Preparation method of water electrolysis hydrogen production composite electrode based on zwitterionic polymer binder

Abstract

The invention relates to a preparation method of a water electrolysis hydrogen production composite electrode based on a zwitterionic polymer binder. According to the method, a traditional ionic binder Nafion is replaced with a zwitterionic polymer polysulfobetaine methacrylate, an electrode-electrolyte interface is optimized through a unique electrically neutral hydration layer structure, the rapid desorption behavior of bubbles is enhanced, and efficient transmission of reaction ions is also promoted; and regulating and controlling the mass ratio of the PSBMA binder to the catalyst by using a spraying process. The invention aims to overcome the defects of high cost, insufficient mass transfer and poor interface stability of the existing Nafion binder, and provides the composite electrode taking PSBMA as the binder and the preparation method of the composite electrode, and the provided composite electrode is simple in preparation process and controllable in cost, and has good popularization and application prospects.

Description

Technical Field

[0001] This invention relates to the field of water electrolysis for hydrogen production technology, specifically to the field of polymer binders. It relates to a composite electrode and its preparation method using zwitterionic polymethyl methacrylate sulfobetaine (PSBMA) as a binder, which is suitable for oxygen evolution reaction (OER) under alkaline conditions. Background Technology

[0002] Hydrogen energy, as the most promising clean energy carrier of the 21st century, possesses core advantages such as high energy density, zero carbon emissions, and renewable recycling, making it a key direction for global energy transformation. Electrolysis of water to produce hydrogen is considered the core pathway for "green hydrogen" production. The electrode, as the core component of the electrolysis reaction, directly determines the electrolysis efficiency and cost. Existing water electrolysis electrodes mostly use perfluorosulfonic acid resins (such as Nafion) as binders. Their hydrophobic backbone and hydrophilic sulfonic acid groups can form a microphase separation structure, creating a complex porous structure in the catalyst layer. While traditional Nafion binders have high proton conductivity, they can cause insufficient gas mass transfer at the three-phase interface, affecting ion and water transport. Furthermore, the bonding between Nafion and transition metal catalysts (such as NiFe layered double hydroxides) is mainly through weak physical adsorption, resulting in insufficient interfacial adhesion. Under the continuous impact of the high-current-density oxygen evolution reaction (OER), catalyst layer stripping easily occurs, leading to electrode structure damage and performance degradation. Therefore, the traditional perfluorosulfonic acid ionomer Nafion currently suffers from problems such as insufficient mass transfer, insufficient interfacial stability, and poor bubble management, which limit its catalytic performance.

[0003] To address the mass transfer limitations of perfluorosulfonic acid ionomers (such as Nafion) in catalyst layers, recent studies have shown that modifying the molecular structure of Nafion by introducing the amphiphilic molecule CF3CF2CF2CH2OH effectively optimizes its hydrophilic-hydrophobic microphase separation structure, improves the water / proton transport channels, and thus alleviates the instability of non-precious metal catalysts at high current densities. However, such Nafion-based modification strategies still struggle to overcome inherent structural limitations such as high cost, insufficient bubble management capabilities, and poor interfacial stability. Summary of the Invention

[0004] The purpose of this invention is to address the limitations of the prior art by providing a method for preparing a composite electrode for water electrolysis to produce hydrogen based on a zwitterionic polymer binder. This method utilizes the zwitterionic polymer poly(sulfonated betaine methacrylate) (PSBMA) to completely replace the traditional ionic binder Nafion. Its unique electrically neutral hydration layer structure optimizes the electrode-electrolyte interface, enhancing both rapid bubble desorption and efficient ion transport. The preparation method employs a spray coating process. By controlling the mass ratio of PSBMA binder to catalyst, a stable interfacial layer is constructed on the catalyst surface, thereby synergistically optimizing catalytic activity and mass transfer efficiency. This invention aims to overcome the shortcomings of existing Nafion binders, such as high cost, insufficient mass transfer, and poor interfacial stability, by providing a composite electrode with PSBMA as the binder and its preparation method. The provided composite electrode preparation process is simple, cost-controllable, and has good prospects for widespread application.

