Preparation method and application of oxygen evolution catalyst based on jet plasma treatment

Abstract

The invention belongs to but not limited to the technical field of catalysts, and discloses a preparation method and application of an oxygen evolution catalyst based on jet plasma treatment.The preparation method comprises the steps that a certain amount of lead oxide, ferrous sulfate, nickel nitrate, thiourea and graphene are weighed and added into 10 mL of deionized water; performing ultrasonic treatment at room temperature for 30 minutes to obtain a mixed solution; freezing and drying for 24 hours to obtain a powder sample; weighing a sample, uniformly spreading the sample in a flat-bottom glass container, and placing the flat-bottom glass container in a jet plasma discharge plume area; cutting the foamed nickel, respectively carrying out ultrasonic treatment for 30 minutes by using a 3 mol / L hydrochloric acid solution, ethanol and deionized water, and standing for 12 hours at room temperature; weighing a catalyst, adding the catalyst into ethanol and a 5% wt Nafion solution, and carrying out ultrasonic treatment for 30 minutes to uniformly mix the ethanol and the Nafion solution; and uniformly coating the treated foamed nickel with the solution, and standing at room temperature for 12 hours to obtain the Pb-NiFe / G / NF catalyst.

Description

Technical Field

[0001] The present invention belongs to but is not limited to the field of catalyst technology, and in particular relates to a preparation method and application of an oxygen evolution catalyst based on jet plasma treatment. Background Art

[0002] The depletion of traditional fossil resources has triggered energy and environmental crises, and the transformation of energy structure is imminent. Hydrogen energy is a new energy source with high calorific value and no pollution, which has wide applications in many fields. Producing hydrogen through water electrolysis is an effective way to alleviate the energy crisis and reduce carbon emissions, but the anodic oxygen evolution reaction (OER) in water electrolysis involves a complex four-electron transfer process with a high overpotential, which limits the efficiency of hydrogen production. For a long time, water electrolysis catalysts have been mainly precious metal oxides such as Ir and Ru, which have high reserves and low costs, making it difficult to achieve large-scale application. Therefore, it is imperative to research and develop new and efficient oxygen evolution reaction catalysts.

[0003] Traditional synthesis methods of oxygen evolution catalysts, such as high-temperature solid-phase reaction, wet chemical method and thermal decomposition method, usually require high temperature and high pressure conditions, huge energy consumption, and complex reaction process, and it is difficult to control the morphology and size of the catalyst. These methods easily lead to agglomeration of catalyst particles, reduction of active sites, and thus reduce catalytic efficiency. In addition, lead-containing catalysts prepared by traditional methods have poor stability during recycling and are prone to structural changes, resulting in performance degradation.

[0004] As an advanced material preparation method, jet plasma technology has demonstrated unique advantages in the field of nanomaterial synthesis. For example, plasma-assisted chemical vapor deposition (PACVD) and plasma spraying technology have been used to prepare high-performance catalytic materials. Using jet plasma technology, high-energy active particles can be generated at lower temperatures, allowing reactants to quickly form nanoscale catalyst particles. This method can not only effectively control the particle size and morphology of the catalyst, increase the specific surface area and the number of active sites, but also improve the dispersion and stability of the catalyst.

[0005] The oxygen evolution catalyst prepared by jet plasma technology has higher catalytic activity and longer service life. This is because the catalyst generated in the jet plasma environment has a unique surface structure and electronic properties, which are conducive to the adsorption and activation of oxygen molecules and promote the oxygen evolution reaction. In addition, the catalyst prepared by the jet plasma method can be regulated in composition, and other elements can be introduced for doping to further improve the catalytic performance. For example, doping with transition metals such as cobalt and nickel can improve the conductivity and stability of the catalyst.

[0006] In contrast, the main problems of traditional technologies include high energy consumption, complex processes, product inhomogeneity and environmental pollution. High temperature conditions not only increase energy consumption, but also cause safety hazards. The complex reaction process makes the catalyst difficult to prepare repeatedly, affecting industrial applications. Some wet chemical methods involve toxic reagents, which bring environmental and health risks. Summary of the invention

[0007] In view of the problems existing in the prior art, the present invention provides a preparation method and application of an oxygen evolution catalyst based on jet plasma treatment.

