A catalyst, a preparation method thereof and an application thereof

Abstract

The present invention discloses a catalyst, a preparation method thereof and an application thereof. Tungsten trioxide nanorods are subjected to a sulfidation reaction with sulfur powder to generate tungsten disulfide, and the tungsten disulfide is subjected to plasma etching to obtain a catalyst intermediate; the catalyst intermediate is dispersed in a rhodium salt solution, separated and dried to obtain a catalyst; alternatively, the tungsten trioxide nanorods can be first loaded on a conductive carrier and then subjected to the steps of sulfidation, plasma etching and rhodium loading to obtain a catalytic material; the catalyst and catalytic material of the present invention can have both low cost and high hydrogen evolution catalytic efficiency, and in particular, exhibit good catalytic activity and stability under both acidic and alkaline conditions, and are expected to be practically applied in the field of electrolytic water hydrogen production.

Description

Technical Field

[0001] The present invention relates to the field of catalysts, and particularly to tungsten disulfide-confined rhodium single-atom catalysts, and specifically relates to a catalyst, a preparation method thereof, and an application thereof in the process of electrocatalytic hydrogen evolution. Background Art

[0002] Hydrogen energy is a clean energy with diverse utilization forms, whose combustion product is only water and no carbon emissions are generated. Currently, hydrogen is mainly produced by reacting coal or natural gas with steam. Although this method can utilize existing coal and natural gas resources, it will consume a large amount of non-renewable resources, produce a large amount of carbon dioxide, exacerbate the greenhouse effect, and is not conducive to large-scale industrial production. Therefore, developing a more environmentally friendly hydrogen energy production route is of great significance for promoting the efficient production and utilization of hydrogen energy. Photo / electrocatalytic water splitting for hydrogen production is one of the hydrogen production routes. Currently, the catalytic material with better catalytic hydrogen evolution efficiency is precious metal platinum. However, due to the low reserves and high cost of platinum metal, it is not conducive to large-scale application.

[0003] It should be noted that the information disclosed in the above background art section is only used for understanding the background of the present application. Therefore, the background section of the present invention may include background information about the problems or environment of the present invention, rather than necessarily describing the prior art. Therefore, the content included in the background art section is not an admission by the applicant of the prior art. Summary of the Invention

[0004] The object of the present invention is to overcome one or more deficiencies in the prior art, and provide a novel catalyst, catalytic material with both low cost and high hydrogen evolution catalytic efficiency, and their preparation methods, especially they can exhibit good catalytic activity and stability under both acidic and alkaline conditions.

[0005] To achieve the above object, a technical solution adopted by the present invention is:

[0006] A preparation method of a catalytic material, the preparation method of the catalytic material includes:

[0007] Mix an acidic tungsten acid aqueous solution, an organic acid, and an ammonium salt to obtain a mixed solution;

[0008] Place a conductive carrier in the mixed solution, perform a hydrothermal reaction to obtain a first intermediate, and then perform a thermal decomposition reaction on the first intermediate under heating conditions to generate a second intermediate, the second intermediate includes the conductive carrier and tungsten trioxide nanorods loaded on the conductive carrier;

[0009] Subject the second intermediate to a sulfidation reaction with sulfur powder to generate a third intermediate, and perform plasma etching on the third intermediate to obtain a fourth intermediate;

[0010] Disperse the fourth intermediate in a rhodium salt solution to prepare the catalytic material.

[0011] According to some specific aspects of the present invention, the tungstate in the aqueous tungstate solution includes sodium tungstate.

[0012] According to some specific aspects of the present invention, the organic acid includes oxalic acid.

[0013] According to some specific aspects of the present invention, the ammonium salt includes ammonium sulfate, ammonium nitrate, etc.

[0014] In some preferred embodiments of the present invention, the molar ratio of the tungstate, the organic acid, and the ammonium salt in the feed is 1:2.5 - 3.5:1.0 - 1.8. Further, the molar ratio of the tungstate, the organic acid, and the ammonium salt in the feed is 1:2.6 - 3.2:1.05 - 1.5.

[0015] According to some preferred aspects of the present invention, control the reaction temperature of the hydrothermal reaction to be 160 - 200 °C. Further, control the reaction temperature of the hydrothermal reaction to be 170 - 190 °C. In some embodiments of the present invention, control the reaction temperature of the hydrothermal reaction to be 175 °C, 180 °C, 185 °C, 190 °C, 195 °C, etc.

[0016] According to some preferred aspects of the present invention, control the reaction time of the hydrothermal reaction to be 8 - 20 h. Further, control the reaction time of the hydrothermal reaction to be 10 - 16 h. In some embodiments of the present invention, control the reaction time of the hydrothermal reaction to be 9 h, 11 h, 12 h, 13 h, 14 h, 15 h, 16 h, 17 h, 18 h, 19 h, etc.

[0017] According to some preferred aspects of the present invention, control the reaction temperature of the thermal decomposition reaction to be 300 - 600 °C; further, control the reaction temperature of the thermal decomposition reaction to be 400 - 550 °C. In some embodiments of the present invention, control the reaction temperature of the thermal decomposition reaction to be 350 °C, 420 °C, 450 °C, 500 °C, 530 °C, 580 °C, etc.

[0018] According to some preferred aspects of the present invention, control the reaction time of the thermal decomposition reaction to be 0.5 - 3 h. Further, control the reaction time of the thermal decomposition reaction to be 0.5 - 2 h. In some embodiments of the present invention, the reaction time of the thermal decomposition reaction is 0.6 h, 0.7 h, 0.8 h, 1 h, 1.2 h, 1.5 h, 1.8 h, etc.

[0019] According to some preferred aspects of the present invention, the heating rate of the thermal decomposition reaction is controlled to be 1-20 °C / min. Further, the heating rate of the thermal decomposition reaction is controlled to be 5-15 °C / min. In some embodiments of the present invention, the heating rate of the thermal decomposition reaction is controlled to be 3 °C / min, 4 °C / min, 6 °C / min, 8 °C / min, 10 °C / min, 12 °C / min, 13 °C / min, 14 °C / min, 15 °C / min, 16 °C / min, 17 °C / min, 18 °C / min, 19 °C / min, etc.

[0020] In some embodiments of the present invention, the preparation method of the second intermediate includes: dispersing the conductive carrier in an organic solvent and / or water, oscillating, drying, placing the dried conductive carrier in nitric acid, heating, and then washing and drying to obtain a pretreated conductive carrier; placing the pretreated conductive carrier in the mixed solution, performing a hydrothermal reaction, taking out the pretreated conductive carrier after the reaction, drying, and performing a thermal decomposition reaction under heating conditions.

[0021] Further, the thermal decomposition reaction is controlled to be carried out in air.

[0022] Further, the organic solvent includes acetone, ethanol, etc.

[0023] According to some specific aspects of the present invention, during the preparation of the second intermediate, the conductive carrier is ultrasonically oscillated in acetone, ethanol, and water in sequence.

[0024] According to some specific aspects of the present invention, during the preparation of the second intermediate, the nitric acid is concentrated nitric acid with a mass concentration of 30%-90%.

[0025] In some embodiments of the present invention, the conductive carrier is carbon cloth, carbon paper, copper foam, or nickel foam.

