Preparation method of a bifunctional electrolytic water nitrogen and phosphorus doped high-entropy catalyst

Abstract

The application provides a preparation method of a bifunctional electrolysis water nitrogen-phosphorus doped high-entropy catalyst, and belongs to the technical field of hydrogen production by electrolysis of water. The method first pretreats a metal substrate, then adsorbs a five-metal precursor solution containing nickel, molybdenum, cobalt, zirconium and iron by immersion, and rapidly constructs a high-entropy oxide structure by using instantaneous Joule heat technology. The core innovation is to use the reducing atmosphere generated by the in-situ decomposition of ammonium hypophosphite and sodium hypophosphite in the Joule heat process to realize the synchronous nitrogen-phosphorus modification of the material surface, which shortens the time-consuming of the traditional process from several hours to seconds and significantly reduces the energy consumption. The finally prepared catalyst has excellent hydrogen evolution (HER) and oxygen evolution (OER) bifunctional activity and chemical stability: the OER overpotential is less than 230 mV, and the HER overpotential is less than 50 mV at a current density of 10 mA·cm ‑2 The electrolysis voltage remains stable in fluctuation electrolysis test, start-stop test and constant current electrolysis, and has excellent stability.

Description

Technical Field

[0001] This invention belongs to the field of water electrolysis technology, specifically relating to a method for preparing a bifunctional nitrogen-phosphorus doped high-entropy catalyst for water electrolysis. Background Technology

[0002] Driven by the global energy crisis and the "dual-carbon" goal, the need for energy transition is becoming increasingly urgent. Building a clean, low-carbon, safe, and efficient modern energy system has become a core national strategy. Hydrogen energy, as a zero-carbon secondary energy source, is becoming a key carrier connecting renewable energy with end-use energy due to its environmentally friendly, clean, widely available, and diverse applications. On the one hand, hydrogen energy can directly replace traditional fossil fuels as a zero-carbon fuel, providing a clean alternative for end-use energy in industry, transportation, and other sectors. On the other hand, addressing the volatility and intermittency of renewable energy generation such as wind and solar power, water electrolysis technology can convert surplus renewable energy into green hydrogen for storage, meeting long-term, large-scale energy storage needs and breaking through the bottleneck of new energy consumption. Furthermore, the Energy Law of the People's Republic of China, which came into effect in 2025, for the first time incorporated hydrogen energy into the national energy management system, marking the beginning of a strategic acceleration period for green hydrogen development.

[0003] Electrolysis of water is a key pathway for obtaining green hydrogen, and it mainly includes four technical routes: alkaline water electrolysis (AWE), proton exchange membrane water electrolysis (PEM), anion exchange membrane water electrolysis (AEM), and solid oxide water electrolysis (SOEC). Among them, AWE currently holds an absolute dominant position in the global water electrolysis hydrogen production market, with a market share exceeding 60%, due to its significant advantages such as high technological maturity, relatively low equipment cost, and compatibility with non-precious metal catalysts. It is the mainstream technology route for large-scale green hydrogen production. However, the performance bottleneck of the core electrode materials of AWE electrolyzers is also prominent—the most commonly used catalysts are still limited to two main categories: precious metal catalysts and Raney nickel catalysts. The former has high preparation costs due to resource scarcity, while the latter has inherent defects such as complicated preparation processes, insufficient catalytic activity, and poor stability. Therefore, developing low-cost, high-stability, and high-activity non-precious metal catalysts suitable for AWE electrolyzers has become a key strategy for reducing the cost of green hydrogen production and promoting the large-scale industrialization of alkaline water electrolysis technology.

