A triangular pyramid-shaped bismuth-lead bimetallic oxide electrocatalyst, its preparation method and application

Abstract

The present invention discloses a triangular pyramid-shaped bismuth-lead bimetallic oxide electrocatalyst, its preparation method and application. The preparation method of the electrocatalyst is to dissolve a bismuth source, urea and a structure inducer in an ethylene glycol solution, prepare a bismuth oxide precursor by a hydrothermal method, wash and dry it, and then calcine it at a high temperature in an air atmosphere to obtain a bismuth oxide product. Finally, the obtained bismuth oxide, a lead source and sodium hypochlorite are placed in an alkaline solution, and a triangular pyramid-shaped bismuth-lead bimetallic oxide electrocatalyst is obtained by a hydrothermal method. The bismuth-lead bimetallic oxide prepared by the present invention is in a triangular pyramid shape, and the unique exposed crystal plane can promote the generation of ozone, and has relatively high performance and Faraday efficiency in the process of preparing ozone by electrolyzing water, and the performance is higher than that of commercial PbO2 and pure Bi2O3; at the same time, the preparation process is simple to operate, the morphology of the catalyst is controllable, the raw materials are low in price, the performance is excellent and the stability is high, which greatly improves the efficiency of preparing ozone by electrolyzing water.

Description

Technical Field

[0001] The present invention belongs to the technical field of electrocatalysis, and particularly relates to a triangular pyramid-shaped bismuth-lead bimetallic oxide electrocatalyst, a preparation method thereof, and an application thereof. Background Art

[0002] With the normalization of the epidemic, the current disinfection products need to be improved urgently due to their own imperfections. As a gas with strong oxidizing properties, ozone is widely used in air purification, sewage treatment, sterilization and disinfection, etc., and is itself reduced to oxygen without the generation of secondary pollution, which makes ozone become a widely concerned disinfectant and has received extensive attention from people.

[0003] At present, the industrial preparation of ozone mainly includes ultraviolet irradiation method, high-voltage discharge method, and electrochemical method, etc. The ultraviolet irradiation method relies on high-frequency ultraviolet irradiation of dry oxygen to generate ozone. However, the ozone produced in this way requires high energy consumption and the concentration of the produced ozone is relatively low, which makes the ultraviolet irradiation method unable to be applied industrially and can only be applicable to a small amount of ozone conditions; while the corona discharge method requires a set of large production equipment, with high investment costs, and needs to generate ozone by high-voltage ionization of air. However, nitrogen oxides (NO x ) will be generated at the same time, which is a carcinogenic substance and is not conducive to the large-scale production and application of this method. Compared with the previous two methods, electrochemistry has attracted people's attention due to its advantages such as small equipment, simple operation, non-toxic and harmless.

[0004] Among them, the main anode catalysts for preparing ozone by electrolyzing water are lead dioxide, noble metal platinum, etc. However, in the electrolysis process, the problem of lead loss in lead dioxide leads to problems such as reaction deactivation and decreased stability, and lead is a substance with relatively high toxicity. These defects limit the further development of the electrolytic water ozone production technology. Therefore, it is of great research significance to develop an electrolytic water anode catalyst with high stability and high efficiency.

[0005] Due to its unique dual active centers and the coordination between them, bimetallic oxides are widely used in the fields of electrocatalysts, supercapacitors, etc. As an adjacent element to lead, bismuth has a similar electronic structure and energy band center to it, which provides potential possibilities for the interaction between the two. There is still no relevant report on the exploration of bismuth-lead bimetallic oxides in the preparation of ozone by electrolyzing water. Summary of the Invention

[0006] Aiming at the disadvantages and deficiencies of the current preparation of ozone, the purpose of the present invention is to provide a relatively efficient and stable triangular pyramid-shaped bismuth-lead bimetallic oxide electrocatalyst, a preparation method thereof, and an application thereof.