[0026] According to some preferred aspects of the present invention, the reaction temperature of the sulfidation reaction is controlled to be 450-750 °C; further, the reaction temperature of the sulfidation reaction is controlled to be 500-700 °C. In some embodiments of the present invention, the reaction temperature of the sulfidation reaction is controlled to be 450 °C, 480 °C, 510 °C, 520 °C, 540 °C, 550 °C, 560 °C, 580 °C, 600 °C, 620 °C, 630 °C, 650 °C, 680 °C, 690 °C, 720 °C, 730 °C, 740 °C, etc.

[0027] In some embodiments of the present invention, the sulfidation reaction is controlled to be carried out under a protective atmosphere, and the protective atmosphere is formed by introducing nitrogen and / or an inert gas. Further, the inert gas includes but is not limited to helium, argon, etc.

[0028] In some embodiments of the present invention, the method for preparing the third intermediate includes: placing sulfur powder at the bottom of a quartz test tube, then placing the second intermediate at the tube mouth end of the quartz test tube, placing the quartz test tube in the quartz tube of a tube furnace, heating from room temperature to a preset reaction temperature under the protection of a protective atmosphere, and maintaining the temperature; wherein, before the temperature reaches the preset reaction temperature, the sulfur powder in the quartz test tube is located in an area outside the heating area of the tube furnace, and when the temperature reaches the preset reaction temperature, slide the tube furnace to move the sulfur powder into the heating area for reaction.

[0029] In some embodiments of the present invention, the addition amount of the sulfur powder is 5%-20% of the second intermediate. Further, in some embodiments of the present invention, the added molar amount of the sulfur powder is more than 2 times, preferably more than 4 times, more preferably more than 8 times, and specifically can be 2-20 times the molar amount of tungsten trioxide on the second intermediate.

[0030] In some embodiments of the present invention, during the preparation of the third intermediate, the preset reaction temperature is 450-750°C.

[0031] According to the present invention, the third intermediate includes tungsten disulfide in a nanosheet structure.

[0032] In some embodiments of the present invention, the time of the plasma etching is controlled to be 10-180 s. Further, the time of the plasma etching is controlled to be 20-150 s. According to some specific aspects of the present invention, the time of the plasma etching is controlled to be 12 s, 15 s, 22 s, 25 s, 30 s, 32 s, 35 s, 36 s, 40 s, 42 s, 45 s, 48 s, 50 s, 55 s, 60 s, 65 s, 70 s, 75 s, 80 s, 85 s, 90 s, 95 s, 100 s, 105 s, 110 s, 115 s, 120 s, 125 s, 130 s, 135 s, 140 s, 145 s, 155 s, 160 s, 165 s, 170 s, 175 s, 178 s, etc.

[0033] In some embodiments of the present invention, the plasma used for the plasma etching includes at least one of argon plasma, oxygen plasma, and air plasma.

[0034] In some embodiments of the present invention, the working power of the plasma etching is 10% to 100% of the maximum power of the plasma generator. According to some specific aspects of the present invention, the working power of the plasma etching is 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, etc. of the maximum power of the plasma generator.

[0035] In some embodiments of the present invention, the rhodium salt solution includes an aqueous solution of rhodium chloride.

[0036] In some embodiments of the present invention, the mass concentration of the rhodium salt solution is 0.5 - 10 mg / mL. Further, the mass concentration of the rhodium salt solution is 1 - 8 mg / mL. According to some specific aspects of the present invention, the mass concentration of the rhodium salt solution is 0.5 mg / mL, 1 mg / mL, 1.5 mg / mL, 2.0 mg / mL, 2.5 mg / mL, 3.0 mg / mL, 3.5 mg / mL, 4.0 mg / mL, 4.5 mg / mL, 5.0 mg / mL, 5.5 mg / mL, 6.0 mg / mL, 6.5 mg / mL, 7.0 mg / mL, 7.5 mg / mL, 8.0 mg / mL, 8.5 mg / mL, 9.0 mg / mL, 9.5 mg / mL, etc.

[0037] In some embodiments of the present invention, the fourth intermediate is immersed in the rhodium salt solution, and the immersion time is controlled to be 10 - 120 min. Further, the immersion time is controlled to be 20 - 100 min. According to some specific aspects of the present invention, the immersion time is controlled to be 15 min, 25 min, 30 min, 35 min, 40 min, 45 min, 50 min, 55 min, 60 min, 65 min, 70 min, 75 min, 80 min, 85 min, 90 min, 95 min, 105 min, etc.

[0038] Another technical solution provided by the present invention: A catalytic material prepared by the preparation method of the above-mentioned catalytic material. Further, in the catalytic material, rhodium exists in the form of single atoms.

[0039] Another technical solution provided by the present invention: A preparation method of a catalyst, the preparation method of the catalyst includes:

[0040] Subjecting tungsten trioxide nanorods to a sulfidation reaction with sulfur powder to generate tungsten disulfide, and the tungsten disulfide is in a nanosheet structure;

[0041] Performing plasma etching on the tungsten disulfide to obtain a catalyst intermediate;

[0042] Dispersing the catalyst intermediate in a rhodium salt solution, separating, and drying to obtain the catalyst.

[0043] Another technical solution provided by the present invention: A catalyst prepared by the preparation method of the above-mentioned catalyst.

[0044] According to the present invention, in the catalyst, rhodium exists in the form of single atoms.

[0045] Another technical solution provided by the present invention: An electrode, the electrode comprising the catalytic material described above, or the catalyst described above.

[0046] Another technical solution provided by the present invention: An application of the catalytic material described above, or the catalyst described above, or the electrode described above in the process of electrolyzing water to produce hydrogen.

[0047] Further, the application is carried out in an acidic medium or a basic medium.

[0048] In some embodiments of the present invention, the acidic medium includes sulfuric acid or an aqueous sulfuric acid solution. The concentration of the aqueous sulfuric acid solution can be 0.1 - 2 mol / L.

[0049] In some embodiments of the present invention, the basic medium includes an aqueous solution of a basic hydroxide, and the aqueous solution of the basic hydroxide can be an aqueous solution of sodium hydroxide or potassium hydroxide, and its concentration can be 0.1 - 5 mol / L.

[0050] In the present invention, the specific reaction equipment, reagent brands, and purities are not particularly limited. For example, when preparing tungsten trioxide by hydrothermal reaction, the hydrothermal reaction apparatus includes available containers such as beakers, flasks, and reaction kettles; when preparing tungsten disulfide by sulfidation reaction, the sulfidation reaction apparatus includes devices such as tube furnaces, resistance furnaces, microwave heating furnaces, reaction kettles, and constant temperature reaction boxes; when manufacturing structural defects on the surface of tungsten disulfide by plasma etching, the plasma generating equipment includes, but is not limited to, plasma generators, plasma cleaners, plasma etchers, etc.; reagents involved in the reaction such as sodium tungstate, hydrochloric acid, oxalic acid, ammonium sulfate, rhodium chloride, etc. are not limited in brand and purity.

