Foamed nickel-based phosphorus-doped / nickel-molybdenum bimetallic mulberry synaptic sphere catalyst constructed by one-step deposition method and application of phosphorus-doped / nickel-molybdenum bimetallic mulberry synaptic sphere catalyst

Abstract

The invention belongs to the technical field of hydrogen evolution catalysts, and particularly relates to a phosphorus-doped / nickel-molybdenum bimetallic mulberry-shaped synaptic sphere catalyst constructed by a one-step deposition method based on foamed nickel and application of the phosphorus-doped / nickel-molybdenum bimetallic mulberry-shaped synaptic sphere catalyst. A nickel source, a molybdenum source and a phosphorus source are used as reactants, a complexing agent is introduced to construct an electrodeposition system, foamed nickel is used as a carrier, the phosphorus-doped / nickel-molybdenum bimetallic mulberry-like synaptic sphere catalyst is obtained through electrodeposition, and the catalyst has extremely low hydrogen evolution overpotential (64 mV) under the current density of 10 mA cm <-2 >, is good in stability and easy to prepare, and can be used as a catalyst for preparing the mulberry-like synaptic sphere catalyst. The method has the characteristics of low cost and no pollution.

Description

Technical Field

[0001] The present invention belongs to the technical field of hydrogen evolution catalysts, and more specifically relates to a phosphorus-doped / nickel-molybdenum bimetallic mulberry-like synaptic sphere catalyst constructed by a one-step deposition method based on nickel foam (NF) and its application. Background Art

[0002] Hydrogen is considered a promising way to address the energy crisis due to its high energy density and environmental harmlessness. Alkaline water electrolysis can achieve efficient and high-purity hydrogen production, and thus has received increasing attention.

[0003] Currently, platinum-based catalysts have excellent catalytic performance in the hydrogen evolution reaction of alkaline water electrolysis. However, due to their high price, the large-scale application of such catalysts is limited. Moreover, in the existing technology, the process for preparing transition metal catalysts is complex, and the cost of large-area preparation is expensive. At the same time, in the field of industrial hydrogen production, the current density during industrial water electrolysis for hydrogen production is generally >200 mA cm -2 When hydrogen is evolved under high current density conditions, the impact force of the generated bubbles on the catalyst is likely to cause the catalyst to fall off from the substrate (the binding force between the catalyst and the substrate is insufficient), thereby affecting the hydrogen evolution stability over a long time. Therefore, how to provide a stable, high-performance, and low-cost hydrogen evolution catalyst has become a difficult problem that needs to be overcome by those skilled in the art. Summary of the Invention

[0004] The object of the present invention is to provide a phosphorus-doped / nickel-molybdenum bimetallic mulberry-like synaptic sphere catalyst constructed by a one-step deposition method based on nickel foam (NF) and its application. Specifically, it provides a phosphorus-doped / nickel-molybdenum bimetallic mulberry-like synaptic sphere constructed by a one-step deposition method based on nickel foam for the hydrogen evolution reaction of alkaline water electrolysis under high current density, so as to solve the problems existing in the above-mentioned prior art and achieve efficient hydrogen evolution in alkaline water electrolysis.

[0005] To achieve the above object, the present invention provides the following solutions:

[0006] One of the technical solutions of the present invention: provides a preparation method for a phosphorus-doped / nickel-molybdenum bimetallic mulberry-like synaptic sphere catalyst constructed by a one-step deposition method based on nickel foam, and the steps include:

[0007] Using a nickel source, a molybdenum source, and a phosphorus source as reactants, introducing a complexing agent to construct an electrodeposition system, and using nickel foam as a carrier, and obtaining the phosphorus-doped / nickel-molybdenum bimetallic mulberry-like synaptic sphere catalyst through electrodeposition.

[0008] Further, the nickel source includes NiCl2·6H2O and / or Ni(NO3)2·6H2O.

[0009] Further, the molybdenum source includes (NH4)6Mo7O24 ·4H2O and / or MoO3.

[0010] Further, the phosphorus source includes NaH2PO2·H2O.

[0011] Further, the complexing agent includes NH4F.

[0012] Further, in the electrodeposition system, the concentration of the nickel source is 0.15 - 0.2 M, the concentration of the molybdenum source is 0.01 - 0.015 M, the concentration of the phosphorus source is 0 - 0.201 M, the concentration of the complexing agent is 1 M, and the concentration of the phosphorus source is not 0.