[0008] The present invention is achieved by a method for preparing an oxygen evolution catalyst based on jet plasma treatment, comprising the following steps:

[0009] Step 1, weigh a certain amount of lead oxide, ferrous sulfate, nickel nitrate, thiourea, and graphene, add them to 10 mL of deionized water; perform ultrasonic treatment for 30 minutes at room temperature to obtain a mixed solution;

[0010] Step 2, freeze-drying the mixed solution of step 1 for 24 hours to obtain a powder sample;

[0011] Step 3, weigh the sample obtained in step 2 and spread it evenly in a flat-bottomed glass container, and place the flat-bottomed glass container in the discharge plume area of ​​the jet plasma;

[0012] Step 4: cutting the nickel foam, ultrasonically treating with 3 mol / L hydrochloric acid solution, ethanol and deionized water for 30 min respectively, and standing at room temperature for 12 h;

[0013] Step 5, weighing the catalyst prepared in step 3, adding it to ethanol and 5%wt Nafion solution, and ultrasonically treating for 30 minutes to make it evenly mixed;

[0014] Step six, evenly apply the solution in step five to the nickel foam treated in step four, and let it stand at room temperature for 12 hours to obtain a Pb-NiFe / G / NF catalyst.

[0015] Furthermore, in step 1, lead oxide is 223.2 mg, ferrous sulfate is 278 mg, nickel nitrate is 290 mg, thiourea is 304.5 mg, and graphene is 100 mg.

[0016] Furthermore, the freeze-drying conditions in step 2 are -80°C and 20Pa.

[0017] Furthermore, in step three, the discharge gas is argon, the gas flow rate is 50 sccm, the RF discharge power is 100 W, and the processing time is 45 min.

[0018] Furthermore, in step 4, the size of the nickel foam is 1 cm×1 cm×1 mm.

[0019] Furthermore, in step five, 10 mg of the catalyst was added to 400 μL of ethanol and 40 μL of 5% wt Nafion solution.

[0020] Another object of the present invention is to provide an oxygen evolution catalyst based on jet plasma treatment prepared by a method for preparing an oxygen evolution catalyst based on jet plasma treatment.

[0021] Another object of the present invention is to provide an application of an oxygen evolution catalyst based on jet plasma treatment in water electrolysis catalysis.

[0022] Another object of the present invention is to provide an application of an oxygen evolution catalyst based on jet plasma treatment in air battery catalysis.

[0023] In combination with the above technical solutions and the technical problems solved, the advantages and positive effects of the technical solutions to be protected by the present invention are as follows:

[0024] First, the present invention performs surface treatment on graphene by jet plasma, thereby loading transition metals on graphene and reducing part of PbO2 to Pb, thereby effectively improving the synthesis efficiency of the oxygen evolution catalyst without generating toxic by-products, thereby improving the performance of the oxygen evolution reaction catalyst.

[0025] The present invention utilizes jet plasma technology to realize the preparation of efficient catalysts under mild conditions, reducing energy consumption and environmental pollution. This is in line with the current concept of green chemistry and sustainable development. In addition, the plasma preparation method has the advantages of simple process, strong controllability, and suitability for large-scale production, which provides feasibility for the industrial application of efficient oxygen evolution catalysts.

[0026] Second, the expected benefits and commercial value of the technical solution of the present invention after transformation are:

[0027] ① With the growing global demand for clean and renewable energy, high-efficiency oxygen evolution catalysts have broad application prospects in the fields of new energy, electrochemical energy storage and environmental governance. The technology of the present invention can meet the urgent market demand for high-performance, low-cost catalysts.

[0028] ② The present invention can improve the performance of the catalyst. Through the doping and etching of plasma, abundant active sites and pore structures are formed on the catalyst surface, which enhances the efficiency of electron transmission and material transfer. This enables the catalyst to exhibit higher electrocatalytic activity and stability in energy conversion fields such as water electrolysis to produce hydrogen. At the same time, plasma treatment is expected to reduce production costs. The jet plasma treatment process is fast and efficient and can be carried out at normal temperature and pressure, reducing energy consumption and equipment investment. The process can use cheap raw materials to further reduce production costs.

