阅读说明：本技术 一种泡沫铜负载镍钼磷基复合材料及其制备方法与应用 (Foam copper loaded nickel-molybdenum-phosphorus-based composite material and preparation method and application thereof ) 是由 王建芝 喻发全 余洪亮 汪贤明 蔡宁 薛亚楠 李辉 于 2021-08-19 设计创作，主要内容包括：本发明提供了一种泡沫铜负载镍钼磷基复合材料及其制备方法与应用,制备方法包括步骤：取过硫酸铵和氢氧化钾,加入去离子水配置成混合液A,将泡沫铜置于混合液A内,静置反应,得到Cu(OH)-(2)/CF；取六水合硝酸钴、四水合硝酸锰以及脲,加入去离子水配置成混合液B,将Cu(OH)-(2)/CF置于混合液B内,于高压反应釜内进行水热反应,清洗、干燥后,得到CoMn LDH@Cu(OH)-(2)/CF复合纳米材料；将CoMn LDH@Cu(OH)-(2)/CF复合纳米材料与磷化原料混合,置于管式炉中进行煅烧,冷却后得到泡沫铜负载镍钼磷基复合材料。本发明制得的中空分层结构的泡沫铜负载镍钼磷基复合材料,有利于活性物质与电解质的充分接触,同时原位生长的纳米结构可以减少电阻,从而表现出优异的电催化剂析氢反应活性。(The invention provides a foam copper loaded nickel-molybdenum-phosphorus-based composite material and a preparation method and application thereof, wherein the preparation method comprises the following steps: taking ammonium persulfate and potassium hydroxide, adding deionized water to prepare a mixed solution A, placing the foamy copper in the mixed solution A, and standing for reaction to obtain Cu (OH) 2 (ii)/CF; taking cobalt nitrate hexahydrate, manganese nitrate tetrahydrate and urea, adding deionized water to prepare mixed solution B, and adding Cu (OH) 2 the/CF is placed in the mixed solution B and is reacted under high pressureHydrothermal reaction in a kettle, cleaning and drying to obtain CoMn LDH @ Cu (OH) 2 a/CF composite nanomaterial; mixing CoMn LDH @ Cu (OH) 2 And mixing the/CF composite nano material with a phosphating raw material, placing the mixture in a tubular furnace for calcining, and cooling to obtain the foam copper loaded nickel-molybdenum-phosphorus-based composite material. The foam copper loaded nickel-molybdenum-phosphorus-based composite material with the hollow layered structure, which is prepared by the invention, is beneficial to the full contact of active substances and electrolyte, and the in-situ grown nano structure can reduce the resistance, thereby showing excellent hydrogen evolution reaction activity of the electrocatalyst.)

1. A preparation method of a foam copper-loaded nickel-molybdenum-phosphorus-based composite material is characterized by comprising the following steps:

s1, adding deionized water into ammonium persulfate and potassium hydroxide to prepare a mixed solution A, placing the pretreated foamy copper into the mixed solution A, and standing for reaction to obtain Cu (OH)₂/CF；

S2, adding deionized water into nickel nitrate hexahydrate, sodium molybdate dihydrate and urea to prepare mixed solution B, and adding Cu (OH)₂Placing the/CF in the mixed solution B, and carrying out hydrothermal reaction in a high-pressure reaction kettle to obtain NiMoL DH @ Cu (OH)₂Washing the nano array with water, and freeze-drying to obtain NiMo LDH @ Cu (OH)₂a/CF composite nanomaterial;

s3, mixing the NiMo LDH @ Cu (OH)₂And mixing the/CF composite nano material with a phosphating raw material, placing the mixture in a tubular furnace for calcining, and cooling to obtain the foam copper loaded nickel-molybdenum-phosphorus-based composite material.

2. The method according to claim 1, wherein in the mixed solution a in step S1, the mass ratio of ammonium persulfate to potassium hydroxide is in the range of 0.1: 1 to 0.3: 2 in the range of.

3. The method for preparing the copper foam according to the claim 1, wherein the step of pretreating the pretreated copper foam in the step S1 comprises sequentially subjecting the copper foam to ultrasonic treatment with absolute ethyl alcohol, hydrochloric acid and deionized water.

4. The method according to claim 2, wherein the conditions of the standing reaction in step S1 include a reaction temperature in the range of 20 ℃ to 30 ℃ and a reaction time in the range of 20min to 60 min.

