NiO / CoP nanocomposite, preparation method thereof and water electrolysis method

Abstract

The embodiment of the present disclosure discloses a NiO / CoP nanocomposite and a preparation method and a water electrolysis method thereof. The NiO / CoP nanocomposite comprises CoP nanowires and NiO nanoparticles loaded on the CoP nanowires. The preparation method of the NiO / CoP nanocomposite comprises the following steps: preparing Co(OH)2 nanowires; performing phosphating treatment on the Co(OH)2 nanowires to obtain CoP nanowires; and loading NiO nanoparticles on the surface of the CoP nanowires to obtain the NiO / CoP nanocomposite. The NiO / CoP nanocomposite can have good HER and OER catalytic functions at the same time, and has low cost.

Description

Technical Field

[0001] This disclosure relates to the field of catalyst technology, and in particular to a NiO / CoP nanocomposite and its preparation method and water electrolysis method. Background Technology

[0002] Hydrogen energy, as a clean energy source with high energy density and zero carbon emissions, has enormous application prospects. Currently, hydrogen is mainly produced through water electrolysis (H2O = H2 + 1 / 2O2). During water electrolysis, hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) occur. The catalyst affects the efficiency of HER and OER, thus affecting the efficiency of water electrolysis.

[0003] Noble metal-based electrocatalysts are typically considered the benchmark electrocatalysts for HER and OER processes, but their high cost and scarcity severely restrict the large-scale commercialization of water electrolysis. Furthermore, noble metal-based electrocatalysts either only exhibit catalytic activity for HER or only for OER, making it difficult to meet the catalytic requirements of water electrolysis. Summary of the Invention

[0004] In view of this, the present disclosure provides a NiO / CoP nanocomposite and its preparation method and water electrolysis method, which can simultaneously have good HER and OER catalytic functions, and at a low cost.

[0005] In a first aspect, embodiments of this disclosure provide a NiO / CoP nanocomposite, employing the following technical solution:

[0006] The NiO / CoP nanocomposite comprises: CoP nanowires and NiO nanoparticles supported on the CoP nanowires.

[0007] Optionally, the atomic ratio between Co in the CoP nanowire and Ni in the NiO nanoparticle is 100:(0.01 to 5.0).

[0008] Optionally, the CoP nanowires have a diameter of 100 nm to 150 nm and a length of 1 μm to 3 μm; the NiO nanoparticles have a particle size of 10 nm to 20 nm.

[0009] Secondly, this disclosure provides a method for preparing NiO / CoP nanocomposites, employing the following technical solution:

[0010] The preparation method of the NiO / CoP nanocomposite includes:

[0011] Preparation of Co(OH)₂ nanowires;

[0012] The Co(OH)2 nanowires were subjected to phosphating treatment to obtain CoP nanowires;

[0013] NiO nanoparticles were loaded onto the surface of the CoP nanowires to obtain a NiO / CoP nanocomposite.

[0014] Optionally, the preparation method of the NiO / CoP nanocomposite further includes:

[0015] The NiO / CoP nanocomposite was annealed.

[0016] Optionally, the preparation of Co(OH)₂ nanowires includes:

[0017] Prepare an alkaline solution containing cobalt ions;

[0018] The substrate was placed in the alkaline solution containing cobalt ions and subjected to a hydrothermal reaction.

[0019] After the hydrothermal reaction was completed, the substrate was cleaned and dried to obtain Co(OH)2 nanowires grown on the substrate.

[0020] Optionally, the preparation of the alkaline solution containing cobalt ions includes:

[0021] Weigh out an appropriate amount of cobalt salt, wherein the cobalt salt is cobalt nitrate hexahydrate, cobalt chloride, or cobalt carbonate;

[0022] Weigh out appropriate amounts of ammonium fluoride and urea, or hexamethylenetetramine;

[0023] Weigh out an appropriate amount of deionized water;

[0024] Dissolve cobalt salt, ammonium fluoride, and urea in deionized water and mix thoroughly, or dissolve cobalt salt and hexamethylenetetramine in deionized water and mix thoroughly to obtain an alkaline solution containing cobalt ions.