[0029] Third, the present invention prepares oxygen evolution catalyst by jet plasma treatment, which solves some key problems existing in the prior art and achieves significant technical progress in catalyst performance and industrial application. Specific technical problems and improvements include:

[0030] 1. Improve catalyst activity:

[0031] Traditional oxygen evolution catalysts have certain limitations in their reaction activity. However, the present invention, by using jet plasma treatment technology, can effectively enhance the surface activity of the catalyst under low temperature conditions, optimize its electronic structure, and thereby significantly improve the oxygen evolution reaction efficiency of the catalyst.

[0032] 2. Improve stability:

[0033] By constructing a Pb-NiFe / G / NF composite material with high stability on the catalyst surface, the present invention can improve the structural stability of the catalyst during long-term use, reduce the loss of active sites during the reaction process, and increase the service life of the catalyst.

[0034] 3. Simplify the preparation process and save energy:

[0035] Compared with the traditional high-temperature calcination process, the present invention adopts a combination of low-temperature freeze-drying and jet plasma treatment, which can complete the efficient preparation of the catalyst at room temperature, reduce energy consumption and reaction time, simplify the process steps, and improve production efficiency.

[0036] 4. Improve the dispersibility of catalyst:

[0037] By adding graphene as a conductivity enhancer and combining it with jet plasma treatment, the catalyst prepared by the present invention can achieve relatively uniform dispersion, further increasing the contact area between the catalyst and the reactants, thereby enhancing the oxygen evolution reaction performance.

[0038] 5. Enhance the feasibility of industrial applications:

[0039] The Pb-NiFe / G / NF catalyst prepared by the present invention not only exhibits excellent oxygen evolution catalytic performance in the laboratory, but also has good large-scale production potential, and is suitable for industrial water electrolysis, energy storage and other fields, thus promoting technological progress in this field.

[0040] In summary, the present invention, by innovatively introducing jet plasma treatment technology, not only solves the problems of existing oxygen evolution catalysts in activity, stability and preparation process, but also significantly improves the performance of the catalyst in industrial applications, and has important commercial application prospects.

[0041] Fourth, the main parameters of the present invention include the materials and process conditions involved in the preparation of the catalyst. First, the specific ratios of lead oxide, ferrous sulfate, nickel nitrate, thiourea and graphene used are accurate, ensuring the uniform distribution of the reactants and good synergy. Secondly, in the freeze-drying step, the conditions of -80°C and 20Pa are adopted, so that the obtained powder sample has high purity and good structural stability. Finally, through jet plasma treatment, the argon gas flow rate is 50sccm, the radio frequency discharge power is 100W, and the treatment time is 45 minutes. The precise control of these parameters ensures the uniform activation of the catalyst surface and improves its electrochemical performance.

[0042] The present invention solves several technical problems of existing oxygen evolution catalysts in industrial applications. Traditional oxygen evolution catalysts often have a high reaction overpotential, resulting in low reaction efficiency. In addition, the structure of the catalyst is prone to deactivation and decomposition during long-term operation. By adopting jet plasma treatment technology, the present invention significantly reduces the overpotential of the catalyst, while improving its long-term stability under complex working conditions, solving the problem of unstable catalyst activity. In addition, the addition of graphene further enhances the conductivity, thereby improving the overall performance of the catalyst.

[0043] One of the significant technical advances of the present invention is that the efficiency of the oxygen evolution reaction is greatly improved. Compared with traditional oxygen evolution catalysts, the Pb-NiFe / G / NF catalyst prepared by the present invention can perform efficient oxygen evolution reaction at a lower potential, effectively reducing energy consumption. Its stability is excellent in long-term electrochemical operation, and it can withstand thousands of hours of continuous reaction without failure, greatly reducing maintenance costs and replacement frequency, especially in the industrial application of water electrolysis and air batteries, with significant economic benefits.

[0044] In addition, the preparation method of the present invention simplifies the process flow, reduces production costs, and also improves the preparation efficiency of the catalyst. Unlike the traditional high-temperature calcination technology, the present invention adopts a combination of low-temperature freeze drying and jet plasma treatment, which not only has lower energy consumption, but also milder operating conditions, and is suitable for large-scale industrial production. These technological advances make the present invention have a wide range of application prospects in the field of new energy, and promote the technological upgrading of industries such as electrolysis of water to produce hydrogen and air batteries. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 A flow chart of a method for preparing an oxygen evolution catalyst based on jet plasma treatment provided in an embodiment of the present invention.

