A NiFe LDH-loaded platinum-ruthenium diatomic electrocatalytic material and preparation method thereof

Abstract

The invention relates to a NiFe LDH-loaded platinum-ruthenium diatomic electrocatalytic material and a preparation method thereof, and belongs to the technical field of electrochemical catalysis. The preparation method of the NiFe LDH-loaded platinum-ruthenium diatomic electrocatalytic material comprises the following steps: S1: dispersing oxidized carbon nanotubes in nitrogen-saturated water to prepare an oxidized carbon nanotube suspension; S2: mixing ferric nitrate nonahydrate, nickel nitrate hexahydrate, ammonium fluoride and hexamethylenetetramine with the oxidized carbon nanotube suspension, and reacting to obtain a nickel-iron double hydroxide / carbon nanotube composite material; S3: adding ruthenium trichloride trihydrate to the nickel-iron double hydroxide / carbon nanotube composite material obtained in step S2 under a nitrogen protection environment, and reacting to obtain a ruthenium@nickel-iron double hydroxide / carbon nanotube composite material; S4: adding chloroplatinic acid hexahydrate to the ruthenium@nickel-iron double hydroxide / carbon nanotube composite material obtained in step S3 under a nitrogen protection environment, and reacting to obtain a platinum-ruthenium@nickel-iron double hydroxide / carbon nanotube composite material. The preparation method is simple and easy for large-scale production, and the obtained product has good electrical conductivity and catalytic activity.

Description

Technical Field

[0001] The invention belongs to the technical field of electrochemical catalysis, and specifically relates to a NiFe LDH-loaded platinum-ruthenium diatomic electrocatalytic material and a preparation method thereof. Background Art

[0002] The excessive use of fossil energy has caused increasingly serious air pollution, seriously endangering people's lives and health, and mankind is facing serious environmental problems and energy shortages. In particular, my country's "carbon peak" task is arduous, and achieving "carbon neutrality" urgently requires the development of efficient, clean and sustainable energy. Hydrogen energy, as a clean secondary energy source, has the advantages of high energy density, zero pollution, zero carbon emissions, and is easy to transport and store, making it an ideal new alternative energy source. The electrolysis of water to produce hydrogen technology has attracted widespread attention due to its mild reaction and high energy conversion efficiency. The electrochemical water decomposition reaction consists of a hydrogen evolution reaction at the cathode and an oxygen evolution reaction at the anode. At present, the precious metal platinum is still the main catalyst for the electrocatalytic hydrogen evolution reaction, but due to its high price, low reserves and insufficient stability, it has seriously hindered the large-scale development of the electrolysis of water to produce hydrogen technology (Adv. Mater. 2018, 30, 1706279). Therefore, it is still necessary to develop a low-content platinum-based efficient hydrogen evolution catalyst.

[0003] Layered nickel-iron hydroxides facilitate contact between catalysts and electrolytes due to their open structure, which is conducive to the diffusion of species participating in the reaction in the liquid phase. The d electron layer of the iron element is easy to lose / gain electrons, has strong reduction / oxidation ability, is easy to form defective structures, and can effectively fix precious metal atoms. Dispersing precious metals on layered nickel-iron hydroxides improves the catalytic performance of the composite catalyst on the one hand, and improves the utilization rate of precious metals on the other hand, which is an effective way to build efficient catalysts. Feng et al. synthesized NiFeRu-LDH so that part of Ru entered the lattice of NiFe-LDH (Adv. Mater. 2018, 30, 1706279). The introduction of Ru reduces the reaction energy barrier of the Volmer step, greatly improving the efficiency of hydrogen evolution. Wang et al. introduced Pt single atoms between the NiFe-LDH layers (Energy Environ. Sci., 2021, 14, 6428-6440). The Pt single atoms between the layers enhance the electron transfer of the LDH carrier and accelerate the decomposition of water. In addition, Ma et al. introduced Pt single atoms in situ into α-phase nickel-iron double hydroxide (Adv. Funct. Mater. 2022, 2203342). Pt single atoms act as highly active sites for hydrogen evolution reaction, greatly enhancing the hydrogen evolution performance of the composite material. However, the catalytic performance of existing layered nickel-iron hydroxides still needs to be improved, which is not conducive to large-scale promotion and application. Summary of the invention

[0004] The purpose of the present invention is to provide a NiFe LDH loaded platinum ruthenium diatomic electrocatalytic material to solve the technical problem that the existing layered nickel iron hydroxide has poor electrochemical hydrogen evolution performance and is not suitable for large-scale promotion and application.