[0007] To achieve the above object, the following technical solutions are proposed:

[0008] A preparation method of a triangular pyramid-shaped bismuth-lead bimetallic oxide electrocatalyst, comprising the following steps:

[0009] 1) Dissolve a bismuth source, urea and a structure inducer in an ethylene glycol solution, stir at room temperature for 30 - 60 minutes, and then ultrasonically disperse for 10 - 30 minutes to obtain a milky white suspension;

[0010] 2) Transfer the milky white suspension obtained in step 1) to a polytetrafluoroethylene inner liner, then place it in a hydrothermal autoclave, perform hydrothermal treatment at 120 - 180 °C for 6 - 12 hours, then naturally cool the obtained solution to room temperature, filter and wash it 3 - 5 times each with deionized water and absolute ethanol, and then vacuum dry at 50 - 80 °C for 10 - 12 hours to obtain a bismuth oxide precursor material;

[0011] 3) Place the bismuth oxide precursor material obtained in step 2) in a tube furnace, and calcine it at 300 - 500 °C for 2 - 6 hours in an air atmosphere to obtain a bismuth oxide material;

[0012] 4) Dissolve the bismuth oxide material obtained in step 3), a lead source and a sodium hypochlorite solution in an inorganic base solution, stir at room temperature for 20 - 40 minutes, then transfer it to a polytetrafluoroethylene inner liner, perform hydrothermal treatment at 60 - 100 °C for 6 - 10 hours, cool it to room temperature, wash it 3 - 5 times each with deionized water and absolute ethanol, and place it in a vacuum dryer at 60 - 80 °C for 10 - 16 hours to obtain a bismuth-lead bimetallic oxide electrocatalyst.

[0013] Further, the bismuth source in step 1) is bismuth nitrate or bismuth chloride.

[0014] Further, the structure inducer in step 1) is polyvinylpyrrolidone or polyethylene glycol, the molecular weight of polyvinylpyrrolidone is 10000, and the molecular weight of polyethylene glycol is 4000.

[0015] Further, the mass ratio of the used bismuth source to the structure inducer is 4 - 5:1, and the mass ratio of the used bismuth source to the volume of ethylene glycol is 1:20 - 30, the mass unit is g, and the volume unit is mL.

[0016] Further, the lead source in step 4) is lead nitrate, lead acetate or lead chloride, preferably lead nitrate, and the mass ratio of bismuth oxide to the lead source is 4 - 5:1, preferably 4:1.

[0017] Further, the inorganic base in step 4) is potassium hydroxide or sodium hydroxide, the concentration is 1 - 2 mol / L, the mass concentration of the sodium hypochlorite is ≥5%, the volume ratio of the inorganic base solution to the sodium hypochlorite solution is 5 - 8:1, and the mass ratio of bismuth oxide to the volume of the inorganic base solution is 3 - 5:1, the mass unit is mg, and the volume unit is mL.

[0018] A triangular pyramid-shaped bismuth-lead bimetallic oxide electrocatalyst prepared by the above preparation method, with the atomic ratio of the two metals being bismuth:lead = 12:1.

[0019] An application of a triangular pyramid-shaped bismuth-lead bimetallic oxide electrocatalyst in the reaction of preparing ozone by electrolyzing water, comprising the following steps: controlling the current voltage through a galvanostat, reacting in an H-type electrolytic cell, keeping the water and gas unobstructed between the two electrode chambers, using a saturated potassium sulfate aqueous solution as the electrolyte, coating the triangular pyramid-shaped bismuth-lead bimetallic oxide electrocatalyst on carbon cloth as the working electrode in the anode chamber, using a platinum sheet as the counter electrode in the cathode chamber, controlling the reaction current at 150 mA, controlling the cell voltage between 3 - 10 V, and performing an electrocatalytic ozone production reaction to obtain an ozone product.

[0020] The beneficial effects of the present invention are as follows:

[0021] 1) The bismuth-lead bimetallic oxide of the present invention has a high active site exposure ratio and a unique molecular structure due to its unique triangular pyramid structure, and can achieve a large catalytic activity and current efficiency;

[0022] 2) In the bimetallic oxide of the present invention, the synergistic effect of bismuth and lead can promote the better adsorption of the O* intermediate during the electrocatalytic ozone production process, which is beneficial to the formation of ozone;

[0023] 3) During the preparation of the triangular pyramid-shaped bismuth-lead bimetallic oxide of the present invention, a specific morphology is formed through appropriate hydrothermal conditions, and Pb element doping is realized by reducing Pb(OH)2 with sodium hypochlorite under alkaline conditions, which is beneficial to the closer combination of the two metals;

