A two-dimensional heteronuclear multimetallic supramolecular material and its preparation method and application

Abstract

The present invention relates to the technical field of catalytic water electrolysis for hydrogen production, and specifically to a two-dimensional heteronuclear multimetallic supramolecular material, its preparation method, and application. The present invention introduces two metal ions, ruthenium and silver, with synergistic catalytic effects, and utilizes organic ligands to construct a stable two-dimensional layered supramolecular structure, thereby significantly improving the charge transfer efficiency of the material and the utilization rate of catalytic active sites. The material can be prepared by a simple one-step solvent method at room temperature, has a uniform structure, controllable composition, and can efficiently catalyze hydrogen and oxygen evolution reactions in alkaline or neutral media, exhibiting excellent electrocatalytic performance and durability. The synthesis method has good operability and controllability for synthesizing multimetallic organic catalysts with higher polymerization degrees. In addition, the prepared heteronuclear multimetallic polymer catalyst has the ability to efficiently catalyze water splitting.

Description

Technical Field

[0001] The present invention relates to the technical field of catalytic water electrolysis for hydrogen production, and in particular to a two-dimensional heteronuclear multi-metallic supramolecular material, a preparation method thereof, and applications thereof. Background Art

[0002] Water electrolysis involves two basic reaction processes, namely hydrogen evolution reaction, whose full English name is Hydrogen Evolution Reaction, abbreviated as HER; and oxygen evolution reaction, whose full English name is Oxygen Evolution Reaction, abbreviated as OER. However, both reactions have high kinetic energy barriers, which limit the overall water decomposition efficiency.

[0003] Traditionally, noble metal catalysts such as Pt, IrO2, and RuO2 have been widely used in HER and OER due to their excellent electrocatalytic performance. However, these materials suffer from resource scarcity, high cost, and poor stability, making them difficult to meet the practical needs of large-scale, low-cost hydrogen production. Therefore, the development of high-performance, low-cost electrocatalytic materials made of non-noble metals or small amounts of noble metals has become a current research hotspot.

[0004] In recent years, multimetallic synergistic catalytic systems have demonstrated excellent water electrolysis performance due to their diverse active sites and strong electronic structure controllability. Metal-coordinated supramolecular materials have become important candidates for electrocatalysis due to their strong structural controllability, high component diversity, and high designability. In particular, the construction of two-dimensional heteronuclear multimetallic supramolecular materials can achieve the synergistic effect of multiple metal ions at the nanoscale, while enhancing charge transfer efficiency and active site exposure, thereby effectively improving electrocatalytic performance.

[0005] In this class of materials, ruthenium (Ru) and silver (Ag) possess complementary electrochemical properties: Ru exhibits excellent OER catalysis, while Ag exhibits high electrical conductivity and HER activity. Synergistically incorporating Ru and Ag into a two-dimensional supramolecular structure is expected to achieve a synergistic enhancement effect, balancing electrical conductivity with multifunctional catalytic performance. Furthermore, by rationally designing the organic ligand structure and the coordination mechanism of the metal center, the electronic structure, porosity, and stability of the material can be further manipulated.

[0006] However, current research on Ru-Ag heteronuclear multimetallic supramolecular materials still faces the following problems: (1) The construction strategy for the stable coexistence of Ru and Ag in the same supramolecular system is still immature, and the precise control of heteronuclear sites is difficult; (2) The formation of two-dimensional structures usually depends on complex synthesis conditions, which limits the possibility of its scalable application. Summary of the Invention

[0007] The purpose of the present invention is to overcome the shortcomings of the existing technology and provide a two-dimensional heteronuclear polymetallic supramolecular material and its preparation method and application, so as to solve the problems of structural instability, limited catalytic activity, complex synthesis and high cost of precious metal use in the existing Ru-Ag heteronuclear polymetallic supramolecular material.

[0008] In order to achieve the above object, the present invention adopts the following technical solutions:

[0009] The first object of the present invention is to provide a two-dimensional heteronuclear multimetallic supramolecular material having the chemical structure shown below:

[0010] or

[0011] .

[0012] Wherein, m is 20 to 800, R is a methoxy group, a short-chain terminal olefin of C1 to C12, or a polyethylene glycol chain, and the molecular weight of the polyethylene glycol chain is 6,000 to 12,000.

[0013] A second object of the present invention is to provide a method for preparing the above-mentioned two-dimensional heteronuclear multimetallic supramolecular material, comprising the following steps:

[0014] S1. Using a terpyridine ligand and a soluble trivalent ruthenium compound as raw materials, a first coordination reaction is carried out in a first reaction solvent system to obtain a metallic ruthenium ligand.

[0015] S2. Using the metal ruthenium ligand and pyrazine as raw materials, a second coordination reaction is carried out in a second reaction solvent system to obtain a metal catalyst.

[0016] S3. Using a metal catalyst and a soluble monovalent silver compound as raw materials, an in-situ reaction is carried out in a third reaction solvent system to obtain a heteronuclear linear catalytic intermediate.

[0017] S4. Using the heteronuclear linear catalytic intermediate and the metal Ru photosensitizer as raw materials, an ion pairing reaction is carried out in a fourth reaction solvent system to obtain a two-dimensional heteronuclear multi-metallic supramolecular material.

[0018] The present invention introduces Ru and Ag, two metal ions with synergistic catalytic effects, and uses organic ligands to construct a stable two-dimensional layered supramolecular structure, significantly improving the material's charge transfer efficiency and the utilization rate of catalytic active sites. The material can be prepared by a simple one-step solvent method at room temperature. It has a uniform structure and controllable composition, and can efficiently catalyze hydrogen and oxygen evolution reactions in alkaline or neutral media, showing excellent electrocatalytic performance and durability. This not only expands the application boundaries of heteronuclear multimetallic supramolecular materials in the field of energy conversion, but also provides a theoretical basis and technical support for the development of non-precious metal or low-precious metal catalytic systems.

[0019] In some embodiments, the mass ratio of the terpyridine ligand to the soluble trivalent ruthenium compound is 1:1-3, the temperature of the first coordination reaction is 65°C-75°C, and the time is 38h-42h.