[0005] Another object of the present invention is to provide a method for preparing a NiFe LDH-loaded platinum-ruthenium diatomic electrocatalytic material.

[0006] In order to achieve the above purpose, the technical solution adopted by the present invention is:

[0007] A method for preparing a NiFe LDH-loaded platinum-ruthenium diatomic electrocatalytic material comprises the following steps:

[0008] S1: dispersing oxidized carbon nanotubes in nitrogen-saturated water to prepare an oxidized carbon nanotube suspension;

[0009] S2: mixing iron nitrate nonahydrate, nickel nitrate hexahydrate, ammonium fluoride and hexamethylenetetramine with the oxidized carbon nanotube suspension to react and obtain a nickel-iron double hydroxide / carbon nanotube composite material;

[0010] S3: adding ruthenium trichloride trihydrate to the nickel iron double hydroxide / carbon nanotube composite material obtained in step S2 under a nitrogen protection environment to react and obtain a ruthenium@nickel iron double hydroxide / carbon nanotube composite material;

[0011] S4: In a nitrogen-protected environment, chloroplatinic acid hexahydrate is added to the ruthenium@nickel iron double hydroxide / carbon nanotube composite material obtained in step S3 to react to obtain a platinum ruthenium@nickel iron double hydroxide / carbon nanotube composite material.

[0012] Furthermore, in step S1, the mass concentration of the oxidized carbon nanotubes in the oxidized carbon nanotube suspension is 0.2-0.8 mg / mL.

[0013] Furthermore, in step S2, 0.2-0.8 mmol of nickel nitrate hexahydrate, 0.1-0.4 mmol of ferric nitrate nonahydrate, 0.6-2.4 mmol of ammonium fluoride and 25-100 mL of hexamethylenetetramine solution are added to the oxidized carbon nanotube suspension prepared by every 20 mg of oxidized carbon nanotubes.

[0014] Furthermore, in step S2, the hexamethylenetetramine solution is a nitrogen-saturated hexamethylenetetramine solution, and the molar concentration of hexamethylenetetramine in the hexamethylenetetramine solution is 0.08 mmol.mL -1 .

[0015] Furthermore, in step S2, the reaction temperature is 80-120° C., and the reaction time is 5-12 hours.

[0016] Furthermore, in step S3, 0.0125-0.4 mmol of ruthenium trichloride trihydrate is added to the oxidized carbon nanotube suspension prepared from 20 mg of oxidized carbon nanotubes.

[0017] Furthermore, in step S3, the reaction temperature is 60-120° C., and the reaction time is 5-18 h.

[0018] Furthermore, in step S4, 0.0125-0.4 mmol of chloroplatinic acid hexahydrate is added to the oxidized carbon nanotube suspension prepared by adding 20 mg of oxidized carbon nanotubes.

[0019] Furthermore, in step S4, the reaction temperature is 20 to 90° C., and the reaction time is 5 to 12 hours.

[0020] Furthermore, in step S1, the oxidized carbon nanotubes are dispersed in nitrogen-saturated water by ultrasonic dispersion for 30 to 60 minutes, and nitrogen is passed for 1 to 2 hours to remove dissolved oxygen in the ultrapure water.

[0021] A NiFe LDH-loaded platinum-ruthenium diatomic electrocatalyst material prepared by the above-mentioned method for preparing the NiFe LDH-loaded platinum-ruthenium diatomic electrocatalyst material.

[0022] Beneficial effects of the present invention:

[0023] The invention adopts hydrothermal synthesis technology, has a relatively simple preparation method, is easy to operate, has low equipment requirements, and is conducive to large-scale industrialization.