[0025] Optionally, the phosphating treatment of the Co(OH)₂ nanowires to obtain CoP nanowires includes:

[0026] Co(OH)2 nanowires were placed in a tube furnace;

[0027] Weigh out an appropriate amount of sodium dihydrogen phosphate and place it upstream of the tube furnace;

[0028] The Co(OH)2 nanowires were phosphated under an argon atmosphere.

[0029] The CoP nanowires were obtained after cooling to room temperature.

[0030] Optionally, the loading of NiO nanoparticles on the surface of the CoP nanowires includes:

[0031] NiO nanoparticles were sputtered onto the surface of CoP nanowires at room temperature in an argon atmosphere using magnetron sputtering.

[0032] Optionally, the substrate is a carbon cloth substrate or a nickel foam substrate.

[0033] Thirdly, embodiments of this disclosure provide a water electrolysis method, the water electrolysis method comprising: using the NiO / CoP nanocomposite described in any one of the above claims as a catalyst, or using the NiO / CoP nanocomposite prepared by any one of the above claims as a catalyst.

[0034] This disclosure provides a NiO / CoP nanocomposite and its preparation method, as well as a water electrolysis method. The NiO / CoP nanocomposite comprises CoP nanowires and NiO nanoparticles loaded on the CoP nanowires. Firstly, during the hydrogen evolution reaction (HER), the loading of NiO nanoparticles on the surface of the CoP nanowires results in the NiO / CoP nanocomposite having more nano-interfaces and stronger electronic interactions. Under the hydrogen evolution reaction (OER) environment, water molecules are more easily adsorbed and decomposed, enhancing water dissociation and activation, thus facilitating the hydrogen evolution step in water electrolysis. Secondly, during the oxygen evolution reaction (OER), the NiO / CoP nanocomposite readily forms high-valence CoOOH active substances during reconstruction, thereby promoting the oxygen evolution reaction. Therefore, the NiO / CoP nanocomposite exhibits high activity for both hydrogen evolution and oxygen evolution. Furthermore, compared to noble metals, the NiO / CoP nanocomposite also has a lower cost.

[0035] The above description is merely an overview of the technical solution disclosed herein. In order to better understand the technical means of this disclosure and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this disclosure more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0036] To more clearly illustrate the technical solutions of the embodiments of this disclosure, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0037] Figure 1 Scanning electron microscopy of the NiO / CoP nanocomposite provided in the embodiments of this disclosure Figure 1 ;

[0038] Figure 2 Scanning electron microscopy of the NiO / CoP nanocomposite provided in the embodiments of this disclosure Figure 2 ;

[0039] Figure 3 Here is a high-resolution transmission electron microscope (TEM) microstructure of the NiO / CoP nanocomposite provided in the embodiments of this disclosure;

[0040] Figure 4 Transmission electron microscopy (TEM) image of a single nanowire of the NiO / CoP nanocomposite provided in the embodiments of this disclosure;

[0041] Figure 5 This is a diagram showing the distribution of Co in a single nanowire of the NiO / CoP nanocomposite provided in this embodiment of the disclosure;

[0042] Figure 6 This is a distribution diagram of P element in a single nanowire of the NiO / CoP nanocomposite provided in the embodiments of this disclosure;

[0043] Figure 7 This is a diagram showing the Ni element distribution in a single nanowire of the NiO / CoP nanocomposite provided in this embodiment of the disclosure;

[0044] Figure 8 X-ray diffraction pattern of NiO / CoP nanocomposite provided in the embodiments of this disclosure;

[0045] Figure 9 The NiO / CoP nanocomposite provided in the embodiments of this disclosure serves as a catalyst at 10 mA cm⁻¹ -2 Service diagram of continuous water electrolysis;

[0046] Figure 10 A flowchart illustrating the preparation method of NiO / CoP nanocomposites provided in this embodiment. Detailed Implementation

[0047] The present disclosure will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of the disclosure. Furthermore, it should be noted that, for ease of description, only the parts relevant to the present disclosure are shown in the accompanying drawings.