[0020] It should be noted that the soluble trivalent ruthenium compound is preferably RuCl3·3H2O. The present invention uses a terpyridine ligand as a core coordination unit, introduces a ruthenium compound RuCl3·3H2O, and conducts an in situ coordination reaction. The first reaction solvent system is anhydrous ethanol. Through the directional coordination effect between the pyridine nitrogen atom and the ruthenium ion, a terpyridine-Ru metal ligand complex with a clear structure and good stability is obtained, which is a metal ruthenium ligand. In this metal ruthenium ligand, the Ru atom is usually located at the central site of the terpyridine skeleton, forming a hexacoordinate or octahedral structure, effectively maintaining the coordination activity of the metal center.

[0021] In some embodiments, the mass ratio of the metal ruthenium ligand to pyrazine is 1 to 3:1, the temperature of the second coordination reaction is 145° C. to 155° C., and the time is 10 h to 16 h.

[0022] It should be noted that after the first coordination reaction is completed, a metal ruthenium ligand is obtained. On this basis, by controlling the reaction conditions such as solvent polarity, temperature, and metal / ligand ratio, pyrazine small molecules are further introduced into the system as auxiliary ligands to undergo a second coordination reaction with the formed metal ruthenium ligand. The second reaction solvent is N,N-dimethylformamide. This strategy achieves precise control of the metal center structure through the primary coordination of terpyridine and metal ruthenium, as well as the regulation of pyrazine, laying a solid foundation for the subsequent construction of highly active and adjustable electrocatalytic materials.

[0023] In some embodiments, the mass ratio of the metal catalyst to the soluble monovalent silver compound is 4 to 10:1, the temperature of the in-situ reaction is 25° C. to 30° C., and the time is 2 h to 4 h.

[0024] It should be noted that the soluble monovalent silver compound is preferably silver hexafluorophosphate AgPF6, and the third reaction solvent is acetonitrile. The metal catalyst is dissolved in the acetonitrile solvent and stirred evenly to obtain a Ru catalyst solution; AgPF6 is added to the solution to carry out an in-situ reaction. In the construction of the core two-dimensional multi-metallic supramolecular material structure, the present invention uses Ru metal complexes as the basic catalytic unit, introduces AgPF6 to carry out an in-situ reaction, and reacts with the Ru center through the Ag + The heteronuclear coordination effect forms a Ru-Ag heteronuclear catalytic complex with a clear linear structure, that is, a heteronuclear linear catalytic intermediate. In this process, Ag + The ions serve as bridging sites, effectively realizing the electronic coupling and spatial configuration regulation between the two metal centers. The resulting heteronuclear linear structure has excellent electron conduction pathways and a stable coordination environment.

[0025] In some embodiments, the mass ratio of the heteronuclear linear catalytic intermediate to the metal Ru photosensitizer is 3 to 5:1, the temperature of the ion pairing reaction is room temperature, and the time is 40 hours to 60 hours.

[0026] It should be noted that before the reaction, the metal Ru photosensitizer is treated with NaOH in a methanol solvent to obtain an anion-rich photosensitizer. An acetonitrile solution containing a heteronuclear linear catalytic intermediate and a methanol solution containing a photosensitizer are mixed in a volume ratio of 1:1 to perform an ion pairing reaction. The ion pairing reaction is performed by standing at room temperature and, under the conditions of precise control of ion concentration, solution polarity and reaction time, mixing the heteronuclear catalytic complex with a pre-designed metal Ru photosensitizer such as Ru(bpy)3 2+ The ion-pair self-assembly of Ru-Ag complexes is driven by electrostatic and non-covalent interactions, forming a two-dimensional layered Ru-Ag heteronuclear multimetallic supramolecular material. This strategy cleverly integrates the principles of coordination chemistry and supramolecular self-assembly, achieving spatially controllable construction of intermetallic synergy and providing a novel design path and structural foundation for the development of high-performance photoelectrocatalytic systems.

[0027] In some embodiments, the structural formula of the metal Ru photosensitizer is as follows:

[0028] .

[0029] It should be noted that the preparation method of the metal Ru photosensitizer includes the following steps:

[0030] Using carboxyl bispyridine and a soluble trivalent ruthenium compound as raw materials, a coordination reaction is carried out in an ethanol solution system at 75°C for 12 hours to 16 hours, wherein the mass ratio of carboxyl bispyridine to the soluble trivalent ruthenium compound is 3:1.

[0031] Furthermore, the preparation method of the terpyridine ligand comprises the following steps:

[0032] A bromobenzene derivative is used as a halogenated aromatic unit, a pyridine compound containing a borate ester is used as a coupling unit, and a carbon-carbon bond coupling reaction is carried out under alkaline conditions and a Pd catalyst reaction system in a protective gas atmosphere to obtain a terpyridine ligand.

[0033] It should be noted that the terpyridine ligand provided by the present invention is a mononuclear terpyridine or a dinuclear terpyridine. When R is a methoxy group, the structural formula of the mononuclear terpyridine is as follows:

[0034] .

[0035] When R is a methoxy group, the structural formula of the binuclear terpyridine is as follows:

[0036] .

[0037] It should be noted that in the process of synthesizing pyridine organic ligands, the present invention innovatively adopts the Suzuki coupling reaction to construct a terpyridine structure, which effectively connects multiple aromatic ring units through carbon-carbon bond coupling, thereby realizing the extension of the intramolecular π conjugated system. By cross-coupling a halogen-containing pyridine derivative with an aromatic monomer containing a borate ester under the action of a Pd catalyst, a terpyridine skeleton structure with high conjugation is obtained. This method is not only simple to operate and highly selective, but also significantly improves the electronic delocalization ability and structural stability of the ligand, laying a good foundation for its application in multi-metal collaborative coordination.

