A fluorine and chlorine co-doped carbon nanosheet-supported platinum nanoclusters hydrogen evolution catalyst and its preparation method

Abstract

This invention relates to a fluorine and chlorine co-doped carbon nanosheet-supported platinum nanoclusters hydrogen evolution catalyst and its preparation method. The catalyst consists of a fluorine / chlorine co-doped two-dimensional carbon nanosupport, platinum nanoclusters supported on its surface, and nitrogen-containing organic ligands. The preparation process includes: using an alkali metal chloride as a template and a chlorine source, and a fluorine-containing polymer as a carbon-fluorine dual source, a layered carbon support is obtained through high-temperature calcination, grinding, and washing; platinum nanoclusters are loaded into a composite structure using a wet chemical method; and nitrogen-containing organic ligands are introduced into an acidic electrolyte to achieve in-situ surface modification. The core innovation of this invention lies in optimizing the hydrogen adsorption energy of the platinum clusters through electronic regulation of the support, while simultaneously utilizing organic ligands to reconstruct the interfacial hydrogen bond network, synergistically improving proton transfer efficiency and electrochemical stability. The resulting catalyst can be directly used as the cathode of a proton exchange membrane electrolyzer, exhibiting a significantly reduced hydrogen evolution overpotential and excellent long-term stability in an acidic environment. It also avoids the use of binders and significantly improves the utilization rate of noble metal atoms, effectively reducing the cost of platinum-based hydrogen production catalysts.

Description

Technical Field

[0001] This invention relates to the fields of materials and energy, specifically to a method for preparing platinum nanoclusters supported on fluorine and chlorine co-doped carbon nanosheets. Background Technology

[0002] Hydrogen energy, as a key clean energy carrier for achieving carbon neutrality, has attracted much attention for its efficient production technology. Proton exchange membrane electrolysis (PEMWE) has become a mainstream technology due to its rapid response and high current density characteristics; however, the cathodic hydrogen evolution reaction (HER) process of this technology still significantly relies on high-load platinum-based catalysts. Currently widely used platinum / carbon catalysts face three major technical bottlenecks: insufficient exposure of active sites due to the large conventional size of platinum particles; easy electrochemical corrosion of carbon supports in strongly acidic environments leading to platinum particle shedding; and low proton transfer efficiency at the reaction interface resulting in high overpotential operation. Although recent research has attempted to improve support performance through doping modification, constructing platinum single-atom structures to optimize atom utilization, or introducing organic molecule modifications to enhance interfacial interactions, these approaches still suffer from insufficient long-term stability of the support, poor tolerance of platinum clusters to acidic environments, and unclear interfacial mass transfer mechanisms. Therefore, developing novel platinum-based catalysts that combine high active site utilization, strong support corrosion resistance, and efficient proton transfer channels has become a key path to overcome existing technological barriers and promote the industrialization of PEMWE.

[0003] Chinese patent CN115799546A discloses a cobalt-doped platinum-iron-nickel-copper alloy hydrogen evolution catalyst and its preparation method. It mentions the shift of the d-band center in the platinum-based catalyst, which optimizes the interaction between the catalyst and the surface adsorbent, thus promoting hydrogen evolution thermodynamics. In the comprehensive utilization system of hydrogen energy, the electrochemical hydrogen evolution reaction is a crucial component; however, the slow kinetic reaction rate is a major challenge for the efficient hydrogen production of platinum-based catalysts under high current.

[0004] Chinese patent CN119465277A discloses a composite electrocatalyst consisting of molybdenum disulfide-supported platinum nanoparticles and its preparation method. The molybdenum disulfide support has a vertically aligned nanosheet structure, exposing abundant highly active edge sulfur sites. These sulfur sites form a synergistic interface with the platinum nanoparticles, effectively reducing the water molecule dissociation energy barrier and accelerating hydrogen generation kinetics. This design combines the advantages of both metallic and non-metallic active sites, exhibiting excellent hydrogen evolution reaction activity and long-term stable operation. However, the high price of the molybdenum disulfide support involved in the aforementioned patent hinders the large-scale application of this technology.

[0005] In summary, low-cost, efficient, and stable platinum-based electrocatalytic hydrogen evolution catalysts supported on carbon materials are urgently needed for development. Summary of the Invention

[0006] The purpose of this invention is to address the shortcomings of existing technologies by providing a method for preparing platinum nanoclusters supported on fluorine and chlorine co-doped carbon nanosheets. The method for preparing platinum nanoclusters supported on fluorine and chlorine co-doped carbon nanosheets provided by this invention is simple, efficient, low-cost, and easily industrialized. Furthermore, the fluorine and chlorine co-doped carbon nanosheet catalyst supporting platinum nanoclusters provided by this invention exhibits excellent catalytic activity in the electrocatalytic hydrogen evolution reaction and shows broad application prospects in various hydrogen production reactions such as water electrolysis, ammonia electrolysis, and hydrazine hydrate electrolysis.

[0007] The technical solution of this invention is implemented as follows: A method for preparing platinum nanoclusters supported on fluorine and chlorine co-doped carbon nanosheets is disclosed, which achieves stable loading of platinum nanoclusters with precise structures on carbon materials at low cost. The method includes the following steps: obtaining fluorine and chlorine co-doped carbon nanosheets using a hard template method, synthesizing platinum nanoclusters with precise structures by a wet chemical method, and ultrasonically combining the two to obtain platinum nanoclusters supported on fluorine and chlorine co-doped carbon nanosheets.