[0024] 4) Compared with the problems of short life, easy generation of toxic substances and low activity of traditional commercial lead dioxide catalysts, the triangular pyramid-shaped bismuth-lead bimetallic oxide electrocatalyst of the present invention is simple to prepare, has high electrocatalytic activity, long life and good stability during the process of preparing ozone by electrolyzing water, and has broad application prospects. Description of the Drawings

[0025] Figure 1a Schematic scanning electron microscope image of the triangular pyramid-shaped bismuth-lead bimetallic oxide electrocatalyst prepared in Example 1 at 10 μm;

[0026] Figure 1b Schematic scanning electron microscope image of the triangular pyramid-shaped bismuth-lead bimetallic oxide electrocatalyst prepared in Example 1 at 5 μm;

[0027] Figure 2a Schematic scanning electron microscope image of the triangular pyramid-shaped bismuth-lead bimetallic oxide electrocatalyst prepared in Example 2 at 10 μm;

[0028] Figure 2b Scanning electron microscope schematic diagram of the triangular pyramid-shaped bismuth-lead bimetallic oxide electrocatalyst prepared in Example 2 at 5 μm;

[0029] Figure 3a Scanning electron microscope schematic diagram of the triangular pyramid-shaped bismuth-lead bimetallic oxide electrocatalyst prepared in Example 3 at 10 μm;

[0030] Figure 3b Transmission electron microscope schematic diagram of the triangular pyramid-shaped bismuth-lead bimetallic oxide electrocatalyst prepared in Example 3 at 5 μm;

[0031] Figure 4a Scanning electron microscope schematic diagram of the triangular pyramid-shaped bismuth-lead bimetallic oxide electrocatalyst prepared in Example 4 at 10 μm;

[0032] Figure 4b Transmission electron microscope schematic diagram of the triangular pyramid-shaped bismuth-lead bimetallic oxide electrocatalyst prepared in Example 4 at 5 μm;

[0033] Figure 5 Comparison chart of real-time detection data of ozone concentration generated when the triangular pyramid-shaped bismuth-lead bimetallic oxide electrocatalyst prepared in Examples 1-4 and Comparative Sample 5 are used for electrocatalytic ozone preparation. Detailed implementation manners

[0034] The present invention will be further described below in conjunction with the accompanying drawings of the specification and specific embodiments, but the protection scope of the present invention is not limited thereto.

[0035] Example 1: Preparation of a triangular pyramid-shaped bismuth-lead bimetallic oxide electrocatalyst, including the following steps:

[0036] 1) Dissolve 1.26 g of bismuth chloride, 0.54 g of urea and 300 mg of polyvinylpyrrolidone with a molecular weight of 10,000 in 25 mL of ethylene glycol solution. After stirring at room temperature for 30 minutes, ultrasonically disperse for 10 minutes to obtain a milky white suspension;

[0037] 2) Transfer the milky white suspension obtained in step 1) to a polytetrafluoroethylene inner liner, hydrothermally treat at 120 °C for 6 hours, then naturally cool the obtained solution to room temperature, filter and wash 3 times each with deionized water and absolute ethanol, and then vacuum dry at 50 °C for 10 h to obtain a bismuth oxide precursor material;

[0038] 3) Place the bismuth oxide precursor material obtained in step 2) in a tubular furnace, calcine at 300 °C in an air atmosphere for 2 hours to obtain bismuth oxide;

[0039] 4) Dissolve 80 mg of bismuth oxide, 16 mg of lead chloride, and 2.5 mL of sodium hypochlorite solution with a mass concentration of 5.2% in 20 mL of 1 mol / L sodium hydroxide solution. After stirring at room temperature for 20 minutes, transfer it to a polytetrafluoroethylene inner lining and hydrothermally treat it at 60 °C for 10 hours. After cooling it to room temperature, wash it 3 times with deionized water and anhydrous ethanol respectively, and place it in a vacuum dryer at 60 °C for 10 hours to obtain a bismuth-lead bimetallic oxide electrocatalyst.

[0040] The schematic diagrams of the scanning electron microscope of the triangular pyramid-shaped bismuth-lead bimetallic oxide electrocatalyst obtained in Example 1 at 10 μm and 5 μm are as Figure 1a and Figure 1b shown. It can be seen from it that the prepared catalyst has a good triangular pyramid morphology, can expose the unique (310) crystal plane, which is beneficial to the exposure of active sites. At the same time, the unique synergistic effect between bismuth and lead on this crystal plane is beneficial to the generation of ozone under the lattice oxygen mechanism, making the electrolysis water reaction easier to proceed.