[0038] In order to separate and purify terpyridine, the present invention comprises the following steps: drying a tetrahydrofuran solvent to obtain a gray-green block solid; directly adding a methanol solution, ultrasonically dispersing the mixture for 30 minutes, heating under reflux at 75°C for 3 hours, cooling to room temperature, and filtering under reduced pressure to obtain a light yellow powder solid; dissolving the yellow powder in dichloromethane, adding neutral alumina (15g, 200-300 mesh) and mixing the sample, performing vacuum rotary evaporation to remove the dichloromethane solvent, and loading the column (the optimal ratio of the height of the pure alumina powder to the height of the sample powder is 5:1), selecting dichloromethane and petroleum ether as eluents, and passing the eluent through the column at a volume ratio of dichloromethane to petroleum ether of 1:1, vacuum rotary evaporation, and drying under reduced pressure at 50°C for 20 hours to obtain the terpyridine as a white powder solid.

[0039] When R is a methoxy group and the terpyridine is a mononuclear terpyridine, the structural formula of the metal catalyst is as follows:

[0040] .

[0041] When R is a methoxy group and the terpyridine is a binuclear terpyridine, the structural formula of the metal catalyst is as follows:

[0042] .

[0043] When R is a methoxy group, n is 30 to 800, and the terpyridine is a mononuclear terpyridine, the structural formula of the heteronuclear linear catalytic intermediate is as follows:

[0044] .

[0045] When R is a methoxy group, n is 20 to 500, and the terpyridine is a dinuclear terpyridine, the structural formula of the heteronuclear linear catalytic intermediate is as follows:

[0046] .

[0047] In some embodiments, the mass ratio of the bromobenzene derivative and the borate-containing pyridine compound is 1:2 to 8, the temperature of the carbon-carbon bond coupling reaction is 95°C to 105°C, the time is 20h to 30h, the bromobenzene derivative is 1,4-dibromo-2,5-dimethoxybenzene, and the borate-containing pyridine compound is 4-boric acid terpyridine.

[0048] It should be noted that the Suzuki coupling reaction uses a bromobenzene derivative as the halogenated aromatic unit and a borate-containing pyridine structure as the coupling unit, achieving a carbon-carbon bond coupling reaction under alkaline conditions and a Pd catalyst. In one specific embodiment, the Suzuki coupling reaction involves sonicating a mixture of 1,4-dibromo-2,5-dimethoxybenzene, 4-boronic acid terpyridine, aqueous sodium hydroxide, and tetrahydrofuran for 15 minutes, then adding the catalyst, palladium tetrakistriphenylphosphine, under nitrogen protection. The reaction system is evacuated and refluxed at 100°C under a nitrogen atmosphere for 20-30 hours to obtain a dinuclear terpyridine. By adjusting the reaction materials during the reaction, mononuclear terpyridine (i.e., a terpyridine skeleton containing only one pyridine center) and dinuclear terpyridine (a terpyridine skeleton containing two pyridine centers) can be obtained. This type of terpyrrolidone ligand has a highly π-conjugated structure and a uniform electron cloud density distribution, which can significantly enhance its stability and synergistic ability in multi-metal coordination reactions, providing an ideal ligand basis for the subsequent construction of two-dimensional heteronuclear supramolecular devices.

[0049] The third object of the present invention is to provide the use of the above-mentioned two-dimensional heteronuclear multi-metallic supramolecular material as a catalyst in the electrolysis of water to produce hydrogen.

[0050] The beneficial effects of the present invention are as follows:

[0051] The two-dimensional heteronuclear multimetallic supramolecular material provided by the present invention significantly improves the charge transfer efficiency of the material and the utilization rate of catalytic active sites by introducing two metal ions with synergistic catalytic effects, Ru and Ag, and using organic ligands to construct a stable two-dimensional layered supramolecular structure. The material can be prepared by a simple one-step solvent room temperature method, with uniform structure and controllable composition. It can also efficiently catalyze hydrogen evolution and oxygen evolution reactions in alkaline or neutral media, showing excellent electrocatalytic performance and durability. It not only expands the application boundaries of heteronuclear multimetallic supramolecular materials in the field of energy conversion, but also provides a theoretical basis and technical support for the development of non-precious metal or low-precious metal catalytic systems.

[0052] The two-dimensional heteronuclear multimetallic supramolecular material provided by the present invention uses a Ru metal catalyst and silver hexafluorophosphate to form a heteronuclear linear complex, which is then self-assembled into a two-dimensional structure through ion pairing with a Ru-based photosensitizer. This configuration not only retains the excellent catalytic activity of the Ru center, but also introduces the electronic regulation function of the Ag ion, achieving a synergistic enhancement effect between metals. Compared with conventional single metal or homonuclear coordination systems, the heteronuclear system constructed by the present invention performs more optimally in terms of electron transport pathways and active site distribution, significantly improving the electrocatalytic performance in the hydrogen evolution reaction.

[0053] In the two-dimensional heteronuclear multimetallic supramolecular material provided by this invention, Ru centers provide efficient hydrogen evolution catalysis, while Ag ions act as bridging metals, effectively regulating charge density and electron migration rate, thereby reducing the reaction overpotential. Furthermore, through the supramolecular assembly of the two-dimensional layered structure, the material exhibits a larger specific surface area and more accessible active sites, significantly enhancing the catalytic reaction rate in the water electrolysis system.

[0054] The two-dimensional heteronuclear multimetallic supramolecular material provided by this invention exhibits excellent electrochemical stability and recyclability, demonstrating superior catalytic activity retention under acidic, alkaline, and neutral conditions, meeting the long-term operational requirements of energy conversion processes. Compared to traditional catalysts, this material offers greater structural tunability and a simple preparation method, providing a new design approach and material platform for the development of high-performance, low-cost hydrogen evolution catalysts. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] Figure 1 This is the NMR image of the mononuclear terpyridine in Example 1 of the present invention.

[0056] Figure 2 This is the NMR image of the dinuclear terpyridine in Example 2 of the present invention.

[0057] Figure 3 Infrared spectra of the mononuclear terpyridine, metal catalyst, heteronuclear linear catalytic intermediate and two-dimensional heteronuclear multi-metallic supramolecular material prepared in Example 1 of the present invention.

[0058] Figure 4 This is a transmission electron micrograph of the two-dimensional heteronuclear multimetallic supramolecular material prepared in Example 1 of the present invention.

[0059] Figure 5 This is a surface scanning electron microscope image of the two-dimensional heteronuclear multi-metallic supramolecular material prepared in Example 1 of the present invention.