[0024] The platinum-ruthenium@nickel-iron double hydroxide / carbon nanotube composite material prepared by the present invention has good electrical conductivity and catalytic activity, and can be applied to the field of water electrolysis. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 X-ray diffraction patterns of the composite materials prepared in Example 1 and Comparative Examples 1-3 of the present invention;

[0026] Figure 2 This is a transmission electron microscope image of the nickel-iron double hydroxide / carbon nanotube composite material in Comparative Example 1 of the present invention;

[0027] Figure 3 It is a transmission electron microscope image of the ruthenium@nickel iron double hydroxide / carbon nanotube composite material in Comparative Example 2 of the present invention;

[0028] Figure 4 It is a transmission electron microscope image of the platinum@nickel iron double hydroxide / carbon nanotube composite material in comparative example 3 of the present invention;

[0029] Figure 5This is a transmission electron microscope image of the platinum-ruthenium@nickel-iron double hydroxide / carbon nanotube composite material in Example 1 of the present invention;

[0030] Figure 6 This is a graph showing the electrocatalytic performance of the composite materials prepared in Example 1 and Comparative Examples 1-3 of the present invention. DETAILED DESCRIPTION

[0031] The present invention will be further described below in conjunction with the embodiments of the present invention and the accompanying drawings.

[0032] Example 1

[0033] The preparation method of the NiFe LDH-loaded platinum-ruthenium diatomic electrocatalytic material of this embodiment comprises the following steps:

[0034] S1: Weigh 20 mg of oxidized carbon nanotubes and add them into a 100 mL beaker containing 50 mL of water. Ultrasonic dispersion is performed for 30 min, and nitrogen is passed for 1 h to remove dissolved oxygen in ultrapure water to make it reach a nitrogen saturated state, thereby obtaining an oxidized carbon nanotube suspension.

[0035] S2: Transfer the nitrogen-saturated carbon nanotube dispersion to a 250 mL three-necked flask, add 0.4 mmol nickel nitrate hexahydrate, 0.2 mmol iron nitrate nonahydrate, and 1.2 mmol ammonium fluoride under nitrogen protection, and after they are dissolved, add 50 mL nitrogen-saturated hexamethylenetetramine solution to the side of the three-necked flask. The molar concentration of the hexamethylenetetramine solution is 0.08 mmol.mL -1 In a three-necked flask protected by nitrogen, a nickel-iron double hydroxide / carbon nanotube composite material was obtained at a hydrothermal temperature of 120°C for 5 hours.

[0036] S3: Under nitrogen protection, 0.15 mmol of ruthenium trichloride trihydrate was added to the nickel iron double hydroxide / carbon nanotube composite material obtained in step S2, and the ruthenium@nickel iron double hydroxide / carbon nanotube composite material was obtained in a three-necked flask under nitrogen protection at a hydrothermal temperature of 120° C. for 18 h.

[0037] S4: Under nitrogen protection, 0.15 mmol of chloroplatinic acid hexahydrate is added to the ruthenium@nickel iron double hydroxide / carbon nanotube composite material obtained in step S3, and the NiFe LDH-loaded platinum-ruthenium diatomic electrocatalytic material is obtained in a three-necked flask under nitrogen protection at a hydrothermal temperature of 60° C. for 5 h.

[0038] The NiFe LDH-loaded platinum-ruthenium diatomic electrocatalytic material of the present embodiment is prepared by the preparation method of the NiFe LDH-loaded platinum-ruthenium diatomic electrocatalytic material of the present embodiment.

[0039] Example 2

[0040] The preparation method of the NiFe LDH-loaded platinum-ruthenium diatomic electrocatalytic material of this embodiment comprises the following steps:

[0041] S1: Weigh 20 mg of oxidized carbon nanotubes and add them into a 100 mL beaker containing 50 mL of water. Ultrasonic dispersion is performed for 30 min, and nitrogen is passed for 1 h to remove dissolved oxygen in ultrapure water to make it reach a nitrogen saturated state, thereby obtaining an oxidized carbon nanotube suspension.

[0042] S2: Transfer the nitrogen-saturated carbon nanotube dispersion to a 250 mL three-necked flask, add 0.2 mmol nickel nitrate hexahydrate, 0.1 mmol iron nitrate nonahydrate, and 0.6 mmol ammonium fluoride under nitrogen protection, and after they are dissolved, add 25 mL nitrogen-saturated hexamethylenetetramine solution to the side of the three-necked flask. The molar concentration of the hexamethylenetetramine solution is 0.08 mmol.ml -1 In a three-necked flask protected by nitrogen, a nickel-iron double hydroxide / carbon nanotube composite material was obtained at a hydrothermal temperature of 120°C for 5 hours.