5. The method according to any one of claims 1 to 4, wherein the hydrothermal reaction conditions in step S2 include a reaction temperature in the range of 160 ℃ to 200 ℃ and a reaction time in the range of 2h to 8 h.

6. The method as claimed in claim 5, wherein the amount of said phosphating raw material of step S3 is calculated according to the phosphorus content, and the phosphating raw material is mixed with NiMo LDH @ Cu (OH)₂The mass ratio of the/CF composite nano material is 1: 1 to 4: 1, in the range of.

7. The method of claim 6, wherein the phosphating material comprises one of sodium phosphate, sodium phosphite and sodium hypophosphite.

8. The method according to claim 5, wherein the calcining conditions of step S3 include: under the protection of inert gas, the calcining temperature is within the range of 300 ℃ to 800 ℃, the calcining heat preservation time is within the range of 40min to 200min, and the temperature rise rate of the tube furnace is within the range of 2 ℃/min to 8 ℃/min.

9. A copper foam supported nickel molybdenum phosphorus-based composite material, which is characterized by being prepared by the preparation method of the copper foam supported nickel molybdenum phosphorus-based composite material according to any one of claims 1 to 8.

10. The application of the copper foam supported nickel molybdenum phosphorus-based composite material as claimed in claim 9 in the field of hydrogen evolution by electrolysis of water.

Technical Field

The invention relates to the technical field of electrolytic water catalytic hydrogen evolution, in particular to a foam copper loaded nickel-molybdenum-phosphorus based composite material and a preparation method and application thereof.

Background

Transition metal compounds, such as oxides, sulfides, phosphides, nitrides, and carbides, etc., have attracted much attention as hydrogen evolution materials that are promising replacements for platinum Pt-based catalysts, while transition metal phosphides have attracted much attention because they have superior catalytic activity and chemical stability than other transition metal compounds.

In recent years, Ni₂Transition metal phosphides such as P, CoP, FeP, WP, MoP and the like are continuously reported in the field of catalysis, and experiments prove that in the transition metal phosphides, the charge density is transferred from the transition metal to P, so that two active sites of metal with positive charge and P with negative charge are formed, and the catalytic activity of the phosphides is enhanced. NiMoP is widely used in catalytic Hydrodesulfurization (HDS), and HDS and hydrogen evolution reactions have relatively similar requirements on surface hydrogen adsorption free energy (Δ GH), so NiMoP may also have good hydrogen evolution performance. In addition, Cu₃P has been reported as an electrocatalyst Hydrogen Evolution Reaction (HER) catalyst, although its catalytic activity is not comparable to that of the already reported phosphides of Fe, Co and Ni, due to Cu₃P has better conductivity, and Cu₃P can be catalyzed when compounded with other materialsDifferent active sites are cooperatively exposed in the process, so that the catalytic capability of the composite material can be improved.

The in-situ loaded three-dimensional porous material is beneficial to enhancing the activity of the catalyst due to the novel structural characteristics, such as large specific surface area caused by pore channels or layered structures with different sizes, and the phenomenon also arouses great interest in the fields of catalysis, energy storage and conversion and the like. However, NiMoP and Cu₃The application of the composite material prepared by P together in the field of hydrogen evolution catalysis is not reported. Therefore, how to enhance the activity and stability of the electrocatalyst through a mature design and synthesis method is still an urgent problem to be solved at present.

Disclosure of Invention

In view of the above, the invention aims to overcome the defects of the prior art, and provides a copper foam loaded nickel-molybdenum-phosphorus-based composite material, and a preparation method and application thereof, so as to expand the application of a transition metal compound in the field of hydrogen production by water electrolysis.

In order to achieve the purpose, the technical scheme of the invention is realized as follows:

a preparation method of a foam copper-loaded nickel-molybdenum-phosphorus-based composite material comprises the following steps:

s1, adding deionized water into ammonium persulfate and potassium hydroxide to prepare a mixed solution A, placing the pretreated foamy copper into the mixed solution A, and standing for reaction to obtain Cu (OH) 2/CF;

s2, adding deionized water into nickel nitrate hexahydrate, sodium molybdate dihydrate and urea to prepare a mixed solution B, placing Cu (OH)2/CF in the mixed solution B, carrying out hydrothermal reaction in a high-pressure reaction kettle to obtain a NiMoL DH @ Cu (OH)2 nano array, and washing, freezing and drying to obtain a NiMo LDH @ Cu (OH)2/CF composite nano material;

s3, mixing the NiMo LDH @ Cu (OH)2/CF composite nano material with a phosphorization raw material, placing the mixture in a tubular furnace for calcination, and cooling to obtain the foam copper loaded nickel-molybdenum-phosphorus-based composite material.