[0013] Optionally, in the electrodeposition system, the concentration of the nickel source is 0.169 M, the concentration of the molybdenum source is 0.012 M, the concentration of the phosphorus source is 0.135 M, and the concentration of the complexing agent is 1 M.

[0014] Further, the deposition voltage of the electrodeposition is -3.5 V to -4.5 V, and the deposition time is 1800 - 3600 s.

[0015] Optionally, the deposition voltage of the electrodeposition is -4 V, and the deposition time is 2700 s.

[0016] When the concentration of the phosphorus source is low, the phosphorus atoms have little influence on the reduction and crystallization process of metal ions, and there are also fewer phosphorus atoms adsorbed on the surface. The adsorption of active hydrogen is too strong, resulting in a decrease in the intrinsic activity. The coating will also fall off during long-term operation, leading to a decline in performance. If the concentration is too high, excessive phosphorus atoms will be adsorbed on the electrode surface, seriously affecting the reduction and diffusion of metal ions and resulting in an unstable deposition process.

[0017] The second technical solution of the present invention: provides a phosphorus-doped / nickel-molybdenum bimetallic mulberry-like synaptic sphere catalyst, and the phosphorus-doped / nickel-molybdenum bimetallic mulberry-like synaptic sphere catalyst is prepared by the above preparation method.

[0018] The third technical solution of the present invention: provides an application of the above phosphorus-doped / nickel-molybdenum bimetallic mulberry-like synaptic sphere catalyst in catalyzing hydrogen evolution from alkaline electrolyzed water.

[0019] The fourth technical solution of the present invention: provides a method for hydrogen evolution from alkaline electrolyzed water, and the method uses the above phosphorus-doped / nickel-molybdenum bimetallic mulberry-like synaptic sphere catalyst to catalyze hydrogen evolution from alkaline electrolyzed water.

[0020] The present invention discloses the following technical effects:

[0021] The present invention uses nickel foam with good electrical conductivity and a special three-dimensional porous structure as the substrate, which can load more catalysts (nickel and molybdenum). Through the synergistic effect between nickel and molybdenum loaded on the nickel foam, hydrogen atoms can be adsorbed and charges can be transferred in a timely manner to form hydrogen gas. When the present invention loads nickel and molybdenum bimetals, doping with phosphorus can effectively improve the structure of the catalyst. In addition, the electrodeposition method can precisely control the morphology and chemical composition of the catalyst, enabling more uniform loading of nickel, molybdenum, and phosphorus. The obtained phosphorus-doped / nickel-molybdenum bimetallic mulberry-like synaptic sphere catalyst achieves a current density of 10 mA cm -2 with an overpotential of only 64 mV. At the same time, the catalyst has excellent stability and can continuously and stably operate at a large current density of 200 mA cm -2 for 15 h.

[0022] The phosphorus-doped / nickel-molybdenum bimetallic mulberry-like synaptic sphere catalyst prepared by the present invention has a special morphology. On the surface of the nickel foam, there are many mulberry-like synaptic spheres. This morphology can provide more reaction sites for the catalytic reaction, and while ensuring the specific surface area, it also has excellent stability. In an alkaline solution, nickel metal has a smaller hydrogen adsorption free energy and exchange current density than other transition metals. Due to the dissolution effect of molybdenum (when a solid substance comes into contact with a solvent, its surface molecules or ions will gradually enter the solvent), the loading of nickel-molybdenum bimetals will endow the catalyst with extremely high hydrogen evolution catalytic activity. Since the reduction potential of NaH2PO2·H2O is low, it is easy to reduce nickel salts into the metallic state, and the doping of phosphorus makes the morphology rougher. Chelating agents (such as NH4F, etc.) can promote the co-reduction process of metal ions and hypophosphite ions. In addition, due to its strong electronegativity and smaller ionic radius, it will promote the nucleation process of phosphides and oxides. Description of the Drawings

[0023] The drawings forming a part of the present invention are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0024] Figure 1 are SEM images of pure nickel foam and the catalyst prepared in Example 4 at different magnifications. Among them, (a)-(c) are pure nickel foam, and (d)-(f) are Example 4.

[0025] Figure 2 is a comparison chart of the hydrogen evolution polarization curves of the catalyst prepared in Example 4 and pure NF.

[0026] Figure 3 is a comparison chart of the hydrogen evolution polarization curves of the catalyst prepared in Example 4 and the catalyst prepared in Comparative Example 1.

[0027] Figure 4 Comparison diagram of hydrogen evolution polarization curves of the catalysts prepared in Example 4, Example 8, Example 9 and Comparative Example 2 (different phosphorus concentrations in the deposition solution).