[0043] S3: Under nitrogen protection, 0.0125 mmol of ruthenium trichloride trihydrate was added to the nickel iron double hydroxide / carbon nanotube composite material obtained in step S2, and the ruthenium@nickel iron double hydroxide / carbon nanotube composite material was obtained in a three-necked flask under nitrogen protection at a hydrothermal temperature of 120° C. for 18 h.

[0044] S4: Under nitrogen protection, 0.0125 mmol of chloroplatinic acid hexahydrate is added to the ruthenium@nickel iron double hydroxide / carbon nanotube composite material obtained in step S3, and the NiFe LDH-loaded platinum-ruthenium diatomic electrocatalytic material is obtained in a three-necked flask under nitrogen protection at a hydrothermal temperature of 60°C for 5 hours.

[0045] The NiFe LDH-loaded platinum-ruthenium diatomic electrocatalytic material of the present embodiment is prepared by the preparation method of the NiFe LDH-loaded platinum-ruthenium diatomic electrocatalytic material of the present embodiment.

[0046] Example 3

[0047] The preparation method of the NiFe LDH-loaded platinum-ruthenium diatomic electrocatalytic material of this embodiment comprises the following steps:

[0048] S1: Weigh 20 mg of oxidized carbon nanotubes and add them into a 100 mL beaker containing 50 mL of water. Ultrasonic dispersion is performed for 30 min, and nitrogen is passed for 1 h to remove dissolved oxygen in ultrapure water to make it reach a nitrogen saturated state, thereby obtaining an oxidized carbon nanotube suspension.

[0049] S2: Transfer the nitrogen-saturated carbon nanotube dispersion to a 250 mL three-necked flask, add 0.8 mmol nickel nitrate hexahydrate, 0.4 mmol iron nitrate nonahydrate, and 2.4 mmol ammonium fluoride under nitrogen protection, and after they are dissolved, add 100 mL nitrogen-saturated hexamethylenetetramine solution to the side of the three-necked flask. The molar concentration of the hexamethylenetetramine solution is 0.08 mmol.ml -1 In a three-necked flask protected by nitrogen, a nickel-iron double hydroxide / carbon nanotube composite material was obtained at a hydrothermal temperature of 120°C for 5 hours.

[0050] S3: Under nitrogen protection, 0.8 mmol of ruthenium trichloride trihydrate was added to the nickel iron double hydroxide / carbon nanotube composite material obtained in step S2, and the ruthenium@nickel iron double hydroxide / carbon nanotube composite material was obtained in a three-necked flask under nitrogen protection at a hydrothermal temperature of 120° C. for 18 h.

[0051] S4: Under nitrogen protection, 0.8 mmol of chloroplatinic acid hexahydrate is added to the ruthenium@nickel iron double hydroxide / carbon nanotube composite material obtained in step S3, and the NiFe LDH-loaded platinum-ruthenium diatomic electrocatalytic material is obtained in a three-necked flask under nitrogen protection at a hydrothermal temperature of 60° C. for 5 h.

[0052] The NiFe LDH-loaded platinum-ruthenium diatomic electrocatalytic material of the present embodiment is prepared by the preparation method of the NiFe LDH-loaded platinum-ruthenium diatomic electrocatalytic material of the present embodiment.

[0053] Example 4

[0054] The preparation method of the NiFe LDH-loaded platinum-ruthenium diatomic electrocatalytic material of this embodiment comprises the following steps:

[0055] S1: Weigh 20 mg of oxidized carbon nanotubes and add them into a 100 mL beaker containing 25 mL of water. Ultrasonic dispersion is performed for 60 min, and nitrogen is passed for 2 h to remove dissolved oxygen in ultrapure water to make it reach a nitrogen saturated state, thereby obtaining an oxidized carbon nanotube suspension.