[0060] Figure 6 This is a surface scanning electron microscope image of the two-dimensional heteronuclear multi-metallic supramolecular material prepared in Example 2 of the present invention.

[0061] Figure 7This is a surface scanning electron microscope image of the two-dimensional heteronuclear multi-metallic supramolecular material prepared in Example 3 of the present invention.

[0062] Figure 8 This is the electrochemical response diagram of the heteronuclear linear catalytic intermediate and the two-dimensional heteronuclear multimetallic supramolecular material prepared in Example 1 of the present invention in the potential range of 1.06 V vs. RHE to 1.14 V vs. RHE. Figure 8 Figure a in the middle is a two-dimensional heteronuclear multimetallic supramolecular material, and Figure b is a heteronuclear linear catalytic intermediate.

[0063] Figure 9 This is a graph showing the electrocatalytic kinetic performance of mononuclear terpyridine, metal catalyst, heteronuclear linear catalytic intermediate and two-dimensional heteronuclear multi-metallic supramolecular material prepared in Example 1 of the present invention in the oxygen evolution reaction.

[0064] Figure 10 This is a graph of the OER performance of the metal catalyst, heteronuclear linear catalytic intermediate and two-dimensional heteronuclear multi-metallic supramolecular material of Example 1 of the present invention at various scanning rates. Figure 10 Figure a is a two-dimensional heteronuclear multimetallic supramolecule, Figure b is a heteronuclear linear catalytic intermediate, and Figure c is a metal catalyst.

[0065] Figure 11 This is a surface scanning electron microscope image of the two-dimensional heteronuclear multi-metallic supramolecular material prepared in Example 4 of the present invention.

[0066] Figure 12 This is a transmission electron micrograph of the two-dimensional heteronuclear multimetallic supramolecular material prepared in Example 4 of the present invention.

[0067] Figure 13 This is a test chart of the cyclic stability of the two-dimensional heteronuclear multi-metallic supramolecular material prepared in Example 4 of the present invention at a constant current density. DETAILED DESCRIPTION

[0068] To enable those skilled in the art to better understand and implement the technical solutions of the present invention, the present invention is further described below with reference to specific examples, but the examples are not intended to limit the present invention. The following experimental and detection methods are conventional methods unless otherwise specified; the reagents and raw materials are commercially available unless otherwise specified.

[0069] The present invention is described in detail below through specific examples. The examples are exemplary and intended to be used to explain the present invention, but should not be understood as limiting the present invention.

[0070] The following is further described through specific examples.

[0071] Example 1

[0072] This embodiment provides a method for preparing a two-dimensional heteronuclear multimetallic supramolecular material, comprising the following steps:

[0073] S1. Obtaining mononuclear terpyridine through Suzuki coupling reaction, specifically:

[0074] 500 mg of 1,4-dibromo-2,5-dimethoxybenzene, 900 mg of 4-boronic acid terpyridine, 18 mL of 1 M sodium hydroxide aqueous solution and 150 mL of tetrahydrofuran were added to a 250 mL single-necked round-bottom flask containing a magnetic rod. The mixed solution was ultrasonically dispersed for 15 minutes to degas the solid dispersion, and then 570 mg of the catalyst tetrakistriphenylphosphine palladium was added under nitrogen protection. The reaction system was evacuated and refluxed at 85°C under a nitrogen atmosphere for 24 hours. After stopping the reaction, it was cooled to room temperature and vacuum evaporated to remove the tetrahydrofuran solvent to obtain a gray-green block solid. 80 mL of methanol solution was directly added, and the mixed solution was ultrasonically dispersed for 30 minutes, heated to reflux at 75°C for 3 hours, cooled to room temperature, and vacuum filtered to obtain a light yellow powder solid. Dissolve all the pale yellow powder in 50 mL of dichloromethane, add 10 g of neutral alumina with a particle size of 200-300 mesh, and mix with the sample. Remove the dichloromethane solvent by rotary evaporation under reduced pressure, then load onto a column (optimal ratio of pure alumina powder to sample powder is 5:1). Elute with dichloromethane and petroleum ether at a volume ratio of 1:2. After rotary evaporation under reduced pressure, vacuum dry at 50°C for 20 h to obtain 1.10 g of a white powdery solid product, mononuclear terpyridine, with a yield of 78%. The preparation reaction scheme is as follows:

[0075] .

[0076] The H NMR spectrum of mononuclear terpyridine is as follows Figure 1 As shown, 1 H NMR (500 MHz, CDCl3) δ (ppm)8.82 (s, 2H, H3′,5′), 8.76 (d, J = 5.00 Hz, 2H, H6,6″), 8.71 (d, J = 5.00 Hz, 2H,H3,3″), 8.00 (d, J = 15.00 Hz, 2H, Ha), 7.91 (t, J = 10.00 Hz, 2H, H4,4″), 7.73(d, J = 5.00 Hz, 2H, Hc), 7.63 (d, J = 5.00 Hz, 2H, Hb), 7.38 (t, J= 10.00 Hz, 2H,H5,5″), 7.02 (d, J = 5.00 Hz, 2H, Hd), 4.04 (t, J = 5.00 Hz, 2H, H -CH3 ).

[0077] S2. A mononuclear terpyridine ligand and a soluble trivalent ruthenium compound are subjected to a first coordination reaction to obtain a metallic ruthenium ligand. The metallic ruthenium ligand and pyrazine are used as raw materials to carry out a second coordination reaction to obtain a metal catalyst, specifically:

[0078] Dissolve 300 mg of the mononuclear terpyridine ligand in 80 mL of chloroform and place in a constant-pressure dropping funnel. Dissolve 300 mg of RuCl₃·3H₂O in 80 mL of anhydrous ethanol and add the mixture to a 250 mL single-necked round-bottom flask. Add the mononuclear terpyridine ligand dropwise to the flask. After the addition is complete, heat under reflux at 75°C for 60 hours. After cooling the reaction to room temperature, filter under reduced pressure to obtain a brown-red solid. Add 100 mL of methanol, sonicate, reflux at 75°C, and filter and wash with suction. Repeat this process until the filtrate is colorless. Remove the solvent by vacuum drying to obtain 350 mg of a reddish-brown solid.