[0028] Figure 5 Hydrogen evolution polarization curve diagram of the catalysts prepared in Example 2, Example 4 and Example 7 (different deposition voltages).

[0029] Figure 6 i-t curve diagram of the catalyst prepared in Example 4.

[0030] Figure 7 XRD pattern of the catalyst prepared in Example 4. Detailed implementation manners

[0031] Now, various exemplary implementation manners of the present invention will be described in detail. This detailed description should not be considered as a limitation of the present invention, but should be understood as a more detailed description of certain aspects, characteristics and implementation schemes of the present invention.

[0032] It should be understood that the terms described in the present invention are only for describing particular implementation manners and are not used to limit the present invention. Additionally, for the numerical ranges in the present invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Any intermediate value within any stated value or stated range, as well as each smaller range between any other stated value or intermediate value within the stated range, is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded from the range.

[0033] Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the art to which the present invention pertains. Although the present invention only describes preferred methods and materials, any methods and materials similar or equivalent to those described herein can also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials related to the documents. In case of conflict with any incorporated document, the content of this specification shall prevail.

[0034] Without departing from the scope or spirit of the present invention, various improvements and changes can be made to the specific implementation manners of the specification of the present invention, which are obvious to those skilled in the art. Other implementation manners obtained from the specification of the present invention are obvious to those skilled in the art. The specification and examples of the present invention are only exemplary.

[0035] Regarding the terms "comprising", "including", "having", "containing", etc. used herein, they are all open-ended terms, meaning including but not limited to.

[0036] It should be noted that the aspects not described in detail in the present invention are all conventional operation means in the art and are not the focus of the present invention.

[0037] The raw materials and reagents involved in the specific implementation scheme of the present invention are all commercially available products.

[0038] In the specific implementation scheme of the present invention, unless otherwise specified, normal temperature and room temperature both refer to 20 - 30 °C.

[0039] In some specific implementation schemes, the present invention provides a preparation method of a phosphorus-doped / nickel-molybdenum bimetallic mulberry-like synaptic sphere catalyst constructed by a one-step deposition method based on nickel foam, and the steps include:

[0040] S1. Pretreat the nickel foam by successively ultrasonicating it with 4 mol L -1 HCl, deionized water, and absolute ethanol for 10 - 30 min, and then drying it in a vacuum drying oven (60 °C) to obtain the pretreated nickel foam;

[0041] S2. Dissolve NiCl₂·6H₂O, (NH₄)₆Mo₇O 24 ·4H₂O, NaH₂PO₂·H₂O, and NH₄F in deionized water and stir for 10 - 30 min to fully dissolve them. Transfer the prepared solution to an electrolytic cell with a two-electrode system as the electrolyte;

[0042] Among them, the concentration of NiCl₂·6H₂O in the electrolyte is 0.15 - 0.2 M, the concentration of (NH₄)₆Mo₇O 24 ·4H₂O is 0.01 - 0.015 M, the concentration of NaH₂PO₂·H₂O is 0 - 0.201 M, the concentration of NH₄F is 1 M, and the concentration of the phosphorus source is not 0;

[0043] S3. Use a graphite rod as the counter electrode, and clamp the pretreated nickel foam prepared in step S1 on a platinum-carbon electrode clamp as the working electrode;

[0044] S4. Electro-deposit the pretreated nickel foam in a constant voltage manner, with the deposition voltage ranging from -3.5 V to -4.5 V and the deposition time ranging from 1800 - 3600 S;

[0045] S5. Rinse the deposited nickel foam successively with deionized water and absolute ethanol, and place it in a vacuum drying oven to dry (60 °C) to obtain the phosphorus-doped / nickel-molybdenum bimetallic mulberry-like synaptic sphere catalyst.

[0046] The Gibbs free energy of hydrogen adsorption of transition metals Ni and Mo is second only to that of Pt-based materials. In terms of price, Ni and Mo metals have great advantages over Pt-based materials. Therefore, Ni and Mo have great potential in electrocatalytic hydrogen evolution. In addition, nickel foam has a porous structure, a very high specific surface area, and excellent electrical conductivity, and can be used as a catalyst substrate. The electrodeposition method is carried out at room temperature without high-cost facilities, and the element loading can be controlled by adjusting the voltage, current, and changing the concentration of the deposition solution. (For example, the loadings of P in Examples 2, 4, and 7 are 7%, 12%, and 18% respectively.) Loading Ni and Mo on nickel foam, through the synergistic effect between the two metals, the hydrogen atoms decomposed from water molecules can be adsorbed on the catalyst surface and charge transfer can occur, causing them to combine into hydrogen gas. By doping an additional P element, the stability and catalytic activity of the catalyst can be increased.