[0004] In AWE systems, the hydrogen evolution reaction (HER) at the cathode and the oxygen evolution reaction (OER) at the anode are typically optimized using different catalysts. This not only increases the complexity of catalyst selection and electrode preparation but also limits the overall efficiency of the electrolyzer and reduces system stability due to potential window differences and interfacial compatibility issues between different materials [ChemRev, 2024, 124, 7.]. In contrast, developing bifunctional catalysts with both HER and OER catalytic activity can simultaneously meet the catalytic requirements of both the anode and cathode with a single material, significantly simplifying electrode preparation processes, reducing catalyst management costs, and improving the overall performance of the electrolyzer through synergistic modification. Therefore, developing high-performance non-precious metal bifunctional catalysts suitable for AWE has significant technological value and industrialization prospects for further improving the economy and practicality of AWE electrolyzers.

[0005] High-entropy materials (HEMs), as emerging multi-component functional materials, achieve simultaneous enhancement of thermodynamic stability and catalytic activity through high-entropy stabilization effects, lattice distortion effects, and cocktail effects. Their multi-element composition provides ample room for regulation in bifunctional catalysis. By selectively screening elements and adjusting their proportions, synergistic optimization of active sites for HER and OER reactions can be achieved, simplifying the preparation process while enhancing adaptability to renewable energy fluctuations. However, existing research indicates that relying solely on the high-entropy effect cannot completely solve the activity and stability bottlenecks in bifunctional water electrolysis catalysis. Although multi-metal synergy can improve the HER / OER bifunctional catalytic activity of catalysts in the whole water splitting reaction, there is still room for further optimization in intrinsic conductivity, surface active site exposure, reaction intermediate adsorption strength, and HER / OER kinetic matching. Some literature has improved the performance of high-entropy oxygen-containing materials through MoS2 composites, oxygen vacancy regulation, or Na-doped electronic state engineering, indicating that pure HEO systems often still require secondary structural regulation or surface chemical modification to overcome performance limitations. [S. Afr. J.Chem. Eng. 2024, 48, 425–435.][ Nat. Commun. 2023, 14, 6019.][ Nat. Commun.2025, 16, 6667.] Furthermore, traditional methods for preparing high-entropy nitrides (HEMs) often employ hydrothermal methods, low-temperature phosphating, electrodeposition, and dealloying, which suffer from lengthy processes, high energy consumption, and uneven element distribution. For example, hydrothermal preparation of high-entropy nitrides requires 6-12 hours, and the low-temperature phosphating method for preparing eggshell-structured high-entropy phosphides requires three steps, both of which are time-consuming. While electrodeposition can prepare metal phosphides under relatively mild conditions, its deposition process is significantly affected by potential, electrolyte composition, mass transfer conditions, and substrate surface conditions, making it difficult to achieve rapid and uniform construction of multi-element high-entropy catalytic layers. [CN 119265624 A][CN117364123 A][CN 108607586 B] Summary of the Invention To address the problems existing in the background technology, this invention provides a method for preparing a bifunctional nitrogen-phosphorus-doped high-entropy catalyst for water electrolysis. A porous nanocatalyst layer is constructed on different metal substrates using a transient Joule heating method within seconds, achieving low-energy consumption and controllable preparation. Differential regulation is implemented based on the different reaction requirements of HER and OER: hypophosphite is introduced as both N and P sources to achieve simultaneous nitridation-phosphorization synergistic modification, and the reducing agent is isolated to protect the catalyst. Nitriding is beneficial for improving the adsorption of hydrogen intermediates and promoting HER activity, while phosphating optimizes OER activity and stability by constructing a POM network, thereby achieving a significant simultaneous improvement in bifunctional activity.