[0041] The triangular pyramid-shaped bismuth-lead bimetallic oxide electrocatalyst of Example 1 is used for the reaction of preparing ozone by electrolyzing water:

[0042] Weigh 10 mg of the prepared triangular pyramid-shaped bismuth-lead bimetallic oxide electrocatalyst powder, mix it with 1000 μL of ethanol and 200 μL of Nafion solution (the mass concentration of the Nafion solution is 5%), and ultrasonically treat it for 30 hours to make the catalyst completely dispersed in the mixed solution of ethanol and Nafion solution to obtain a uniform catalyst slurry. Cut the carbon cloth into a size of about 3 cm × 2 cm, and uniformly drop all the catalyst slurry on the carbon cloth. After drying, it is used as the working electrode (that is, the triangular pyramid-shaped bismuth-lead bimetallic oxide electrocatalyst is coated on the carbon cloth as the working electrode).

[0043] Control the current and voltage of the reaction through a galvanostat. Use an H-type electrolytic cell as the reaction vessel. In the anode chamber, use the triangular pyramid-shaped bismuth-lead bimetallic oxide electrocatalyst coated on the carbon cloth as the working electrode; in the cathode chamber, use a platinum sheet as the counter electrode, and the electrolyte is a saturated potassium sulfate solution. One gas outlet of the H-type electrolytic cell is connected to an ozone detector to monitor the generated amount of ozone in real time, objectively reflecting the catalytic performance of the catalyst. During the whole process of electrocatalytic ozone preparation, the reaction current is controlled at 150 mA, the cell voltage is controlled between 3 - 10 V, and the reaction time is 180 minutes. As the reaction proceeds, the ozone concentration will increase significantly. After 180 minutes of reaction, the ozone concentration can reach 3498 ppb.

[0044] To verify the catalytic stability of the triangular pyramid-shaped bismuth-lead bimetallic oxide electrocatalyst prepared in Example 1, after the working electrode in the anode chamber after the above reaction was placed for 24 hours, a repeated electrocatalytic ozone preparation reaction experiment was carried out (the working electrode in the anode chamber was placed for 24 h each time after use and then used for the next time). In the experiment of the first repetition of the reaction of the working electrode in the anode chamber, the ozone concentration after the reaction reached 3 h could reach 3475 ppb. In the experiment of the second repetition of the reaction of the working electrode in the anode chamber, the ozone concentration after the reaction reached 3 h could reach 3391 ppb. In the experiment of the third repetition of the reaction of the working electrode in the anode chamber, the ozone concentration after the reaction reached 3 h could reach 3315 ppb. It can be seen that during the repeated use of the working electrode in the anode chamber, the electrocatalytic effect was basically not weakened, indicating that the triangular pyramid-shaped bismuth-lead bimetallic oxide electrocatalyst prepared in Example 1 has good stability.

[0045] Example 2: Preparation of a triangular pyramid-shaped bismuth-lead bimetallic oxide, comprising the following steps:

[0046] 1) Dissolve 1.5 g of bismuth nitrate, 0.54 g of urea and 300 mg of polyethylene glycol with a molecular weight of 4000 in 30 mL of ethylene glycol solution, stir at room temperature for 60 minutes, and then ultrasonically disperse for 30 minutes to obtain a milky white suspension;

[0047] 2) Transfer the milky white suspension obtained in step 1) to a polytetrafluoroethylene liner, hydrothermally treat at 140 °C for 8 hours, then naturally cool the obtained solution to room temperature, filter and wash 3 times with deionized water and absolute ethanol respectively, and then vacuum dry at 70 °C for 12 h to obtain a bismuth oxide precursor material;

[0048] 3) Place the bismuth oxide precursor material obtained in step 2) in a tubular furnace, calcine at 350 °C in an air atmosphere for 3 hours to obtain bismuth oxide;

[0049] 4) Dissolve 100 mg of bismuth oxide, 20 mg of lead nitrate and 5 mL of sodium hypochlorite solution with a mass concentration of 5.2% in 30 mL of 1.5 mol / L potassium hydroxide solution, stir at room temperature for 30 minutes, then transfer it to a polytetrafluoroethylene liner, hydrothermally treat at 70 °C for 8 hours, cool it to room temperature, wash 3 times with deionized water and absolute ethanol respectively, and place it in a vacuum dryer at 70 °C for 12 hours to obtain a bismuth-lead bimetallic oxide electrocatalyst.