[0047] Example 1

[0048] The preparation steps of the phosphorus-doped / nickel-molybdenum bimetallic mulberry-like synaptic sphere catalyst include:

[0049] S1. Pretreat the nickel foam by ultrasonically treating it with 4 mol L -1 HCl, deionized water, and absolute ethanol for 20 min, and then drying it in a vacuum drying oven (60 °C) to obtain the pretreated nickel foam;

[0050] S2. Dissolve NiCl2·6H2O, (NH4)6Mo7O 24 ·4H2O, NaH2PO2·H2O, and NH4F in deionized water and stir for 20 min to completely dissolve them. Transfer the prepared solution to an electrolytic cell with a two-electrode system as the electrolyte;

[0051] Among them, the concentration of NiCl2·6H2O in the electrolyte is 0.169 M, the concentration of (NH4)6Mo7O 24 ·4H2O is 0.012 M, the concentration of NaH2PO2·H2O is 0.135 M, and the concentration of NH4F is 1 M;

[0052] S3. Use a graphite rod as the counter electrode, and clamp the pretreated nickel foam prepared in step S1 on a platinum-carbon electrode clamp as the working electrode;

[0053] S4. Electrodeposit the pretreated nickel foam in a constant voltage manner, with a deposition voltage of -3.5 V and a deposition time of 1800 S;

[0054] S5. Rinse the deposited nickel foam successively with deionized water and absolute ethanol, and place it in a vacuum drying oven to dry (60 °C) to obtain the phosphorus-doped / nickel-molybdenum bimetallic mulberry-like synaptic sphere catalyst.

[0055] Example 2

[0056] The preparation steps of the phosphorus-doped / nickel-molybdenum bimetallic mulberry-like synaptic sphere catalyst include:

[0057] S1. Pretreat the nickel foam by successively ultrasonicating it in 4 mol L -1 HCl, deionized water, and absolute ethanol for 20 min, and then drying it in a vacuum drying oven (60 °C) to obtain the pretreated nickel foam;

[0058] S2. Dissolve NiCl2·6H2O, (NH4)6Mo7O 24 ·4H2O, NaH2PO2·H2O, and NH4F in deionized water and stir for 20 min to fully dissolve them. Transfer the prepared solution to an electrolytic cell with a two-electrode system as the electrolyte;

[0059] Among them, the concentration of NiCl2·6H2O in the electrolyte is 0.169 M, the concentration of (NH4)6Mo7O 24 ·4H2O is 0.012 M, the concentration of NaH2PO2·H2O is 0.135 M, and the concentration of NH4F is 1 M;

[0060] S3. Use a graphite rod as the counter electrode, and clamp the pretreated nickel foam obtained in step S1 on a platinum-carbon electrode clamp as the working electrode;

[0061] S4. Electro-deposit the pretreated nickel foam in a constant voltage manner, with a deposition voltage of -3.5 V and a deposition time of 2700 s;

[0062] S5. Rinse the deposited nickel foam successively with deionized water and absolute ethanol, and place it in a vacuum drying oven to dry (60 °C) to obtain the phosphorus-doped / nickel-molybdenum bimetallic mulberry-like synaptic sphere catalyst.

[0063] Example 3

[0064] The preparation steps of the phosphorus-doped / nickel-molybdenum bimetallic mulberry-like synaptic sphere catalyst include:

[0065] S1. Pretreat the nickel foam by successively ultrasonicating it in 4 mol L -1 HCl, deionized water, and absolute ethanol for 20 min, and then drying it in a vacuum drying oven (60 °C) to obtain the pretreated nickel foam;

[0066] S2. Dissolve NiCl2·6H2O, (NH4)6Mo7O 24·4H2O, NaH2PO2·H2O, and NH4F were dissolved in deionized water and stirred for 20 min to ensure complete dissolution. The prepared solution was transferred to an electrolytic cell with a two-electrode system as the electrolyte.

[0067] Among them, the concentration of NiCl2·6H2O in the electrolyte was 0.169 M, the concentration of (NH4)6Mo7O 24 ·4H2O was 0.012 M, the concentration of NaH2PO2·H2O was 0.135 M, and the concentration of NH4F was 1 M.