[0006] Compared with existing high-entropy electrode preparation technologies, this invention has the following technical features: This invention employs a preparation strategy that deeply integrates Joule heating with synergistic nitrogen and phosphorus modification, achieving second-level preparation through ultra-fast heating. Compared to traditional hour-level synthesis processes, energy consumption is significantly reduced, and elemental segregation is effectively suppressed. Furthermore, this invention introduces a self-made isolation device. Unlike traditional methods that directly contact the reducing agent, phosphating agent, or nitriding agent with the catalyst, this invention achieves spatial separation between the nitrogen phosphating agent and the HEO catalyst through an isolation device. This not only prevents solid byproducts generated during pyrolysis from directly contacting and contaminating the catalyst surface, but also isolates the reduction zone from the external environment through graphite paper wrapping, enhancing gas-solid interface mass transfer and effectively guiding the NH3 / PH3 gaseous active species released during AHP / SHP pyrolysis, allowing them to fully diffuse to the catalyst surface to complete in-situ nitrogen phosphating. In summary, this invention solves problems such as separation of anode and cathode catalysts, excessively long preparation processes, and the complexity and susceptibility to contamination in the nitrogen phosphating steps.

[0007] A method for preparing a bifunctional nitrogen-phosphorus-doped high-entropy catalyst for water electrolysis, characterized by comprising the following steps: 1. First, the metal substrate is pretreated as the base material: it is ultrasonically treated sequentially in ethanol, hydrochloric acid, and ultrapure water for 5-30 minutes to remove impurities and oxide layers from the substrate surface. The metal substrate can be any one of nickel mesh, nickel foam, nickel-iron, nickel-aluminum, or nickel sheet.

[0008] 2. Then, place the pretreated metal substrate from step 1 into a beaker containing a mixed solution of nickel, molybdenum, cobalt, zirconium, and iron sources, and immerse it at room temperature for 10–30 seconds. The nickel source is one or more of nickel acetate, nickel chloride, nickel sulfate, and nickel nitrate; the molybdenum source is one or more of sodium molybdate, molybdenum chloride, and ammonium molybdate; the cobalt source is one or more of cobalt chloride, cobalt sulfate, and cobalt nitrate; the zirconium source is one or more of zirconium chloride, zirconium sulfate, and zirconium nitrate; and the iron source is one or more of ferric chloride, ferric sulfate, ferric nitrate, and ferric acetate. The aqueous solution containing the nickel, molybdenum, cobalt, zirconium, and iron sources is prepared by mixing them in a ratio of Ni:Mo:Co:Zr:Fe = 3:3:1:1:1, with a total metal concentration of 50–500 mmol / L.

[0009] 3. Further, place the material obtained in step 2 in the center of the prepared graphite paper, then place it in a Joule heating device, activate the infrared temperature probe, and then, in an air atmosphere, first perform Joule drying under parameter 1 conditions, then perform Joule heat treatment under parameter 2 conditions, and finally allow it to cool naturally to room temperature. The heat treatment parameters are: 1 power P = 60~150W, t = 20~90s; 2 P = 400~700W, t = 10~50s.

[0010] 4. Repeat steps 2 and 3 of impregnation, Joule drying and heat treatment 2 to 15 times to obtain a metal substrate fully loaded with HEO.

[0011] 5. Weigh 50-500 mg of ammonium hypophosphite (AHP) and 50-500 mg of sodium hypophosphite (SHP), mix them evenly, and then spread them into a specially made isolation box. The isolation box is 2-8 cm long, 1-5 cm wide, and 0.5-2 cm high. Place a sheet of graphite paper on the isolation box, and then place the HEO material obtained in step 4 on the graphite paper; finally, wrap the above device and HEO material with graphite paper.

[0012] 6. Finally, the graphite paper (containing an isolation box and a metal substrate fully loaded with HEO) prepared in step 5 is placed in a Joule heating device and subjected to Joule heat treatment with parameter 2 under vacuum conditions. The high-entropy catalyst is treated in situ using the reducing atmosphere generated by the thermal shock decomposition of the reducing agent to obtain nitrogen and phosphorus-doped high-entropy catalyst material. An isolation device is used to prevent the pyrolysis residue of the reducing agent from contaminating the catalyst material. Attached Figure Description

[0013] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope of protection; those skilled in the art can obtain other related drawings based on these drawings without creative effort.