[0005] The technical solution of this invention is as follows: The preparation of a composite electrode for hydrogen production by water electrolysis based on a zwitterionic polymer binder is characterized by the following steps: Step 1: Preparation of NiFe LDH catalyst: Ni(NO3)2·6H2O, Fe(NO3)3·9H2O, urea, and ammonium fluoride were added to deionized water and stirred. The mixture was then subjected to hydrothermal reaction at 95-105 °C for 10-12 hours. The product was washed with water, filtered, and dried to obtain the NiFe LDH catalyst. The molar ratio is Ni(NO3)2·6H2O to Fe(NO3)3·9H2O = 2:1; Add 0.52-1.04 g Ni(NO3)2·6H2O, 3.84-7.68 g urea, and 0.5-1.0 g ammonium fluoride to every 50-100 mL of deionized water; The stirring is carried out at 550-600 rpm for 1-2 hours; the drying is carried out at 60-80℃ overnight.

[0006] Step 2: Dissolve PSBMA in water to prepare a PSBMA solution with a mass concentration of 1%-5%; Step 3, Preparation of catalyst slurry: The NiFe LDH catalyst prepared in step 1 is dispersed in a mixed solvent, then mixed with the PSBMA solution in step 2, and ultrasonically dispersed to obtain a composite slurry; The mixed solvent consists of isopropanol and water in a volume ratio of 10:9; 4-5 mg of NiFe LDH catalyst is added to every 950 μL of the mixed solvent. The mass ratio of PSBMA to catalyst is 0.1-1:1; The ultrasonic dispersion includes: placing the sample in an ultrasonic cleaner and ultrasonically treating it for 1-2 hours at a power of 200-300 W and a frequency of 40 kHz. Step 4: Preparation of composite electrode: The composite slurry is coated onto the surface of the electrode substrate by spraying, and then vacuum dried at 60-80 ℃ for 0.5-1 hours to obtain the composite electrode; Among them, each 1cm 2 Spray 0.8-1.5 mg of composite slurry onto the substrate.

[0007] The spraying method described herein uses a nozzle diameter of 0.3-0.5 mm, a spraying pressure of 0.2-0.4 MPa, and a distance of 5-10 cm between the nozzle and the substrate.

[0008] The electrode substrate is carbon paper or carbon cloth.

[0009] The composite electrode prepared by the method is used as a working electrode in the electrolysis of water to produce hydrogen.

[0010] The process includes the following steps: In a standard three-electrode system, Hg / HgO is used as the reference electrode, a platinum sheet is used as the counter electrode, the composite electrode is used as the working electrode, the electrolyte is a 0.5-1 M KOH solution, and electrolysis is performed at a constant voltage of 1.45~1.95 V (vs. RHE) to obtain hydrogen gas; The composite electrode is activated before application, including 300-500 cyclic voltammetric scans in 1 M KOH solution at a scan rate of 20-50 mV / s. -1 .

[0011] The essential features of this invention are: This invention is the first to propose and apply zwitterionic polymers as a key binder component in the catalyst layer of the oxygen evolution reaction in water electrolysis, replacing traditional perfluorosulfonic acid ionomers. Sulfomethylate (SBMA) is selected as the monomer, and azobisisobutyronitrile (AIBN) is used as the initiator to polymerize it into poly(sulfomethylate) (PSBMA). Its molecular side chains simultaneously carry positive charges (quaternary ammonium cations) and negative charges (sulfonate anions), exhibiting overall electroneutrality. Using the zwitterionic polymer PSBMA instead of Nafion as the binder, as a typical zwitterionic polymer, its molecular structure simultaneously contains equimolar proportions of quaternary ammonium cations (-N... + (CH3)3) and sulfonate anion (-SO3) -The catalyst exhibits overall electroneutrality and can form a stable bound water layer in the interfacial region through strong ion hydration. This creates a dynamic, stable, and highly active reaction interface at the catalyst-electrolyte interface, promoting bubble desorption on the electrode and improving ion transport efficiency. By controlling the mass ratio between PSBMA and the catalyst, the microstructure of the catalyst layer can be regulated, balancing structural integrity, active site exposure, and the relationship between electron / ion / gas transport channels. This technology effectively overcomes the problems of insufficient mass transfer, insufficient interfacial stability, and poor bubble management capabilities of traditional Nafion binders, providing key material support for the development of large-scale, long-life water electrolysis hydrogen production devices.