[0068] S3: Using a graphite rod as the counter electrode, the pretreated nickel foam prepared in step S1 was clamped on a platinum-carbon electrode clip as the working electrode.

[0069] S4: Electro-depositing the pretreated nickel foam in a constant voltage manner, with a deposition voltage of -4 V and a deposition time of 1800 s.

[0070] S5: The deposited nickel foam was rinsed successively with deionized water and absolute ethanol and then dried in a vacuum drying oven (60 °C) to obtain the phosphorus-doped / nickel-molybdenum bimetallic mulberry-like synaptic sphere catalyst.

[0071] Example 4

[0072] The preparation steps of the phosphorus-doped / nickel-molybdenum bimetallic mulberry-like synaptic sphere catalyst include:

[0073] S1: Pretreating the nickel foam by ultrasonically treating it with 4 mol L -1 HCl, deionized water, and absolute ethanol for 20 min, and then drying it in a vacuum drying oven (60 °C) to obtain the pretreated nickel foam.

[0074] S2: Dissolving NiCl2·6H2O, (NH4)6Mo7O 24 ·4H2O, NaH2PO2·H2O, and NH4F in deionized water and stirring for 20 min to ensure complete dissolution. The prepared solution was transferred to an electrolytic cell with a two-electrode system as the electrolyte.

[0075] Among them, the concentration of NiCl2·6H2O in the electrolyte was 0.169 M, the concentration of (NH4)6Mo7O 24 ·4H2O was 0.012 M, the concentration of NaH2PO2·H2O was 0.135 M, and the concentration of NH4F was 1 M.

[0076] S3: Using a graphite rod as the counter electrode, the pretreated nickel foam prepared in step S1 was clamped on a platinum-carbon electrode clip as the working electrode.

[0077] S4. Electro-deposit the pretreated nickel foam in a constant voltage manner, with a deposition voltage of -4 V and a deposition time of 2700 s;

[0078] S5. Rinse the deposited nickel foam successively with deionized water and absolute ethanol, and then dry it in a vacuum drying oven (60 °C) to obtain the phosphorus-doped / nickel-molybdenum bimetallic mulberry-like synaptic sphere catalyst.

[0079] Example 5

[0080] The preparation steps of the phosphorus-doped / nickel-molybdenum bimetallic mulberry-like synaptic sphere catalyst include:

[0081] S1. Pretreat the nickel foam by ultrasonically treating it successively with 4 mol L -1 HCl, deionized water, and absolute ethanol for 20 min, and then dry it in a vacuum drying oven (60 °C) to obtain the pretreated nickel foam;

[0082] S2. Dissolve NiCl2·6H2O, (NH4)6Mo7O 24 ·4H2O, NaH2PO2·H2O, and NH4F in deionized water, and stir for 20 min to fully dissolve them. Transfer the prepared solution to an electrolytic cell with a two-electrode system as the electrolyte;

[0083] Among them, the concentration of NiCl2·6H2O in the electrolyte is 0.169 M, the concentration of (NH4)6Mo7O 24 ·4H2O is 0.012 M, the concentration of NaH2PO2·H2O is 0.135 M, and the concentration of NH4F is 1 M;

[0084] S3. Use a graphite rod as the counter electrode, and clamp the pretreated nickel foam prepared in step S1 on a platinum-carbon electrode clamp as the working electrode;

[0085] S4. Electro-deposit the pretreated nickel foam in a constant voltage manner, with a deposition voltage of -4 V and a deposition time of 3600 s;

[0086] S5. Rinse the deposited nickel foam successively with deionized water and absolute ethanol, and then dry it in a vacuum drying oven (60 °C) to obtain the phosphorus-doped / nickel-molybdenum bimetallic mulberry-like synaptic sphere catalyst.

[0087] Example 6

[0088] The preparation steps of the phosphorus-doped / nickel-molybdenum bimetallic mulberry-like synaptic sphere catalyst include:

[0089] S1. Pretreat the nickel foam by ultrasonically treating it successively with 4 mol L -1Ultrasonicate the nickel foam in HCl, deionized water, and absolute ethanol for 20 min, and then dry it in a vacuum drying oven (60 °C) to obtain pretreated nickel foam;

[0090] S2. Dissolve NiCl2·6H2O, (NH4)6Mo7O 24 ·4H2O, NaH2PO2·H2O, and NH4F in deionized water, and stir for 20 min to fully dissolve them. Transfer the prepared solution to an electrolytic cell with a two-electrode system as the electrolyte;