[0048] It should be noted that, where there is no conflict, the embodiments and features described in this disclosure can be combined with each other. The technical solutions of this disclosure will now be described in detail with reference to the accompanying drawings and embodiments.

[0049] Unless otherwise stated, the exemplary implementations / embodiments shown are to be understood as providing exemplary features of various details that provide ways in which the technical concepts of this disclosure can be implemented in practice. Therefore, unless otherwise stated, the features of various implementations / embodiments may be additionally combined, separated, interchanged and / or rearranged without departing from the technical concepts of this disclosure.

[0050] The use of crosshairs and / or shading in the accompanying drawings is generally used to clarify the boundaries between adjacent components. Thus, unless otherwise stated, the presence or absence of crosshairs or shading does not convey or indicate any preference or requirement for the specific material, material properties, dimensions, proportions, commonalities between the illustrated components, or any other characteristics, properties, etc., of the components. Furthermore, in the accompanying drawings, the dimensions and relative dimensions of components may be exaggerated for clarity and / or descriptive purposes. When exemplary embodiments can be implemented differently, a specific process sequence may be performed in a different order than that described. For example, two consecutively described processes may be performed substantially simultaneously or in the reverse order of their description. Furthermore, the same reference numerals denote the same components.

[0051] The terminology used herein is for the purpose of describing particular embodiments and is not intended to be limiting. As used herein, unless the context clearly indicates otherwise, the singular forms “a” and “the” are intended to include the plural forms as well. Furthermore, when the terms “comprising” and / or “including” and variations thereof are used in this specification, it indicates the presence of the stated features, integrals, steps, operations, parts, components, and / or groups thereof, but does not exclude the presence or addition of one or more other features, integrals, steps, operations, parts, components, and / or groups thereof. It should also be noted that, as used herein, the terms “substantially,” “about,” and other similar terms are used as approximate terms rather than as terms of degree, thus explaining the inherent biases in measurements, calculated values, and / or provided values ​​that would be recognized by one of ordinary skill in the art.

[0052] This disclosure provides a NiO / CoP nanocomposite, specifically, as shown in the embodiments below. Figures 1 to 7 As shown, the NiO / CoP nanocomposite comprises: CoP nanowires and NiO nanoparticles supported on the CoP nanowires.

[0053] Optionally, the atomic ratio between Co in the CoP nanowires and Ni in the NiO nanoparticles is 100:(0.01–5.0), so that both CoP and NiO can have a large amount of contact with water during water electrolysis. For example, the atomic ratio between Co in the CoP nanowires and Ni in the NiO nanoparticles is 100:0.05, 100:0.1, 100:0.5, 100:1.0, 100:2.0, 100:3.0, 100:4.0, or 100:5.0. Optionally, the diameter of the CoP nanowires is 100 nm–150 nm, and the length is 1 μm–3 μm, for example, 2 μm; the particle size of the NiO nanoparticles is 10 nm–20 nm, for example, 15 nm.

[0054] In this embodiment of the disclosure, Figure 1 and Figure 2 The overall morphology of the NiO / CoP nanocomposite is shown, and the NiO / CoP nanocomposite exhibits a good nanowire configuration. Figure 3 Microscopic lattice characterization results from high-resolution transmission electron microscopy (HRTEM) show that NiO nanoparticles were successfully loaded onto the CoP nanowires. Figure 3 The (200) interplanar spacing of NiO and the (112) interplanar spacing of CoP are also shown. Figures 4 to 7 The X-ray energy dispersive spectroscopy elemental distribution analysis results further verified that NiO nanoparticles were uniformly loaded onto CoP nanowires.

[0055] In this embodiment of the disclosure, such as Figure 8 As shown, both the obtained CoP nanowires and NiO / CoP nanocomposites exhibit good crystallinity, and the successful synthesis of NiO / CoP nanocomposites is confirmed by comparison with the PDF card.