Optionally, in the mixed solution a in step S1, the mass ratio of the ammonium persulfate to the potassium hydroxide is in a range from 0.1: 1 to 0.3: 2 in the range of.

Optionally, the step of pretreating the pretreated copper foam in step S1 includes sequentially subjecting the copper foam to ultrasonic treatment with absolute ethanol, hydrochloric acid, and deionized water.

Alternatively, the conditions of the standing reaction in step S1 include a reaction temperature in the range of 20 ℃ to 30 ℃ and a reaction time in the range of 20min to 60 min.

Alternatively, the conditions of the hydrothermal reaction in step S2 include a reaction temperature in the range of 160 ℃ to 200 ℃ and a reaction time in the range of 2h to 8 h.

Optionally, the amount of the phosphorizing raw material in step S3 is calculated according to the content of phosphorus, and the mass ratio of the phosphorizing raw material to the NiMo LDH @ cu (oh)2/CF composite nanomaterial is 1: 1 to 4: 1, in the range of.

Optionally, the phosphating raw material comprises one of sodium phosphate, sodium phosphite and sodium hypophosphite.

Alternatively, the calcining conditions of step S3 include: under the protection of inert gas, the calcining temperature is within the range of 300 ℃ to 800 ℃, the calcining heat preservation time is within the range of 40min to 200min, and the temperature rise rate of the tube furnace is within the range of 2 ℃/min to 8 ℃/min.

The invention also aims to provide a copper foam loaded nickel-molybdenum-phosphorus-based composite material, which is prepared by adopting the preparation method of the copper foam loaded nickel-molybdenum-phosphorus-based composite material.

The third purpose of the invention is to provide an application of the copper foam loaded nickel-molybdenum-phosphorus-based composite material in the field of hydrogen evolution through water electrolysis.

Compared with the prior art, the foam copper loaded nickel-molybdenum-phosphorus-based composite material and the preparation method and application thereof provided by the invention have the following advantages:

(1) the invention utilizes the abundant three-dimensional pore structure of the foam copper to grow Cu (OH) on the surface₂Generating a hollow layered structure NiMo LDH @ Cu (OH) by a hydrothermal method through a nano array rod₂/CF, finally reacting with sodium hypophosphite in a tube furnace to prepare NiMoP @ Cu with a hollow layered structure₃P nano array, the hollow layered structure is favorable for NiMoP @ Cu due to the large specific surface area₃The full contact of P and electrolyte accelerates the mass transfer, thereby enhancing the hydrogen evolution reaction activity of the electrocatalyst; furthermore, Cu₃An electron transfer effect exists between P and NiMoP, the charge transfer resistance is reduced, the catalytic activity is enhanced, and the NiMoP @ Cu is endowed with a synergistic effect between the P and the NiMoP₃The P/CF has more active sites, which is beneficial to further enhancing the hydrogen evolution activity of the composite material.

(2) The preparation method provided by the invention is simple, the raw materials are easy to obtain, the reaction conditions are easy to achieve, and the obtained product has a great industrial application prospect.

Drawings

In order to more clearly illustrate the technical solutions of the present invention or the prior art, the drawings needed for the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and those skilled in the art can also obtain other drawings according to the drawings without creative efforts.

FIG. 1(a) shows Cu (OH) according to example 1 of the present invention₂FIG. 1(b) is a scanning electron micrograph of NiMo LDH @ Cu (OH) according to example 1 of the present invention₂FIG. 1(c) is a scanning electron micrograph of NiMoP @ Cu3P/CF according to example 1 of the present invention;

FIG. 2 shows CF, Cu (OH)₂/CF、Cu₃P/CF、NiMo LDH/CF、NiMoP/CF、NiMo [email protected](OH)₂/CF and NiMoP @ Cu₃Impedance plot of P/CF;

FIG. 3 shows NiMoP @ Cu according to an embodiment of the present invention₃XRD pattern of P/CF;

FIG. 4 shows pure copper foam, Cu (OH)₂/CF，Cu₃P/CF，NiMo LDH/CF，NiMoP/CF，NiMo [email protected](OH)₂/CF, commercial platinum-carbon catalyst and NiMoP @ Cu₃LSV graph of P/CF.