[0050] The schematic diagrams of the scanning electron microscope of the triangular pyramid-shaped bismuth-lead bimetallic oxide electrocatalyst obtained in Example 2 at 10 μm and at 5 μm are as Figure 2a and Figure 2bAs shown, it can be seen that the prepared catalyst has a good triangular pyramid morphology.

[0051] The triangular pyramid-shaped bismuth-lead bimetallic oxide electrocatalyst of Example 2 is used for the reaction of preparing ozone by electrolyzing water:

[0052] During the preparation process of the electrode anode using the catalyst prepared in Example 1, the catalyst of Example 1 added was replaced with the catalyst prepared in Example 2 of the same mass, and the other operating conditions were the same as those in the experiment of preparing ozone by electrolyzing water in Example 1. The variation relationship of the ozone concentration generated by the electrolytic water catalytic reaction with the reaction time is as Figure 5 shown. It can be seen that after 200 minutes, the concentration of gaseous ozone generated reached 3094 ppb, and the prepared triangular pyramid-shaped bismuth-lead bimetallic oxide has good ozone-producing performance.

[0053] Example 3: Preparation of a triangular pyramid-shaped bismuth-lead bimetallic oxide, including the following steps:

[0054] 1) Dissolve 1.26 g of bismuth chloride, 0.54 g of urea and 300 mg of polyvinylpyrrolidone with a molecular weight of 10,000 in 35 mL of ethylene glycol solution. After stirring at room temperature for 60 minutes, ultrasonically disperse for 30 minutes to obtain a milky white suspension;

[0055] 2) Transfer the milky white suspension obtained in step 1) to a polytetrafluoroethylene inner liner, hydrothermally treat at 160 °C for 10 hours. After the obtained solution is naturally cooled to room temperature, filter and wash 5 times each with deionized water and absolute ethanol, and then vacuum dry at 80 °C for 10 hours to obtain a bismuth oxide precursor material;

[0056] 3) Place the bismuth oxide precursor material obtained in step 2) in a tubular furnace, calcine at 400 °C in an air atmosphere for 4 hours to obtain bismuth oxide;

[0057] 4) Dissolve 120 mg of bismuth oxide, 30 mg of lead acetate and 5 mL of sodium hypochlorite solution with a concentration of 5.2% in 35 mL of 1.5 mol / L potassium hydroxide solution. After stirring at room temperature for 30 minutes, transfer it to a polytetrafluoroethylene inner liner, hydrothermally treat at 80 °C for 9 hours. After cooling to room temperature, wash 5 times each with deionized water and absolute ethanol, and place it in a vacuum dryer at 80 °C for 14 hours to obtain a bismuth-lead bimetallic oxide electrocatalyst.

[0058] The schematic diagrams of the scanning electron microscope of the triangular pyramid-shaped bismuth-lead bimetallic oxide electrocatalyst obtained in Example 3 at 10 μm and the scanning electron microscope schematic diagram at 5 μm are as Figure 3a and Figure 3b shown. It can be seen from it that the prepared catalyst has a good triangular pyramid morphology.

[0059] The triangular pyramid-shaped bismuth-lead bimetallic oxide electrocatalyst of Example 3 is used for the reaction of preparing ozone by electrolyzing water:

[0060] During the preparation process of the electrode anode using the catalyst prepared in Example 1, replace the catalyst of Example 1 added with the catalyst prepared in Example 3 with the same mass, and the other operating conditions are the same as those in the experimental process of preparing ozone by electrolyzing water in Example 1. The variation relationship of the ozone concentration generated by the electrolytic water catalytic reaction with the reaction time is as follows Figure 5 shown. It can be seen that after 180 minutes, the concentration of gaseous ozone generated reaches 2865 ppb, and the prepared triangular pyramid-shaped bismuth-lead bimetallic oxide has good ozone-producing performance.