[0079] 200 mg of a reddish-brown solid, 60 mg of pyrazine, and 15 mL of DMF were added to a 50 mL single-necked round-bottom flask. The mixture was ultrasonically dispersed for 30 minutes, and 0.05 mL of nitrogen-ethylmorpholine was added. The mixture was heated under reflux at 150°C for 24 hours. After the reaction was terminated and cooled to room temperature, anhydrous ether was slowly added dropwise to the reaction flask until the solution became colorless and a red solid precipitated. The solid was dissolved in methanol, and 8 g of neutral alumina with a particle size of 200-300 mesh was added to the sample. The methanol solvent was removed by vacuum rotary evaporation, and the sample was loaded onto a column (the optimal ratio of pure alumina powder to sample powder was 6:1). Dichloromethane and methanol were used as eluents, and the column was passed through with a dichloromethane:methanol volume ratio of 100:0.75. After vacuum rotary evaporation, the column was dried under vacuum at 50°C for 20 hours to obtain a purple powdery solid metal catalyst. The preparation reaction scheme is as follows:

[0080] .

[0081] S3. Using a metal catalyst and a soluble monovalent silver compound, an in-situ reaction is performed to obtain a heteronuclear linear catalytic intermediate; specifically:

[0082] Dissolve 100 mg of the metal catalyst obtained in S2 and 50 mg of silver hexafluorophosphate (slightly in excess) in 100 mL of acetonitrile and allow to react at room temperature for 20 h. After the reaction ceases, vacuum filtration is performed to remove the precipitated AgCl. The filtrate is then rotary evaporated under reduced pressure to yield a red solid. The solid is dissolved in methanol, sonicated for 30 minutes, and vacuum filtered to yield a red solid. This solid is then dried under vacuum at 50°C for 20 h to yield 85 mg of a red powdery solid product with an 80% yield. This is the heteronuclear linear catalytic intermediate. The preparation reaction scheme is as follows:

[0083] .

[0084] S4. An ion pairing reaction is performed with a heteronuclear linear catalytic intermediate and a metal Ru photosensitizer to obtain a two-dimensional heteronuclear multimetallic supramolecular material, specifically:

[0085] Dissolve 20 mg of the heteronuclear linear catalytic intermediate obtained in S3 in 5 mL of acetonitrile solution, and dissolve 10 mg of the Ru-based photosensitizer in 5 mL of 0.1 mol·L -1 A methanolic NaOH solution was added to obtain an anion-rich photosensitizer. Equal volumes of the acetonitrile solution and the methanol solution were mixed and then allowed to stand in the dark for 50 hours to allow self-assembly through electrostatic guidance and ion pairing, resulting in a two-dimensional heteronuclear multimetallic supramolecular material with good stability. The preparation reaction route is as follows:

[0086] .

[0087] n is 200 and m is 150.

[0088] Example 2

[0089] This example provides a method for preparing a two-dimensional heteronuclear multimetallic supramolecular material. The difference from Example 1 is that 10 mg of the heteronuclear linear catalytic intermediate obtained in S3 is dissolved in 5 mL of acetonitrile solution, and 6 mg of the Ru-based photosensitizer is dissolved in 5 mL of 0.1 mol·L -1 The anion-rich photosensitizer was obtained by mixing equal volumes of the acetonitrile solution and the methanol solution. The mixture was then allowed to stand in the dark for 50 hours to allow the mixture to self-assemble through electrostatic guidance and ion pairing, resulting in a two-dimensional heteronuclear multimetallic supramolecular material with good stability.

[0090] Example 3

[0091] This example provides a method for preparing a two-dimensional heteronuclear multimetallic supramolecular material. The difference from Example 1 is that 50 mg of the heteronuclear linear catalytic intermediate obtained in S3 is dissolved in 15 mL of acetonitrile solution, and 20 mg of the Ru-based photosensitizer is dissolved in 15 mL of 0.1 mol·L -1The anion-rich photosensitizer was obtained by mixing equal volumes of the acetonitrile solution and the methanol solution. The mixture was then allowed to stand in the dark for 50 hours to allow the mixture to self-assemble through electrostatic guidance and ion pairing, resulting in a two-dimensional heteronuclear multimetallic supramolecular material with good stability.

[0092] Example 4

[0093] This embodiment provides a method for preparing a two-dimensional heteronuclear multimetallic supramolecular material, comprising the following steps:

[0094] S1. Obtain dinuclear terpyridine through Suzuki coupling reaction, specifically:

[0095] 900 mg (3.01 mmol) of 1,4-dibromo-2,5-dimethoxybenzene, 2.33 g (6.60 mmol) of 4-boronic acid terpyridine, 18 mL of 1 M sodium hydroxide aqueous solution, and 200 mL of tetrahydrofuran were added to a 250 mL single-necked round-bottom flask containing a magnetic rod. The mixture was ultrasonically dispersed for 15 min to degas the solid dispersion, and then 430 mg (0.36 mmol) of tetrakistriphenylphosphine palladium catalyst was added. Under nitrogen protection, the reaction system was evacuated and the air was replaced three times. The reaction system was then evacuated and ventilated and refluxed at 85°C under a nitrogen atmosphere for 48 h. After stopping the reaction and cooling to room temperature, the tetrahydrofuran solvent was removed by vacuum rotary evaporation to obtain a gray-green block solid. 80 mL of methanol solution was directly added, and the mixture was ultrasonically dispersed for 30 min, heated under reflux at 75°C for 3 h, cooled to room temperature, and filtered under reduced pressure to obtain a light yellow powder solid. Dissolve all the pale yellow powder in 50 mL of dichloromethane, add 15 g of neutral alumina with a particle size of 200-300 mesh, and mix with the sample. Remove the dichloromethane solvent by rotary evaporation under reduced pressure, and load onto a column (optimal ratio of pure alumina powder to sample powder is 5:1). Elute with dichloromethane and petroleum ether at a volume ratio of 1:2. After rotary evaporation under reduced pressure, vacuum dry at 50°C for 20 h to obtain 1.87 g of a white powdery solid product, the binuclear terpyridine ligand, in a 62% yield. The preparation reaction scheme is as follows:

[0096] .