[0014] Figure 1 This is a scanning electron microscope (SEM) image of the nitrogen-phosphorus synergistically modified bifunctional high-entropy electrocatalyst obtained in Example 2.

[0015] Figure 2 The image shows the XRD pattern of the nitrogen-phosphorus synergistic modified bifunctional high-entropy electrocatalyst obtained in Example 2.

[0016] Figure 3 The OER / HER-LSV curves of the catalysts modified with different nitrogen phosphating agents in Examples 1-2 are shown.

[0017] Figure 4 The OER / HER-LSV curves of catalysts modified with reagents containing different total amounts of nitrogen and phosphorus are shown in Examples 3-6.

[0018] Figure 5 The OER / HER-LSV curves for catalysts prepared with different substrates in Examples 7-11 of this invention are shown.

[0019] Figure 6The graph shows the 100-hour constant current stability test of the nitrogen-phosphorus synergistic modified bifunctional high-entropy electrocatalyst obtained in Example 2 in 30wt% KOH electrolyte at room temperature.

[0020] Figure 7 The LSV comparison diagram is shown for the nitrogen-phosphorus synergistic modified bifunctional high-entropy electrocatalyst obtained in Example 2, in 30wt% KOH electrolyte, before and after start-up, shutdown and fluctuation tests at 80℃.

[0021] Figure 8 The graph shows the start-stop stability test results of the nitrogen-phosphorus synergistic modified bifunctional high-entropy electrocatalyst obtained in Example 2 in 30wt% KOH electrolyte at 80°C.

[0022] Figure 9 The graph shows the fluctuation stability test results of the nitrogen-phosphorus synergistic modified bifunctional high-entropy electrocatalyst obtained in Example 2 in 30wt% KOH electrolyte at 80°C.

[0023] Figure 10 This is a schematic diagram illustrating the structure and working principle of a nitrogen phosphorus gas phase transport isolation device. Specific Implementation To better illustrate the technical features of the present invention, specific embodiments are described below: Example 1 First, cut the nickel mesh into strips of 1.5cm × 4cm. Then, sequentially sonicate it in anhydrous ethanol for 30 minutes, in 1mol / L hydrochloric acid solution for 30 minutes, wash it with ultrapure water, and sonicate it in anhydrous ethanol for 5 minutes. After treatment, dry it with a hair dryer. Prepare a Ni / Mo / Co / Zr / Fe pentagonal metal precursor solution, with a molar ratio of Ni, Mo, Co, Zr, and Fe of 3:3:1:1:1 and a total metal ion concentration of 500mmol / L. Stir magnetically until homogeneous. Immerse the pretreated nickel mesh in the precursor solution until fully wetted. Remove it and place it in the center of a 6cm × 10cm graphite paper (wrapped in three folds) to create a uniform, conductive, and heat-conducting environment. Then, a staged Joule heat treatment was performed: first, a Joule drying step was performed, and the system was treated at 100W for 20 seconds to evaporate the solvent and initially fix the precursor; then, the power was directly increased to 650W and maintained for 30 seconds, causing the system to instantly heat up to 900–1000℃. The above impregnation-Joule drying-Joule heat treatment steps were repeated 4 times to obtain a nickel mesh substrate fully loaded with HEO. Finally, nitrogen phosphating surface modification was performed: the nickel mesh loaded with HEO material was placed on top of graphite paper above an isolation box, and a mixed solid consisting of 125mg dicyandiamide and 350mg sodium hypophosphite was placed inside the isolation box. The entire substrate was wrapped with graphite paper and treated at 620W for 40 seconds (local temperature approximately 400–600℃), causing simultaneous nitriding and phosphating reactions on the material surface. After treatment, the substrate was allowed to cool naturally to obtain the final catalyst.

[0025] Example 2 The steps are the same as in Example 1, except that the nitrogen phosphating agent placed in the isolation device is a mixed solid composed of 205.6 mg ammonium hypophosphite and 87.5 mg sodium hypophosphite.