[0051] Due to the application of the above technical solution, the present invention has the following advantages compared with the prior art:

[0052] Based on the problem that the existing catalytic materials for hydrogen evolution have a trade-off between cost and hydrogen evolution efficiency, during a large number of experimental studies, it was unexpectedly found that when rhodium is loaded on tungsten disulfide nanosheets with a specific morphology in the form of single atoms or when rhodium is loaded on tungsten disulfide nanosheets with a specific morphology and a carbon conductor in the form of single atoms, the obtained catalytic material has excellent hydrogen evolution catalytic activity and can achieve excellent hydrogen production effects during the electrocatalytic hydrogen evolution process as an electrolytic water catalyst. In particular, excellent catalytic activity and catalytic stability can be exerted regardless of whether the electrolyte is acidic or alkaline. Through further research and analysis, the inventor believes that during the sulfidation process of tungsten trioxide with a one-dimensional rod-like structure, not only tungsten disulfide is generated, but also a ultrathin nanosheet structure is imparted to tungsten disulfide. At the same time, combined with plasma etching, not only a large number of defect site structures can be generated on the surface of tungsten disulfide, but also the basal plane sites of tungsten disulfide can be activated to a certain extent. When further combined with the adsorption of rhodium ions, these sites can serve as adsorption sites for rhodium particles and firmly confine rhodium particles, preventing the aggregation and crystallization of metal atoms and further enabling rhodium to exist in the form of single atoms, effectively increasing the number of active sites of the catalyst, activating the catalytically inert disulfide basal plane, improving the conductivity of the catalyst, and reducing the charge transfer resistance.

[0053] Experimental investigations show that the synthesized electrocatalyst exhibits good catalytic activity and stability under both acidic and alkaline conditions. For example, after 10,000 cycles of cyclic voltammetry scanning in the potential range of 0 to -0.2 V, the polarization curve still basically coincides with the initial polarization curve, and it is expected to achieve practical applications in the field of electrolytic water hydrogen production and has practical value. Description of the Drawings

[0054] Figure 1 It is the scanning electron microscope image of tungsten trioxide grown on carbon cloth in Example 1 of the present invention;

[0055] Figure 2 It is the scanning electron microscope image of the catalytic material prepared in Example 1 of the present invention;

[0056] Figure 3 It is the element distribution map of the catalytic material prepared in Example 1 of the present invention;

[0057] Figure 4 It is the X-ray diffraction spectrum of the catalytic material prepared in Example 1 of the present invention;

[0058] Figure 5 It is the test chart of the catalytic hydrogen evolution reaction performance of the catalytic material prepared in Example 1 of the present invention in an acidic medium;

[0059] Figure 6This is a test chart of the catalytic hydrogen evolution reaction performance of the catalytic material obtained in Example 1 of the present invention in an alkaline medium;

[0060] Figure 7 This is a polarization curve graph of the catalytic hydrogen evolution reaction stability test of the catalytic material obtained in Example 1 of the present invention in an acidic medium;

[0061] Figure 8 This is a polarization curve graph of the catalytic hydrogen evolution reaction stability test of the catalytic material obtained in Example 1 of the present invention in an alkaline medium. Detailed implementation manners

[0062] Currently, transition metal dichalcogenides have low costs and certain catalytic activities, and have received extensive attention in the field of catalysis. However, for general transition metal dichalcogenides such as tungsten disulfide, their active sites are mainly at the edge sites, and the basal plane is catalytically inert, which results in a large number of basal plane sites being unable to play a catalytic role; moreover, their semiconductor characteristics and the stacking of two-dimensional sheets inhibit the catalytic performance of tungsten disulfide for the hydrogen evolution reaction. Therefore, it is usually difficult to use low-cost transition metal dichalcogenides for the catalysis of the hydrogen evolution reaction.

[0063] Based on a large number of experimental studies, the inventors of the present invention unexpectedly found during the experiment: when rhodium is loaded on tungsten disulfide nanosheets with a specific morphology in the form of single atoms or rhodium is loaded on tungsten disulfide nanosheets with a specific morphology and carbon conductors in the form of single atoms, through the synergistic effect between components, not only the problem that the basal plane sites of conventional tungsten disulfide are catalytically inert is solved, enabling both the edge sites and basal plane sites of tungsten disulfide nanosheets to exhibit high catalytic performance and a hydrogen binding energy comparable to that of platinum metal, but also the negative effects of the semiconductor characteristics and stacking structure of conventional tungsten disulfide on the hydrogen evolution performance of tungsten disulfide can be inhibited. In particular, it also plays a role in inhibiting the high surface energy of single atoms, enabling their stable loading. Finally, the obtained catalytic material has excellent hydrogen evolution catalytic activity and can achieve excellent hydrogen production effects during the electrocatalytic hydrogen evolution process as an electrolyzed water catalyst.

[0064] The above scheme is further described below in conjunction with specific embodiments; it should be understood that these embodiments are used to illustrate the basic principles, main features, and advantages of the present invention, and the present invention is not limited by the scope of the following embodiments; the implementation conditions adopted in the embodiments can be further adjusted according to specific requirements, and the implementation conditions not specified are usually the conditions in conventional experiments.

[0065] Unless otherwise specified in the following embodiments, all raw materials are obtained through commercial purchases.

[0066] In the following, the carbon cloth used is treated as follows: The carbon cloth is ultrasonically treated in acetone, ethanol, and water for 30 minutes in sequence, and then placed in a vacuum drying oven and dried at 60°C. The dried carbon cloth is placed in concentrated nitric acid (mass concentration of 75%) and refluxed at 100°C for 2 hours; then the carbon cloth is soaked in deionized water to remove the residual nitric acid; finally, it is placed in a vacuum drying oven and dried at 60°C to obtain a carbon cloth with surface hydrophilicity.

[0067] Example 1:

[0068] This example provides a catalytic material and a preparation method thereof. The preparation method includes:

[0069] 1.8 g of sodium tungstate is dissolved in 50 mL of deionized water, and the pH value of the solution is adjusted to 1.2 with 3 mol / L dilute hydrochloric acid. 1.575 g of oxalic acid is added, and the solution is diluted to 125 mL with deionized water. Then, 20 mL of the above mixed solution is taken, and 1 g of ammonium sulfate is added. The cut carbon cloth (20 mm × 15 mm) is placed in the solution and ultrasonically treated for 5 minutes to completely soak the carbon cloth; then the carbon cloth is hung on a glass support, placed in a 25 mL reaction kettle, the above mixed solution is added, and it is kept at a constant temperature of 180°C for 12 hours. After the reaction is completed, the carbon cloth is taken out, rinsed with deionized water, and then dried. The dried carbon cloth is put into a tubular furnace, and in the air, it is heated from room temperature to 450°C and kept at a constant temperature for 1 hour, with a heating rate of 10°C / min. After the reaction is completed, it is naturally cooled to room temperature to obtain a carbon cloth loaded with tungsten trioxide.

[0070] Weigh 50 mg of sulfur powder and place it at the bottom of a quartz test tube. Then place the carbon cloth loaded with tungsten trioxide at the tube mouth end of the quartz test tube. Place the quartz test tube in the quartz tube of the tubular furnace. Under argon protection, it is heated from room temperature to 600°C at a rate of 10°C / min and kept at a constant temperature for 30 minutes. Before the temperature reaches 600°C, the sulfur powder in the quartz test tube is located in the area outside the heating area of the tubular furnace. When the temperature reaches 600°C, slowly slide the tubular furnace to move the sulfur powder into the heating area for reaction. After the reaction is completed, it is naturally cooled to room temperature to obtain a carbon cloth grown with tungsten disulfide.