[0012] The mechanism is as follows: In alkaline media, the sulfonate group at the end of the side chain of the PSBMA molecule can act as a highly efficient hydrated hydrogen ion (H3O). + The migration sites create continuous proton transport pathways throughout the entire catalyst layer, significantly enhancing proton conductivity. Simultaneously, zwitterionic groups induce a dense bound water layer on the catalyst surface through strong ion-water interactions. This hydrated layer effectively reduces the adhesion energy and interaction forces between oxygen bubbles and the catalyst interface, promoting rapid bubble formation, growth, and detachment. This avoids problems such as pore blockage, active site shielding, or physical stripping of the catalyst layer caused by bubble accumulation, playing a crucial role in maintaining catalytic stability at high current densities. By precisely controlling the mass ratio of polymer to catalyst, PSBMA can form a thin and uniform coating structure on the catalyst particle surface. This coating layer firmly binds the catalyst particles while retaining and constructing a rich mesoporous and macroporous hierarchical pore structure. This multi-level pore system facilitates sufficient electrolyte penetration, rapid mass transfer of reactant ions, and timely removal of gaseous products, thus exhibiting excellent mass transport characteristics and electrochemical performance.

[0013] The beneficial effects of this invention are: The zwitterionic PSBMA-based composite electrode PN-0.1 prepared in this invention exhibits good OER catalytic performance at 50 mA cm⁻¹. -2 The overpotential at current density is only 278 mV, and at 100 mA cm⁻¹ -2 The overpotential is 305 mV, while the charge transfer resistance is as low as 1.96 Ω. Compared with composite electrodes using Nafion binder, PN-0.1 exhibits lower overpotential at 100 mA cm⁻¹. -2 The overpotential decreased by 31.15%, and the charge transfer resistance decreased by 21.28% at 50 mA cm⁻¹. -2Stability tests were conducted on PN-0.1 at high current density for up to 100 hours, and its performance showed almost no degradation, further demonstrating the electrode's excellent chemical stability under high current density conditions. In summary, the PSBMA-based composite electrode developed in this invention combines excellent electrocatalytic activity, high structural stability, and efficient mass transfer characteristics, making it suitable for high-performance alkaline water electrolysis systems. Attached Figure Description

[0014] Figure 1 The Fourier transform infrared spectrum of PSBMA; Figure 2 The image shows a scanning electron microscope (SEM) image of the NiFe LDH catalyst. Figure 3 The image shows a scanning electron microscope (SEM) image of the composite electrode obtained in Example 1. Figure 4 Linear sweep voltammetry curves of the composite electrodes obtained in Example 1 and Comparative Example 1; Figure 5 Nyquist plots of the composite electrodes obtained in Example 1 and Comparative Example 1; Detailed Implementation

