs SCE); under single illumination conditions, the OCP shifts negative to -0.65 V (vs SCE); under single magnetic field conditions, the OCP is -0.45 V (vs SCE); under optical and magnetic dual field conditions, the OCP rapidly shifts negative to -0.88 V (vs SCE) and remains stable within 1000 hours of testing, indicating that the metal substrate is in an effective cathodic protection state and the optical and magnetic synergistic effect significantly improves the cathodic protection effect.

[0034] (2) Electrochemical Impedance Spectroscopy (EIS) Test: Nyquist plot of EIS spectrum (e.g.) Figure 3 The results show that the coating has the smallest impedance arc radius under optical and magnetic dual-field conditions in the low-frequency region; the charge transfer resistance (Rct) is calculated by equivalent circuit fitting: Rct is 8.5 × 10⁻⁶ under dark conditions. 5 Ω·cm 2 Under single illumination, Rct is 3.2 × 10⁻⁶. 5 Ω·cm 2 Under a single magnetic field, Rct is 7.8 × 10⁻⁶. 5 Ω·cm 2 Under optical and magnetic dual-field conditions, Rct decreases to 1.1 × 10⁻⁶. 5 Ω·cm 2 This demonstrates that the photomagnetic synergy significantly reduces the charge transfer resistance at the interface between the coating and the metal substrate, optimizes the interfacial reaction kinetics, and improves the charge transport efficiency.

[0035] This invention introduces a photomagnetic synergistic regulation mechanism into the design of metal-organic coordination polymer anti-corrosion coatings, and applies it to the cathodic protection of metal substrates. For example... Figure 4 As shown, the directional migration of photogenerated electrons is achieved through the LLCT effect, and carrier recombination is suppressed by the spin polarization effect controlled by a magnetic field. This addresses the core problem of low carrier utilization in existing photo-assisted cathodic protection technologies from two dimensions. Experimental verification shows that under dual optical and magnetic field conditions, the photocurrent response intensity of the coating is increased by more than 2.5 times compared to the single optical field condition, and the charge transfer efficiency is increased by more than 3 times.

[0036] The specific mechanism by which the anti-corrosion coating of the present invention achieves efficient cathodic protection through the synergistic control mechanism of optical and magnetic dual fields is as follows: Light-induced ligand-ligand charge transfer (LLCT) effect: Under specific wavelength illumination (365 nm ultraviolet light) excitation, strong ligand-ligand electronic transitions (LLCT) occur within the Co(bpy)(dhbq)(bq) metal-organic coordination polymer system. Since the highest occupied molecular orbital (HOMO) energy of 1,4-benzoquinone (BQ) is higher than that of 2,5-dihydroxy-1,4-benzoquinone (DHBQ), photogenerated electrons migrate directionally from the 1,4-benzoquinone (BQ) ligand to the 2,5-dihydroxy-1,4-benzoquinone (DHBQ) ligand. This enriches the photogenerated electrons at the more electrochemically active DHBQ ligand sites, providing a sufficient electron source for subsequent electron transfer to the metal matrix and achieving cathodic protection. Simultaneously, photogenerated holes remain on the BQ ligand, preventing direct recombination between holes and electrons.

[0037] Magnetic field-controlled spin polarization and carrier lifetime extension effect: After introducing an external static magnetic field (200 mT), the central metal Co in Co(bpy)(dhbq)(bq) 2+ The high-spin state (S = 3 / 2) with unpaired electrons can act as a "spin filter." Under the influence of a magnetic field, Co undergoes a Zeeman splitting effect. 2+ The d-orbital energy level splits, increasing spin polarization; simultaneously, the magnetic field strengthens Co. 2+ The spin-orbit coupling (SOC) effect between the d orbitals and the π orbitals of the organic ligands effectively suppresses the nonradiative recombination of photogenerated electron-hole pairs, significantly prolongs the carrier lifetime, and provides a sufficient time window for the directional migration of photogenerated electrons from the DHBQ ligand to the metal matrix.

[0038] Photomagnetic synergistic enhancement mechanism: The synergistic effect of light field and magnetic field achieves directional enrichment of photogenerated electrons through the LLCT effect on the one hand, and efficient suppression of carrier recombination through magnetic field modulation on the other hand. The combined effect of the two significantly reduces the charge transfer resistance (Rct) at the interface between the coating and the metal substrate, optimizes the dynamic process of interface charge transport and ion migration, and ultimately achieves efficient spin-selective separation and directional migration of photogenerated electrons to the surface of the metal substrate, so that the electrode potential of the metal substrate is stably shifted negatively to below the corrosion potential, achieving the effect of efficient cathodic protection.

[0039] This invention is not limited to the specific embodiments described above. For those skilled in the art, all modifications made based on the above concept without creative effort fall within the protection scope of this invention.