Detailed Description

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail below.

In the description of the present invention, it should be noted that the terms "first" and "second" mentioned in the embodiments of the present invention are only used for descriptive purposes and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature.

In the description of embodiments of the present application, the description of the term "some embodiments" means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. Throughout this specification, the schematic representations of the terms used above do not necessarily refer to the same implementation or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

It should be noted that the term "in.

The embodiment of the invention provides a preparation method of a foam copper loaded nickel-molybdenum-phosphorus-based composite material, which comprises the following steps:

s1, taking ammonium persulfate and potassium hydroxide, adding deionized water to prepare a mixed solution A, placing the pretreated foamy copper into the mixed solution A, and standing for reaction to obtain Cu (OH)₂/CF；

S2, taking nickel nitrate hexahydrate Ni (NO)₃)₂·6H₂O, sodium molybdate dihydrate H₄MoNa₂O₆And urea, adding deionized water to prepare mixed solution B, and adding Cu (OH)₂Placing the/CF in the mixed solution B, and carrying out hydrothermal reaction in a high-pressure reaction kettle to obtain NiMoL DH @ Cu (OH)₂Washing the nano array with water, and freeze-drying to obtain NiMo LDH @ Cu (OH)₂a/CF composite nanomaterial;

s3, mixing NiMo LDH @ Cu (OH)₂Mixing the/CF composite nano material with the phosphorization raw material, placing the mixture in a tubular furnace for calcining, and cooling to obtain the foam copperLoad nickel molybdenum phosphorus base composite material NiMoP @ Cu₃P。

The invention utilizes the abundant three-dimensional pore structure of the foam copper to grow Cu (OH) on the surface₂Generating a hollow layered structure NiMo LDH @ Cu (OH) by a hydrothermal method through a nano array rod₂/CF, finally reacting with sodium hypophosphite in a tube furnace to prepare NiMoP @ Cu with a hollow layered structure₃P nano array, the hollow layered structure is favorable for NiMoP @ Cu due to the large specific surface area₃The full contact of P and electrolyte accelerates the mass transfer, thereby enhancing the hydrogen evolution reaction activity of the electrocatalyst; in addition, an electron transfer effect exists between the Cu3P and the NiMoP, so that the charge transfer resistance is reduced, the catalytic activity is enhanced, and the synergistic effect between the two enables the NiMoP @ Cu3P/CF to have more active sites, thereby being beneficial to further enhancing the hydrogen evolution activity of the composite material.

Specifically, in the mixed solution a in step S1, the mass ratio of ammonium persulfate to potassium hydroxide is 0.1: 1 to 0.3: 2 in the range of. After mixing ammonium sulfate and potassium hydroxide, the conditions of standing reaction include reaction temperature in the range of 20-30 ℃ and reaction time in the range of 20-60 min.

The invention takes the foam copper as the substrate, utilizes the capillary action of the foam copper with large specific surface area and proper pore size and the inner wall of the pore, and adopts a normal temperature refining method to synthesize Cu (OH) on the surface in situ₂The loss of the catalyst can be effectively reduced by the nanorod array.

Further, the copper foam is subjected to pretreatment, wherein the pretreatment comprises the steps of sequentially carrying out ultrasonic treatment on the copper foam in absolute ethyl alcohol, hydrochloric acid and deionized water, cleaning and airing. Namely, the foamy copper is treated by ultrasonic in absolute ethyl alcohol for 5-20min, then treated by ultrasonic in concentrated hydrochloric acid for 10-40min, then treated by ultrasonic in distilled water for 5-20min, and finally dried for standby.

In step S2, the conditions for hydrothermal reaction after mixing nickel nitrate hexahydrate, sodium molybdate dihydrate and urea include a reaction temperature in the range of 160 ℃ to 200 ℃ and a reaction time in the range of 2h to 8 h.

Wherein the molar ratio of nickel nitrate hexahydrate, sodium molybdate dihydrate and urea is 1: 1: 5 to 4: 1: within 5.