[0097] The H NMR spectrum of the binuclear terpyridine ligand is shown in Figure 2 As shown, 1 H NMR (400 MHz, CDCl3) δ 8.85(s, 4H, H 3′,5′ ), 8.78 (d, J = 5.30 Hz, 4H, H 6,6″ ), 8.72 (d, J= 7.90 Hz, 4H, H 3,3″ ),8.05 (d, J = 8.40 Hz, 4H, H a ), 7.92 (t, J = 9.60 Hz, 4H, H 4,4″ ), 7.80 (d, J = 8.40Hz, 4H, H b ), 7.40 (t, J = 12.30 Hz, 4H, H 5,5″ ), 7.11 (s, 2H, H c ), 3.90 (s, 6H, H -OCH3 ).

[0098] S2. A first coordination reaction is carried out with a binuclear terpyridine ligand and a soluble trivalent ruthenium compound to obtain a binuclear metal ruthenium ligand. A second coordination reaction is carried out with the binuclear metal ruthenium ligand and pyrazine as raw materials to obtain a binuclear metal catalyst, specifically:

[0099] Dissolve 400 mg of the dinuclear terpyridine ligand in 120 mL of chloroform and place in a constant-pressure dropping funnel. Dissolve 400 mg of RuCl₃·3H₂O in 100 mL of anhydrous ethanol and add the mixture to a 250 mL single-necked round-bottom flask. Add the dinuclear terpyridine ligand dropwise to the flask. After the addition is complete, heat and reflux at 75°C for 60 hours. After cooling the reaction to room temperature, filter under reduced pressure to obtain a brown-red solid. Add 100 mL of methanol, sonicate, reflux at 75°C, and filter and wash with suction. Repeat this process until the filtrate is colorless. Remove the solvent by vacuum drying to obtain 350 mg of a reddish-brown solid.

[0100] 100 mg of a reddish-brown solid, 40 mg of pyrazine, and 10 mL of DMF were added to a 50 mL single-necked round-bottom flask. The mixture was ultrasonically dispersed for 30 minutes, and 0.03 mL of nitrogen-ethylmorpholine was added. The mixture was heated under reflux at 150°C for 24 hours. After the reaction was terminated and cooled to room temperature, anhydrous ether was slowly added dropwise to the reaction flask until the solution became colorless and a red solid precipitated. The solid was dissolved in methanol, and 8 g of neutral alumina with a particle size of 200-300 mesh was added to the sample. The methanol solvent was removed by rotary evaporation under reduced pressure, and the sample was loaded onto a column (the optimal ratio of pure alumina powder to sample powder was 6:1). Dichloromethane and methanol were used as eluents, and the column was passed through a dichloromethane:methanol volume ratio of 100:1.25. After rotary evaporation under reduced pressure, the column was vacuum-dried at 50°C for 20 hours to obtain a purple powdery solid metal catalyst, which is the binuclear metal catalyst. The preparation reaction scheme is as follows:

[0101] .

[0102] S3. Using a binuclear metal catalyst and a soluble monovalent silver compound, an in situ reaction is performed to obtain a heteronuclear linear catalytic intermediate; specifically:

[0103] 100 mg of the binuclear metal catalyst obtained in S2 and 50 mg of silver hexafluorophosphate (slightly in excess) were dissolved in 100 mL of acetonitrile and allowed to react at room temperature for 20 h. After the reaction ceased, the precipitated AgCl was removed by filtration under reduced pressure. The filtrate was then rotary evaporated under reduced pressure to yield a red solid. The solid was dissolved in methanol, sonicated for 30 minutes, and filtered under reduced pressure to yield a red solid. This solid was then vacuum-dried at 50°C for 20 h to yield 85 mg of a red powdery solid product with an 80% yield. This was the heteronuclear linear catalytic intermediate. The preparation reaction route is shown below:

[0104] .

[0105] S4. An ion pairing reaction is performed with a heteronuclear linear catalytic intermediate and a metal Ru photosensitizer to obtain a two-dimensional heteronuclear multimetallic supramolecular material, specifically:

[0106] Dissolve 20 mg of the heteronuclear linear catalytic intermediate obtained in S3 in 5 mL of acetonitrile solution, and dissolve 10 mg of the Ru-based photosensitizer in 5 mL of 0.1 mol·L -1 A methanolic NaOH solution was added to obtain an anion-rich photosensitizer. Equal volumes of the acetonitrile solution and the methanol solution were mixed and then allowed to stand in the dark for 50 hours to allow self-assembly through electrostatic guidance and ion pairing, resulting in a two-dimensional heteronuclear multimetallic supramolecular material with good stability. The preparation reaction route is as follows:

[0107] .

[0108] n is 200 and m is 300.

[0109] The mononuclear terpyridine, metal catalyst, heteronuclear linear catalytic intermediate and two-dimensional heteronuclear polymetallic supramolecular material prepared in Example 1 were subjected to structural and morphological tests, wherein the mononuclear terpyridine was named Tpy, the metal catalyst was named Ty-Ru, the heteronuclear linear catalytic intermediate was named Ty-Ru-Ag and the two-dimensional heteronuclear polymetallic supramolecular material was named Ty-Ru-Ag-Ru.

[0110] Figure 3 The infrared spectra of the mononuclear terpyridine, metal catalyst, heteronuclear linear catalytic intermediate and two-dimensional heteronuclear multimetallic supramolecular material prepared in Example 1 of the present invention are shown in FIG. Figure 3As shown in Figure 2, the free Typy ligand exhibits typical aromatic CH, C=N and C=C vibration peaks. After Ru coordination, the absorption peaks of C=N and C=C regions are red-shifted, indicating that the metal-ligand coordination affects the electronic structure of the aromatic skeleton. + After the formation of Typy-Ru-Ag, the absorption peaks in the CO and CC regions of the spectrum are significantly enhanced or split, indicating that the structural symmetry is destroyed and a new coordination environment is formed. The final constructed Typy-Ru-Ag-Ru trinuclear complex shows the most complex vibration mode, especially at 1000 cm -1 ~1600cm -1 Multiple sub-peaks appear within this range, reflecting the perturbation of the conjugated system and the enhanced vibrational coupling caused by the polynuclear metal center. Overall, the infrared spectrum clearly reflects the systematic changes in molecular vibrational characteristics from a single ligand to a multi-metal complex, and can be effectively used to confirm the structure of the complex and infer the coordination mode.