[0056] The above NiO / CoP nanocomposites have at least the following technical effects:

[0057] On the one hand, during the HER process, due to the loading of NiO nanoparticles on the surface of CoP nanowires, the NiO / CoP nanocomposite has more nano-interfaces and stronger electronic interactions. Under the hydrogen evolution service environment, water molecules are more easily adsorbed and decomposed, enhancing water dissociation and activation, making the hydrogen evolution step of water electrolysis easier to carry out.

[0058] On the other hand, during the OER process, the NiO / CoP nanocomposite readily forms high-valence CoOOH active substances during reconstruction, which in turn promotes the oxygen evolution reaction.

[0059] Furthermore, in this embodiment, inexpensive and abundant Co and Ni are integrated, and compared with precious metals, NiO / CoP nanocomposites have a lower cost.

[0060] Furthermore, by designing the unique structure and adjusting the metal composition of the NiO / CoP nanocomposite, the resulting NiO / CoP nanocomposite can possess both high activity of HER and OER while exhibiting good long-term stability.

[0061] In this embodiment, the water electrolysis performance of the NiO / CoP nanocomposite was tested as follows: Water electrolysis was carried out in a 1 mol / L alkaline KOH electrolyte at 25°C. The NiO / CoP nanocomposite grown on carbon cloth or nickel foam was used as the cathode and anode for water electrolysis, respectively. The catalytic performance of the catalyst was studied by controlling and monitoring the voltage or current using an electrochemical workstation. When a constant current was applied to the electrolysis cell system, the overall water electrolysis performance of the catalyst was studied. At this time, an oxidation reaction occurred at the anode of the working electrode, producing oxygen (OH-). - Oxidized to O2), a reduction reaction occurs at the cathode of the working electrode, producing hydrogen gas (H2O). + (Reduced to H2), the measured voltage curve reflects the overall water electrolysis performance of the catalyst.

[0062] like Figure 9 As shown, a water electrolysis device using NiO / CoP nanocomposite as catalysts on both the cathode and anode can achieve an electrolysis speed of 10 mA cm⁻¹. -2 At a current density of 1.55V, it can continuously drive the electrolysis of water to produce hydrogen and oxygen for more than 48 hours, and exhibits strong stability.

[0063] Furthermore, this disclosure provides a method for preparing NiO / CoP nanocomposites, specifically, as follows: Figure 10 As shown, the preparation method of this NiO / CoP nanocomposite includes:

[0064] Step S1: Prepare Co(OH)2 nanowires.

[0065] Optionally, the preparation of Co(OH)₂ nanowires includes:

[0066] Sub-step S11: Prepare an alkaline solution containing cobalt ions.

[0067] Optionally, an alkaline solution containing cobalt ions is prepared, including:

[0068] Weigh out an appropriate amount of cobalt salt, which is cobalt nitrate hexahydrate, cobalt chloride, or cobalt carbonate.

[0069] Weigh out appropriate amounts of ammonium fluoride and urea, or hexamethylenetetramine;

[0070] Weigh out an appropriate amount of deionized water;

[0071] Dissolve cobalt salt, ammonium fluoride, and urea in deionized water and mix thoroughly, or dissolve cobalt salt and hexamethylenetetramine in deionized water and mix thoroughly to obtain an alkaline solution containing cobalt ions.

[0072] The above mixing process can be carried out by magnetic stirring and ultrasonic treatment. Taking the preparation of an alkaline solution containing cobalt ions by cobalt nitrate hexahydrate, ammonium fluoride and urea as an example, the weighed cobalt nitrate hexahydrate is 0.2g to 1.2g; ammonium fluoride is 0.1g to 0.6g; urea is 0.3g to 1.8g, and all are dissolved in 35mL to 220mL of deionized water.

[0073] Sub-step S12: Place the substrate in an alkaline solution containing cobalt ions and carry out a hydrothermal reaction.

[0074] Optionally, the substrate is a carbon cloth substrate or a nickel foam substrate. In this preparation method, the area of ​​the substrate can be increased from the conventional 1×1 cm². 2 The area has been increased to 6×8cm 2 .