[0046] Figure 2 The X-ray diffraction pattern of the Pb-NiFe / G catalyst of Example 1 is provided for the embodiments of the present invention.

[0047] Figure 3A scanning electron microscope photograph of the Pb-NiFe / G catalyst of Example 1 is provided for the present invention.

[0048] Figure 4 The XPS graph of the Pb-NiFe / G catalyst of Example 1 is provided for the examples of the present invention.

[0049] Figure 5 Provided are oxygen evolution polarization curves of different catalysts for the embodiments of the present invention.

[0050] Figure 6 A constant voltage it diagram of the OER of a Pb-NiFe / G catalyst in 1 M KOH is provided for an embodiment of the present invention. DETAILED DESCRIPTION

[0051] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0052] The following are two specific application examples, which demonstrate the potential of the oxygen evolution catalyst of the present invention in practical applications:

[0053] Application Example 1: Industrial water electrolysis to produce hydrogen

[0054] In the process of industrial water electrolysis to produce hydrogen, the oxygen evolution reaction (OER) is a key step that limits efficiency. Traditional oxygen evolution catalysts (such as precious metal-based catalysts) are expensive and have poor stability, making them difficult to promote in large-scale industrial applications.

[0055] 1. The Pb-NiFe / G / NF catalyst prepared by the present invention is used to replace the traditional noble metal catalyst as an anode oxygen evolution catalyst in a water electrolysis device.

[0056] 2. In the water electrolysis system, water is electrolyzed to generate hydrogen and oxygen by providing an external power source, wherein the oxygen evolution catalyst of the present invention can effectively reduce the reaction overpotential and improve the oxygen evolution reaction efficiency.

[0057] 3. The application of the catalyst of the present invention not only reduces the energy consumption of water electrolysis, but also improves the overall stability and life of the equipment, and reduces the cost of frequent catalyst replacement.

[0058] The energy consumption of the oxygen evolution reaction is reduced by about 15%.

[0059] The catalyst has improved stability and can maintain high efficiency performance during more than 1,000 hours of continuous operation, reducing operating and maintenance costs.

[0060] Since it does not rely on expensive precious metal materials, the catalyst cost is greatly reduced and it is suitable for large-scale industrial applications.

[0061] Application Example 2: Renewable Energy Storage Electrolyzer

[0062] With the rapid development of renewable energy (such as solar energy and wind energy), intermittent power storage is a challenge that needs to be solved urgently. Water electrolysis energy storage battery is an important technology for realizing energy conversion and storage, and the performance of oxygen evolution catalyst directly affects the efficiency of electrolysis cell.

[0063] 1. In the electrolysis unit of the water electrolysis energy storage battery, the Pb-NiFe / G / NF catalyst of the present invention is used as the anode, and is combined with other energy storage materials to carry out oxygen evolution reaction.

[0064] 2. During the charging phase of the energy storage process, electrical energy is converted into chemical energy (hydrogen and oxygen) through a water decomposition reaction; during the discharging phase, water is generated through the combination of hydrogen and oxygen, while electrical energy is released at the same time.

[0065] The catalyst of the present invention can carry out efficient oxygen evolution reaction at a relatively low potential, thereby improving the charging efficiency of the energy storage battery.

[0066] The high stability and corrosion resistance of the catalyst material ensure that it maintains its performance over long charge and discharge cycles, reducing the performance degradation of the energy storage battery.

[0067] Such electrolyzer systems are suitable for energy storage in large power grids, especially to ensure a smooth supply of electricity when wind or solar power generation fluctuates greatly.

[0068] These two application examples fully demonstrate the wide application potential of the oxygen evolution catalyst of the present invention in the field of energy conversion and storage, especially in the application prospects in water electrolysis and energy storage equipment.

[0069] The present invention provides a method for preparing an oxygen evolution catalyst based on jet plasma treatment, which can prepare an efficient oxygen evolution catalyst based on lead oxide, ferrous sulfate, nickel nitrate, thiourea and graphene through precise material ratios and process steps. The method adopts ultrasonic treatment and freeze drying technology to ensure uniform dispersion and purity of the material. By freeze drying under low temperature and low pressure conditions, high-quality powder samples can be obtained, laying the foundation for subsequent jet plasma treatment. The process is simple and easy to operate, suitable for large-scale production, and has significant technical advantages.