[0008] This invention utilizes a mixture of a carbon-fluorine source, a chlorine source, and a template agent, followed by high-temperature calcination in an inert atmosphere. After washing and drying, a layered fluorine-chlorine co-doped carbon support is obtained. Platinum salts and a reducing agent are dissolved in a solvent and reacted under a reducing atmosphere to generate a platinum nanocluster solution. The resulting platinum nanocluster solution is mixed with the obtained fluorine-chlorine co-doped carbon support in a specific mass ratio, and then ultrasonically dispersed and centrifuged to obtain a platinum nanocluster-loaded composite material. The strong interaction between the support and the metal regulates the electronic structure of platinum, and the in-situ modification with nitrogen-containing organic ligands improves the hydrogen bonding environment around the active sites, which is beneficial for the occurrence of electrochemically catalytic hydrogen evolution reactions. Furthermore, this invention shows broad application prospects in various hydrogen production reactions such as water electrolysis, ammonia electrolysis, and hydrazine hydrate electrolysis.

[0009] In the preparation method of platinum nanoclusters supported on fluorine and chlorine co-doped carbon nanosheets as described above, the carbon-containing fluorine source is any one of fluorinated polymers such as polyvinylidene fluoride, polytetrafluoroethylene, or perfluoroalkoxy polymers.

[0010] In the preparation method of platinum nanoclusters supported on fluorine and chlorine co-doped carbon nanosheets as described above, the chlorine source is any one of alkali metal chlorides such as lithium chloride, sodium chloride, or potassium chloride.

[0011] In the preparation method of platinum nanoclusters supported on fluorine and chlorine co-doped carbon nanosheets as described above, the template agent is any one of alkali metal chlorides such as lithium chloride, sodium chloride, or potassium chloride.

[0012] The method for preparing platinum nanoclusters supported on fluorine and chlorine co-doped carbon nanosheets as described above, wherein the platinum salt is selected from any one of sodium hexachloroplatinate, chloroplatinic acid, or potassium tetrachloroplatinate.

[0013] In the method for preparing platinum nanoclusters supported on fluorine and chlorine co-doped carbon nanosheets as described above, the reducing agent is selected from any one of sodium acetate, sodium citrate, or sodium borohydride.

[0014] In the method for preparing platinum nanoclusters supported on fluorine and chlorine co-doped carbon nanosheets as described above, the solvent is any one of methanol, ethanol, or tetrahydrofuran.

[0015] The method for preparing platinum nanoclusters supported on fluorine and chlorine co-doped carbon nanosheets as described above, wherein the mass ratio between the platinum nanoclusters and the fluorine and chlorine co-doped carbon support is any one of 1:5, 1:20, 1:50 or 1:200.

[0016] In the method for preparing platinum nanoclusters supported on fluorine and chlorine co-doped carbon nanosheets as described above, the nitrogen-containing organic ligand is any one of pyridine derivatives such as 4,4'-bipyridine, 2,6-diaminopyridine, or 4-dimethylaminopyridine.

[0017] Based on the same inventive concept, the present invention also provides a fluorine and chlorine co-doped carbon nanosheet-supported platinum nanoclusters, which are prepared by the preparation method described above.

[0018] The beneficial effects of this invention are:

[0019] 1. This invention utilizes platinum nanoclusters with atomically precise structures combined with fluorine and chlorine co-doped carbon nanosheets to obtain a hydrogen evolution catalyst for platinum nanoclusters supported on fluorine and chlorine co-doped carbon nanosheets. This catalyst can be directly used in electrocatalytic reactions, avoiding the use of other carbon material additives and significantly reducing the amount of platinum required.

[0020] 2. The fluorine and chlorine co-doped carbon nanosheets supporting platinum nanoclusters obtained in this invention have an optimized electronic structure and good electrocatalytic hydrogen evolution reaction effect, which is very beneficial to the promotion and development of green hydrogen energy. Attached Figure Description

[0021] Figure 1 This is the X-ray powder diffraction (XRD) pattern of the fluorine and chlorine co-doped carbon nanosheets prepared in Example 1.

[0022] Figure 2 This is a transmission electron microscope (TEM) image of the fluorine and chlorine co-doped carbon nanosheets prepared in Example 1;

[0023] Figure 3 These are the mass spectrometry data of the platinum nanoclusters prepared in Example 1;

[0024] Figure 4 The ultraviolet data and structure of the platinum nanoclusters prepared in Example 1 are shown.

[0025] Figure 5 This is a transmission electron microscope (TEM) image of platinum nanoclusters supported on fluorine and chlorine co-doped carbon nanosheets prepared in Example 1;

[0026] Figure 6 The energy dispersive spectrum of platinum nanoclusters supported on fluorine and chlorine co-doped carbon nanosheets prepared in Example 1;

[0027] Figure 7 The X-ray photoelectron spectroscopy results are shown for the platinum nanoclusters supported on fluorine and chlorine co-doped carbon nanosheets prepared in Example 1.