[0071] The carbon cloth grown with tungsten disulfide is treated in argon plasma for 60 seconds, and the plasma etching power is set to 100% of the maximum power (specifically 150 W). Then it is soaked in an aqueous solution of rhodium trichloride at a concentration of 5 mg / mL for 30 minutes. Then the carbon cloth is taken out, the excess solution is blotted with absorbent paper, and it is placed in a vacuum drying oven for storage to obtain the catalytic material.

[0072] Example 2:

[0073] This example provides a catalytic material and a preparation method thereof. The preparation method includes:

[0074] 1.8 g of sodium tungstate was dissolved in 50 mL of deionized water. The pH value of the solution was adjusted to 1.2 with 3 mol / L dilute hydrochloric acid. 1.575 g of oxalic acid was added, and the solution was diluted to 125 mL with deionized water. Then, 20 mL of the above mixed solution was taken and 1 g of ammonium sulfate was added. The cut carbon cloth (20 mm × 15 mm) was placed in the solution and sonicated for 5 minutes to completely wet the carbon cloth. Then the carbon cloth was hung on a glass support, placed in a 25 mL reaction kettle, and the above mixed solution was added. It was kept at a constant temperature of 180 °C for 12 hours. After the reaction, the carbon cloth was taken out, rinsed with deionized water, and then dried. The dried carbon cloth was put into a tube furnace. In air, it was heated from room temperature to 600 °C at a heating rate of 10 °C / min and kept at a constant temperature for 1 hour. After the reaction, it was naturally cooled to room temperature to obtain carbon cloth loaded with tungsten trioxide.

[0075] 50 mg of sulfur powder was weighed and placed at the bottom of a quartz test tube. Then the carbon cloth loaded with tungsten trioxide was placed at the mouth end of the quartz test tube. The quartz test tube was placed in the quartz tube of the tube furnace. Under argon protection, it was heated from room temperature to 600 °C at a rate of 10 °C / min and kept at a constant temperature for 30 minutes. Before the temperature reached 600 °C, the sulfur powder in the quartz test tube was in the area outside the heating area of the tube furnace. When the temperature reached 600 °C, the tube furnace was slowly slid to move the sulfur powder into the heating area for reaction. After the reaction, it was naturally cooled to room temperature to obtain carbon cloth grown with tungsten disulfide.

[0076] The carbon cloth grown with tungsten disulfide was treated in argon plasma for 60 seconds, and the plasma etching power was set to 100% of the maximum power (specifically 150 W). Then it was soaked in an aqueous solution of rhodium trichloride at a concentration of 5 mg / mL for 30 min. Then the carbon cloth was taken out, the excess solution was blotted with blotting paper, and it was placed in a vacuum drying oven for storage to obtain the catalytic material.

[0077] Example 3:

[0078] This example provides a catalytic material and its preparation method. The preparation method includes:

[0079] 1.8 g of sodium tungstate was dissolved in 50 mL of deionized water. The pH value of the solution was adjusted to 1.2 with 3 mol / L dilute hydrochloric acid. 1.575 g of oxalic acid was added, and the solution was diluted to 125 mL with deionized water. Then, 20 mL of the above mixed solution was taken and 1 g of ammonium sulfate was added. The cut carbon cloth (20 mm × 15 mm) was placed in the solution and ultrasonicated for 5 minutes to make the carbon cloth fully wetted. Then the carbon cloth was hung on a glass support, placed in a 25 mL reaction kettle, and the above mixed solution was added. It was kept at a constant temperature of 180 °C for 12 hours. After the reaction ended, the carbon cloth was taken out, rinsed with deionized water, and then dried. The dried carbon cloth was put into a tubular furnace. In air, it was heated from room temperature to 450 °C at a heating rate of 10 °C / min and kept at a constant temperature for 1 hour. After the reaction ended, it was naturally cooled to room temperature to obtain carbon cloth loaded with tungsten trioxide.

[0080] 50 mg of sulfur powder was weighed and placed at the bottom of a quartz test tube. Then the carbon cloth loaded with tungsten trioxide was placed at the tube mouth end of the quartz test tube. The quartz test tube was placed in the quartz tube of the tubular furnace. Under argon protection, it was heated from room temperature to 450 °C at a rate of 10 °C / min and kept at a constant temperature for 30 minutes. Before the temperature reached 450 °C, the sulfur powder in the quartz test tube was located in the area outside the heating area of the tubular furnace. When the temperature reached 450 °C, the tubular furnace was slowly slid to move the sulfur powder into the heating area for reaction. After the reaction ended, it was naturally cooled to room temperature to obtain carbon cloth grown with tungsten disulfide.

[0081] The carbon cloth grown with tungsten disulfide was treated in argon plasma for 60 seconds, and the plasma etching power was set to 100% of the maximum power (specifically 150 W). Then it was soaked in an aqueous solution of rhodium trichloride with a concentration of 5 mg / mL for 30 min. Then the carbon cloth was taken out, the excess solution was blotted with blotting paper, and it was placed in a vacuum drying oven for storage to obtain the catalytic material.

[0082] Example 4:

[0083] This example provides a catalytic material and its preparation method. The preparation method includes:

[0084] 1.8 g of sodium tungstate was dissolved in 50 mL of deionized water. The pH value of the solution was adjusted to 1.2 with 3 mol / L dilute hydrochloric acid. 1.575 g of oxalic acid was added, and the solution was diluted to 125 mL with deionized water. Then, 20 mL of the above mixed solution was taken, and 1 g of ammonium sulfate was added. The cut carbon cloth (20 mm × 15 mm) was placed in the solution and ultrasonicated for 5 minutes to make the carbon cloth completely wetted; then the carbon cloth was hung on a glass support, placed in a 25 mL autoclave, and the above mixed solution was added. It was kept at a constant temperature of 180 °C for 12 hours. After the reaction was completed, the carbon cloth was taken out, rinsed with deionized water, and then dried. The dried carbon cloth was put into a tube furnace. In air, it was heated from room temperature to 450 °C and kept at a constant temperature for 1 hour with a heating rate of 10 °C / min. After the reaction was completed, it was naturally cooled to room temperature to obtain carbon cloth loaded with tungsten trioxide.

[0085] 50 mg of sulfur powder was weighed and placed at the bottom of a quartz test tube. Then the carbon cloth loaded with tungsten trioxide was placed at the mouth end of the quartz test tube. The quartz test tube was placed in the quartz tube of the tube furnace. Under argon protection, it was heated from room temperature to 750 °C at a rate of 10 °C / min and kept at a constant temperature for 30 minutes. Before the temperature reached 750 °C, the sulfur powder in the quartz test tube was located in the area outside the heating area of the tube furnace. When the temperature reached 750 °C, the tube furnace was slowly slid to move the sulfur powder into the heating area for reaction. After the reaction was completed, it was naturally cooled to room temperature to obtain carbon cloth grown with tungsten disulfide.

[0086] The carbon cloth grown with tungsten disulfide was treated in an argon plasma for 60 seconds, and the plasma etching power was set to 100% of the maximum power (specifically 150 W). Then it was soaked in an aqueous solution of rhodium trichloride at a concentration of 5 mg / mL for 30 min. Then the carbon cloth was taken out, the excess solution was blotted with blotting paper, and it was stored in a vacuum drying oven to obtain a catalytic material.