[0026] Example 3 First, cut the nickel mesh into strips of 1.5cm × 4cm. Then, sequentially sonicate it in anhydrous ethanol for 30 minutes, in 1mol / L hydrochloric acid solution for 30 minutes, wash it with ultrapure water, and sonicate it in anhydrous ethanol for 5 minutes. After treatment, dry it with a hair dryer. Prepare a Ni / Mo / Co / Zr / Fe pentagonal metal precursor solution, with a molar ratio of Ni, Mo, Co, Zr, and Fe of 3:3:1:1:1 and a total metal ion concentration of 200mmol / L. Stir magnetically until homogeneous. Immerse the pretreated nickel mesh in the precursor solution until fully wetted. Remove it and place it in the center of a 6cm × 10cm graphite paper (wrapped in three folds) to create a uniform, conductive, and heat-conducting environment. Then, a staged Joule heat treatment was performed: first, a Joule drying step was performed, and the solvent was evaporated and the precursor was initially fixed at 100W for 20 seconds; then, the power was directly increased to 650W and maintained for 30 seconds, so that the system temperature instantly rose to 900–1000℃. The above impregnation-Joule drying-Joule heat treatment steps were repeated 4 times to obtain a nickel mesh substrate fully loaded with HEO. Finally, nitrogen phosphating surface modification was performed: the nickel mesh loaded with HEO material was placed on graphite paper above an isolation box, and a mixed solid consisting of 25mg dicyandiamide and 50mg sodium hypophosphite was placed inside the isolation box. The whole thing was wrapped in graphite paper and treated at 620W for 40 seconds (local temperature about 400–600℃), so that the material surface underwent nitriding and phosphating reactions simultaneously. After the treatment was completed, it was naturally cooled to obtain the final catalyst.

[0027] Example 4 The steps are the same as in Example 3, except that the nitrogen phosphating agent placed in the isolation device is a mixed solid consisting of 25 mg dicyandiamide and 150 mg sodium hypophosphite.

[0028] Example 5 The steps are the same as in Example 1, except that the nitrogen phosphating agent placed in the isolation device is a mixed solid composed of 137.1 mg ammonium hypophosphite and 175 mg sodium hypophosphite.

[0029] Example 6 The steps are the same as in Example 1, except that the nitrogen phosphating agent placed in the isolation device is a mixed solid composed of 68.5 mg ammonium hypophosphite and 262.5 mg sodium hypophosphite.

[0030] Example 7 The steps are the same as in Example 1, except that the substrate is replaced with nickel-iron foam.

[0031] Example 8 The steps are the same as in Example 1, except that the substrate is replaced with nickel foam.

[0032] Example 9 The steps are the same as in Example 1, except that the substrate is replaced with a Raney nickel mesh.

[0033] Example 10 The steps are the same as in Example 1, except that the substrate is replaced with a nickel sheet.

[0034] Figure 1 The image shows the SEM image of the material prepared in Example 2. It can be seen from the image that after appropriate N and P synergistic optimization, the surface of the HEA material also exhibits a uniformly dispersed multi-level nanoparticle array and a dense pore structure, which is consistent with the structural characteristics of high-entropy materials.

[0035] Figure 2 The image shows the XRD pattern of the material prepared in Example 2. As can be seen from the image, the nitrogen-phosphorus doped bifunctional high-entropy catalyst mainly exhibits a CoMoO4 structure, which does not match the elemental ratio Co / Mo≈1 / 3. This indicates that different cations share lattice sites, confirming the formation of a single-phase solid solution and verifying the high-entropy characteristics and abundant lattice defects of the material.

[0036] The oxygen evolution and hydrogen evolution catalytic performance of the materials prepared in Examples 1 and 2 are shown in the figure. Figure 3 As can be seen from the linear sweep voltammetry curves, the AHP / SHP synergistic modification strategy has a more significant effect on improving catalytic performance than DCDA / SHP. At a current density of 10 mA·cm-2, the OER overpotential is only 223 mV and the HER overpotential is only 42 mV.