[0061] Example 4: Preparation of a triangular pyramid-shaped bismuth-lead bimetallic oxide, including the following steps:

[0062] 1) Dissolve 1.5 g of bismuth nitrate, 0.54 g of urea and 0.3 g of polyethylene glycol with a molecular weight of 4000 in 35 mL of ethylene glycol solution. After stirring at room temperature for 40 minutes, ultrasonically disperse for 20 minutes to obtain a milky white suspension;

[0063] 2) Transfer the milky white suspension obtained in step 1) to a polytetrafluoroethylene inner liner, perform hydrothermal treatment at 180 °C for 12 hours. After the obtained solution is naturally cooled to room temperature, filter and wash it 3 times each with deionized water and absolute ethanol, and then vacuum dry at 80 °C for 12 h to obtain a bismuth oxide precursor material;

[0064] 3) Place the bismuth oxide precursor material obtained in step 2) in a tube furnace, calcine at 500 °C in an air atmosphere for 6 hours to obtain bismuth oxide;

[0065] 4) Dissolve 150 mg of bismuth oxide, 30 mg of lead nitrate and 5 mL of sodium hypochlorite with a concentration of 5.2% in 40 mL of 2 mol / L sodium hydroxide solution. After stirring at room temperature for 30 minutes, transfer it to a polytetrafluoroethylene inner liner, perform hydrothermal treatment at 100 °C for 10 hours. After cooling it to room temperature, wash it 5 times each with deionized water and absolute ethanol, and place it in a vacuum dryer at 80 °C for 16 hours to obtain a bismuth-lead bimetallic oxide electrocatalyst.

[0066] The schematic diagrams of the scanning electron microscope of the triangular pyramid-shaped bismuth-lead bimetallic oxide electrocatalyst obtained in Example 4 at 10 μm and the scanning electron microscope schematic diagram at 5 μm are as follows Figure 4a and Figure 4b shown. From this, it can be seen that the prepared catalyst has a better triangular pyramid morphology.

[0067] The triangular pyramid-shaped bismuth-lead bimetallic oxide electrocatalyst of Example 4 is used for the reaction of preparing ozone by electrolyzing water:

[0068] During the preparation process of the electrode anode using the catalyst prepared in Example 1, the catalyst of Example 1 added was replaced with the catalyst of Example 3 with the same mass, and the remaining operating conditions were the same as those in the experiment of preparing ozone by electrolyzing water in Example 1. The variation relationship of the ozone concentration generated by the electrolytic water catalytic reaction with the reaction time is as Figure 5 shown. It can be seen that after 180 minutes, the concentration of gaseous ozone generated reached 3832 ppb, and the prepared triangular pyramid-shaped bismuth-lead bimetallic oxide has good ozone-producing performance.

[0069] Comparative Example 5: Prepare a commercial lead dioxide catalyst and use it for electrocatalytic ozone preparation

[0070] Weigh 16 mg of commercial lead dioxide catalyst (purchased from Hongzuo Reagent Network), mix it with 1000 μL of ethanol and 200 μL of Nafion solution (the mass concentration of the Nafion solution is 5%), and ultrasonicate for 1 hour to completely disperse the commercial lead dioxide catalyst in the mixed solution of ethanol and Nafion solution, obtaining a uniform catalyst slurry. Cut the carbon cloth into a size of about 3 cm × 2 cm, and uniformly drop all the dispersed catalyst slurry on the carbon cloth. After drying, it is used as the working electrode (that is, the material with Pt / C catalyst coated on the carbon cloth is used as the working electrode).

[0071] The voltage and current are controlled by a constant current instrument, and the reaction is carried out using an H-type electrolytic cell. In the anodic chamber, the material with commercial lead dioxide catalyst coated on the carbon cloth is used as the working electrode; in the cathodic chamber, a platinum sheet is used as the counter electrode, and the electrolyte is a saturated potassium sulfate aqueous solution. One end of the H-type electrolytic cell is connected to an ozone detector to detect the generation of ozone in real time. During the electrocatalytic ozone production reaction, the current is controlled at 150 mA, the cell voltage is controlled between 3 - 10 V, and the reaction time is 180 minutes. As the reaction progresses, the real-time detection graph of the ozone concentration obtained by the electrocatalytic reaction is as Figure 5 shown. As can be seen from Figure 5 the above, as the reaction progresses, the ozone concentration gradually increases, and the ozone concentration when the reaction time reaches 180 minutes can reach 2043 ppb. The electrocatalysts obtained in each example of the present invention have high electrocatalytic activity, long lifespan, and good stability.