[0091] Among them, the concentration of NiCl2·6H2O in the electrolyte is 0.169 M, the concentration of (NH4)6Mo7O 24 ·4H2O is 0.012 M, the concentration of NaH2PO2·H2O is 0.135 M, and the concentration of NH4F is 1 M;

[0092] S3. Use a graphite rod as the counter electrode, and clamp the pretreated nickel foam prepared in step S1 on a platinum-carbon electrode clamp as the working electrode;

[0093] S4. Electro-deposit the pretreated nickel foam in a constant voltage manner. The deposition voltage is -4.5 V, and the deposition time is 1800 s;

[0094] S5. Rinse the deposited nickel foam successively with deionized water and absolute ethanol, and place it in a vacuum drying oven to dry (60 °C) to obtain a phosphorus-doped / nickel-molybdenum bimetallic mulberry-like synaptic sphere catalyst.

[0095] Example 7

[0096] The preparation steps of the phosphorus-doped / nickel-molybdenum bimetallic mulberry-like synaptic sphere catalyst include:

[0097] S1. Pretreat the nickel foam by successively ultrasonicating it in 4 mol L -1 HCl, deionized water, and absolute ethanol for 20 min, and then dry it in a vacuum drying oven (60 °C) to obtain pretreated nickel foam;

[0098] S2. Dissolve NiCl2·6H2O, (NH4)6Mo7O 24 ·4H2O, NaH2PO2·H2O, and NH4F in deionized water, and stir for 20 min to fully dissolve them. Transfer the prepared solution to an electrolytic cell with a two-electrode system as the electrolyte;

[0099] Among them, the concentration of NiCl2·6H2O in the electrolyte is 0.169 M, the concentration of (NH4)6Mo7O 24· The concentration of H2O is 0.012 M, the concentration of NaH2PO2·H2O is 0.135 M, and the concentration of NH4F is 1 M;

[0100] S3. Using a graphite rod as the counter electrode, the pretreated nickel foam prepared in step S1 is clamped on the platinum-carbon electrode clip as the working electrode;

[0101] S4. Electro-depositing the pretreated nickel foam in a constant voltage manner, with a deposition voltage of -4.5 V and a deposition time of 2700 s;

[0102] S5. Rinse the deposited nickel foam successively with deionized water and absolute ethanol, and then place it in a vacuum drying oven to dry (60 °C), thus obtaining the phosphorus-doped / nickel-molybdenum bimetallic mulberry-like synaptic sphere catalyst.

[0103] Example 8

[0104] The preparation steps of the catalyst with different phosphorus concentrations in the deposition solution include:

[0105] S1. Pretreat the nickel foam, ultrasonically clean it with 4 mol / L -1 HCl, deionized water, and absolute ethanol for 20 min, and then dry it in a vacuum drying oven (60 °C) to obtain the pretreated nickel foam;

[0106] S2. Dissolve NiCl2·6H2O, (NH4)6Mo7O 24 ·4H2O, NaH2PO2·H2O, and NH4F in deionized water, and stir for 20 min to fully dissolve them. Transfer the prepared solution to the electrolytic cell of a two-electrode system as the electrolyte;

[0107] Among them, the concentration of NiCl2·6H2O in the electrolyte is 0.169 M, (NH4)6Mo7O 24 ·4H2O is 0.012 M, the concentration of NaH2PO2·H2O is 0.067 M, and the concentration of NH4F is 1 M;

[0108] S3. Using a graphite rod as the counter electrode, the pretreated nickel foam prepared in step S1 is clamped on the platinum-carbon electrode clip as the working electrode;

[0109] S4. Electro-depositing the pretreated nickel foam in a constant voltage manner, with a deposition voltage of -4 V and a deposition time of 2700 s;

[0110] S5. Rinse the deposited nickel foam successively with deionized water and absolute ethanol, and then place it in a vacuum drying oven to dry (60 °C), thus obtaining the phosphorus-doped / nickel-molybdenum bimetallic mulberry-like synaptic sphere catalyst.