[0028] Figure 8 Linear voltammetric scan curve of the electrochemical hydrogen evolution reaction catalyzed by platinum nanoclusters supported on fluorine and chlorine co-doped carbon nanosheets prepared in Example 1;

[0029] Figure 9 Stability test of the electrochemical hydrogen evolution reaction catalyzed by the fluorine and chlorine co-doped carbon nanosheets supported on platinum nanoclusters prepared in Example 1;

[0030] Figure 10 Stability test of platinum nanoclusters supported on fluorine and chlorine co-doped carbon nanosheets prepared in Example 1 in an electrolyte containing 4-dimethylaminopyridine for the catalytic electrochemical hydrogen evolution reaction. Detailed Implementation

[0031] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. The term "and / or" as used in this specification includes any and all combinations of one or more of the associated listed items.

[0033] Unless otherwise specified, the experimental methods used in the following examples are conventional methods.

[0034] Unless otherwise specified, all materials and reagents used in the following examples are commercially available.

[0035] A method for preparing platinum nanoclusters supported on fluorine and chlorine co-doped carbon nanosheets includes the following steps: 1) Weigh a certain amount of fluoropolymer and place it in a mixed solution of acetone and water, and stir for 12 hours to form a homogeneous solution; add a certain amount of alkali metal chloride to the solution and mix, transfer to a crucible and calcine at 600-900℃ for 1-5 hours under an inert atmosphere; after ball milling, the calcined product is washed with ultrapure water to remove the alkali metal chloride, and centrifuged to remove large carbon particles; the obtained black product is freeze-dried under vacuum for 24 hours to obtain a fluorine-chlorine co-doped carbon support.

[0036] 2) Dissolve the platinum salt and reducing agent in methanol and stir the reaction under a reducing atmosphere for 1-24 hours; add sodium hydroxide methanol solution dropwise to the reaction system and continue to maintain the reducing atmosphere for 1-24 hours to generate a green platinum nanocluster solution.

[0037] 3) Weigh a certain amount of platinum nanoclusters and add them to a certain volume of ethanol. Sonicate for 5 minutes, add a certain amount of the fluorine-chlorine co-doped carbon support prepared in step 1, mix ultrasonically for 15 minutes, and then centrifuge to obtain platinum nanoclusters supported on fluorine and chlorine co-doped carbon nanosheets.

[0038] This invention utilizes fluoropolymers, alkali metal chlorides, platinum salts, reducing agents, and solvents as raw materials to synthesize fluorine- and chlorine-co-doped carbon nanosheets supporting platinum nanoclusters through a three-step process: high-temperature calcination, wet chemical synthesis, and solution loading. In this invention, the fluoropolymer provides both carbon and fluorine sources for the synthesis of the carbon nanosheet carrier, the alkali metal chloride provides the chlorine source and acts as a hard template, and the reducing agent reduces the platinum salt to platinum nanoclusters. This invention uses a three-step process of high-temperature calcination, wet chemical synthesis, and solution loading to prepare fluorine- and chlorine-co-doped carbon nanosheets supporting platinum nanoclusters, resulting in controllable elemental composition and platinum cluster size, which is beneficial for large-scale production. This invention does not impose any special limitations on the fluoropolymers, alkali metal chlorides, platinum salts, reducing agents, and solvents; all are commercially available products. There are no special limitations on the ultrasonic methods used in steps 1) and 3); any ultrasonic method known to those skilled in the art is acceptable.

[0039] Preferably, the carbon-containing fluorine source is any one of polyvinylidene fluoride, polytetrafluoroethylene, or perfluoroalkoxy polymers; more preferably, the carbon-containing fluorine source is selected from polyvinylidene fluoride or polytetrafluoroethylene; most preferably, the carbon-containing fluorine source is selected from polyvinylidene fluoride, resulting in a better structure of the carbon nanosheets.

[0040] Preferably, the chlorine source and the template agent are any one of alkali metal chlorides such as lithium chloride, sodium chloride, or potassium chloride; more preferably, the chlorine source and the template agent are selected from sodium chloride or potassium chloride; most preferably, the chlorine source and the template agent are selected from sodium chloride.

[0041] Preferably, the platinum salt is selected from any one of sodium hexachloroplatinate, chloroplatinic acid, or potassium tetrachloroplatinate; more preferably, the platinum salt is selected from sodium hexachloroplatinate or potassium tetrachloroplatinate; most preferably, the platinum salt is selected from sodium hexachloroplatinate, which can synthesize platinum nanoclusters with controllable atomic number, including Pt8, Pt10, and Pt12.

[0042] Preferably, the reducing agent is selected from any one of sodium acetate, sodium citrate, or sodium borohydride; more preferably, the reducing agent is selected from any one of sodium acetate or sodium citrate; most preferably, the reducing agent is selected from sodium acetate.

[0043] Preferably, the solvent is any one of methanol, ethanol or tetrahydrofuran; more preferably, the solvent is methanol or ethanol; most preferably, the solvent is selected from methanol.