[0056] S2: Transfer the nitrogen-saturated carbon nanotube dispersion to a 250 mL three-necked flask, add 0.4 mmol nickel nitrate hexahydrate, 0.2 mmol iron nitrate nonahydrate, and 1.2 mmol ammonium fluoride under nitrogen protection, and after they are dissolved, add 50 mL nitrogen-saturated hexamethylenetetramine solution to the side of the three-necked flask. The molar concentration of the hexamethylenetetramine solution is 0.08 mmol.ml -1 In a three-necked flask protected by nitrogen, a nickel-iron double hydroxide / carbon nanotube composite material was obtained at a hydrothermal temperature of 80°C for 12 h.

[0057] S3: Under nitrogen protection, 0.15 mmol of ruthenium trichloride trihydrate was added to the nickel iron double hydroxide / carbon nanotube composite material obtained in step S2, and the ruthenium@nickel iron double hydroxide / carbon nanotube composite material was obtained under the conditions of hydrothermal temperature of 60° C. for 5 h in a three-necked flask under nitrogen protection.

[0058] S4: Under nitrogen protection, 0.15 mmol of chloroplatinic acid hexahydrate is added to the ruthenium@nickel iron double hydroxide / carbon nanotube composite material obtained in step S3, and the NiFe LDH-loaded platinum-ruthenium diatomic electrocatalytic material is obtained in a three-necked flask under nitrogen protection at a hydrothermal temperature of 20° C. for 12 h.

[0059] The NiFe LDH-loaded platinum-ruthenium diatomic electrocatalytic material of the present embodiment is prepared by the preparation method of the NiFe LDH-loaded platinum-ruthenium diatomic electrocatalytic material of the present embodiment.

[0060] Example 5

[0061] The preparation method of the NiFe LDH-loaded platinum-ruthenium diatomic electrocatalytic material of this embodiment comprises the following steps:

[0062] S1: Weigh 20 mg of oxidized carbon nanotubes and add them into a 100 mL beaker containing 50 mL of water. Ultrasonic dispersion is performed for 30 min, and nitrogen is passed for 1 h to remove dissolved oxygen in ultrapure water to make it reach a nitrogen saturated state, thereby obtaining an oxidized carbon nanotube suspension.

[0063] S2: Transfer the nitrogen-saturated carbon nanotube dispersion to a 250 mL three-necked flask, add 0.3 mmol nickel nitrate hexahydrate, 0.3 mmol iron nitrate nonahydrate, and 1.2 mmol ammonium fluoride under nitrogen protection, and after they are dissolved, add 50 mL nitrogen-saturated hexamethylenetetramine solution to the side of the three-necked flask. The molar concentration of the hexamethylenetetramine solution is 0.08 mmol.ml -1 In a three-necked flask protected by nitrogen, a nickel-iron double hydroxide / carbon nanotube composite material was obtained at a hydrothermal temperature of 120°C for 5 hours.

[0064] S3: Under nitrogen protection, 0.15 mmol of ruthenium trichloride trihydrate was added to the nickel iron double hydroxide / carbon nanotube composite material obtained in step S2, and the ruthenium@nickel iron double hydroxide / carbon nanotube composite material was obtained in a three-necked flask under nitrogen protection at a hydrothermal temperature of 120° C. for 18 h.

[0065] S4: Under nitrogen protection, 0.15 mmol of chloroplatinic acid hexahydrate is added to the ruthenium@nickel iron double hydroxide / carbon nanotube composite material obtained in step S3, and the NiFe LDH-loaded platinum-ruthenium diatomic electrocatalytic material is obtained in a three-necked flask under nitrogen protection at a hydrothermal temperature of 90° C. for 5 h.

[0066] The NiFe LDH-loaded platinum-ruthenium diatomic electrocatalytic material of the present embodiment is prepared by the preparation method of the NiFe LDH-loaded platinum-ruthenium diatomic electrocatalytic material of the present embodiment.

[0067] Comparative Example 1

[0068] The preparation method of the composite material of this comparative example comprises the following steps:

[0069] S1: Weigh 20 mg of oxidized carbon nanotubes and add them into a 100 mL beaker containing 50 mL of water. Ultrasonic dispersion is performed for 30 min, and nitrogen is passed for 1 h to remove dissolved oxygen in ultrapure water to make it reach a nitrogen saturated state, thereby obtaining an oxidized carbon nanotube suspension.