[0015] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0016] This invention proposes a hydrothermal synthesis method for NiFe layered double hydroxides (LDHs), introducing self-polymerized PSBMA to replace traditional Nafion as a binder for the powdered catalyst. The regulatory effect of the polymer-to-catalyst mass ratio on the performance of the oxygen evolution reaction (OER) in water electrolysis was systematically studied. PSBMA, with its zwitterionic properties, constructs a stable interfacial bond and an efficient charge transport pathway in the composite electrode: the quaternary ammonium groups are anchored to the catalyst support via electrostatic interactions, while the sulfonic acid groups form hydrogen bonds with the metal hydroxyl groups on the NiFe LDH surface, thus establishing a tight interface and significantly reducing charge transfer resistance. Regarding the mass transfer mechanism, the bound water layer formed by the strong hydration of the PSBMA side chains not only promotes the rapid conduction of hydroxyl ions in the alkaline medium, providing the necessary ion transport channel for the OER reaction, but also, due to its low interfacial energy, facilitates the rapid desorption of generated bubbles, effectively balancing conductivity and reactant / product mass transfer requirements. Electrochemical tests show that the PN-0.1 electrode at 100 mA cm⁻¹... -2 The overpotential at current density is only 305 mV, and the charge transfer resistance (R) is... ct ) and interface resistance (R s The resistances were as low as 1.96 Ω and 2.47 Ω, respectively. At 50 mA cm⁻¹-2 Even after 100 hours of continuous operation, the electrode maintained stable performance with minimal degradation, demonstrating excellent charge transport efficiency and long-term durability. This study provides a new approach for developing high-performance, low-cost non-fluorinated binder systems, achieving a significant improvement in overall electrode performance through interface design and structural control.

[0017] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. However, the following examples are for illustrative purposes only and should not be considered as any limitation on the present invention.

[0018] Example 1: The specific steps for preparing a composite electrode for hydrogen production by water electrolysis based on a zwitterionic polymer binder are as follows: Step 1: Preparation of NiFe LDH catalyst: The NiFe LDH catalyst was prepared using a hydrothermal method. 0.52 g (1.8 mmol) of nickel nitrate hexahydrate (Ni(NO3)2·6H2O), 0.36 g (0.9 mmol) of ferric nitrate nonahydrate (Fe(NO3)3·9H2O), 3.84 g of urea (CO(NH2)2), and 0.5 g of ammonium fluoride (NH4F) were dissolved in 50 mL of deionized water. The mixture was stirred continuously at 550 rpm for 1 h at room temperature to form a uniform, clear, blue-green solution. The solution was then transferred to a polytetrafluoroethylene-lined high-pressure reactor and subjected to a hydrothermal reaction in an electrically heated oven at 100 °C for 12 h. After the reaction was completed, the reaction system was allowed to cool naturally to room temperature. The product was washed three times with deionized water, filtered and collected. The reaction product was placed in an electric heating drying oven at 60 °C overnight to obtain the catalyst NiFe LDH, which was yellowish-brown. Step 2, Preparation of PSBMA Solution: First, prepare the polymer PSBMA. Weigh 4 g of sulfobetaine methacrylate (SBMA) monomer and dissolve it in 30 mL of deionized water. Transfer the solution to a three-necked flask, and then purge the flask with high-purity nitrogen gas (purity ≥99.99%) at a flow rate of 100 mL / min to remove oxygen. -1 Nitrogen was continuously purged for 30 minutes. Then, 40 mg of initiator (AIBN) was added, and polymerization was carried out at 70 °C for 20 h. During the reaction, a magnetic stirring rate of 350 rpm was maintained to ensure uniform mixing. After the reaction, the product was collected, dialyzed with deionized water, and lyophilized to obtain solid PSBMA. PSBMA was dissolved in water to prepare a 1% (w / w) PSBMA solution.

[0019]