[0075] Optionally, the substrate can be cleaned before sub-step S12. When a carbon cloth substrate is used, it is washed continuously for 30 minutes with acetone, ethanol and deionized water in sequence, then immersed in a mixed acid solution (concentrated sulfuric acid and concentrated nitric acid, volume ratio 1:3) and sonicated for 6-8 hours. Finally, an appropriate size is taken out, cleaned with deionized water and dried for later use. When a nickel foam substrate is used, it is washed continuously for 30-60 minutes with ethanol and deionized water in sequence, then immersed in hydrochloric acid solution and sonicated for 6-8 hours. Finally, an appropriate size is taken out, cleaned with deionized water and dried for later use.

[0076] Optionally, during the hydrothermal reaction, after the substrate is placed in an alkaline solution containing cobalt ions, the entire substrate is placed in a hydrothermal reactor and reacted at 100–150°C for 6–15 hours.

[0077] After sub-step S13, the hydrothermal reaction is completed, the substrate is cleaned and dried to obtain Co(OH)2 nanowires grown on the substrate.

[0078] For example, after the hydrothermal reaction is completed, the substrate is cooled to room temperature, removed, cleaned, and dried in a forced-air drying oven at 60°C for 6-8 hours to obtain Co(OH)2 nanowires grown on the substrate.

[0079] Step S2: Phosphate the Co(OH)2 nanowires to obtain CoP nanowires.

[0080] Optionally, Co(OH)₂ nanowires are phosphated to obtain CoP nanowires, comprising:

[0081] Sub-step S21: Place the Co(OH)2 nanowires in a tube furnace.

[0082] Sub-step S22: Weigh an appropriate amount of sodium dihydrogen phosphate and place it upstream of the tube furnace.

[0083] Sub-step S23: Phosphating Co(OH)2 nanowires under argon atmosphere protection.

[0084] For example, under an argon atmosphere, at 1–3 °C for min -1 The Co(OH)2 nanowires were phosphated by heating at 300-400℃ for 1-3 hours.

[0085] Sub-step S24: After cooling to room temperature, CoP nanowires are obtained.

[0086] Step S3: Load NiO nanoparticles onto the surface of CoP nanowires to obtain NiO / CoP nanocomposite.

[0087] Optionally, NiO nanoparticles are loaded onto the surface of CoP nanowires, including sputtering NiO nanoparticles onto the surface of CoP nanowires at room temperature using magnetron sputtering in an argon atmosphere. Exemplarily, during magnetron sputtering, the sputtering pressure is 1.0–3.0 Pa, the sputtering power is 50–120 W, and the sputtering time is 1–15 min.

[0088] Optionally, the preparation method of NiO / CoP nanocomposites further includes:

[0089] Step S4: Anneal the NiO / CoP nanocomposite. For example, CoP nanowires loaded with NiO nanoparticles are annealed at 300–400°C under argon protection for 1–3 hours. Annealing improves the interfacial strength between the NiO nanoparticles and the CoP nanowires, resulting in stronger adhesion of the NiO nanoparticles.

[0090] To better enable those skilled in the art to understand the preparation process of the NiO / CoP nanocomposite in the embodiments of this disclosure, three specific preparation methods are described below as examples.

[0091] Example 1

[0092] The preparation method of NiO / CoP nanocomposites includes the following steps:

[0093] (1) Weigh 0.2060g cobalt nitrate hexahydrate, 0.1000g ammonium fluoride and 0.3806g urea, add them to a mixture of 32mL deionized water and 3mL ethanol, stir magnetically for 30min and sonicate for 10min until they are evenly mixed.

[0094] (2) 2×4cm 2The carbon cloth was placed in the solution prepared in (1), and then the above solution was placed in a 50mL hydrothermal reactor and reacted at 120℃ for 10h. After cooling to room temperature, the carbon cloth was taken out and washed with deionized water and ethanol for 10min in sequence, and then placed in a forced-air drying oven at 60℃ for 8h to generate Co(OH)2 nanowires.

[0095] (3) Phosphating treatment was carried out in a tube furnace. Co(OH)2 nanowires grown on carbon cloth were placed in the center of the tube furnace, and 0.8000g of NaH2PO2·H2O was weighed and placed at the upstream of the tube furnace. Under the protection of argon atmosphere at 300sccm, the heating rate was 1℃min. -1 CoP nanowires were obtained by heating at 400℃ for 1 hour and then cooling to room temperature.