[0072] The content described in this specification is only a list of the implementation forms of the inventive concept, and the protection scope of the present invention should not be regarded as limited to the specific forms stated in the embodiments.

Claims

1. A preparation method of a triangular pyramid-shaped bismuth-lead bimetallic oxide electrocatalyst, characterized in that It includes the following steps: 1) Dissolve the bismuth source, urea and structure inducer in ethylene glycol solution. After stirring at room temperature for 30 - 60 minutes, perform ultrasonic dispersion for 10 - 30 minutes to obtain a milky white suspension; 2) Transfer the milky white suspension obtained in step 1) to a polytetrafluoroethylene inner liner, then place it in a hydrothermal reactor, perform hydrothermal treatment at 120 - 180 °C for 6 - 12 hours. After the obtained solution is naturally cooled to room temperature, filter and wash it 3 - 5 times each with deionized water and absolute ethanol, and then vacuum dry it at 50 - 80 °C for 10 - 12 hours to obtain a bismuth oxide precursor material; 3) Place the bismuth oxide precursor material obtained in step 2) in a tubular furnace, and calcine it at 300 - 500 °C for 2 - 6 hours in an air atmosphere to obtain a bismuth oxide material; 4) Dissolve the bismuth oxide material, lead source and sodium hypochlorite solution obtained in step 3) in an inorganic base solution. After stirring at room temperature for 20 - 40 minutes, transfer it to a polytetrafluoroethylene inner liner, perform hydrothermal treatment at 60 - 100 °C for 6 - 10 hours. After cooling it to room temperature, wash it 3 - 5 times each with deionized water and absolute ethanol, and place it in a vacuum dryer at 60 - 80 °C for 10 - 16 hours to obtain a bismuth-lead bimetallic oxide electrocatalyst; The mass ratio of the used bismuth source to the structure inducer is 4 - 5:1, and the mass ratio of the used bismuth source to the volume of ethylene glycol is 1:20 - 30, with the mass unit being g and the volume unit being mL; The structure inducer described in step 1) is polyvinylpyrrolidone or polyethylene glycol. The molecular weight of polyvinylpyrrolidone is 10,000, and the molecular weight of polyethylene glycol is 4,000.

2. The preparation method of a triangular pyramid-shaped bismuth-lead bimetallic oxide electrocatalyst according to claim 1, characterized in that The bismuth source in step 1) is bismuth nitrate or bismuth chloride.

3. The preparation method of a triangular pyramid-shaped bismuth-lead bimetallic oxide electrocatalyst according to claim 1, wherein The lead source in step 4) is lead nitrate, lead acetate or lead chloride, and the mass ratio of bismuth oxide to the lead source is 4 - 5:

1.

4. The preparation method of a triangular pyramid-shaped bismuth-lead bimetallic oxide electrocatalyst according to claim 1, wherein The inorganic base in step 4) is potassium hydroxide or sodium hydroxide, the solution concentration is 1 - 2 mol / L, the mass concentration of the sodium hypochlorite is ≥5%, the volume ratio of the inorganic base solution to the sodium hypochlorite solution is 5 - 8:1, and the mass ratio of bismuth oxide to the volume of the inorganic base solution is 3 - 5:1, with the mass unit being mg and the volume unit being mL.

5. A triangular pyramid-shaped bismuth-lead bimetallic oxide electrocatalyst prepared by the preparation method according to any one of claims 1-4, characterized in that The atomic ratio of the two metals is bismuth:lead = 12:

1.

6. Application of the triangular pyramid-shaped bismuth-lead bimetallic oxide electrocatalyst as described in claim 5 in the reaction of preparing ozone by electrolyzing water.

7. The application according to claim 6, characterized in that It includes the following steps: Control the current and voltage through a galvanostat, react in an H-type electrolytic cell, keep the water and gas unobstructed between the two electrode chambers, use a saturated potassium sulfate aqueous solution as the electrolyte, coat the triangular pyramid-shaped bismuth-lead bimetallic oxide electrocatalyst on carbon cloth as the working electrode in the anode chamber, use a platinum sheet as the counter electrode in the cathode chamber, control the reaction current at 150 mA, control the cell voltage between 3 - 10 V, and perform an electrocatalytic reaction to produce ozone to obtain an ozone product.

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