A hollow iron-nickel selenide polyhedral material, its preparation method and application

Abstract

This invention belongs to the field of materials synthesis and discloses a hollow iron-nickel selenide polyhedral material, its preparation method, and its applications. The preparation method involves first adding a metal-organic framework (ZIF-8) and a nickel precursor to a methanol solution to obtain a hollow nickel hydroxide polyhedral material; then adding a potassium ferricyanide aqueous solution and the obtained hollow nickel hydroxide polyhedral material to an ethanol solution to obtain a hollow nickel-iron bimetallic organic framework (MOF) polyhedral material; finally, heating the obtained hollow nickel-iron bimetallic MOF polyhedral material and selenium powder to obtain a hollow iron-nickel selenide polyhedral material. The preparation method of this invention is simple and controllable. The prepared hollow iron-nickel selenide polyhedral material possesses unique hollow structure, heteroatom doping, and carbon material composite characteristics. It has abundant catalytic active sites, facilitating ion transport and thus enhancing its conductivity. It is a structurally stable catalyst with excellent electrocatalytic oxygen evolution performance.

Description

Technical Field

[0001] This invention belongs to the field of materials synthesis, specifically relating to a hollow iron-nickel selenide polyhedral material, its preparation method, and its application. Background Technology

[0002] Electrically driven water splitting has become a very promising strategy for producing clean and renewable hydrogen. However, the oxygen evolution reaction (OER) occurring at the anolyte, involving complex multi-electron transfer reactions, has become a major bottleneck limiting water splitting efficiency. Therefore, there is an urgent need for efficient OER catalysts to lower the energy barrier and thus reduce the overpotential (η). Although noble metal (such as Ir and Ru)-based catalysts exhibit excellent OER performance, their scarcity and high cost severely limit their large-scale application. In recent years, nickel selenide has emerged as a promising OER catalyst due to its high conductivity, low band gap, high chemical stability, and low cost. However, the catalytic activity of nickel selenide catalysts is still far from meeting the requirements of practical applications. Therefore, the development of a metal selenide material with simple processing, low cost, high reproducibility, stable structure, and excellent catalytic performance is of great theoretical and practical value for OER reactions. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of the prior art and provide a hollow iron-nickel selenide polyhedral material, its preparation method, and its application. Specifically, the following technical solution is adopted:

[0004] According to a first aspect of the present invention, a method for preparing a hollow iron-nickel selenide polyhedral material includes the following steps:

[0005] First, the metal-organic framework ZIF-8 and the nickel precursor were added to a methanol solution for a solvothermal reaction to obtain hollow nickel hydroxide polyhedron material. Then, potassium ferricyanide aqueous solution and the obtained hollow nickel hydroxide polyhedron material were added to an ethanol solution, stirred evenly, centrifuged, washed, and dried to obtain hollow nickel-iron bimetallic organic framework polyhedron material. Finally, the obtained hollow nickel-iron bimetallic organic framework polyhedron material and selenium powder were heated at a heating rate of 3℃ / min. The reaction ended when the temperature reached 350℃ to obtain hollow nickel-iron selenide polyhedron material.

[0006] This invention improves the catalytic performance of synthesized materials through electronic modulation and the construction of favorable geometric structures. On the one hand, by incorporating iron metal atoms into the nickel selenide lattice, the adsorption and desorption capacity of active sites for oxygen-containing intermediates can be balanced by rationally adjusting the d-band center, which can significantly improve its catalytic performance. On the other hand, by designing and constructing hollow structures, more electrochemical active sites can be exposed, thereby improving electrocatalytic performance.

[0007] The preparation method of this invention is simple and controllable, and the required raw materials are widely available and inexpensive. The prepared hollow iron-nickel selenide polyhedral material has unique hollow structure, heteroatom doping, and carbon material composite characteristics. It has advantages such as high specific surface area, high mass transfer efficiency, and rapid charge transport, and can generate abundant surface active sites and high diffusion efficiency, which facilitates ion transport and enhances its conductivity. It is a structurally stable catalyst with excellent OER catalytic performance, and is more suitable for industrial production.