[0087] Example 5:

[0088] This example provides a catalytic material and its preparation method. The preparation method includes:

[0089] 1.8 g of sodium tungstate was dissolved in 50 mL of deionized water. The pH value of the solution was adjusted to 1.2 with 3 mol / L dilute hydrochloric acid. 1.575 g of oxalic acid was added, and the solution was diluted to 125 mL with deionized water. Then, 20 mL of the above mixed solution was taken, and 1 g of ammonium sulfate was added. The cut carbon cloth (20 mm × 15 mm) was placed in the solution and ultrasonicated for 5 minutes to completely wet the carbon cloth; then the carbon cloth was hung on a glass support, placed in a 25 mL reaction kettle, and the above mixed solution was added. It was kept at a constant temperature of 180 °C for 12 hours. After the reaction, the carbon cloth was taken out, rinsed with deionized water, and then dried. The dried carbon cloth was put into a tubular furnace. In air, it was heated from room temperature to 450 °C and kept at a constant temperature for 1 hour with a heating rate of 10 °C / min. After the reaction, it was naturally cooled to room temperature to obtain carbon cloth loaded with tungsten trioxide.

[0090] 50 mg of sulfur powder was weighed and placed at the bottom of a quartz test tube. Then the carbon cloth loaded with tungsten trioxide was placed at the mouth end of the quartz test tube. The quartz test tube was placed in the quartz tube of the tubular furnace. Under argon protection, it was heated from room temperature to 600 °C at a rate of 10 °C / min and kept at a constant temperature for 30 minutes. Before the temperature reached 600 °C, the sulfur powder in the quartz test tube was in the area outside the heating area of the tubular furnace. When the temperature reached 600 °C, the tubular furnace was slowly slid to move the sulfur powder into the heating area for reaction. After the reaction, it was naturally cooled to room temperature to obtain carbon cloth grown with tungsten disulfide.

[0091] The carbon cloth grown with tungsten disulfide was treated in argon plasma for 30 seconds, and the plasma etching power was set to 100% of the maximum power (specifically 150 W). Then it was soaked in an aqueous solution of rhodium trichloride at a concentration of 5 mg / mL for 30 min. Then the carbon cloth was taken out, the excess solution was blotted with blotting paper, and it was stored in a vacuum drying oven to obtain the catalytic material.

[0092] Example 6:

[0093] This example provides a catalytic material and its preparation method. The preparation method includes:

[0094] 1.8 g of sodium tungstate was dissolved in 50 mL of deionized water. The pH value of the solution was adjusted to 1.2 with 3 mol / L dilute hydrochloric acid. 1.575 g of oxalic acid was added, and the solution was diluted to 125 mL with deionized water. Then, 20 mL of the above mixed solution was taken and 1 g of ammonium sulfate was added. The cut carbon cloth (20 mm × 15 mm) was placed in the solution and ultrasonically treated for 5 minutes to completely wet the carbon cloth. Then the carbon cloth was hung on a glass support, placed in a 25 mL reaction kettle, and the above mixed solution was added. It was kept at a constant temperature of 180 °C for 12 hours. After the reaction ended, the carbon cloth was taken out, rinsed with deionized water, and then dried. The dried carbon cloth was put into a tube furnace. In air, it was heated from room temperature to 450 °C and kept at a constant temperature for 1 hour with a heating rate of 10 °C / min. After the reaction ended, it was naturally cooled to room temperature to obtain carbon cloth loaded with tungsten trioxide.

[0095] 50 mg of sulfur powder was weighed and placed at the bottom of a quartz test tube. Then the carbon cloth loaded with tungsten trioxide was placed at the tube mouth end of the quartz test tube. The quartz test tube was placed in the quartz tube of the tube furnace. Under argon protection, it was heated from room temperature to 600 °C at a rate of 10 °C / min and kept at a constant temperature for 30 minutes. Before the temperature reached 600 °C, the sulfur powder in the quartz test tube was in the area outside the heating area of the tube furnace. When the temperature reached 600 °C, the tube furnace was slowly slid to move the sulfur powder into the heating area for reaction. After the reaction ended, it was naturally cooled to room temperature to obtain carbon cloth grown with tungsten disulfide.

[0096] The carbon cloth grown with tungsten disulfide was treated in argon plasma for 120 seconds, and the plasma etching power was set to 100% of the maximum power (specifically 150 W). Then it was soaked in an aqueous solution of rhodium trichloride at a concentration of 5 mg / mL for 30 min. Then the carbon cloth was taken out, the excess solution was blotted with blotting paper, and it was placed in a vacuum drying oven for storage to obtain a catalytic material.

[0097] Example 7:

[0098] This example provides a catalytic material and a preparation method thereof. The preparation method includes:

[0099] 1.8 g of sodium tungstate was dissolved in 50 mL of deionized water. The pH value of the solution was adjusted to 1.2 with 3 mol / L dilute hydrochloric acid. 1.575 g of oxalic acid was added, and the solution was diluted to 125 mL with deionized water. Then, 20 mL of the above mixed solution was taken, and 1 g of ammonium sulfate was added. The cut carbon cloth (20 mm × 15 mm) was placed in the solution and sonicated for 5 minutes to completely wet the carbon cloth; then the carbon cloth was hung on a glass support, placed in a 25 mL autoclave, and the above mixed solution was added. It was kept at a constant temperature of 180 °C for 12 hours. After the reaction ended, the carbon cloth was taken out, rinsed with deionized water, and then dried. The dried carbon cloth was put into a tube furnace, and in air, it was heated from room temperature to 450 °C and kept at a constant temperature for 1 hour with a heating rate of 10 °C / min. After the reaction ended, it was naturally cooled to room temperature to obtain carbon cloth loaded with tungsten trioxide.

[0100] 50 mg of sulfur powder was weighed and placed at the bottom of a quartz test tube. Then the carbon cloth loaded with tungsten trioxide was placed at the mouth end of the quartz test tube. The quartz test tube was placed in the quartz tube of the tube furnace. Under argon protection, it was heated from room temperature to 600 °C at a rate of 10 °C / min and kept at a constant temperature for 30 minutes. Before the temperature reached 600 °C, the sulfur powder in the quartz test tube was in the area outside the heating area of the tube furnace. When the temperature reached 600 °C, the tube furnace was slowly slid to move the sulfur powder into the heating area for reaction. After the reaction ended, it was naturally cooled to room temperature to obtain carbon cloth grown with tungsten disulfide.

[0101] The carbon cloth grown with tungsten disulfide was treated in argon plasma for 60 seconds, and the plasma etching power was set to 50% of the maximum power (specifically 150 W). Then it was soaked in an aqueous solution of rhodium trichloride at 5 mg / mL for 30 min. Then the carbon cloth was taken out, the excess solution was blotted with blotting paper, and it was stored in a vacuum drying oven to obtain a catalytic material.

[0102] Example 8:

[0103] This example provides a catalytic material and its preparation method. The preparation method includes:

[0104] 1.8 g of sodium tungstate was dissolved in 50 mL of deionized water. The pH value of the solution was adjusted to 1.2 with 3 mol / L dilute hydrochloric acid. 1.575 g of oxalic acid was added, and the solution was diluted to 125 mL with deionized water. Then, 20 mL of the above mixed solution was taken and 1 g of ammonium sulfate was added. The cut carbon cloth (20 mm×15 mm) was placed in the solution and ultrasonicated for 5 minutes to make the carbon cloth fully wetted. Then the carbon cloth was hung on a glass support, placed in a 25 mL reaction kettle, and the above mixed solution was added. It was kept at a constant temperature of 180 °C for 12 hours. After the reaction, the carbon cloth was taken out, rinsed with deionized water, and then dried. The dried carbon cloth was put into a tube furnace. In air, it was heated from room temperature to 450 °C at a heating rate of 10 °C / min and kept at a constant temperature for 1 hour. After the reaction, it was naturally cooled to room temperature to obtain carbon cloth loaded with tungsten trioxide.