[0096] (4) NiO nanoparticles were sputtered on the surface of CoP nanowires by magnetron sputtering under an argon atmosphere with a sputtering pressure of 1.0 Pa, a sputtering power of 80 W, and a sputtering time of 1 min to obtain NiO / CoP nanocomposite.

[0097] (5) Annealing the NiO / CoP nanocomposite at 300℃ under argon protection for 2h.

[0098] Example 2

[0099] The preparation method of NiO / CoP nanocomposites includes the following steps:

[0100] (1) Weigh 0.4120g cobalt nitrate hexahydrate, 0.2000g ammonium fluoride and 0.6000g urea, add them to a mixture of 70mL deionized water and 5mL ethanol, stir magnetically for 30min and sonicate for 10min until they are evenly mixed.

[0101] (2) 3×5cm 2 The carbon cloth was placed in the solution prepared in (1), and then the solution was placed in a 100mL hydrothermal reactor and reacted at 120℃ for 10h. After cooling to room temperature, the carbon cloth was taken out and washed with deionized water and ethanol for 10min in sequence, and then placed in a drying oven at 60℃ for 8h to generate Co(OH)2 nanowires.

[0102] (3) Phosphating treatment was carried out in a tube furnace. Co(OH)2 nanowires grown on carbon cloth were placed in the center of the tube furnace, and 1.5000g of NaH2PO2·H2O was weighed and placed at the upstream of the tube furnace. Under the protection of argon atmosphere at 500sccm, the heating rate was 1℃min. -1 CoP nanowires were obtained by heating at 400℃ for 1 hour and then cooling to room temperature.

[0103] (4) NiO nanoparticles were sputtered on the surface of CoP nanowires by magnetron sputtering under an argon atmosphere with a sputtering pressure of 1.0 Pa, a sputtering power of 80 W, and a sputtering time of 5 min to obtain NiO / CoP nanocomposite.

[0104] (5) Annealing the NiO / CoP nanocomposite at 300℃ under argon protection for 2h.

[0105] Example 3

[0106] The preparation method of NiO / CoP nanocomposites includes the following steps:

[0107] (1) Weigh 2.4750g of cobalt nitrate hexahydrate, 0.6000g of ammonium fluoride and 1.5000g of urea, add them to a mixture of 200mL of deionized water and 20mL of ethanol, stir magnetically for 60min and sonicate for 30min until the mixture is homogeneous.

[0108] (2) 6×8cm 2 The foamed nickel was placed in the solution prepared in (1), and then the above solution was placed in a 300mL hydrothermal reactor and reacted at 120℃ for 15h. After cooling to room temperature, the carbon cloth was taken out and washed with deionized water and ethanol for 10min in sequence, and then placed in a forced-air drying oven at 60℃ for 8h to generate Co(OH)2 nanowires.

[0109] (3) Phosphating treatment was carried out in a tube furnace. Co(OH)2 nanowires grown on carbon cloth were placed in the center of the tube furnace, and 5.0000g of NaH2PO2·H2O was weighed and placed at the upstream of the tube furnace. Under the protection of argon atmosphere at 500sccm, the heating rate was 1℃min. -1 CoP nanowires were obtained by heating at 400℃ for 1 hour and then cooling to room temperature.

[0110] (4) NiO nanoparticles were sputtered on the surface of CoP nanowires by magnetron sputtering under an argon atmosphere with a sputtering pressure of 1.0 Pa, a sputtering power of 80 W, and a sputtering time of 15 min to obtain NiO / CoP nanocomposite.

[0111] (5) Annealing the NiO / CoP nanocomposite at 300℃ under argon protection for 2h.

[0112] Furthermore, this disclosure provides a water electrolysis method, which includes: using a NiO / CoP nanocomposite as a catalyst, or using a NiO / CoP nanocomposite prepared by any of the above preparation methods as a catalyst. Exemplarily, the NiO / CoP nanocomposite can be directly grown on carbon cloth electrodes or nickel foam electrodes serving as positive and negative electrodes during the preparation process.