[0111] Figure 4 This is a transmission electron micrograph of a single core of the two-dimensional heteronuclear multimetallic supramolecular material prepared in Example 1 of the present invention. Figure 5 This is a surface scanning electron microscope image of the two-dimensional heteronuclear multimetallic supramolecular material prepared in Example 1 of the present invention. Figure 4 and Figure 5 As shown, the transmission electron microscope image shows a single nanorod structure with a scale of about 100nm, clear edges, and a smooth surface. The dark area represents a high-density area, and the bright edge may be a shell or a composite structure, indicating that the material has high crystallinity and a possible core-shell structure. The surface scanning electron microscope image has a magnification of 10,000 times and shows multiple rectangular or columnar crystals with a length of several microns and a width of about several hundred nanometers. The crystals are arranged in an orderly manner and have regular edges, indicating that the sample has good preferred orientation and crystallinity. Overall, the material exhibits typical one-dimensional nanostructure and micron-scale ordered stacking characteristics, and may have excellent electronic, optical or catalytic properties. TEM images are suitable for observing nanostructure and interface information, while SEM images show the overall morphology and growth state of the sample. The combination of the two can fully reveal the structural characteristics and potential application value of the material.

[0112] Figure 6 This is a surface scanning electron microscope image of the two-dimensional heteronuclear multi-metallic supramolecular material prepared in Example 2 of the present invention. Figure 7 This is a surface scanning electron microscope image of the two-dimensional heteronuclear multimetallic supramolecular material prepared in Example 3 of the present invention. Figure 6 and Figure 7As shown, the materials synthesized under different concentration conditions exhibit significantly different morphological characteristics: at lower concentrations, mainly slender one-dimensional nanorod structures are formed with good dispersion and lengths of up to tens of microns; while at higher concentrations, distinct coarse prismatic crystals with regular morphology and flat crystal faces appear, accompanied by some rod-like crystals. This indicates that the precursor concentration has a significant impact on the nucleation and growth mode of the crystal, with higher concentrations favoring the formation of large, regular crystal structures.

[0113] Figure 8 This is the electrochemical response diagram of the heteronuclear linear catalytic intermediate and the two-dimensional heteronuclear multimetallic supramolecular material prepared in Example 1 of the present invention in the potential range of 1.06 V vs. RHE to 1.14 V vs. RHE. Figure 8 Figure a is a two-dimensional heteronuclear multimetallic supramolecular material, and Figure b is a heteronuclear linear catalytic intermediate. Figure 8 As shown, both exhibit a good nearly rectangular symmetrical structure, indicating that they have significant capacitive behavior and excellent reversibility. The current density in the figure increases with the increase of scan rate or number of cycles, reflecting the excellent electron / ion transport ability of the material. Among them, the current density of the Ty-Ru-Ag-Ru curve is slightly higher than that of Ty-Ru-Ag as a whole, and the rectangular structure is more ideal, indicating that it may have a higher specific capacitance or a better conductive network structure. Comprehensive analysis shows that the two sets of images reflect the significant differences in the double layer or pseudocapacitive behavior of the materials, which is helpful to compare the performance of different samples in energy storage or electrocatalytic systems.

[0114] The two-dimensional heteronuclear multimetallic supramolecular material prepared in Example 1 was used as a catalyst for hydrogen electrolysis. Specifically, the catalyst's electrocatalytic oxygen evolution performance was evaluated using a three-electrode system. The electrolyte consisted of 1.0 M KOH, a catalyst-loaded glassy carbon electrode as the working electrode, a platinum wire as the counter electrode, and Hg / HgO as the reference electrode. The catalyst was mixed with 6 mg of the two-dimensional heteronuclear multimetallic supramolecular material (Tpy-Ru-Ag-Ru) prepared in Example 1, 4 mL of ethanol, water, and 0.05 mL of Nafion. After ultrasonic treatment, the mixture was drop-coated on the electrode surface and allowed to air dry before testing. All potential data were converted to potential relative to the reversible hydrogen electrode (RHE). Testing methods included linear sweep voltammetry (LSV) for overpotential assessment, Tafel slope analysis for reaction kinetics, electrochemical impedance spectroscopy (EIS) for charge transfer impedance, and galvanostatic chronopotentiometry for long-term stability testing. This experimental process systematically evaluates the oxygen evolution activity and stability of electrocatalysts in alkaline systems and demonstrates strong versatility and reproducibility.

[0115] Figure 9This is a graph showing the electrocatalytic kinetic performance of mononuclear terpyridine, metal catalyst, heteronuclear linear catalytic intermediate and two-dimensional heteronuclear multimetallic supramolecular material in oxygen evolution reaction prepared in Example 1 of the present invention. Figure 9 As shown, the Tafel slope is 37.85mV·dec of Tpy-Ru -1 to 24.28mV·dec of Ty-Ru-Ag-Ru -1 The Tafel slope of Tpy-Ru-Ag-Ru is the lowest, indicating that it can achieve higher current densities at lower overpotentials, resulting in faster kinetic reaction rates and superior electrocatalytic activity. This intuitively reveals the performance differences between different materials in the OER process, providing an important basis for catalyst screening and optimization.

[0116] Figure 10 This is a comparison chart of the OER performance of the metal catalyst, heteronuclear linear catalytic intermediate, and two-dimensional heteronuclear multi-metallic supramolecular material of Example 1 of the present invention at various scan rates. Figure 10 Figure a is a two-dimensional heteronuclear multimetallic supramolecule, Figure b is a heteronuclear linear catalytic intermediate, and Figure c is a metal catalyst. Figure 10 As shown, all curves show a typical sharp rise in current in the high potential region, indicating good oxygen evolution catalytic properties. The curves at different scan rates in each sub-graph highly overlap, indicating that the samples have excellent stability in electrochemical tests. By comparing the starting potential and the -2 At the corresponding potential, the Typy-Ru-Ag-Ru sample has the lowest onset potential and the fastest current response, indicating the best OER activity; whereas the Typy-Ru sample has the highest onset potential and the worst performance. Overall, this graph clearly demonstrates the reaction starting point, kinetics, and stability of different catalysts during the OER process.