[0044] Preferably, the mass ratio between the platinum nanoclusters and the fluorine-chlorine co-doped carbon support is any one of 1:5, 1:20, 1:50, or 1:200; more preferably, the mass ratio between the platinum nanoclusters and the fluorine-chlorine co-doped carbon support is any one of 1:50 or 1:200; most preferably, the mass ratio between the platinum nanoclusters and the fluorine-chlorine co-doped carbon support is 1:50.

[0045] Preferably, the nitrogen-containing organic ligand added in situ by electrochemical means is any one of pyridine derivatives such as 4,4'-bipyridine, 2,6-diaminopyridine, or 4-dimethylaminopyridine; more preferably, the nitrogen-containing organic ligand added in situ by electrochemical means is 2,6-diaminopyridine or 4-dimethylaminopyridine; most preferably, the nitrogen-containing organic ligand added in situ by electrochemical means is 4-dimethylaminopyridine.

[0046] The phase composition of the fluorine and chlorine co-doped carbon nanosheets prepared in this invention was determined by X-ray powder diffraction pattern using a Shimadzu XRD-6100 powder diffractometer.

[0047] The microstructures of the fluorine and chlorine co-doped carbon nanosheets and the platinum nanoclusters supported on the fluorine and chlorine co-doped carbon nanosheets prepared in this invention were determined by transmission electron microscopy (TEM) images using a JEOL JEM2100F transmission electron microscope from Japan.

[0048] The electrocatalytic performance of the fluorine and chlorine co-doped carbon nanosheets supporting platinum nanoclusters prepared in this invention was measured using a Shanghai Chenhua CHI660E electrochemical workstation.

[0049] To further understand this application, the following detailed description, in conjunction with embodiments, illustrates a fluorine and chlorine co-doped carbon nanosheet-supported platinum nanoclusters and their preparation method. It should be noted that the following embodiments are for illustrative purposes only and should not be construed as limiting the scope of protection of this invention.

[0050] Example 1 A method for preparing platinum nanoclusters supported on fluorine and chlorine co-doped carbon nanosheets includes the following steps:

[0051] 1) Dissolve 0.30 g of polyvinylidene fluoride in 5 mL of acetone aqueous solution (2:3 volume ratio) and stir continuously for 12 hours. Then, add 3 g of sodium chloride to the solution and mix thoroughly. Transfer the solution to a crucible for calcination. The calcination process is carried out at 900°C for 90 minutes under an argon atmosphere. After the tube furnace cools to room temperature, the resulting powder is first ball-milled. The milled product is washed five times with ultrapure water to completely remove sodium chloride; this process lasts for three days. Subsequently, large-diameter carbon particles in the product are removed by controlled centrifugation. Finally, the black product is freeze-dried under vacuum for 24 hours to obtain fluorine and chlorine co-doped carbon nanosheets.

[0052] 2) Dissolve 0.3 g of sodium chloroplatinate hexahydrate and 0.32 g of sodium acetate trihydrate in 15 mL of methanol. React overnight in a carbon monoxide atmosphere at 25°C, 1 atm, and 1560 rpm to form a filamentous brownish-red solution. Then, under a continuous carbon monoxide atmosphere, slowly add 3 mL of methanol solution containing 20 mg of sodium hydroxide to the system over 1 hour until a green platinum nanocluster solution is formed.

[0053] 3) The synthesized platinum nanoclusters were dispersed in 5 mL of ethanol and sonicated for 5 minutes to form a suspension. 5 mg of the aforementioned fluorine and chlorine co-doped carbon nanosheets were added to the system, and sonication was continued for 15 minutes. The suspension was then centrifuged at 10,000 rpm for 5 minutes to finally obtain platinum nanoclusters supported on fluorine and chlorine co-doped carbon nanosheets.

[0054] Figure 1 This is the X-ray powder diffraction (XRD) pattern of platinum nanoclusters supported on fluorine and chlorine co-doped carbon nanosheets prepared in this embodiment. Figure 1 It can be seen that the fluorine and chlorine co-doped carbon nanosheets prepared in this embodiment are amorphous carbon materials.

[0055] Figure 2 This is a transmission electron microscope (TEM) image of platinum nanoclusters supported on fluorine and chlorine co-doped carbon nanosheets prepared in this embodiment. It can be seen that the carbon support prepared in this embodiment exhibits the morphology of nanosheets.

[0056] Figure 3 These are the mass spectrometry data of the platinum nanoclusters prepared in this embodiment. Figure 4 The images show the UV data and structure of the platinum nanoclusters prepared in this embodiment. Together, they demonstrate that the synthesized platinum nanoclusters consist of 10 atoms and have a precise structure.

[0057] Figure 5This is a transmission electron microscope (TEM) image of platinum nanoclusters supported on fluorine and chlorine co-doped carbon nanosheets prepared in this embodiment. It can be seen that the platinum nanoclusters prepared in this embodiment are uniformly dispersed on the carbon support.

[0058] Figure 6 The energy dispersive spectrum of the fluorine and chlorine co-doped carbon nanosheets loaded with platinum nanoclusters prepared in this embodiment shows that the composite material contains elements such as carbon, fluorine, chlorine and platinum.

[0059] Figure 7 The X-ray photoelectron spectroscopy of the fluorine and chlorine co-doped carbon nanosheets loaded with platinum nanoclusters prepared in this embodiment shows that platinum in the composite material has both zero and positive valence.