[0070] By introducing jet plasma technology, the present invention effectively improves the surface activity of the material during the catalyst surface treatment process. The treatment process uses argon discharge for plasma treatment, which ensures uniform activation of the catalyst surface and improves the stability and conductivity of the catalyst. After 45 minutes of radio frequency discharge treatment, the prepared catalyst exhibits excellent performance in application, especially the catalytic reaction efficiency in water electrolysis and air batteries is significantly improved. This method not only improves the activity of the catalyst, but also enhances its stability in long-term use.

[0071] The present invention solves the technical difficulties in the activity and stability of existing oxygen evolution catalysts. Traditional oxygen evolution catalysts usually have the problems of high overpotential, low reaction efficiency and short service life. The present invention significantly reduces the overpotential of the oxygen evolution reaction through jet plasma treatment and multi-component synergy, and enhances the long-term stability of the catalyst under complex working conditions. The nickel foam is combined with the prepared catalyst as a carrier to further increase the contact area between the catalyst and the reaction medium, thereby accelerating the electrochemical reaction rate.

[0072] The present invention has achieved significant technical progress in the application of new energy fields such as water electrolysis and air batteries. The Pb-NiFe / G / NF catalyst prepared by jet plasma treatment shows the advantages of low energy consumption and high efficiency in the process of water electrolysis, and its application in air batteries also improves the charging and discharging efficiency and service life of the battery. The preparation process of the catalyst has good operability and large-scale production potential, providing efficient and stable catalyst materials for the new energy industry.

[0073] like Figure 1 As shown, a method for preparing an oxygen evolution catalyst based on jet plasma treatment provided by an embodiment of the present invention comprises the following steps:

[0074] Step 1, weighing 223.2 mg of the lead oxide, 278 mg of ferrous sulfate, 290 mg of nickel nitrate, 304.5 mg of thiourea, and 100 mg of graphene, adding them to 10 mL of deionized water; and ultrasonically treating for 30 min at room temperature;

[0075] Step 2, freeze-drying the mixed solution of step 1 at -80°C and 20Pa for 24 hours to obtain a powder sample;

[0076] Step 3, weigh the sample obtained in step 2 and spread it evenly in a flat-bottomed glass container, the discharge gas is argon, the gas flow rate is 50 sccm, the RF discharge power is 100 W, the treatment time is 45 min, and the flat-bottomed glass container is placed in the jet plasma discharge plume area;

[0077] Step 4: cutting the nickel foam into a size of 1 cm×1 cm×1 mm, ultrasonically treating with 3 mol / L hydrochloric acid solution, ethanol and deionized water for 30 min respectively, and standing at room temperature for 12 h;

[0078] Step 5, weigh 10 mg of the catalyst prepared in step 3, add 400 μL of ethanol and 40 μL of 5% wt Nafion solution, and perform ultrasonic treatment for 30 min to mix evenly;

[0079] Step six, take 100 μL of the solution in step five and evenly apply it on the nickel foam treated in step four, and let it stand at room temperature for 12 hours to obtain a Pb-NiFe / G / NF catalyst.

[0080] The preparation method of the oxygen evolution catalyst based on jet plasma treatment of the present invention utilizes multi-step chemical and physical treatment to prepare a Pb-NiFe / G / NF catalyst with excellent electrocatalytic performance. First, in step 1, lead oxide, ferrous sulfate, nickel nitrate, thiourea and graphene are added to deionized water in proportion, and a uniform mixed solution is formed after ultrasonic treatment. Ultrasonic treatment helps to accelerate the dispersion and uniform mixing of these raw materials, ensure the uniformity of subsequent reactions, and improve the reactivity of the material.

[0081] In step 2, the mixed solution is freeze-dried at -80°C and 20 Pa to effectively remove moisture and obtain a powder sample. Freeze-drying can maintain the original structural characteristics of the sample and prevent the material from agglomerating during the drying process, thereby providing a good precursor material for subsequent plasma treatment.

[0082] Next, in step three, the freeze-dried powder is evenly spread in a flat-bottomed glass container and treated in the jet plasma discharge plume area. Jet plasma activates reactants through high-energy discharge, and by adjusting the argon flow and radio frequency discharge power, the surface of the material can be deeply modified to improve the surface activity of the material, giving it better electrocatalytic performance, especially in the oxygen evolution reaction (OER).