Claims

1. A metal-organic coordination polymer anticorrosive slurry based on synergistic regulation of photomagnetism, characterized in that, The anticorrosion slurry comprises a solid component metal organic coordination polymer material, conductive carbon black and epoxy resin, and is formed by dispersing the solid component in a xylene solvent; wherein the mass percentage of each component in the solid component is 20-30% for the metal organic coordination polymer material, 20-30% for the conductive carbon black and 40-50% for the epoxy resin; and the metal organic coordination polymer material is Co(bpy)(dhbq)(bq).

2. The metal-organic coordination polymer anticorrosive slurry based on synergistic regulation of photomagnetism according to claim 1, characterized in that, The mass-volume ratio of the solid component to the xylene solvent in the anticorrosion slurry is 1 g:5 mL, and the viscosity of the slurry is 500-1500 mPa·s.

3. The metal-organic coordination polymer anticorrosive slurry based on synergistic regulation of photomagnetism according to claim 1, characterized in that, The metal-organic coordination polymer material has a crystal particle size of 50-200 nm and a specific surface area of 150-300 m 2 / g.

4. The metal-organic coordination polymer anticorrosive slurry based on synergistic regulation of photomagnetism according to claim 1, characterized in that, The anticorrosion slurry further comprises dispersed magnet powder, and the mass of the magnet powder accounts for 10-15% of the mass of the solid component composed of the metal organic coordination polymer material, the conductive carbon black and the epoxy resin.

5. An anticorrosion coating, characterized by, The coating is formed by coating the anticorrosion slurry of claim 1 on the surface of a metal substrate and drying.

6. A method of producing the corrosion protection coating according to claim 5, characterized in that The method comprises the following steps: a) metal substrate pretreatment: the metal substrate is polished with 400-mesh, 800-mesh and 1200-mesh sandpaper in sequence until the surface is smooth, ultrasonically cleaned with anhydrous ethanol for 15 minutes, dried with nitrogen and then placed in a desiccator for standby; b) slurry preparation: the metal organic coordination polymer material, the conductive carbon black, the magnet powder and the epoxy resin are mixed in a mass ratio of 3:3:4, xylene solvent is added, ultrasonic dispersion is performed for 30 minutes, and then magnetic stirring is performed for 2 hours to obtain a uniformly dispersed slurry; c) coating: the slurry is coated on the surface of the pretreated metal substrate by using a doctor blade coating method, and the wet film thickness is controlled to be 100-150 μm; d) drying: the coated metal substrate is dried in a vacuum drying oven at 80°C for 12 hours to obtain an anticorrosion coating.

7. Cathodic protection of the application of the corrosion protection coating to the metal substrate according to claim 5, characterized in that, When in use, the light-magnetic synergistic regulation is performed by applying 365 nm wavelength light and a 200 mT external static magnetic field, and the open circuit potential of the metal substrate after the regulation is stabilized below-0.85 V (vs SCE).

8. Cathodic protection of the application of the corrosion protection coating to the metal substrate according to claim 7, characterized in that, The metal substrate comprises low-carbon steel, stainless steel or aluminum alloy material; and the application environment comprises marine, petroleum and chemical industry, bridge construction.

9. Use of the corrosion protection coating according to claim 7, characterized in that The light intensity of the light irradiation is 100-150 mW·cm -2 The magnetic field is a static magnetic field or a low-frequency alternating magnetic field, and the frequency of the alternating magnetic field is 50-100 Hz.

10. An anticorrosion coating, characterized by, The coating is formed by coating the anticorrosion slurry of claim 4 on the surface of a metal substrate and drying. The method comprises the following steps: a) metal substrate pretreatment: the metal substrate is polished with 400-mesh, 800-mesh and 1200-mesh sandpaper in sequence until the surface is smooth, ultrasonically cleaned with anhydrous ethanol for 15 minutes, dried with nitrogen and then placed in a desiccator for standby; b) slurry preparation: the metal organic coordination polymer material, the conductive carbon black, the magnet powder and the epoxy resin are mixed in a mass ratio of 3:3:4, xylene solvent is added, ultrasonic dispersion is performed for 30 minutes, and then magnetic stirring is performed for 2 hours to obtain a uniformly dispersed slurry; c) coating: the slurry is coated on the surface of the pretreated metal substrate by using a doctor blade coating method, and the wet film thickness is controlled to be 100-150 μm; d) drying: the coated metal substrate is dried in a vacuum drying oven at 80°C for 12 hours to obtain an anticorrosion coating. When in use, the light-magnetic synergistic regulation is performed by applying 365 nm wavelength light and a 200 mT external static magnetic field, and the open circuit potential of the metal substrate after the regulation is stabilized below-0.85 V (vs SCE). The metal substrate comprises low-carbon steel, stainless steel or aluminum alloy material; and the application environment comprises marine, petroleum and chemical industry, bridge construction.

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