[0117] Figure 11 This is a transmission electron micrograph of the two-dimensional heteronuclear multimetallic supramolecular material prepared in Example 4 of the present invention. Figure 12 This is a scanning electron microscope image of the two-dimensional heteronuclear multimetallic supramolecular material prepared in Example 4 of the present invention. Figure 11 As shown in the figure, the material presents a regular one-dimensional nanorod structure with a diameter of about 100 nm, clear edges and a smooth surface. The dark area represents the high-density area inside, while the bright band at the edge may correspond to the outer shell or composite structure, suggesting that the material may have a core-shell structure and has high crystallinity and structural integrity. Figure 12The results further reveal the sample's overall micrometer-scale morphology. Its surface is composed of numerous long, columnar or columnar crystals, several micrometers in length and hundreds of nanometers in width. These crystals are orderly arranged with regular edges, indicating good preferred orientation and crystal growth behavior. Combined transmission electron microscopy and scanning electron microscopy observations reveal that the material exhibits not only highly ordered structural features at the nanoscale, but also strong structural consistency and nucleation control at the micrometer scale, suggesting potential applications in electronics, optical materials, and catalysis.

[0118] Figure 13 This is a test chart of the cyclic stability of the two-dimensional heteronuclear multi-metallic supramolecular material prepared in Example 4 of the present invention at a constant current density. Figure 13 As shown, at 2 mA·cm -2 The material was tested at a constant current density of 1.4 V and maintained a voltage between 1.4 V and 2.0 V over 400 cycles. The voltage fluctuations were uniform and showed no significant voltage drift, demonstrating the material's excellent stability and structural integrity during long-term electrochemical operation. The periodicity of the voltage fluctuations indicates good reversibility during charge and discharge, making it suitable for electrocatalytic systems requiring high stability, such as the oxygen evolution reaction (OER) or water electrolysis devices. Overall, the material exhibits excellent cycle life and electrochemical durability, demonstrating its potential for further application.

[0119] The above description is merely a preferred embodiment of the present invention, and the above specific embodiment is not intended to limit the present invention. Various variations and modifications are possible within the technical scope of the present invention. Any modifications, alterations, or equivalent substitutions made by a person skilled in the art based on the above description are within the scope of protection of the present invention.

Claims

1. A two-dimensional heteronuclear multimetallic supramolecular material, characterized in that: The supramolecular material has the chemical structural formula shown below: or ； Here, m is 20 to 800.

2. A method for preparing the two-dimensional heteronuclear multimetallic supramolecular material according to claim 1, characterized in that: The following steps are involved: Using a terpyridine ligand and a soluble trivalent ruthenium compound as raw materials, a first coordination reaction is carried out in a first reaction solvent system to obtain a metallic ruthenium ligand; Using a metal ruthenium ligand and pyrazine as raw materials, a second coordination reaction is carried out in a second reaction solvent system to obtain a metal catalyst; Using a metal catalyst and a soluble monovalent silver compound as raw materials, an in-situ reaction is carried out in a third reaction solvent system to obtain a heteronuclear linear catalytic intermediate; Using heteronuclear linear catalytic intermediates and metal Ru photosensitizer as raw materials, an ion pairing reaction is carried out in a fourth reaction solvent system to obtain a two-dimensional heteronuclear multi-metallic supramolecular material.

3. The method for preparing the two-dimensional heteronuclear multimetallic supramolecular material according to claim 2, characterized in that: The mass ratio of the terpyridine ligand to the soluble trivalent ruthenium compound is 1:1-3, the temperature of the first coordination reaction is 65°C-75°C, and the time is 38h-42h.

4. The method for preparing a two-dimensional heteronuclear multimetallic supramolecular material according to claim 2, characterized in that: The mass ratio of the metal ruthenium ligand to pyrazine is 1 to 3:1, the temperature of the second coordination reaction is 145° C. to 155° C., and the time is 10 h to 16 h.

5. The method for preparing the two-dimensional heteronuclear multimetallic supramolecular material according to claim 2, characterized in that: The mass ratio of the metal catalyst to the soluble monovalent silver compound is 4 to 10:1, the temperature of the in-situ reaction is 25 to 30° C., and the time is 2 to 4 hours.

6. The method for preparing the two-dimensional heteronuclear multimetallic supramolecular material according to claim 2, characterized in that: The mass ratio of the heteronuclear linear catalytic intermediate to the metal Ru photosensitizer is 3 to 5:1, the temperature of the ion pairing reaction is room temperature, and the time is 40 hours to 60 hours.

7. The method for preparing the two-dimensional heteronuclear multimetallic supramolecular material according to claim 2, characterized in that: The structural formula of the metal Ru photosensitizer is as follows: 。 8. The method for preparing the two-dimensional heteronuclear multimetallic supramolecular material according to claim 2, characterized in that: The preparation method of the terpyridine ligand comprises the following steps: A bromobenzene derivative is used as a halogenated aromatic unit, a pyridine compound containing a borate ester is used as a coupling unit, and a carbon-carbon bond coupling reaction is carried out under alkaline conditions and a Pd catalyst reaction system in a protective gas atmosphere to obtain a terpyridine ligand.

9. The method for preparing the two-dimensional heteronuclear multimetallic supramolecular material according to claim 8, characterized in that: The mass ratio of the bromobenzene derivative and the pyridine compound containing the boric acid ester is 1:2 to 8, the temperature of the carbon-carbon bond coupling reaction is 95°C to 105°C, the time is 20h to 30h, the bromobenzene derivative is 1,4-dibromo-2,5-dimethoxybenzene, and the pyridine compound containing the boric acid ester is 4-boric acid terpyridine.

10. Use of the two-dimensional heteronuclear multimetallic supramolecular material according to claim 1 as a catalyst in hydrogen production by water electrolysis.

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