[0083] Step 4: Processing nickel foam, by cutting the nickel foam into size and treating it with solution, so that its surface is clean and highly active. Nickel foam, as a supporting material for the catalyst, can be treated with hydrochloric acid, ethanol and deionized water by ultrasonic treatment to remove oxides and impurities on the surface, improve its ability to bind to the catalyst, and provide an ideal substrate for the deposition of the catalyst.

[0084] In step 5, the catalyst treated with jet plasma is mixed with ethanol and Nafion solution, and then subjected to ultrasonic treatment to form a uniform catalyst coating solution. The ultrasonic treatment ensures that the catalyst is fully dispersed in the solution and provides good adhesion through the Nafion solution, so that the catalyst is uniformly deposited on the nickel foam during the coating process.

[0085] Finally, in step six, the evenly mixed catalyst solution is coated on the treated nickel foam and left to stand at room temperature for 12 hours to allow the catalyst to evenly adhere and stably form a catalytic layer. After this series of process treatments, the obtained Pb-NiFe / G / NF catalyst has good structural stability and efficient oxygen evolution catalytic performance, and is suitable for fields such as electrochemical water splitting.

[0086] Figure 2 The X-ray diffraction pattern of the Pb-NiFe / G catalyst prepared in Example 1 is as follows: Figure 1 It can be seen that the Pb-NiFe / G catalyst contains NiFe, Pb, and PbO2, and PbO2 is partially reduced to Pb.

[0087] Figure 3 This is a scanning electron microscope photo of the Pb-NiFe / G catalyst prepared in Example 1. Figure 3 It can be seen that the particles are loaded on the graphene, combined with Figure 2 It can be seen that they are NiFe, Pb, and PbO2 nanoparticles. NiFe is successfully loaded on graphene. Figure 3 It can be clearly seen that the graphene flakes are in a curled shape with obvious wrinkles on the edges. This structure can effectively reduce the free energy of the system.

[0088] Figure 4 The XPS spectrum of the Pb-NiFe / G catalyst prepared in Example 1 is shown in FIG. Figure 4 It can be seen that Pb-NiFe / G contains elements such as Pb, Ni, and Fe, which indicates that after jet plasma treatment, elements such as Pb, Ni, and Fe are successfully loaded onto graphene and become catalytic active sites.

[0089] Comparative Example 1

[0090] The only difference from Example 1 is that there is no jet plasma treatment in step (3), so a sample without plasma treatment is obtained.

[0091] Comparative Example 2

[0092] The size of the cut nickel foam was 1 cm×1 cm×1 mm, and it was ultrasonically treated with 3 mol / L hydrochloric acid solution, ethanol and deionized water for 30 min respectively, and then allowed to stand at room temperature for 12 h.

[0093] Comparative Example 3

[0094] (1) Cut the nickel foam into a size of 1 cm × 1 cm × 1 mm, treat it with 3 mol / L hydrochloric acid solution, ethanol and deionized water for 30 min, and let it stand at room temperature for 12 h;

[0095] (2) Weigh 10 mg of IrO2, add 400 μL of ethanol and 40 μL of 5% wt Nafion solution, and ultrasonicate for 30 min to mix well;

[0096] (3) Take 100uL of the solution in step (2) and evenly apply it to the nickel foam treated in step (1), and let it stand at room temperature for 12h to obtain IrO2 / NF catalyst.

[0097] Figure 5 At 5mV s -1 Polarization curves of Example 1, Comparative Example 1, Comparative Example 2, and Comparative Example 3 at a scan rate of . The test environment is 1M KOH solution, and the anodic oxygen evolution reaction (OER) catalytic performance of each catalyst is measured using a classic three-electrode system at room temperature. Among them, Example 1 is a Pb-NiFe / G catalyst after plasma treatment, Comparative Example 1 is a Pb-NiFe / G catalyst without plasma treatment, Comparative Example 2 is a nickel foam without a catalyst, and Comparative Example 3 is a traditional precious metal (IrO2) catalyst. At the same current density, the voltage required for the catalyst corresponding to Comparative Example 1 is lower than that of Comparative Example 2, and the voltage required for the catalyst corresponding to Comparative Example 2 is lower than that of Comparative Example 3. At the same time, the voltage required for Example 1 is the lowest. That is, the plasma-treated Pb-NiFe / G catalyst exhibits excellent OER catalytic activity, and is significantly better than the IrO2 catalyst.