[0060] Electrocatalytic hydrogen evolution performance test: At room temperature, using a standard three-electrode system and a Shanghai Chenhua CHI760E electrochemical workstation, the catalytic activity of platinum nanoclusters supported on fluorine and chlorine co-doped carbon nanosheets prepared in this example for electrocatalytic hydrogen evolution was analyzed and evaluated. The test method employed linear voltammetry, and the analysis was performed in a 0.5 mol / L sulfuric acid aqueous solution at a scan rate of 5 mV / s.

[0061] Figure 8 The linear voltammetric scan curve of the electrochemical hydrogen evolution reaction catalyzed by the fluorine and chlorine co-doped carbon nanosheets supported on platinum nanoclusters prepared in this embodiment shows that the obtained material exhibits a hydrogen evolution overpotential of only 67 mV, demonstrating excellent catalytic hydrogen evolution activity.

[0062] Figure 9 The stability test of the electrochemical hydrogen evolution reaction catalyzed by the fluorine and chlorine co-doped carbon nanosheets supported on platinum nanoclusters prepared in this embodiment shows that the obtained material has excellent catalytic stability, with a stability time of up to 10 hours.

[0063] Electrocatalytic hydrogen evolution performance test of in-situ addition of nitrogen-containing organic ligands: Figure 10 The stability test of the fluorine and chlorine co-doped carbon nanosheets supporting platinum nanoclusters prepared in this embodiment in the catalytic electrochemical hydrogen evolution reaction in an electrolyte with added 4-dimethylaminopyridine showed that the addition of 4-dimethylaminopyridine to a 0.5 mol / L sulfuric acid aqueous solution significantly improved the current fluctuation during the stability test, which is attributed to the improvement of hydrogen evolution kinetics, and the stability time was increased to 50 hours.

[0064] Example 2 A method for preparing platinum nanoclusters supported on fluorine and chlorine co-doped carbon nanosheets includes the following steps: 1) Dissolve 0.60 g of polyvinylidene fluoride in 5 mL of acetone aqueous solution (2:3 v / v) and stir continuously for 12 hours. Then add 3 g of sodium chloride to the solution and mix thoroughly. Transfer the solution to a crucible for calcination. The calcination process is carried out at 900°C for 90 minutes under an argon atmosphere. After the tube furnace cools to room temperature, the resulting powder is first ball-milled. The milled product is washed five times with ultrapure water to completely remove sodium chloride; this process lasts for three days. Subsequently, large-diameter carbon particles in the product are removed by controlled centrifugation. Finally, the black product is freeze-dried under vacuum for 24 hours to obtain fluorine and chlorine co-doped carbon nanosheets.

[0065] 2) Dissolve 0.3 g of sodium chloroplatinate hexahydrate and 0.32 g of sodium acetate trihydrate in 15 mL of methanol. React overnight in a carbon monoxide atmosphere at 25°C, 1 atm, and 1560 rpm to form a filamentous brownish-red solution. Then, under a continuous carbon monoxide atmosphere, slowly add 3 mL of methanol solution containing 20 mg of sodium hydroxide to the system over 1 hour until a green platinum nanocluster solution is formed.

[0066] 3) The synthesized platinum nanoclusters were dispersed in 5 mL of ethanol and sonicated for 5 minutes to form a suspension. 5 mg of the aforementioned fluorine and chlorine co-doped carbon nanosheets were added to the system, and sonication was continued for 15 minutes. The suspension was then centrifuged at 10,000 rpm for 5 minutes to finally obtain platinum nanoclusters supported on fluorine and chlorine co-doped carbon nanosheets.

[0067] Example 3 A method for preparing platinum nanoclusters supported on fluorine and chlorine co-doped carbon nanosheets includes the following steps: 1) Dissolve 0.30 g of polyvinylidene fluoride in 5 mL of acetone aqueous solution (2:3 v / v) and stir continuously for 12 hours. Then add 9 g of sodium chloride to the solution and mix thoroughly. Transfer the solution to a crucible for calcination. The calcination process is carried out at 900°C for 90 minutes under an argon atmosphere. After the tube furnace cools to room temperature, the resulting powder is first ball-milled. The milled product is washed five times with ultrapure water to completely remove sodium chloride; this process lasts for three days. Subsequently, large-diameter carbon particles in the product are removed by controlled centrifugation. Finally, the black product is freeze-dried under vacuum for 24 hours to obtain fluorine and chlorine co-doped carbon nanosheets.

[0068] 2) Dissolve 0.3 g of sodium chloroplatinate hexahydrate and 0.32 g of sodium acetate trihydrate in 15 mL of methanol. React overnight in a carbon monoxide atmosphere at 25°C, 1 atm, and 1560 rpm to form a filamentous brownish-red solution. Then, under a continuous carbon monoxide atmosphere, slowly add 3 mL of methanol solution containing 20 mg of sodium hydroxide to the system over 1 hour until a green platinum nanocluster solution is formed.

[0069] 3) The synthesized platinum nanoclusters were dispersed in 5 mL of ethanol and sonicated for 5 minutes to form a suspension. 5 mg of the aforementioned fluorine and chlorine co-doped carbon nanosheets were added to the system, and sonication was continued for 15 minutes. The suspension was then centrifuged at 10,000 rpm for 5 minutes to finally obtain platinum nanoclusters supported on fluorine and chlorine co-doped carbon nanosheets.