In step S3, the phosphating material comprises sodium phosphate Na₃PO₄Sodium phosphite Na₂HPO₃·5H₂O and sodium hypophosphite NaH₂PO₂·H₂And O is one of the compounds. Wherein the dosage of the phosphorization raw material is calculated according to the content of phosphorus, and the phosphorization raw material and NiMo LDH @ Cu (OH)₂The mass ratio of the/CF composite nano material is 1: 1 to 4: 1, in the range of.

NiMo [email protected](OH)₂After the/CF composite nano material is mixed with the phosphorization raw material, the calcining conditions comprise that: under the protection of inert gas, the calcining temperature is within the range of 300 ℃ to 800 ℃, the calcining heat preservation time is within the range of 40min to 200min, and the temperature rise rate of the tube furnace is within the range of 2 ℃/min to 8 ℃/min. Among them, the inert gas is preferably argon gas.

The preparation method provided by the invention is simple, the raw materials are easy to obtain, the reaction conditions are easy to achieve, and the obtained product has a great industrial application prospect.

The invention further provides a foam copper loaded nickel-molybdenum-phosphorus-based composite material which is prepared by the preparation method of the foam copper loaded nickel-molybdenum-phosphorus-based composite material.

The foam copper loaded nickel-molybdenum-phosphorus-based composite material NiMoP @ Cu is disclosed by the invention₃P, compared to single metal phosphides, bi-or multi-metal phosphides can adjust the charge properties between metals, enhancing the synergistic effect and thus increasing the catalytic activity. That is, Cu₃An electron transfer effect exists between P and NiMoP, so that the charge transfer resistance is reduced, and the catalytic activity is enhanced. NiMoP and Cu₃Synergistic effect between P endows NiMoP @ Cu₃The P/CF has more active sites, and is beneficial to enhancing the hydrogen evolution activity and stability of the composite material.

The invention further provides application of the copper foam loaded nickel-molybdenum-phosphorus-based composite material in the field of hydrogen evolution through electrolysis of water. The copper foam loaded nickel-molybdenum-phosphorus-based composite material can be directly used as a cathode in a photoelectric decomposition water battery, shows excellent photoelectric hydrogen evolution activity and stability, and has wide application prospects in the aspects of photoelectric decomposition of water and the like.

On the basis of the above embodiments, the present invention will be further illustrated by the following specific examples of the preparation method of the copper foam supported nickel-molybdenum-phosphorus-based composite material. It should be understood that these examples are for illustrative purposes only and are not intended to limit the scope of the present invention. The following examples are examples of experimental procedures not specified under specific conditions, generally according to the conditions recommended by the manufacturer. Unless otherwise indicated, percentages and parts are by mass.

Example 1

The embodiment provides a preparation method of a foam copper-loaded nickel-molybdenum-phosphorus-based composite material, which comprises the following steps:

s1, cutting the foam copper into 1 x 3cm²Several pieces in shape, placing into anhydrous ethanol, ultrasonic treating for 15min, and adding 1mol L^-1And (3) ultrasonically cleaning the oxide on the surface of the foam copper for 30min by hydrochloric acid, and finally ultrasonically cleaning the foam copper for 10min by using deionized water. Then 0.41g of ammonium persulfate and 2.53g of potassium hydroxide are respectively taken out of the two beakers, 7.5ml of deionized water is respectively added to form solutions, and then the solutions are mixed and subjected to ultrasonic treatment for 5min to prepare clear solutions; placing the pretreated foam copper into the mixed solution, standing for 20min, washing with deionized water for several times to change the color of the foam copper from golden yellow to bright blue to obtain Cu (OH)₂/CF。

S2, 1mmol of nickel nitrate hexahydrate, 1mmol of sodium molybdate dihydrate and 5mmol of urea are weighed into a 50mL conical flask, 30mL of deionized water is added, ultrasonic treatment is carried out for 10min to form a uniform and transparent pale green solution, the solution is transferred into a 50mL inner lining of polytetrafluoroethylene, and Cu (OH)₂the/CF leans against the inner lining wall obliquely, the cover of the stainless steel reaction kettle is screwed down, the stainless steel reaction kettle is placed in a muffle furnace, and the hydrothermal reaction is carried out for 2 hours at 160 ℃ to obtain NiMoL DH @ Cu (OH)₂And (3) a nano array, after the reaction kettle is cooled to room temperature, repeatedly washing the foam copper by using deionized water, wherein the color of the foam copper is changed from bright blue to light green, and obtaining NiMo LDH @ Cu (OH)₂the/CF composite nanometer material.