[0098] Figure 6 The constant voltage It curve of the Pb-NiFe / G catalyst prepared in Example 1 in a 1M KOH alkaline environment. After 50 hours of fixed potential (1.53V vs. RHE) testing, the current density did not show a significant decrease, which indicates that Pb-NiFe / G has long-term OER catalytic stability under alkaline conditions.

[0099] Example 1: Preparation of Pb-NiFe / G / NF catalyst and application in water electrolysis oxygen evolution reaction (OER)

[0100] 1. Raw material preparation: Weigh 223.2 mg of lead oxide, 278 mg of ferrous sulfate, 290 mg of nickel nitrate, 304.5 mg of thiourea and 100 mg of graphene, add to 10 mL of deionized water, and ultrasonically treat at room temperature for 30 minutes to obtain a uniform mixed solution.

[0101] 2. Freeze drying: freeze-dry the mixture at -80°C and 20Pa for 24 hours to obtain a powder sample.

[0102] 3. Plasma treatment: The obtained powder sample was evenly spread in a flat-bottomed glass container, argon was used as the discharge gas, the gas flow rate was 50 sccm, the RF discharge power was 100 W, and it was treated in the jet plasma discharge plume area for 45 minutes to obtain a plasma-modified catalyst.

[0103] 4. Pretreatment of nickel foam: Cut the nickel foam into a size of 1 cm×1 cm×1 mm, and ultrasonically clean it with 3 mol / L hydrochloric acid solution, ethanol and deionized water for 30 minutes respectively, and let it stand for 12 hours.

[0104] 5. Catalyst coating: 10 mg of the plasma-treated catalyst was mixed with 400 μL of ethanol and 40 μL of 5% Nafion solution, and treated under ultrasound for 30 minutes to obtain a uniform catalyst suspension. 100 μL of the suspension was coated on the pretreated nickel foam and allowed to stand at room temperature for 12 hours to form a uniform catalytic layer to obtain the Pb-NiFe / G / NF catalyst.

[0105] 6. Application test: The prepared catalyst was used for oxygen evolution reaction (OER) test of water electrolysis. The results showed that the catalyst has excellent electrochemical activity, and the low overpotential and high current density indicate its superior performance in OER.

[0106] Example 2: Optimizing the plasma treatment time of Pb-NiFe / G / NF catalyst

[0107] 1. Raw material preparation: As in Example 1, lead oxide, ferrous sulfate, nickel nitrate, thiourea and graphene were used in the same proportion, and a mixed solution was obtained after ultrasonic treatment for 30 minutes.

[0108] 2. Freeze drying: Freeze drying was performed at -80°C and 20 Pa for 24 hours to obtain a powder sample.

[0109] 3. Plasma treatment optimization: Spread the powder sample evenly in a glass container, adjust the jet plasma treatment time to 60 minutes, maintain the discharge gas flow rate at 50 sccm, and the RF discharge power at 100 W to explore the effect of treatment time on catalyst performance.

[0110] 4. Nickel foam treatment: Same as in Example 1, nickel foam was treated with acid, ethanol and deionized water respectively.

[0111] 5. Catalyst coating: The catalyst treated with plasma for 60 minutes was mixed with 400 μL of ethanol and 40 μL of 5% Nafion solution, ultrasonically treated for 30 minutes, coated on the nickel foam, and allowed to stand at room temperature for 12 hours to form a uniform catalytic layer.

[0112] 6. Performance test and comparison: The catalyst was used for water electrolysis OER reaction and compared with Example 1. The results showed that extending the plasma treatment time further improved the activity of the catalyst, reduced the overpotential, and significantly increased the current density, proving the effect of plasma treatment time on improving catalyst performance.

[0113] Figure 2 The physical structure of Pb-NiFe / G characterized by XRD is shown. The results show that Pb-NiFe / G contains NiFeLDH, PbO2 and Pb. This shows that after plasma treatment, part of the PbO2 in the catalyst is reduced to Pb, and the bimetallic compound NiFe LDH is successfully synthesized. At the same time, plasma treatment affects the band structure of graphene, turning its carriers into hole type. This opens the band gap of graphene, which is beneficial to the loading of catalytic active sites.