[0070] Example 4 A method for preparing platinum nanoclusters supported on fluorine and chlorine co-doped carbon nanosheets includes the following steps: 1) Dissolve 0.30 g of polyvinylidene fluoride in 5 mL of acetone aqueous solution (2:3 v / v) and stir continuously for 12 hours. Then add 3 g of sodium chloride to the solution and mix thoroughly. Transfer the solution to a crucible for calcination. The calcination process is carried out at 700°C for 90 minutes under an argon atmosphere. After the tube furnace cools to room temperature, the resulting powder is first ball-milled. The milled product is washed five times with ultrapure water to completely remove sodium chloride; this process lasts for three days. Subsequently, large-diameter carbon particles in the product are removed by controlled centrifugation. Finally, the black product is freeze-dried under vacuum for 24 hours to obtain fluorine and chlorine co-doped carbon nanosheets.

[0071] 2) Dissolve 0.3 g of sodium chloroplatinate hexahydrate and 0.32 g of sodium acetate trihydrate in 15 mL of methanol. React overnight in a carbon monoxide atmosphere at 25°C, 1 atm, and 1560 rpm to form a filamentous brownish-red solution. Then, under a continuous carbon monoxide atmosphere, slowly add 3 mL of methanol solution containing 20 mg of sodium hydroxide to the system over 1 hour until a green platinum nanocluster solution is formed.

[0072] 3) The synthesized platinum nanoclusters were dispersed in 5 mL of ethanol and sonicated for 5 minutes to form a suspension. 5 mg of the aforementioned fluorine and chlorine co-doped carbon nanosheets were added to the system, and sonication was continued for 15 minutes. The suspension was then centrifuged at 10,000 rpm for 5 minutes to finally obtain platinum nanoclusters supported on fluorine and chlorine co-doped carbon nanosheets.

[0073] Example 5 A method for preparing platinum nanoclusters supported on fluorine and chlorine co-doped carbon nanosheets includes the following steps: 1) Dissolve 0.30 g of polyvinylidene fluoride in 5 mL of acetone aqueous solution (2:3 v / v) and stir continuously for 12 hours. Then add 3 g of sodium chloride to the solution and mix thoroughly. Transfer the solution to a crucible for calcination. The calcination process is carried out at 900°C for 180 minutes under an argon atmosphere. After the tube furnace cools to room temperature, the resulting powder is first ball-milled. The milled product is washed five times with ultrapure water to completely remove sodium chloride; this process lasts for three days. Subsequently, large-diameter carbon particles in the product are removed by controlled centrifugation. Finally, the black product is freeze-dried under vacuum for 24 hours to obtain fluorine and chlorine co-doped carbon nanosheets.

[0074] 2) Dissolve 0.3 g of sodium chloroplatinate hexahydrate and 0.32 g of sodium acetate trihydrate in 15 mL of methanol. React overnight in a carbon monoxide atmosphere at 25°C, 1 atm, and 1560 rpm to form a filamentous brownish-red solution. Then, under a continuous carbon monoxide atmosphere, slowly add 3 mL of methanol solution containing 20 mg of sodium hydroxide to the system over 1 hour until a green platinum nanocluster solution is formed.

[0075] 3) The synthesized platinum nanoclusters were dispersed in 5 mL of ethanol and sonicated for 5 minutes to form a suspension. 5 mg of the aforementioned fluorine and chlorine co-doped carbon nanosheets were added to the system, and sonication was continued for 15 minutes. The suspension was then centrifuged at 10,000 rpm for 5 minutes to finally obtain platinum nanoclusters supported on fluorine and chlorine co-doped carbon nanosheets.

[0076] Example 6 A method for preparing platinum nanoclusters supported on fluorine and chlorine co-doped carbon nanosheets includes the following steps: 1) Dissolve 0.30 g of polyvinylidene fluoride in 5 mL of acetone aqueous solution (2:3 volume ratio) and stir continuously for 12 hours. Then, add 3 g of sodium chloride to the solution and mix thoroughly. Transfer the solution to a crucible for calcination. The calcination process is carried out at 900°C for 90 minutes under an argon atmosphere. After the tube furnace cools to room temperature, the resulting powder is first ball-milled. The milled product is washed five times with ultrapure water to completely remove sodium chloride; this process lasts for three days. Subsequently, large-diameter carbon particles in the product are removed by controlled centrifugation. Finally, the black product is freeze-dried under vacuum for 24 hours to obtain fluorine and chlorine co-doped carbon nanosheets.

[0077] 2) Dissolve 0.6 g of sodium chloroplatinate hexahydrate and 0.64 g of sodium acetate trihydrate in 15 mL of methanol. React overnight in a carbon monoxide atmosphere at 25°C, 1 atm, and 1560 rpm stirring speed to form a filamentous brownish-red solution. Then, under a continuous carbon monoxide atmosphere, slowly add 3 mL of methanol solution containing 20 mg of sodium hydroxide to the system over 1 hour until a green platinum nanocluster solution is formed.