[0111] Example 9

[0112] The preparation steps of the catalyst with different phosphorus concentrations in the deposition solution include:

[0113] S1. Pretreat the nickel foam by successively ultrasonicating it with 4 mol / L -1 HCl, deionized water, and absolute ethanol for 20 min, and then drying it in a vacuum drying oven (60 °C) to obtain the pretreated nickel foam;

[0114] S2. Dissolve NiCl2·6H2O, (NH4)6Mo7O 24 ·4H2O, NaH2PO2·H2O, and NH4F in deionized water and stir for 20 min to fully dissolve them. Transfer the prepared solution to an electrolytic cell with a two-electrode system as the electrolyte;

[0115] Among them, the concentration of NiCl2·6H2O in the electrolyte is 0.169 M, the concentration of (NH4)6Mo7O 24 ·4H2O is 0.012 M, the concentration of NaH2PO2·H2O is 0.201 M, and the concentration of NH4F is 1 M;

[0116] S3. Use a graphite rod as the counter electrode, and clamp the pretreated nickel foam obtained in step S1 on a platinum-carbon electrode clamp as the working electrode;

[0117] S4. Electro-deposit the pretreated nickel foam in a constant voltage manner. The deposition voltage is -4 V and the deposition time is 2700 s;

[0118] S5. Rinse the deposited nickel foam successively with deionized water and absolute ethanol, and place it in a vacuum drying oven to dry (60 °C) to obtain the phosphorus-doped / nickel-molybdenum bimetallic mulberry-like synaptic sphere catalyst.

[0119] Comparative Example 1

[0120] The preparation steps of the deposition solution without the complexing agent (NH4F) include:

[0121] S1. Pretreat the nickel foam by successively ultrasonicating it with 4 mol / L -1 HCl, deionized water, and absolute ethanol for 20 min, and then drying it in a vacuum drying oven (60 °C) to obtain the pretreated nickel foam;

[0122] S2. Dissolve NiCl2·6H2O, (NH4)6Mo7O 24 ·4H2O, and NaH2PO2·H2O in deionized water and stir for 20 min to fully dissolve them. Transfer the prepared solution to an electrolytic cell with a two-electrode system as the electrolyte;

[0123] Among them, the concentration of NiCl2·6H2O in the electrolyte is 0.169 M, and the concentration of (NH4)6Mo7O 24 ·4H2O is 0.012 M, and the concentration of NaH2PO2·H2O is 0.135 M;

[0124] S3. Using a graphite rod as the counter electrode, the pretreated nickel foam obtained in step S1 is clamped on a platinum-carbon electrode clamp as the working electrode;

[0125] S4. Electro-depositing the pretreated nickel foam in a constant voltage manner, with a deposition voltage of -4 V and a deposition time of 2700 S;

[0126] S5. Rinse the deposited nickel foam successively with deionized water and absolute ethanol, and then place it in a vacuum drying oven to dry (60 °C) to obtain the catalyst.

[0127] Comparative Example 2

[0128] The preparation steps of the catalyst without phosphorus doping include:

[0129] S1. Pretreat the nickel foam by ultrasonicating it successively with 4 mol L -1 HCl, deionized water, and absolute ethanol for 20 min, and then dry it in a vacuum drying oven (60 °C) to obtain the pretreated nickel foam;

[0130] S2. Dissolve NiCl2·6H2O, (NH4)6Mo7O 24 ·4H2O, and NH4F in deionized water, and stir for 20 min to fully dissolve them. Transfer the prepared solution to an electrolytic cell with a two-electrode system as the electrolyte;

[0131] Among them, the concentration of NiCl2·6H2O in the electrolyte is 0.169 M, and the concentration of (NH4)6Mo7O 24 ·4H2O is 0.012 M, and the concentration of NH4F is 1 M;

[0132] S3. Using a graphite rod as the counter electrode, the pretreated nickel foam obtained in step S1 is clamped on a platinum-carbon electrode clamp as the working electrode;

[0133] S4. Electro-depositing the pretreated nickel foam in a constant voltage manner, with a deposition voltage of -4 V and a deposition time of 2700 S;

[0134] S5. Rinse the deposited nickel foam successively with deionized water and absolute ethanol, and then place it in a vacuum drying oven to dry (60 °C) to obtain the catalyst.

[0135] Test Example

[0136] Figure 1 SEM images of pure nickel foam and the catalyst prepared in Example 4 at different magnification factors. Among them, (a)-(c) are pure nickel foam, and (d)-(f) are Example 4. The figure shows that before modification, the surface of NF is smooth, while after modification, mulberry-like synaptic spheres are evenly distributed on the surface.

[0137] Taking the catalyst prepared in Example 4 as the working electrode, the electrochemical performance test was carried out using a three-electrode system on a CHI760E electrochemical workstation, and the results are as Figures 2 - 3 shown. The test conditions were as follows: using 1 mol L -1 KOH as the electrolyte, a graphite rod as the counter electrode, and a reference electrode of Hg / HgO. Moreover, using the catalyst prepared in Example 4 with an area of 1 cm -2 , the hydrogen production rate at a current density of 200 mA cm -2 was 4 mL min -1 .