[0105] 50 mg of sulfur powder was weighed and placed at the bottom of a quartz test tube. Then the carbon cloth loaded with tungsten trioxide was placed at the mouth end of the quartz test tube. The quartz test tube was placed in the quartz tube of the tube furnace. Under argon protection, it was heated from room temperature to 600 °C at a rate of 10 °C / min and kept at a constant temperature for 30 minutes. Before the temperature reached 600 °C, the sulfur powder in the quartz test tube was in the area outside the heating area of the tube furnace. When the temperature reached 600 °C, the tube furnace was slowly slid to move the sulfur powder into the heating area for reaction. After the reaction, it was naturally cooled to room temperature to obtain carbon cloth grown with tungsten disulfide.

[0106] The carbon cloth grown with tungsten disulfide was treated in argon plasma for 60 seconds, and the plasma etching power was set to 75% of the maximum power (specifically 150 W). Then it was soaked in an aqueous solution of rhodium trichloride at a concentration of 5 mg / mL for 30 min. Then the carbon cloth was taken out, the excess solution was blotted with blotting paper, and it was placed in a vacuum drying oven for storage to obtain the catalytic material.

[0107] Example 9:

[0108] This example provides a catalytic material and its preparation method. The preparation method includes:

[0109] 1.8 g of sodium tungstate was dissolved in 50 mL of deionized water. The pH value of the solution was adjusted to 1.2 with 3 mol / L dilute hydrochloric acid. 1.575 g of oxalic acid was added, and the solution was diluted to 125 mL with deionized water. Then, 20 mL of the above mixed solution was taken, and 1 g of ammonium sulfate was added. The cut carbon cloth (20 mm×15 mm) was placed in the solution and ultrasonicated for 5 minutes to make the carbon cloth completely infiltrated. Then the carbon cloth was hung on a glass support, placed in a 25 mL reaction kettle, and the above mixed solution was added. It was kept at a constant temperature of 180 °C for 12 hours. After the reaction ended, the carbon cloth was taken out, rinsed with deionized water, and then dried. The dried carbon cloth was put into a tubular furnace. In air, it was heated from room temperature to 450 °C at a heating rate of 10 °C / min and kept at a constant temperature for 1 hour. After the reaction ended, it was naturally cooled to room temperature to obtain carbon cloth loaded with tungsten trioxide.

[0110] 50 mg of sulfur powder was weighed and placed at the bottom of a quartz test tube. Then the carbon cloth loaded with tungsten trioxide was placed at the mouth end of the quartz test tube. The quartz test tube was placed in the quartz tube of the tubular furnace. Under argon protection, it was heated from room temperature to 600 °C at a rate of 10 °C / min and kept at a constant temperature for 30 minutes. Before the temperature reached 600 °C, the sulfur powder in the quartz test tube was in the area outside the heating area of the tubular furnace. When the temperature reached 600 °C, the tubular furnace was slowly slid to move the sulfur powder into the heating area for reaction. After the reaction ended, it was naturally cooled to room temperature to obtain carbon cloth grown with tungsten disulfide.

[0111] The carbon cloth grown with tungsten disulfide was treated in air plasma for 60 seconds, and the plasma etching power was set to 100% of the maximum power (specifically 150 W). Then it was soaked in an aqueous solution of rhodium trichloride at a concentration of 5 mg / mL for 30 min. Then the carbon cloth was taken out, the excess solution was blotted with blotting paper, and it was placed in a vacuum drying oven for storage to obtain the catalytic material.

[0112] Example 10:

[0113] This example provides a catalytic material and its preparation method. The preparation method includes:

[0114] 1.8 g of sodium tungstate was dissolved in 50 mL of deionized water. The pH value of the solution was adjusted to 1.2 with 3 mol / L dilute hydrochloric acid. 1.575 g of oxalic acid was added, and the solution was diluted to 125 mL with deionized water. Then, 20 mL of the above mixed solution was taken and 1 g of ammonium sulfate was added. The cut carbon cloth (20 mm×15 mm) was placed in the solution and ultrasonicated for 5 minutes to make the carbon cloth completely wetted. Then the carbon cloth was hung on a glass support, placed in a 25 mL reaction kettle, and the above mixed solution was added. It was kept at a constant temperature of 180 °C for 12 hours. After the reaction, the carbon cloth was taken out, rinsed with deionized water, and then dried. The dried carbon cloth was put into a tube furnace. In air, it was heated from room temperature to 450 °C and kept at a constant temperature for 1 hour with a heating rate of 10 °C / min. After the reaction, it was naturally cooled to room temperature to obtain carbon cloth loaded with tungsten trioxide.

[0115] 50 mg of sulfur powder was weighed and placed at the bottom of a quartz test tube. Then the carbon cloth loaded with tungsten trioxide was placed at the mouth end of the quartz test tube. The quartz test tube was placed in the quartz tube of the tube furnace. Under argon protection, it was heated from room temperature to 600 °C at a rate of 10 °C / min and kept at a constant temperature for 30 minutes. Before the temperature reached 600 °C, the sulfur powder in the quartz test tube was in the area outside the heating area of the tube furnace. When the temperature reached 600 °C, the tube furnace was slowly slid to move the sulfur powder into the heating area for reaction. After the reaction, it was naturally cooled to room temperature to obtain carbon cloth grown with tungsten disulfide.

[0116] The carbon cloth grown with tungsten disulfide was treated in oxygen plasma for 60 seconds, and the plasma etching power was set to 100% of the maximum power (specifically 150 W). Then it was soaked in an aqueous solution of rhodium trichloride at 5 mg / mL for 30 min. Then the carbon cloth was taken out, the excess solution was blotted with blotting paper, and it was placed in a vacuum drying oven for storage to obtain the catalytic material.

[0117] Example 11:

[0118] This example provides a catalytic material and its preparation method. The preparation method includes:

[0119] 1.8 g of sodium tungstate was dissolved in 50 mL of deionized water. The pH value of the solution was adjusted to 1.2 with 3 mol / L dilute hydrochloric acid. 1.575 g of oxalic acid was added, and the solution was diluted to 125 mL with deionized water. Then, 20 mL of the above mixed solution was taken and 1 g of ammonium sulfate was added. The cut carbon cloth (20 mm × 15 mm) was placed in the solution and ultrasonicated for 5 minutes to completely wet the carbon cloth. Then the carbon cloth was hung on a glass support, placed in a 25 mL reaction kettle, and the above mixed solution was added. It was kept at a constant temperature of 180 °C for 12 hours. After the reaction, the carbon cloth was taken out, rinsed with deionized water, and then dried. The dried carbon cloth was put into a tube furnace. In air, it was heated from room temperature to 450 °C at a heating rate of 10 °C / min and kept at a constant temperature for 1 hour. After the reaction, it was naturally cooled to room temperature to obtain carbon cloth loaded with tungsten trioxide.