[0078] 3) The synthesized platinum nanoclusters were dispersed in 5 mL of ethanol and sonicated for 5 minutes to form a suspension. 5 mg of the aforementioned fluorine and chlorine co-doped carbon nanosheets were added to the system, and sonication was continued for 15 minutes. The suspension was then centrifuged at 10,000 rpm for 5 minutes to finally obtain platinum nanoclusters supported on fluorine and chlorine co-doped carbon nanosheets.

[0079] Example 7 A method for preparing platinum nanoclusters supported on fluorine and chlorine co-doped carbon nanosheets includes the following steps: 1) Dissolve 0.30 g of polyvinylidene fluoride in 5 mL of acetone aqueous solution (2:3 volume ratio) and stir continuously for 12 hours. Then, add 3 g of sodium chloride to the solution and mix thoroughly. Transfer the solution to a crucible for calcination. The calcination process is carried out at 900°C for 90 minutes under an argon atmosphere. After the tube furnace cools to room temperature, the resulting powder is first ball-milled. The milled product is washed five times with ultrapure water to completely remove sodium chloride; this process lasts for three days. Subsequently, large-diameter carbon particles in the product are removed by controlled centrifugation. Finally, the black product is freeze-dried under vacuum for 24 hours to obtain fluorine and chlorine co-doped carbon nanosheets.

[0080] 2) Dissolve 0.3 g of sodium chloroplatinate hexahydrate and 0.32 g of sodium acetate trihydrate in 30 mL of methanol. React overnight in a carbon monoxide atmosphere at 25°C, 1 atm, and 1560 rpm stirring speed to form a filamentous brownish-red solution. Then, under a continuous carbon monoxide atmosphere, slowly add 3 mL of methanol solution containing 20 mg of sodium hydroxide to the system over 1 hour until a green platinum nanocluster solution is formed.

[0081] 3) The synthesized platinum nanoclusters were dispersed in 5 mL of ethanol and sonicated for 5 minutes to form a suspension. 5 mg of the aforementioned fluorine and chlorine co-doped carbon nanosheets were added to the system, and sonication was continued for 15 minutes. The suspension was then centrifuged at 10,000 rpm for 5 minutes to finally obtain platinum nanoclusters supported on fluorine and chlorine co-doped carbon nanosheets.

[0082] Example 8 A method for preparing platinum nanoclusters supported on fluorine and chlorine co-doped carbon nanosheets includes the following steps: 1) Dissolve 0.30 g of polyvinylidene fluoride in 5 mL of acetone aqueous solution (2:3 volume ratio) and stir continuously for 12 hours. Then, add 3 g of sodium chloride to the solution and mix thoroughly. Transfer the solution to a crucible for calcination. The calcination process is carried out at 900°C for 90 minutes under an argon atmosphere. After the tube furnace cools to room temperature, the resulting powder is first ball-milled. The milled product is washed five times with ultrapure water to completely remove sodium chloride; this process lasts for three days. Subsequently, large-diameter carbon particles in the product are removed by controlled centrifugation. Finally, the black product is freeze-dried under vacuum for 24 hours to obtain fluorine and chlorine co-doped carbon nanosheets.

[0083] 2) Dissolve 0.3 g of sodium chloroplatinate hexahydrate and 0.32 g of sodium acetate trihydrate in 15 mL of methanol. React overnight in a carbon monoxide atmosphere at 60°C, 1 atm, and 1560 rpm stirring speed to form a filamentous brownish-red solution. Then, under a continuous carbon monoxide atmosphere, slowly add 3 mL of methanol solution containing 20 mg of sodium hydroxide to the system over 1 hour until a green platinum nanocluster solution is formed.

[0084] 3) The synthesized platinum nanoclusters were dispersed in 5 mL of ethanol and sonicated for 5 minutes to form a suspension. 5 mg of the aforementioned fluorine and chlorine co-doped carbon nanosheets were added to the system, and sonication was continued for 15 minutes. The suspension was then centrifuged at 10,000 rpm for 5 minutes to finally obtain platinum nanoclusters supported on fluorine and chlorine co-doped carbon nanosheets.

[0085] Example 9 A method for preparing platinum nanoclusters supported on fluorine and chlorine co-doped carbon nanosheets includes the following steps: 1) Dissolve 0.30 g of polyvinylidene fluoride in 5 mL of acetone aqueous solution (2:3 volume ratio) and stir continuously for 12 hours. Then, add 3 g of sodium chloride to the solution and mix thoroughly. Transfer the solution to a crucible for calcination. The calcination process is carried out at 900°C for 90 minutes under an argon atmosphere. After the tube furnace cools to room temperature, the resulting powder is first ball-milled. The milled product is washed five times with ultrapure water to completely remove sodium chloride; this process lasts for three days. Subsequently, large-diameter carbon particles in the product are removed by controlled centrifugation. Finally, the black product is freeze-dried under vacuum for 24 hours to obtain fluorine and chlorine co-doped carbon nanosheets.

[0086] 2) Dissolve 0.3 g of sodium chloroplatinate hexahydrate and 0.32 g of sodium acetate trihydrate in 15 mL of methanol. React overnight in a carbon monoxide atmosphere at 25°C, 1 atm, and 1560 rpm stirring speed to form a filamentous brownish-red solution. Then, under a continuous carbon monoxide atmosphere, slowly add 3 mL of methanol solution containing 20 mg of sodium hydroxide to the system over 3 hours until a green platinum nanocluster solution is formed.