[0138] Figure 2 This is a comparative diagram of the hydrogen evolution polarization curves of the catalyst prepared in Example 4 and pure NF. It can be seen from the figure that the overpotential of the modified catalyst (η 10 = 64 mV) is much lower than that of pure NF (η 10 = 242 mV), indicating that the modified catalyst has more excellent hydrogen evolution kinetics.

[0139] Figure 3 This is a comparative diagram of the hydrogen evolution polarization curves of the catalyst prepared in Example 4 and the catalyst prepared in Comparative Example 1. It can be seen from the figure that the complexing agent plays an important role in the electrodeposition process of the catalyst. The catalyst deposited from the deposition solution with a complexing agent shows higher intrinsic activity.

[0140] Figure 4 This is a comparative diagram of the hydrogen evolution polarization curves of the catalysts prepared in Example 4, Example 8, Example 9, and Comparative Example 2 (different phosphorus concentrations in the deposition solution). It can be seen from the figure that when the phosphorus source concentration is 0.135 M, the catalyst shows the most excellent hydrogen evolution activity.

[0141] Figure 5 This is a hydrogen evolution polarization curve diagram of the catalysts prepared in Example 2, Example 4, and Example 7 (different deposition voltages). It can be seen from the figure that when the deposition voltage is -4 V, the catalyst shows the most excellent hydrogen evolution activity.

[0142] Figure 6 This is an i-t curve diagram of the catalyst prepared in Example 4. The figure shows that when the catalyst reaches 200 mAcm -2After the current density of the hydrogen evolution reaction is extremely stable and operates continuously at a current density of 200 mA cm -2 for 15 h, which indicates that it can operate stably for a long time at a relatively high current density and can adapt to industrial scenarios.

[0143] Figure 7 XRD pattern of the catalyst prepared in Example 4. In the XRD pattern, the corresponding diffraction peaks of NiP and MoNiP can be seen. This indicates that P is successfully doped into the nickel-molybdenum bimetal, and the successful doping of P improves the stability and catalytic activity of the catalyst.

[0144] The various embodiments in this specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments. For the same and similar parts between the various embodiments, reference may be made to each other.

[0145] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A preparation method of a phosphorus-doped / nickel-molybdenum bimetallic mulberry-like synaptic sphere catalyst constructed by a one-step deposition method based on nickel foam, characterized in that the steps Comprising: Using a nickel source, a molybdenum source, and a phosphorus source as reactants, introducing a complexing agent to construct an electrodeposition system, using nickel foam as a carrier, and obtaining the phosphorus-doped / nickel-molybdenum bimetallic mulberry-like synaptic sphere catalyst through electrodeposition.

2. The preparation method according to claim 1, characterized in that, The nickel source includes NiCl2·6H2O and / or Ni(NO3)2·6H2O.

3. The preparation method according to claim 1, characterized in that, The molybdenum source includes (NH4)6Mo7O 24 ·4H2O and / or MoO3.

4. The preparation method according to claim 1, characterized in that The phosphorus source includes NaH2PO2·H2O.

5. The preparation method according to claim 1, characterized in that, The complexing agent includes NH4F.

6. The preparation method according to claim 1, wherein In the electrodeposition system, the concentration of the nickel source is 0.15 - 0.2 M, the concentration of the molybdenum source is 0.01 - 0.015 M, the concentration of the phosphorus source is 0 - 0.201 M, the concentration of the complexing agent is 1 M, and the concentration of the phosphorus source is not 0.

7. The preparation method according to claim 1, characterized in that, The deposition voltage of the electrodeposition is -3.5 V to -4.5 V, and the deposition time is 1800 - 3600 s.

8. A phosphorus-doped / nickel-molybdenum bimetallic mulberry-like synaptic sphere catalyst, characterized in that, The phosphorus-doped / nickel-molybdenum bimetallic mulberry-like synaptic sphere catalyst is prepared by the preparation method according to any one of claims 1 - 7.

9. Use of the phosphorus-doped / nickel-molybdenum bimetallic mulberry-like synaptic sphere catalyst according to claim 8 in catalyzing hydrogen evolution in alkaline water electrolysis.

10. A method for hydrogen evolution by alkaline electrolyzed water, characterized in that, The method uses the phosphorus-doped / nickel-molybdenum bimetallic mulberry-like synaptic sphere catalyst according to claim 8 to catalyze hydrogen evolution in alkaline water electrolysis.

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