S3, respectively filling two quartz boats with NiMo LDH @ Cu (OH)₂/CF and 1g NaH₂PO₂·H₂O, placing two quartz boats in a tube furnace and flowingPhosphating under Ar atmosphere with NaH₂PO₂·H₂Placing O at the upstream of Ar airflow, preserving heat for 2h at the temperature of 300 ℃ for phosphorization, heating the tubular furnace at the speed of 2 ℃/min, cooling to room temperature after the reaction is finished, and changing the color of the foam copper to black to obtain the foam copper loaded nickel-molybdenum-phosphorus-based composite material NiMoP @ Cu₃P。

Cu (OH) of example 1₂/CF、NiMo [email protected](OH)₂/CF and NiMoP @ Cu₃P/CF was tested to obtain the SEM image shown in FIG. 1. Wherein, FIG. 1(a) shows Cu (OH)₂Scanning Electron micrograph of/CF, as can be seen from FIG. 1(a), prepared Cu (OH)₂The nano rods grow on the surface of the foam copper regularly and vertically, the surfaces of the nano rods are smooth and uniform in size, and the average diameter of the nano rods is about 500 nm.

FIG. 1(b) is NiMo LDH @ Cu (OH)₂In the scanning electron microscope image of/CF, as can be seen from FIG. 1(b), the nanorods are uniformly arranged on the foam copper substrate, the size of the nanorods is about 1 μm, and a pore structure formed by interleaving and stacking nanosheets is grown on the surface of the nanorods, so that the specific surface area of the material can be increased, and the catalytic performance of the material can be improved.

FIG. 1(c) is NiMoP @ Cu₃The scanning electron micrograph of P/CF, as can be seen from FIG. 1(c), the rod-like structure of the material after phosphorization still exists, the diameter of the nanorod is about 800-900nm, and the surface of the nanorod becomes smooth due to the reduction of the nanosheet structure, which is probably due to the volume shrinkage of the NiMo LDH nanosheet during the phosphorization process.

Example 2

The embodiment provides a preparation method of a copper foam loaded nickel-molybdenum-phosphorus-based composite material, which is different from the embodiment 1 in that:

in step S2, carrying out hydrothermal reaction at 180 ℃ for 2h to obtain NiMoL DH @ Cu (OH)₂A nano-array;

the other steps and parameters were the same as in example 1.

FIG. 2 shows CF, Cu (OH) according to example 2₂/CF、Cu₃P/CF、NiMo LDH/CF、NiMoP/CF、NiMo [email protected](OH)₂/CF and NiMoP @ Cu₃Impedance diagram of P/CF, wherein FIG. 2(a) is CF, Cu (OH)₂/CF、Cu₃P/CF、NiMo LDH/CF、NiMoP/CF、NiMo [email protected](OH)₂/CF and NiMoP @ Cu₃Nyquist plot for P/CF tested at open circuit voltage and applied voltage (-0.2V vers RHE). As can be seen from the figure, the solution resistances (Rs) of all the synthetic materials are small (Rs)<5 Ω) of the two, wherein NiMoP @ Cu₃Rs of P/CF was minimal (2.5. omega.), indicating a rod-like structure of NiMoP @ Cu₃The contact between P and CF substrates is good to reduce the resistance.

NiMoP @ Cu as shown in FIG. 2(b)₃Charge transfer resistance (R) of P/CF_ct) About 12.1 omega at an overpotential of-200 mV versus RHE, lower than the charge transfer resistance of other synthetic materials. The result further shows that the NiMoP with the nano-sheet structure and the Cu with the hollow structure₃The transfer of electrons between P results in a composite material with a lower charge transfer resistance. NiMoP @ Cu₃Close contact between P and CF and NiMoP and Cu₃Electron transfer between P is responsible for enhanced conductive performance.

Example 3

The embodiment provides a preparation method of a copper foam loaded nickel-molybdenum-phosphorus-based composite material, which is different from the embodiment 1 in that:

in step S3, the temperature is kept at 350 ℃ for 4h for phosphorization to obtain NiMoP @ Cu₃P；

The other steps and parameters were the same as in example 1.