[0070] S2: Transfer the nitrogen-saturated carbon nanotube dispersion to a 250 mL three-necked flask, add 0.4 mmol nickel nitrate hexahydrate, 0.2 mmol iron nitrate nonahydrate, and 1.2 mmol ammonium fluoride under nitrogen protection, and after they are dissolved, add 50 mL nitrogen-saturated hexamethylenetetramine solution to the side of the three-necked flask. The molar concentration of the hexamethylenetetramine solution is 0.08 mmol.mL -1 In a three-necked flask protected by nitrogen, a nickel-iron double hydroxide / carbon nanotube composite material was obtained at a hydrothermal temperature of 120°C for 5 hours.

[0071] The composite material of this comparative example is prepared by adopting the preparation method of the composite material of this comparative example.

[0072] Comparative Example 2

[0073] The preparation method of the composite material of this comparative example comprises the following steps:

[0074] S1: Weigh 20 mg of oxidized carbon nanotubes and add them into a 100 mL beaker containing 50 mL of water. Ultrasonic dispersion is performed for 30 min, and nitrogen is passed for 1 h to remove dissolved oxygen in ultrapure water to make it reach a nitrogen saturated state, thereby obtaining an oxidized carbon nanotube suspension.

[0075] S2: Transfer the nitrogen-saturated carbon nanotube dispersion to a 250 mL three-necked flask, add 0.4 mmol nickel nitrate hexahydrate, 0.2 mmol iron nitrate nonahydrate, and 1.2 mmol ammonium fluoride under nitrogen protection, and after they are dissolved, add 50 mL nitrogen-saturated hexamethylenetetramine solution to the side of the three-necked flask. The molar concentration of the hexamethylenetetramine solution is 0.08 mmol.mL -1 In a three-necked flask protected by nitrogen, a nickel-iron double hydroxide / carbon nanotube composite material was obtained at a hydrothermal temperature of 120°C for 5 hours.

[0076] S3: Under nitrogen protection, 0.15 mmol of ruthenium trichloride trihydrate was added to the nickel iron double hydroxide / carbon nanotube composite material obtained in step S2, and the ruthenium@nickel iron double hydroxide / carbon nanotube composite material was obtained in a three-necked flask under nitrogen protection at a hydrothermal temperature of 120° C. for 18 h.

[0077] The composite material of this comparative example is prepared by adopting the preparation method of the composite material of this comparative example.

[0078] Comparative Example 3

[0079] The preparation method of the composite material of this comparative example comprises the following steps:

[0080] S1: Weigh 20 mg of oxidized carbon nanotubes and add them into a 100 mL beaker containing 50 mL of water. Ultrasonic dispersion is performed for 30 min, and nitrogen is passed for 1 h to remove dissolved oxygen in ultrapure water to make it reach a nitrogen saturated state, thereby obtaining an oxidized carbon nanotube suspension.

[0081] S2: Transfer the nitrogen-saturated carbon nanotube dispersion to a 250 mL three-necked flask, add 0.4 mmol nickel nitrate hexahydrate, 0.2 mmol iron nitrate nonahydrate, and 1.2 mmol ammonium fluoride under nitrogen protection, and after they are dissolved, add 50 mL nitrogen-saturated hexamethylenetetramine solution to the side of the three-necked flask. The molar concentration of the hexamethylenetetramine solution is 0.08 mmol.mL -1 In a three-necked flask protected by nitrogen, a nickel-iron double hydroxide / carbon nanotube composite material was obtained at a hydrothermal temperature of 120°C for 5 hours.

[0082] S3: Under nitrogen protection, 0.15 mmol of chloroplatinic acid hexahydrate is added to the nickel-iron double hydroxide / carbon nanotube composite material obtained in step S2, and the mixture is hydrothermally heated at 60° C. for 5 h in a three-necked flask under nitrogen protection to obtain a platinum@nickel-iron double hydroxide / carbon nanotube composite material.

[0083] The composite material of this comparative example is prepared by adopting the preparation method of the composite material of this comparative example.

[0084] Test Example 1

[0085] The X-ray diffraction patterns of the composite materials of Example 1 and Comparative Examples 1-3 were measured. The results are as follows: Figure 1 The diffraction peaks measured in Example 1 and Comparative Examples 1-3 correspond to the diffraction peaks of NiFe LDH, and no single substance Pt, Ru or RuO is observed. 2 The diffraction peaks of show that Pt and Ru in the composite material synthesized according to the present invention have high dispersibility.