[0114] Figure 3 This is a SEM image of Pb-NiFe / G. Due to the impact of high-energy plasma particles, a rich pore structure is formed on the graphene surface. This structure can fully expose a large number of active sites and accelerate the removal of bubbles generated on the electrode surface. Therefore, this structure greatly enhances the mass transfer process and provides a pathway for oxygen.

[0115] Figure 4 The XPS spectrum of Pb-NiFe / G is shown in Figure 2. In its full XPS spectrum, the presence of Pb 4f, Ni 2p, and Fe 2p was observed. This verifies the results of XRD and further indicates that Pb is reduced and NiFe LDH is synthesized.

[0116] Figure 5 and Figure 6 The OER catalytic performance test results of Pb-NiFe / G are presented. The results show that Pb-NiFe / G has efficient electrocatalytic performance and good stability. This is attributed to the synergistic effect of plasma combining doping and etching. At the same time, the etching effect of plasma provides a low-resistance diffusion channel for oxygen and electrolyte, generates a large number of oxygen vacancies, improves the distribution of active sites on the graphene surface, and thus improves the catalytic performance.

[0117] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any modifications, equivalent substitutions and improvements made by any technician familiar with the technical field within the technical scope disclosed by the present invention and within the spirit and principle of the present invention should be covered by the protection scope of the present invention.

Claims

1. A method for preparing an oxygen evolution catalyst based on jet plasma treatment, characterized in that: The following steps are involved: Step 1, weigh a certain amount of lead oxide, ferrous sulfate, nickel nitrate, thiourea, and graphene, add them to 10 mL of deionized water; perform ultrasonic treatment for 30 minutes at room temperature to obtain a mixed solution; Step 2, freeze-drying the mixed solution of step 1 for 24 hours to obtain a powder sample; Step 3, weigh the sample obtained in step 2 and spread it evenly in a flat-bottomed glass container, and place the flat-bottomed glass container in the discharge plume area of ​​the jet plasma; Step 4: cutting the nickel foam, ultrasonically treating with 3 mol / L hydrochloric acid solution, ethanol and deionized water for 30 min respectively, and standing at room temperature for 12 h; Step 5, weighing the catalyst prepared in step 3, adding it to ethanol and 5%wt Nafion solution, and ultrasonically treating for 30 minutes to make it evenly mixed; Step six, evenly apply the solution in step five to the nickel foam treated in step four, and let it stand at room temperature for 12 hours to obtain a Pb-NiFe / G / NF catalyst.

2. The method for preparing an oxygen evolution catalyst based on jet plasma treatment according to claim 1, characterized in that: In step 1, lead oxide is 223.2 mg, ferrous sulfate is 278 mg, nickel nitrate is 290 mg, thiourea is 304.5 mg, and graphene is 100 mg.

3. The method for preparing an oxygen evolution catalyst based on jet plasma treatment according to claim 1, characterized in that: The freeze-drying conditions in step 2 are -80°C and 20Pa.

4. The method for preparing an oxygen evolution catalyst based on jet plasma treatment according to claim 1, characterized in that: In step three, the discharge gas is argon, the gas flow rate is 50 sccm, the RF discharge power is 100 W, and the processing time is 45 min.

5. The method for preparing an oxygen evolution catalyst based on jet plasma treatment according to claim 1, characterized in that: The size of the nickel foam in step 4 is 1 cm×1 cm×1 mm.

6. The method for preparing an oxygen evolution catalyst based on jet plasma treatment according to claim 1, characterized in that: In step five, 10 mg of the catalyst was added to 400 μL of ethanol and 40 μL of 5% wt Nafion solution.

7. An oxygen evolution catalyst based on jet plasma treatment prepared by the method for preparing an oxygen evolution catalyst based on jet plasma treatment according to any one of claims 1 to 6.

8. Use of the oxygen evolution catalyst based on jet plasma treatment as claimed in claim 7 in water electrolysis catalysis.

9. Use of the oxygen evolution catalyst based on jet plasma treatment as claimed in claim 7 in air battery catalysis.

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