[0008] The preparation process of the metal-organic framework ZIF-8 used in this invention is as follows: Zinc acetate dihydrate and 2-methylimidazole are added to methanol, stirred at room temperature for 1 hour, allowed to stand for 24 hours, centrifuged, washed, and dried to obtain the metal-organic framework ZIF-8. The mass ratio of zinc acetate dihydrate to 2-methylimidazole is 0.878 g: 1.314 g.

[0009] Preferably, the nickel precursor includes at least one of nickel nitrate, nickel chloride, and nickel sulfate.

[0010] Preferably, the ratio of metal-organic framework ZIF-8, nickel precursor, and methanol is 180 mg:(540 mg-1260 mg):(20 mL-40 mL). More preferably, the ratio of metal-organic framework ZIF-8, nickel precursor, and methanol is 180 mg:900 mg:30 mL. When the metal-organic framework ZIF-8 is in excess, it leads to incomplete etching, making it difficult to form a hollow structure and potentially resulting in a core-shell structure, which fails to achieve the structure required by this invention. When the nickel precursor is in excess, the wall thickness of the formed hollow polyhedron increases, affecting the mass transfer rate. The hollow nickel hydroxide polyhedron material obtained by the more preferred ratio has a moderate wall thickness, and the hollow structure is stable and will not collapse, facilitating subsequent experiments.

[0011] Preferably, the temperature of the solvothermal reaction is 90℃-150℃ and the time is 0.5h-2h.

[0012] Preferably, the ratio of potassium ferricyanide aqueous solution to hollow nickel hydroxide polyhedral material is (2mL-6mL):(35mg-45mg); the potassium ferricyanide aqueous solution is prepared by potassium ferricyanide and water in a ratio of (15mg-25mg):(2mL-6mL).

[0013] Preferably, the mass ratio of hollow nickel-iron bimetallic organic framework polyhedron material to selenium powder is 1g:(5g-15g). More preferably, the mass ratio of hollow nickel-iron bimetallic organic framework polyhedron material to selenium powder is 1g:10g. When the mass ratio is 1g:(5g-15g), the concentration of selenium powder after volatilization is moderate, avoiding both incomplete selenization due to low concentration and structural collapse due to excessive concentration corroding the hollow framework.

[0014] According to a second aspect of the present invention, a hollow iron-nickel selenide polyhedral material is provided, which is prepared by any of the methods described above.

[0015] The hollow iron-nickel selenide polyhedral material prepared by this invention has unique hollow structure, heteroatom doping and carbon material composite characteristics. It has advantages such as high specific surface area, high mass transfer efficiency and fast charge transport. It can generate abundant surface active sites and high diffusion efficiency, which facilitates ion transport and enhances its conductivity. It is a catalyst with stable structure and excellent OER catalytic performance, and is more suitable for industrial production.

[0016] According to a third aspect of the invention, hollow iron-nickel selenide polyhedral materials are provided for use in the preparation of oxygen evolution reaction catalysts.

[0017] The beneficial effects of this invention are as follows: the preparation method of this invention is simple and controllable, and the required raw materials are widely available and inexpensive. The prepared hollow iron-nickel selenide polyhedral material has unique hollow structure, heteroatom doping, and carbon material composite characteristics. It has advantages such as high specific surface area, high mass transfer efficiency, and rapid charge transport, and can generate abundant surface active sites and high diffusion efficiency, facilitating ion transport and thus enhancing its conductivity. It is a structurally stable catalyst with excellent OER catalytic performance, and is more suitable for industrial production. Attached Figure Description

[0018] Figure 1 The images shown are scanning electron microscope images; where (a) is the hollow nickel selenide polyhedral material prepared in Example 1, and (b) is the hollow nickel selenide polyhedral material prepared by high-temperature selenization of nickel hydroxide.

[0019] Figure 2 The images shown are transmission electron microscope (TEM) images; where (a) is the hollow nickel selenide polyhedral material prepared in Example 1, and (b) is the hollow nickel selenide polyhedral material prepared by high-temperature selenization of nickel hydroxide.

[0020] Figure 3 The XRD pattern and XPS spectrum of the hollow iron-nickel selenide polyhedral material prepared in Example 1 are shown; where (a) is the XRD pattern, (b) is the Se 3d XPS spectrum, (c) is the Fe 2p XPS spectrum, and (d) is the Ni 2p XPS spectrum.