[0086] Test Example 2

[0087] The transmission electron microscopy images of the composite materials of Example 1 and Comparative Examples 1-3 were measured, and the results were as follows: Figure 2-5 It can be seen that the composite materials in Example 1 and Comparative Examples 1-3 are mainly in the form of sheets, which is consistent with Figure 1 The surface scanning image shows that the various elements in the composite material are evenly dispersed.

[0088] Test Example 3

[0089] The electrocatalytic performance of the composite materials of Example 1 and Comparative Examples 1-3 was measured. The results are as follows: Figure 6 shown. Figure 6 By comparing the electrocatalytic hydrogen evolution performance of the composite materials in Example 1 and Comparative Examples 1-3, it can be found that compared with the nickel-iron double hydroxide / carbon nanotube composite material, the ruthenium@nickel-iron double hydroxide / carbon nanotube composite material modified with Ru alone, and the platinum@nickel-iron double hydroxide / carbon nanotube composite material modified with Pt alone, the PtRu co-modified NiFe LDH loaded platinum-ruthenium diatomic electrocatalytic material exhibits better electrocatalytic performance and better kinetic performance, and is a highly efficient catalyst for hydrogen evolution by electrolysis of water.

Claims

1. A method for preparing a NiFe LDH-loaded platinum-ruthenium diatomic electrocatalytic material, It is characterized in that The following steps are involved: S1: dispersing oxidized carbon nanotubes in nitrogen-saturated water to prepare an oxidized carbon nanotube suspension; S2: mixing ferric nitrate nonahydrate, nickel nitrate hexahydrate, ammonium fluoride and hexamethylenetetramine with the oxidized carbon nanotube suspension, reacting to obtain a nickel-iron double hydroxide / carbon nanotube composite material; for every 20 mg of the oxidized carbon nanotube suspension prepared by oxidizing the carbon nanotubes, 0.2-0.8 mmol of nickel nitrate hexahydrate, 0.1-0.4 mmol of ferric nitrate nonahydrate, 0.6-2.4 mmol of ammonium fluoride and 25-100 mL of hexamethylenetetramine solution are added; the reaction temperature is 80-120° C., and the reaction time is 5-12 h; S3: under nitrogen protection, adding ruthenium trichloride trihydrate to the nickel iron double hydroxide / carbon nanotube composite material obtained in step S2 to react and obtain a ruthenium@nickel iron double hydroxide / carbon nanotube composite material; 0.0125-0.4 mmol of ruthenium trichloride trihydrate is added to each 20 mg of oxidized carbon nanotube suspension prepared by oxidized carbon nanotubes; the reaction temperature is 60-120° C., and the reaction time is 5-18 h; S4: Under nitrogen protection, add chloroplatinic acid hexahydrate to the ruthenium@nickel iron double hydroxide / carbon nanotube composite material obtained in step S3 to react to obtain a platinum ruthenium@nickel iron double hydroxide / carbon nanotube composite material; 0.0125-0.4 mmol chloroplatinic acid hexahydrate is added for every 20 mg of oxidized carbon nanotube suspension prepared by oxidizing carbon nanotubes; the reaction temperature is 20-90°C, and the reaction time is 5-12 hours.

2. The method for preparing the NiFe LDH-supported platinum-ruthenium diatomic electrocatalytic material according to claim 1, It is characterized in that In step S1, the mass concentration of the oxidized carbon nanotubes in the oxidized carbon nanotube suspension is 0.2-0.8 mg / mL.

3. The method for preparing the NiFe LDH-supported platinum-ruthenium diatomic electrocatalytic material according to claim 1, It is characterized in that In step S1, the oxidized carbon nanotubes are dispersed in nitrogen-saturated water by ultrasonic dispersion for 30 to 60 minutes, and nitrogen is passed for 1 to 2 hours to remove dissolved oxygen in the ultrapure water.

4. A NiFe LDH-supported platinum-ruthenium diatomic electrocatalyst material prepared by the method for preparing the NiFe LDH-supported platinum-ruthenium diatomic electrocatalyst material as claimed in claim 1.

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