[0113] In the description of this specification, the references to terms such as "one embodiment / mode," "some embodiments / modes," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment / mode or example is included in at least one embodiment / mode or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment / mode or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments / modes or examples. Furthermore, without contradiction, those skilled in the art can combine and integrate the different embodiments / modes or examples described in this specification, as well as the features of different embodiments / modes or examples.

[0114] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0115] Those skilled in the art should understand that the above embodiments are merely for illustrating the present disclosure and are not intended to limit the scope of the disclosure. Those skilled in the art can make other changes or modifications based on the above disclosure, and these changes or modifications still fall within the scope of the present disclosure.

Claims

1. A NiO / CoP nanocomposite, characterized in that, include: CoP nanowires and NiO nanoparticles loaded on the CoP nanowires. The atomic ratio between Co in the CoP nanowires and Ni in the NiO nanoparticles is 100:(0.01~5.0). The CoP nanowires have a diameter of 100 nm to 150 nm and a length of 1 μm to 3 μm; the NiO nanoparticles have a particle size of 10 nm to 20 nm.

2. A method for preparing NiO / CoP nanocomposite, characterized in that, include: Preparation of Co(OH)₂ nanowires; The Co(OH)2 nanowires were subjected to phosphating treatment to obtain CoP nanowires; NiO nanoparticles were loaded onto the surface of the CoP nanowires to obtain a NiO / CoP nanocomposite. The atomic ratio between Co in the CoP nanowires and Ni in the NiO nanoparticles is 100:(0.01~5.0). The CoP nanowires have a diameter of 100 nm to 150 nm and a length of 1 μm to 3 μm; the NiO nanoparticles have a particle size of 10 nm to 20 nm.

3. The method for preparing NiO / CoP nanocomposite according to claim 2, characterized in that, Also includes: The NiO / CoP nanocomposite was annealed.

4. The method for preparing NiO / CoP nanocomposite according to claim 2, characterized in that, The preparation of Co(OH)₂ nanowires includes: Prepare an alkaline solution containing cobalt ions; The substrate was placed in the alkaline solution containing cobalt ions and subjected to a hydrothermal reaction. After the hydrothermal reaction was completed, the substrate was cleaned and dried to obtain Co(OH)2 nanowires grown on the substrate.

5. The method for preparing the NiO / CoP nanocomposite according to claim 4, characterized in that, The preparation of the alkaline solution containing cobalt ions includes: Weigh out an appropriate amount of cobalt salt, wherein the cobalt salt is cobalt nitrate hexahydrate, cobalt chloride, or cobalt carbonate; Weigh out appropriate amounts of ammonium fluoride and urea, or hexamethylenetetramine; Weigh out an appropriate amount of deionized water; Dissolve cobalt salt, ammonium fluoride, and urea in deionized water and mix thoroughly, or dissolve cobalt salt and hexamethylenetetramine in deionized water and mix thoroughly to obtain an alkaline solution containing cobalt ions.

6. The method for preparing NiO / CoP nanocomposite according to claim 2, characterized in that, The phosphating treatment of the Co(OH)2 nanowires to obtain CoP nanowires includes: Co(OH)2 nanowires were placed in a tube furnace; Weigh out an appropriate amount of sodium dihydrogen phosphate and place it upstream of the tube furnace; The Co(OH)2 nanowires were phosphated under an argon atmosphere. The CoP nanowires were obtained after cooling to room temperature.

7. The method for preparing NiO / CoP nanocomposite according to claim 2, characterized in that, The loading of NiO nanoparticles on the surface of the CoP nanowires includes: NiO nanoparticles were sputtered onto the surface of CoP nanowires at room temperature in an argon atmosphere using magnetron sputtering.

8. A method for water electrolysis, characterized in that, include: The NiO / CoP nanocomposite as described in claim 1 is used as a catalyst, or the NiO / CoP nanocomposite prepared by any one of the preparation methods described in claims 2 to 7 is used as a catalyst.

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