[0020] Step 3, Preparation of catalyst slurry: Weigh 5 mg of the NiFe LDH catalyst prepared in Step 1 and disperse it in 950 μL of isopropanol / water (volume ratio of isopropanol / water is 10:9) mixed solvent, then add 50 μL of PSBMA solution prepared in Step 2 and mix. The mass ratio of PSBMA to NiFe LDH is 0.1. After ultrasonic dispersion, a composite slurry is obtained. Place the above mixture in an ultrasonic cleaner and ultrasonically treat it for 2 h at a power of 200 W and a frequency of 40 kHz. Step 4, Preparation of composite electrode: The composite slurry is coated onto the surface of the substrate carbon paper using a spraying method. 250 μL of the catalyst slurry prepared in Step 3 is uniformly sprayed onto the pretreated carbon paper substrate (1 cm × 2 cm), with a spraying area of ​​1 cm × 1 cm. Then, it is vacuum dried at 60 ℃ for 30 minutes to obtain the final composite electrode 1, denoted as PN-0.1. The oxygen evolution reaction (OER) performance of the composite electrode was evaluated using a standard three-electrode system on a Shanghai Chenhua CHI760E electrochemical workstation. The working electrode was the aforementioned composite electrode (geometric area 1 cm²). 2 The counter electrode was a platinum sheet (1 cm × 1 cm), and the reference electrode was Hg / HgO (containing 1 M KOH filling solution, with a standard electrode potential of 0.0098 V). All tests were performed in 1.0 M KOH electrolyte. Linear sweep voltammetry (LSV) measurements were performed at 5 mV s. -1 The scan rate was set at a certain threshold, and the obtained voltammetric curves were used as polarization curves for analysis after IR compensation. Electrochemical impedance spectroscopy (EIS) measurements were performed at a constant potential of 1.48 V (vs. RHE) with a frequency range of 0.1 Hz to 100 kHz and an AC amplitude of 5 mV.

[0021] Test results show that composite electrode 1 exhibits the highest current density at a potential of 1.61 V (vs. RHE), reaching 301 mA cm⁻¹. -2 This indicates that the electrode exhibits a high OER reaction rate at this overpotential (η = 1.61 V – 1.23 V = 0.38 V).

[0022] Example 2: The preparation process of the PSBMA-based composite electrode is basically the same as that in Example 1, except that in step 3, the volume of PSBMA solution added is changed from 50 μL to 100 μL, and the mass ratio of PSBMA to NiFe LDH is changed to 0.2; in step 4, the amount of catalyst slurry sprayed is changed to 260 μL, and finally composite electrode 2 is obtained, denoted as PN-0.2.

[0023] Test results show that composite electrode 2 exhibits the highest current density at a potential of 1.61 V (vs. RHE), reaching 301 mA cm⁻¹. -2 This indicates that the electrode exhibits a high OER reaction rate at this overpotential (η = 0.38 V).

[0024] Example 3: The preparation process of the PSBMA-based composite electrode is basically the same as that in Example 1, except that in step 3, the volume of PSBMA solution added is changed from 50 μL to 150 μL, and the mass ratio of PSBMA to NiFe LDH is changed to 0.3; in step 4, the amount of catalyst slurry sprayed is changed to 275 μL, and finally composite electrode 3 is obtained, denoted as PN-0.3.

[0025] Test results show that composite electrode 3 exhibits the highest current density at a potential of 1.62 V (vs. RHE), reaching 301 mA cm⁻¹. -2 This indicates that the electrode exhibits a high OER reaction rate at this overpotential (η = 0.39 V).

[0026] Example 4: The preparation process of the PSBMA-based composite electrode is basically the same as that in Example 1, except that in step 3, the volume of PSBMA solution added is changed from 50 μL to 250 μL, and the mass ratio of PSBMA to NiFe LDH is changed to 0.5; in step 4, the amount of catalyst slurry sprayed is changed to 300 μL, and finally composite electrode 4 is obtained, denoted as PN-0.5.

[0027] Test results show that composite electrode 4 exhibits the highest current density at a potential of 1.64 V (vs. RHE), reaching 301 mA cm⁻¹. -2 This indicates that the electrode exhibits a high OER reaction rate at this overpotential (η = 0.41 V).

[0028] Example 5: The preparation process of the PSBMA-based composite electrode is basically the same as that in Example 1, except that in step 3, the volume of PSBMA solution added is changed from 50 μL to 500 μL, and the mass ratio of PSBMA to NiFe LDH is changed to 1; in step 4, the amount of catalyst slurry sprayed is changed to 360 μL, and finally composite electrode 5 is obtained, denoted as PN-1.

[0029] Test results show that composite electrode 5 exhibits the highest current density at a potential of 1.65 V (vs. RHE), reaching 301 mA cm⁻¹. -2This indicates that the electrode exhibits a high OER reaction rate at this overpotential (η = 0.42 V).