FIG. 3 is the NiMoP @ Cu prepared in example 3₃XRD pattern of P/CF, as can be seen from FIG. 3, distinct diffraction peaks appear at 36.1 °, 39.3 °, 41.7 °, 45.1 °, 46.2 °, 47.3 °, 53.4 °, 66.6 ° and 77.3 °, corresponding to Cu, respectively₃The (112), (202), (211), (300), (113), (212), (104), (214) and (412) crystal planes of P; diffraction peaks at 40.8 °, 44.6 °, 47.3 °, 54.2 °, 72.3 ° and 74.7 ° correspond to the (111), (201), (210), (300), (311) and (400) crystal planes of Ni2P, respectively. Diffraction peaks at 27.6 °, 31.9 °, 43.2 °, 57.7 °, 67.2 ° and 74.4 ° correspond to the (001), (100), (101), (110), (102) and (201) crystal planes of MoP, respectively. These results are shown in the tableAlthough Cu is successfully prepared on the foam copper substrate₃P、Ni₂P and MoP. Ni₂The diffraction peaks of P and MoP are slightly shifted, indicating Ni₂P and MoP with Cu₃There is an interaction between P to affect Ni₂Diffraction peak positions of P and MoP.

Example 4

The embodiment provides a preparation method of a copper foam loaded nickel-molybdenum-phosphorus-based composite material, which is different from the embodiment 1 in that:

in step S2, carrying out hydrothermal reaction at 180 ℃ for 4h to obtain NiMoL DH @ Cu (OH)₂A nano-array;

in step S3, the temperature is kept at 350 ℃ for 4h for phosphorization to obtain NiMoP @ Cu₃P；

The other steps and parameters were the same as in example 1.

CF, Cu (OH) obtained as described in example 4₂/CF，Cu₃P/CF，NiMo LDH/CF，NiMoP/CF，NiMo [email protected](OH)₂/CF，[email protected]₃P/CF was electrochemically tested, and in this test, all electrochemical tests were performed on the chenghua 760E electrochemical workstation. During testing, a standard three-electrode system is adopted, a newly prepared electrode material is directly used as a working electrode, a graphite rod is used as a counter electrode, and a saturated calomel electrode is used as a reference electrode. The test temperature was 25 ℃ and the electrolyte was N during the test₂Saturated 1m koh. In the test, all voltages were calibrated by the formula, calibrating the voltage relative to the saturated calomel electrode to the voltage relative to the standard hydrogen electrode:

E(RHE)＝E(SCE)+0.242+0.059pH

linear voltammetric scan (LSV): the overpotential of the catalytic material under different current densities can be obtained through linear voltammetry scanning. When LSV test is carried out, the scanning speed is 2mV/s, the iR compensation is automatically carried out by the instrument according to the test result, the compensation degree is 85%, and the test result is shown in figure 4.

The curves in FIG. 4 represent, in order from left to right, CF, NiMo LDH/CF, Cu (OH)₂/CF、Cu₃P/CF、NiMoP/CF、NiMo [email protected](OH)₂/CF、[email protected]₃P/CF and 20%LSV curve of Pt/C.

As can be seen, NiMoP @ Cu₃P/CF at a current density of 10mA cm^-2And 100mAcm^-2When the voltage is higher than the voltage, the required overpotential is 81mV and 226mV, which are both lower than Cu₃P/CF(η₁₀176mV) and NiMoP/CF (η)₁₀156 mV). This result indicates that the hollow structure facilitates sufficient contact of the active site with the electrolyte and gas evolution, while Cu₃The synergistic effect of P and NiMoP is also responsible for enhancing the HER activity of the composite. NiMoP @ Cu₃P/CF at 10mAcm^-2The overpotential of the time is also higher than that of NiMo LDH @ Cu (OH)₂/CF(η₁₀111mV) low indicates that the phosphide has better HER activity than the precursor hydroxide.

Although the present disclosure has been described above, the scope of the present disclosure is not limited thereto. Various changes and modifications may be effected therein by one of ordinary skill in the pertinent art without departing from the spirit and scope of the present disclosure, and these changes and modifications are intended to be within the scope of the present disclosure.