[0037] The OER and HER catalytic performance of the materials prepared in Examples 3-6 are shown in the figures. Figure 4 The linear sweep voltammetric curves show that the increase in nitridation depth plays a decisive role in improving hydrogen evolution performance, while the increase in phosphating degree significantly optimizes oxygen evolution performance, confirming that the nitrogen-phosphorus synergistic modification strategy optimizes OER and HER respectively.

[0038] The catalytic performance of the catalysts prepared in Examples 7-11 for OER and HER are shown in the figures. Figure 5 The linear sweep voltammetry curves show that the preparation method exhibits excellent electrochemical performance on different substrates, indicating that the method has good substrate universality. The performance difference mainly stems from the difference in substrate surface area. On nickel sheet substrates with smaller surface areas, the active sites are less exposed, resulting in relatively poor activity. On foamed nickel-iron substrates with larger specific surface areas, the activity is better.

[0039] The constant current stability test of the catalyst prepared in Example 2 is shown in [reference needed]. Figure 6 As can be seen from the voltage-time curve, the overall voltage of the material remains stable after 100 hours of high current density electrolysis, demonstrating excellent stability.

[0040] The intermittent electrolysis stability test of the catalyst prepared in Example 2 is shown in [reference needed]. Figures 7-9 ,Depend on Figure 7 As can be seen, after start-up, shutdown, and fluctuation tests, the overpotential shifted negatively by 62 mV and 38 mV respectively at a current density of 500 mA·cm⁻², indicating that activation and reconstruction occurred on the catalyst surface, increasing the exposure of active sites or reducing mass transfer resistance, thus enabling the material to exhibit self-optimizing behavior under harsh operating conditions; Figure 8 and Figure 9 It can be seen that after the material undergoes rigorous high-temperature fluctuation electrolysis and start-stop tests simulating industrial conditions, the overall voltage remains stable, proving that the material has excellent resistance to fluctuations and start-stop stability.

[0041] Schematic diagrams of the structure and working principle of the nitrogen phosphorus gas-phase transport isolation device used in Examples 1-10 are shown below. Figure 10 ,Depend on Figure 10 It is evident that the isolation device separates the nitrogen phosphating agent from the catalyst, preventing solid byproduct contamination; while the graphite paper wrapping promotes gas-phase mass transfer, achieving in-situ nitrogen phosphating.

[0042] In summary, this invention provides a method for preparing a bifunctional nitrogen-phosphorus-doped high-entropy catalyst for water electrolysis. The method utilizes a rapid instantaneous Joule heating process to prepare the material, constructs a high-entropy structure through non-equilibrium rapid heating and cooling, and simultaneously achieves in-situ simultaneous nitridation and phosphating of the material using the reducing atmosphere generated by hypophosphite pyrolysis, thus constructing a water electrolysis catalyst with both HER and OER functions. This catalyst exhibits low HER and OER overpotentials and demonstrates excellent stability in high-current constant-current electrolysis tests, start-stop electrolysis tests, and fluctuating electrolysis tests.