[0030] Comparative Example 1: The preparation of Nafion-based composite electrodes includes the following specific steps: Step 1, Preparation of NiFe LDH catalyst: Same as Step 1 in Example 1; Step 2, Preparation of catalyst slurry: It is basically the same as step 3 in Example 1, except that 50 μL of Nafion solution is added instead of 50 μL of LPSBMA solution. Among them, Nafion solution is a well-known material with a specification of 5 wt.% and is manufactured by Shanghai Admas Co., Ltd. Step 3, Preparation of composite electrode: Same as step 4 in Example 1, denoted as Blank.

[0031] Test results show that the Nafion-based composite electrode exhibits the highest current density at 1.85 V (vs. RHE), reaching 301 mA cm⁻¹. -2 This indicates that the electrode exhibits a high OER reaction rate at this overpotential (η = 0.62 V).

[0032] Table 1 shows the process conditions for preparing the working electrode and the oxygen evolution performance of the resulting working electrode.

[0033] Table 1. Process conditions for preparing the working electrode and the oxygen evolution performance of the obtained working electrode in water electrolysis.

[0034] From Table 1 and Appendix Figure 3 , 4 Performance data from the examples and comparative examples show that, compared to the comparative examples, the oxygen evolution reaction (OER) catalytic performance of the composite electrodes 1-5 in this invention is significantly improved. Test results indicate that composite electrodes 1-5 achieve high current densities at relatively low overpotentials, demonstrating their excellent catalytic activity. Simultaneously, the charge transfer resistance (R) of composite electrodes 1-5 was measured at 1.48 V (vs. RHE). ct The low levels of both composite electrodes indicate that they possess efficient charge transport kinetics and a small reaction energy barrier. Comparing Example 1 and Comparative Example 1, it can be concluded that Example 1 exhibits a lower energy barrier at 100 mA cm⁻¹. -2 The overpotential at the current density decreased by 31.15%, and the charge transfer resistance decreased by 21.28%. Comparing Example 5 and Comparative Example 1, it can be seen that Example 5 at 100 mA cm⁻¹... -2 The overpotential at current density decreased by 25.51%, and the charge transfer resistance decreased by 14.46%. (From the attached...) Figure 1 From this, we can conclude that it is 1729 cm. -1 The peak at 1483 cm⁻¹ corresponds to the stretching vibration of the ester carbonyl group (-C=O). -1 The peak at that location belongs to the quaternary ammonium group (-N). + CH bending vibration of (CH3)3, 1180 cm⁻¹ -1 and 1041 cm -1 The peak at that point is a sulfonic acid group (-SO3). - The S=O asymmetric and symmetric stretching vibrations of the PSBMA are observed. The presence of these characteristic peaks verifies the structural composition of the PSBMA. (From the attached...) Figure 2 , 3 As can be observed, the optimized PN-0.1 composite electrode has an ideal mesoscopic pore structure and a uniform polymer coating, providing an ideal pathway for electrolyte wetting and gas release.

[0035] In summary, this invention utilizes NiFe LDH as a catalyst and poly(sulfobetaine methacrylate) (PSBMA) as a binder to successfully construct a PNX (X is the mass ratio of polymer to catalyst, I / C) composite electrode system. This aims to address the limitations in catalytic performance caused by insufficient mass transfer, inadequate interfacial stability, and poor bubble management in traditional perfluorosulfonic acid ionomers (such as Nafion). Its core innovation lies in utilizing the zwitterionic properties of the PSBMA molecular structure to construct a dynamic, stable, and functionalized solid-liquid interface microenvironment on the catalyst particle surface and within the pores of the catalyst layer. This binder forms a dense bound water layer through strong ion hydration. This water layer not only provides efficient proton transport channels but also promotes bubble release during the reaction process, preventing gas blockage of active sites and physical damage to the catalyst layer. Furthermore, the thin-layer coating structure and abundant hierarchical pores formed by optimizing the polymer ratio ensure strong adhesion between catalyst particles and achieve sufficient electrolyte wetting and rapid mass transfer of reaction products, thus exhibiting excellent reaction kinetics and structural stability on a macroscopic scale.