[0087] 3) The synthesized platinum nanoclusters were dispersed in 5 mL of ethanol and sonicated for 5 minutes to form a suspension. 5 mg of the aforementioned fluorine and chlorine co-doped carbon nanosheets were added to the system, and sonication was continued for 15 minutes. The suspension was then centrifuged at 10,000 rpm for 5 minutes to finally obtain platinum nanoclusters supported on fluorine and chlorine co-doped carbon nanosheets.

[0088] Example 10 A method for preparing platinum nanoclusters supported on fluorine and chlorine co-doped carbon nanosheets includes the following steps: 1) Dissolve 0.30 g of polyvinylidene fluoride in 5 mL of acetone aqueous solution (2:3 volume ratio) and stir continuously for 12 hours. Then, add 3 g of sodium chloride to the solution and mix thoroughly. Transfer the solution to a crucible for calcination. The calcination process is carried out at 900°C for 90 minutes under an argon atmosphere. After the tube furnace cools to room temperature, the resulting powder is first ball-milled. The milled product is washed five times with ultrapure water to completely remove sodium chloride; this process lasts for three days. Subsequently, large-diameter carbon particles in the product are removed by controlled centrifugation. Finally, the black product is freeze-dried under vacuum for 24 hours to obtain fluorine and chlorine co-doped carbon nanosheets.

[0089] 2) Dissolve 0.3 g of sodium chloroplatinate hexahydrate and 0.32 g of sodium acetate trihydrate in 15 mL of methanol. React overnight in a carbon monoxide atmosphere at 25°C, 1 atm, and 1560 rpm to form a filamentous brownish-red solution. Then, under a continuous carbon monoxide atmosphere, slowly add 3 mL of methanol solution containing 20 mg of sodium hydroxide to the system over 1 hour until a green platinum nanocluster solution is formed.

[0090] 3) The synthesized platinum nanoclusters were dispersed in 5 mL of ethanol and sonicated for 5 minutes to form a suspension. 50 mg of the aforementioned fluorine and chlorine co-doped carbon nanosheets were added to the system, and sonication was continued for 15 minutes. The suspension was then centrifuged at 10,000 rpm for 5 minutes to finally obtain platinum nanoclusters supported on fluorine and chlorine co-doped carbon nanosheets.

Claims

1. A method for preparing platinum nanoclusters supported on fluorine and chlorine co-doped carbon nanosheets, characterized in that, Includes the following steps: (a) Preparation of fluorine-chlorine co-doped carbon support: A carbon-containing fluorine source, a chlorine-containing source, and a template agent are mixed and calcined at high temperature in an inert atmosphere. After washing and drying, a layered fluorine-chlorine co-doped carbon support is obtained. (b) Synthesis of platinum nanoclusters: Platinum salt and reducing agent are dissolved in a solvent and reacted under a reducing atmosphere to generate a platinum nanocluster solution; (c) Platinum nanoclusters loaded: The platinum nanocluster solution obtained in step (b) and the fluorine-chlorine co-doped carbon support obtained in step (a) are mixed in the mass ratio of the two, and then ultrasonically dispersed and centrifuged to obtain a composite material loaded with platinum nanoclusters. (d) Organic ligand modification: The composite material obtained in step (c) is contacted with a nitrogen-containing organic ligand solution to achieve surface modification.

2. The preparation method according to claim 1, characterized in that, The carbon-containing fluorine source in step (a) is any one of fluorinated polymers such as polyvinylidene fluoride, polytetrafluoroethylene, or perfluoroalkoxy polymers.

3. The preparation method according to claim 1, characterized in that, The chlorine source in step (a) is any one of alkali metal chlorides such as lithium chloride, sodium chloride, or potassium chloride.

4. The preparation method according to claim 1, characterized in that, The template agent in step (a) is any one of alkali metal chlorides such as lithium chloride, sodium chloride, or potassium chloride.

5. The preparation method according to claim 1, characterized in that, The platinum salt in step (b) is selected from any one of sodium hexachloroplatinate, chloroplatinic acid, or potassium tetrachloroplatinate.

6. The preparation method according to claim 1, characterized in that, The reducing agent in step (b) is selected from any one of sodium acetate, sodium citrate, or sodium borohydride.

7. The preparation method according to claim 1, characterized in that, The solvent in step (b) is any one of methanol, ethanol or tetrahydrofuran.

8. The preparation method according to claim 1, characterized in that, In step (c), the mass ratio between the synthesized platinum nanoclusters with controllable atomic number and the fluorine-chlorine co-doped carbon support is any one of 1:5, 1:20, 1:50 or 1:

200.

9. The preparation method according to claim 1, characterized in that, The nitrogen-containing organic ligand in step (d) is any one of pyridine derivatives such as 4,4'-bipyridine, 2,6-diaminopyridine, or 4-dimethylaminopyridine.

10. A platinum nanocluster supported on fluorine and chlorine co-doped carbon nanosheets, characterized in that, It is prepared by the preparation method described in any one of claims 1 to 9.

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