[0120] 50 mg of sulfur powder was weighed and placed at the bottom of a quartz test tube. Then the carbon cloth loaded with tungsten trioxide was placed at the mouth end of the quartz test tube. The quartz test tube was placed in the quartz tube of the tube furnace. Under argon protection, it was heated from room temperature to 600 °C at a rate of 10 °C / min and kept at a constant temperature for 30 minutes. Before the temperature reached 600 °C, the sulfur powder in the quartz test tube was in the area outside the heating area of the tube furnace. When the temperature reached 600 °C, the tube furnace was slowly slid to move the sulfur powder into the heating area for reaction. After the reaction, it was naturally cooled to room temperature to obtain carbon cloth grown with tungsten disulfide.

[0121] The carbon cloth grown with tungsten disulfide was treated in an argon plasma for 60 seconds, and the plasma etching power was set to 100% of the maximum power (specifically 150 W). Then it was soaked in an aqueous solution of rhodium trichloride at a concentration of 1 mg / mL for 30 min. Then the carbon cloth was taken out, the excess solution was blotted with blotting paper, and it was stored in a vacuum drying oven to obtain the catalytic material.

[0122] Example 12:

[0123] This example provides a catalytic material and a preparation method thereof. The preparation method includes:

[0124] 1.8 g of sodium tungstate was dissolved in 50 mL of deionized water. The pH value of the solution was adjusted to 1.2 with 3 mol / L dilute hydrochloric acid. 1.575 g of oxalic acid was added, and the solution was diluted to 125 mL with deionized water. Then, 20 mL of the above mixed solution was taken and 1 g of ammonium sulfate was added. The cut carbon cloth (20 mm×15 mm) was placed in the solution and ultrasonically treated for 5 minutes to completely wet the carbon cloth. Then the carbon cloth was hung on a glass support, placed in a 25 mL autoclave, and the above mixed solution was added. It was kept at a constant temperature of 180 °C for 12 hours. After the reaction, the carbon cloth was taken out, rinsed with deionized water, and then dried. The dried carbon cloth was put into a tubular furnace. In air, it was heated from room temperature to 450 °C and kept at a constant temperature for 1 hour with a heating rate of 10 °C / min. After the reaction, it was naturally cooled to room temperature to obtain carbon cloth loaded with tungsten trioxide.

[0125] Weigh 50 mg of sulfur powder and place it at the bottom of a quartz test tube. Then place the carbon cloth loaded with tungsten trioxide at the tube mouth end of the quartz test tube. Place the quartz test tube in the quartz tube of the tubular furnace. Under argon protection, it was heated from room temperature to 600 °C at a rate of 10 °C / min and kept at a constant temperature for 30 minutes. Before the temperature reached 600 °C, the sulfur powder in the quartz test tube was in the area outside the heating area of the tubular furnace. When the temperature reached 600 °C, the tubular furnace was slowly slid to move the sulfur powder into the heating area for reaction. After the reaction, it was naturally cooled to room temperature to obtain carbon cloth grown with tungsten disulfide.

[0126] The carbon cloth grown with tungsten disulfide was treated in an argon plasma for 60 seconds, and the plasma etching power was set to 100% of the maximum power (specifically 150 W). Then it was soaked in an aqueous solution of rhodium trichloride at 2 mg / mL for 30 min. Then the carbon cloth was taken out, the excess solution was blotted with blotting paper, and it was stored in a vacuum drying oven to obtain the catalytic material.

[0127] Comparative Example 1:

[0128] Preparation of WS2 / CC sample:

[0129] This example provides a catalytic material and its preparation method. The preparation method includes:

[0130] 1.8g sodium tungstate was dissolved in 50mL deionized water, and the pH value of the solution was adjusted to 1.2 with 3mol / L dilute hydrochloric acid, 1.575g oxalic acid was added, and the solution was diluted to 125mL with deionized water. Then, 20mL of the above mixed solution was taken and 1g of ammonium sulfate was added. The cut carbon cloth (20mm×15mm) was placed in the solution for 5 minutes for ultrasonic treatment to completely soak the carbon cloth; then the carbon cloth was hung on a glass bracket and placed in a 25mL reactor, and the above mixed solution was added. The mixture was kept at 180℃ for 12 hours. After the reaction, the carbon cloth was taken out, rinsed with deionized water, and then dried. The dried carbon cloth was placed in a tubular furnace, heated from room temperature to 450℃ in air, and kept at this temperature for 1 hour, with a heating rate of 10℃ / min. After the reaction, it was naturally cooled to room temperature to obtain a carbon cloth loaded with tungsten trioxide.

[0131] Weigh 50mg of sulfur powder and place it at the bottom of a quartz test tube. Then place the carbon loaded with tungsten trioxide at the mouth of the quartz test tube. Place the quartz test tube in a quartz tube of a tube furnace. Under argon protection, heat the temperature from room temperature to 600℃ at 10℃ / min and keep the temperature constant for 30 minutes. Before the temperature reaches 600℃, the sulfur powder in the quartz test tube is located outside the heating area of ​​the tube furnace. When the temperature reaches 600℃, slowly slide the tube furnace to move the sulfur powder into the heating area for reaction. After the reaction is completed, cool naturally to room temperature to obtain a carbon cloth with tungsten disulfide grown.

[0132] The carbon cloth on which tungsten disulfide was grown was treated in argon plasma for 60 seconds, and the plasma etching power was set to 100% of the maximum power (specifically 150 W) to obtain a catalytic material.

[0133] Performance Test:

[0134] The tungsten trioxide grown on the carbon cloth in Example 1 of the present invention was characterized by a scanning electron microscope. It can be seen that the morphology of the tungsten trioxide grown on the carbon cloth presents a one-dimensional rod-like structure. After the sulfurization reaction, Figure 2 As shown, it can be seen that the grown tungsten disulfide presents an ultra-thin nanosheet structure. This structural transformation should be determined by the "sandwich" crystal structure of tungsten disulfide.

[0135] The element distribution of the catalytic material (also called tungsten disulfide confined rhodium single atom catalyst) prepared in Example 1 is characterized, and its element distribution diagram is shown in Figure 3 As shown, sulfur (A), tungsten (B), and rhodium (C) elements are evenly distributed, indicating that rhodium metal is successfully confined in tungsten disulfide, and the X-ray diffraction spectrum (XRD, see Figure 4 ) No characteristic peaks of rhodium or rhodium oxide were found (at 2 θ =The diffraction peaks at 23° and 24° are the diffraction peaks of residual tungsten trioxide. Therefore, rhodium is confined within the defect sites of tungsten disulfide in the form of single atoms. It is believed that the formation of single atoms benefits from the presence of defect sites on the basal plane of tungsten disulfide. These defect sites can serve as adsorption sites for rhodium particles and firmly confine single rhodium atoms, preventing the aggregation and crystallization of metal atoms. Moreover, during the catalyst synthesis process, high-temperature processes are avoided, thus preventing the high-temperature aggregation of metals.