[0036] The above descriptions are merely several preferred embodiments of the present invention, but the present invention is not limited to the specific implementation methods described above. The specific implementation methods described above are illustrative and not restrictive. Researchers in the art, under the guidance of the present invention and in accordance with the spirit and principles of the present invention, can make improvements and modifications, all of which fall within the protection scope of the present invention.

[0037] Matters not covered in this invention are common knowledge.

Claims

1. Preparation of a composite electrode for hydrogen production by water electrolysis based on a zwitterionic polymer binder, characterized in that, The method includes the following steps: Step 1: Preparation of NiFe LDH catalyst: Ni(NO3)2·6H2O, Fe(NO3)3·9H2O, urea, and ammonium fluoride were added to deionized water and stirred. The mixture was then subjected to hydrothermal reaction at 95-105 °C for 10-12 hours. The product was washed with water, filtered, and dried to obtain the NiFe LDH catalyst. The molar ratio is Ni(NO3)2·6H2O to Fe(NO3)3·9H2O = 2:1; Add 0.52-1.04 g Ni(NO3)2·6H2O, 3.84-7.68 g urea, and 0.5-1.0 g ammonium fluoride to every 50-100 mL of deionized water; Step 2: Dissolve PSBMA in water to prepare a PSBMA solution with a mass concentration of 1%-5%; Step 3, Preparation of catalyst slurry: The NiFe LDH catalyst prepared in step 1 is dispersed in a mixed solvent, then mixed with the PSBMA solution in step 2, and ultrasonically dispersed to obtain a composite slurry; The mixed solvent consists of isopropanol and water in a volume ratio of 10:9; 4-5 mg of NiFe LDH catalyst is added to every 950 μL of the mixed solvent. The mass ratio of PSBMA to catalyst is 0.1-1:1; Step 4: Preparation of composite electrode: The composite slurry is coated onto the surface of the electrode substrate by spraying, and then vacuum dried at 60-80℃ for 0.5-1 hours to obtain the composite electrode; Among them, each 1cm 2 Spray 0.8-1.5 mg of composite slurry onto the substrate.

2. The preparation of the water electrolysis hydrogen production composite electrode based on a zwitterionic polymer binder as described in claim 1, characterized in that, The stirring is carried out at 550-600 rpm for 1-2 hours; the drying is carried out at 60-80℃ overnight.

3. The preparation of the composite electrode for hydrogen production by water electrolysis based on a zwitterionic polymer binder as described in claim 1, characterized in that, The ultrasonic dispersion includes: placing the sample in an ultrasonic cleaner and ultrasonically treating it for 1-2 hours at a power of 200-300 W and a frequency of 40 kHz.

4. The preparation of the water electrolysis hydrogen production composite electrode based on a zwitterionic polymer binder as described in claim 1, characterized in that, The spraying method described herein uses a nozzle diameter of 0.3-0.5 mm, a spraying pressure of 0.2-0.4 MPa, and a distance of 5-10 cm between the nozzle and the substrate.

5. The preparation of the composite electrode for hydrogen production by water electrolysis based on a zwitterionic polymer binder as described in claim 1, characterized in that, The electrode substrate is carbon paper or carbon cloth.

6. The application of the composite electrode prepared by the method described in claim 1, characterized in that, It is used as a working electrode in the electrolysis of water to produce hydrogen.

7. The application as described in claim 6, characterized in that, The process includes the following steps: In a standard three-electrode system, Hg / HgO is used as the reference electrode, a platinum sheet is used as the counter electrode, the composite electrode is used as the working electrode, the electrolyte is a 0.5-1 M KOH solution, and electrolysis is performed at a constant voltage of 1.45~1.95 V to obtain hydrogen gas.

8. The application as described in claim 7, characterized in that, The composite electrode is activated before application, including 300-500 cyclic voltammetric scans in 1 M KOH solution at a scan rate of 20-50 mV / s. -1 .

Images