Claims

1. A method for preparing a bifunctional nitrogen-phosphorus-doped high-entropy catalyst for water electrolysis, characterized in that: First, high-entropy oxide (HEO) is loaded onto a metal substrate via Joule heating in seconds. Then, the system is wrapped with graphite paper, and hypophosphite is subjected to Joule heating to achieve in-situ co-doping of nitrogen and phosphorus to enhance bifunctional activity. The preparation method of this bifunctional nitrogen-phosphorus-doped high-entropy catalyst for water electrolysis includes the following steps: (1) Pretreatment of the metal substrate: ultrasonic treatment in ethanol, hydrochloric acid and ultrapure water for 5-30 min respectively to remove impurities and oxide layer on the substrate surface. (2) Place the pretreated metal substrate in step (1) into a beaker containing a mixed solution of nickel source, molybdenum source, cobalt source, zirconium source and iron source, soak it at room temperature for 10~30s, wrap it in the center of graphite paper, then dry it with Joule heat under parameter 1, and then perform Joule heat treatment under parameter 2 to obtain a metal substrate loaded with HEO. (3) Repeat the impregnation, Joule drying and heat treatment steps in step (2) 2 to 15 times to obtain a metal substrate fully loaded with HEO. (4) Ammonium hypophosphite (AHP) and sodium hypophosphite (SHP) are evenly spread in a specially made isolation box, and then a piece of graphite paper is placed on the isolation box. The metal substrate with fully loaded HEO obtained in step (3) is placed on the graphite paper. The isolation device and HEO material are wrapped with graphite paper. Then, under vacuum protection, Joule heat treatment with parameter 2 is performed to pyrolyze AHP and SHP and use the NH3 and PH3 gases generated by their pyrolysis to perform in-situ nitrogen phosphorization on the material to obtain a nitrogen-phosphorus co-doped high-entropy catalyst material.

2. The method for preparing a bifunctional nitrogen-phosphorus-doped high-entropy catalyst for water electrolysis according to claim 1, characterized in that, In step (1), the metal substrate is any one of nickel mesh, nickel foam, nickel-iron foam, Raney nickel mesh, or nickel sheet.

3. The method for preparing a bifunctional nitrogen-phosphorus-doped high-entropy catalyst for water electrolysis according to claim 1, characterized in that, In step (2), the nickel source is one or more of nickel acetate, nickel chloride, nickel sulfate, and nickel nitrate; the molybdenum source is one or more of sodium molybdate, ammonium molybdate, and molybdenum chloride; the cobalt source is one or more of cobalt chloride, cobalt sulfate, and cobalt nitrate; the zirconium source is one or more of zirconium chloride, zirconium sulfate, and zirconium nitrate; and the iron source is one or more of ferric chloride, ferric sulfate, ferric nitrate, and ferric acetate.

4. The method for preparing a bifunctional nitrogen-phosphorus-doped high-entropy catalyst for water electrolysis according to claim 1, characterized in that, In step (2), the aqueous solution containing nickel source, molybdenum source, cobalt source, zirconium source and iron source is prepared by mixing in the molar ratio of Ni:Mo:Zr:Co:Fe=3:3:1:1:1, and the total metal concentration is 50~500mmol / L.

5. The method for preparing a bifunctional nitrogen-phosphorus-doped high-entropy catalyst for water electrolysis according to claim 1, characterized in that, In step (2), parameter 1 is power P=60~150W and time t=20~90s, and parameter 2 is P=400~700W and t=10~50s.

6. The method for preparing a bifunctional nitrogen-phosphorus-doped high-entropy catalyst for water electrolysis according to claim 1, characterized in that, In step (4), the isolation box is 2-8cm long, 1-5cm wide, and 0.5-2cm high. The top cover can be opened and closed freely. The material is one of nickel mesh, stainless steel mesh, porous titanium mesh, or porous ceramic sheet. The purpose is to isolate the solid products generated during the pyrolysis of the catalyst and reducing agent.

7. The method for preparing a bifunctional nitrogen-phosphorus-doped high-entropy catalyst for water electrolysis according to claim 1, characterized in that, In step (4), the mass of ammonium hypophosphite (AHP) weighed is 50~500mg, the mass of sodium hypophosphite (SHP) weighed is 50~500mg, and the two are mixed evenly and placed inside the isolation box.

8. A method for preparing a bifunctional nitrogen-phosphorus-doped high-entropy catalyst for water electrolysis, characterized in that, Prepared using the preparation method described in any one of claims 1 to 7.

9. The application of the preparation method of the bifunctional nitrogen-phosphorus doped high-entropy catalyst for water electrolysis as described in any one of claims 1 to 7 in the field of hydrogen production by water electrolysis.

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