[0136] The catalytic hydrogen evolution reaction performance of the catalytic material (also known as tungsten disulfide-confined rhodium single-atom catalyst) prepared in Example 1 was tested in an acidic medium. The specific test process was as follows: An aqueous solution of 0.5 M H2SO4 (pH = 0.3) was prepared as the electrolyte, a graphite rod was used as the counter electrode, a saturated calomel electrode was used as the reference electrode, and the prepared catalytic material was used as the working electrode. Linear sweep curve tests were carried out on a Shanghai Chenhua electrochemical workstation (model CHI760) through a three-electrode system at a scan rate of 5 mV·s -1 。

[0137] The test results are shown in Figure 5 As shown, in an acidic medium (0.5 mol / L sulfuric acid aqueous solution), the overpotential for the catalytic hydrogen evolution reaction of the tungsten disulfide-confined rhodium single-atom catalyst (Rh@WS2 / CC) to reach a current density of 10 mA·cm -2 is only 110 mV, much lower than that of the WS2 / CC sample without bound rhodium single atoms (185 mV).

[0138] The catalytic hydrogen evolution reaction performance of the catalytic material (also known as tungsten disulfide-confined rhodium single-atom catalyst) prepared in Example 1 was tested in a basic medium. The specific test process was as follows: An aqueous solution of 1 M KOH (pH = 13.6) was prepared as the electrolyte, a graphite rod was used as the counter electrode, a saturated calomel electrode was used as the reference electrode, and the prepared catalytic material was used as the working electrode. Linear sweep curve tests were carried out on a Shanghai Chenhua electrochemical workstation (model CHI760) through a three-electrode system at a scan rate of 5 mV·s -1 。

[0139] The test results are shown in Figure 6 As shown, in a basic medium (1 mol / L potassium hydroxide aqueous solution), the overpotential for the catalytic hydrogen evolution reaction of the tungsten disulfide-confined rhodium single-atom catalyst to reach a current density of 10 mA·cm -2 is only 24 mV, not only much lower than that of the WS2 / CC sample without bound rhodium single atoms (285 mV), but also comparable to that of the commercial Pt / C catalyst.

[0140] The above performance characterization results indicate that the catalytic material prepared by the present invention can be applied to hydrogen production by electrolyzing water within a wide pH value range. Moreover, since the active component of the catalytic material grows in-situ on the conductive carrier, the combination between the active component of the catalytic material and the conductive carrier is very firm and not easily detached during the electrolysis of water. In addition, the confinement effect of tungsten disulfide defect sites on rhodium single atoms also enhances the stability of rhodium active sites. As Figure 7 shown in (corresponding to acidic medium: 0.5 mol / L sulfuric acid aqueous solution) and Figure 8 shown in (corresponding to alkaline medium: 1 mol / L potassium hydroxide aqueous solution), after 10,000 cycles of cyclic voltammetry scanning in the potential range of 0 to -0.2 V, the polarization curve basically coincides with the initial polarization curve, indicating that the catalytic material has excellent stability.

[0141] The above embodiments are only used to illustrate the technical concept and features of the present invention, and the purpose is to enable those skilled in the art to understand the content of the present invention and implement it accordingly. It should not be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit and essence of the present invention should be covered within the protection scope of the present invention.

[0142] In the ranges disclosed herein, the endpoints and any value are not limited to the exact range or value. These ranges or values should be understood to include values close to these ranges or values. For numerical ranges, the endpoint values of each range, between the endpoint values of each range and a single point value, and between single point values can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be regarded as specifically disclosed herein.

Claims

1. A method for preparing a catalytic material, characterized in that: The preparation method of the catalytic material comprises: Mixing an acidic tungstate aqueous solution, an organic acid and an ammonium salt to obtain a mixed solution; wherein the molar ratio of the tungstate, the organic acid and the ammonium salt is 1:2.5-3.5:1.0-1.8; Placing a conductive carrier in the mixed solution to perform a hydrothermal reaction to obtain a first intermediate, and then performing a thermal decomposition reaction on the first intermediate under heating conditions to generate a second intermediate, wherein the second intermediate includes the conductive carrier and tungsten trioxide nanorods supported on the conductive carrier; Allow the second intermediate to undergo a sulfurization reaction with sulfur powder to generate a third intermediate, and perform plasma etching on the third intermediate to obtain a fourth intermediate; wherein the amount of sulfur powder added is 5%-20% of the second intermediate; The fourth intermediate is immersed in a rhodium salt solution to prepare the catalytic material.

2. The method for preparing a catalytic material according to claim 1, characterized in that: The tungstate in the tungstate aqueous solution includes sodium tungstate; and / or, the organic acid includes oxalic acid; and / or, the ammonium salt includes ammonium sulfate.

3. The method for preparing a catalytic material according to claim 1, characterized in that: The reaction temperature of the hydrothermal reaction is controlled to be 160-200° C.; and / or, the reaction time of the hydrothermal reaction is controlled to be 8-20 hours.

4. The method for preparing a catalytic material according to claim 1, characterized in that: The reaction temperature of the thermal decomposition reaction is controlled to be 300-600°C; and / or, the reaction time of the thermal decomposition reaction is controlled to be 0.5-3h; and / or, the heating rate of the thermal decomposition reaction is controlled to be 1-20°C / min.

5. The method for preparing a catalytic material according to claim 1, characterized in that: The preparation method of the second intermediate comprises: dispersing the conductive carrier in an organic solvent and / or water, shaking, drying, placing the dried conductive carrier in nitric acid, heating, then washing, drying, and obtaining a pretreated conductive carrier; placing the pretreated conductive carrier in the mixed solution, performing a hydrothermal reaction, taking out the pretreated conductive carrier after the reaction, drying, and performing a thermal decomposition reaction under heating conditions; and / or, The conductive carrier is carbon cloth, carbon paper, foam copper or foam nickel.

6. The method for preparing a catalytic material according to claim 1, characterized in that: The reaction temperature of the vulcanization reaction is controlled to be 450-750° C.; and / or the vulcanization reaction is controlled to be carried out under a protective atmosphere, wherein the protective atmosphere is formed by introducing nitrogen and / or an inert gas.

7. The method for preparing a catalytic material according to claim 1, characterized in that: The preparation method of the third intermediate comprises: placing sulfur powder at the bottom end of a quartz test tube, then placing the second intermediate at the tube mouth end of the quartz test tube, placing the quartz test tube in a quartz tube of a tube furnace, heating the temperature from room temperature to a preset reaction temperature under the protection of a protective atmosphere, and keeping the temperature; wherein, before the temperature reaches the preset reaction temperature, the sulfur powder in the quartz test tube is located in an area outside the heating area of ​​the tube furnace, and when the temperature reaches the preset reaction temperature, the tube furnace is slid to move the sulfur powder into the heating area for reaction; and / or, The third intermediate includes tungsten disulfide in a nanosheet structure.

8. The method for preparing a catalytic material according to claim 1, characterized in that: The plasma etching time is controlled to be 10-180s; and / or the plasma used in the plasma etching includes at least one of argon plasma, oxygen plasma, and air plasma; and / or the working power of the plasma etching is 10% to 100% of the maximum power of the plasma generator.

9. The method for preparing a catalytic material according to claim 1, characterized in that: The rhodium salt solution includes a rhodium chloride aqueous solution; and / or the mass concentration of the rhodium salt solution is 0.5-10 mg / mL; and / or the immersion time is controlled to be 10-120 min.

10. A catalytic material prepared by the method for preparing a catalytic material according to any one of claims 1 to 9.

11. An electrode, characterized in that: The electrode comprises the catalytic material of claim 10.

12. Use of the catalytic material according to claim 10, or the electrode according to claim 11, in a process of producing hydrogen by electrolysis of water.

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