[0021] Figure 4 The figure shows the oxygen evolution performance curve; where (a) is the hollow nickel selenide polyhedral material prepared in Example 1, and (b) is the hollow nickel selenide polyhedral material prepared by high-temperature selenization of nickel hydroxide.

[0022] Figure 5The figure shown is a test diagram of the oxygen evolution stability of the hollow iron-nickel selenide polyhedral material prepared in Example 1. Detailed Implementation

[0023] The following will provide a clear and complete description of the concept and technical effects of the present invention in conjunction with the embodiments and accompanying drawings, so as to fully understand the purpose, solution and effects of the present invention. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of this application can be combined with each other.

[0024] Example 1:

[0025] A hollow iron-nickel selenide polyhedral material, the preparation method of which includes the following steps:

[0026] 1) Preparation of metal-organic framework ZIF-8: Weigh 0.878 g zinc acetate dihydrate and dissolve it in 20 mL methanol. Quickly pour it into 80 mL methanol solution containing 1.314 g 2-methylimidazole and stir at room temperature for 1 h. After standing for 24 h, collect the product by centrifugation, wash it 3 times with ethanol, and finally dry it at 60 °C for 12 h.

[0027] 2) Preparation of hollow nickel hydroxide polyhedral material: Weigh 180 mg ZIF-8 and 900 mg nickel chloride and disperse them in 30 mL methanol. Then transfer them to a high-pressure reactor and react at 120 °C for 1 h. After cooling to room temperature, wash the resulting precipitate three times with deionized water and ethanol, respectively.

[0028] 3) Preparation of nickel-iron bimetallic-organic framework: Weigh 40 mg of hollow nickel hydroxide polyhedral material and disperse it in 36 mL of ethanol. Quickly pour in 4 mL of aqueous solution containing 20 mg of potassium ferricyanide and stir at room temperature. Collect the product by centrifugation, wash it three times with water and three times with ethanol, and finally dry it at 60 °C for 12 h.

[0029] 4) Preparation of hollow iron-nickel selenide polyhedron material: Weigh 15mg of nickel-iron bimetallic-organic framework and 150mg of selenium powder and place them at both ends of a quartz boat. Then place the boat in a tube furnace with the selenium powder at the upstream end. Under an inert atmosphere, heat the furnace from room temperature to 350℃ at a heating rate of 3℃ / min to obtain hollow iron-nickel selenide polyhedrons.

[0030] The inventors also conducted relevant tests on the hollow iron-nickel selenide polyhedral material prepared in this embodiment, and the test results are as follows.

[0031] like Figure 1The images shown are scanning electron microscope images; (a) is the hollow nickel selenide polyhedron material prepared in Example 1, and (b) is the hollow nickel selenide polyhedron material prepared by high-temperature selenization of nickel hydroxide. It can be seen that Figure (a) is the successfully synthesized nickel selenide polyhedron, while the nickel selenide polyhedron material obtained by high-temperature selenization of nickel hydroxide (Figure (b)) has partial structural damage due to the lack of protection from nitrogen-doped carbon material.

[0032] like Figure 2 The images shown are transmission electron microscope (TEM) images; (a) is the hollow iron-nickel selenide polyhedron material prepared in Example 1, and (b) is the hollow nickel selenide polyhedron material prepared by high-temperature selenization of nickel hydroxide. It can be seen that Figure (a) is the successfully synthesized hollow iron-nickel selenide polyhedron, while the nickel selenide polyhedron material in Figure (b) has some structural damage due to the lack of protection from nitrogen-doped carbon material.

[0033] like Figure 3 The figures show the XRD and XPS spectra of the hollow nickel selenide polyhedral material prepared in Example 1; (a) is the XRD pattern, (b) is the Se 3d XPS spectrum, (c) is the Fe 2p XPS spectrum, and (d) is the Ni 2p XPS spectrum. Figure (a) shows the XRD pattern of the sample, indicating that only one set of diffraction peaks was detected, which can be well attributed to cubic NiSe2, and no diffraction peaks related to Fe compounds were found. Figures (bd) show further XPS characterization, which detected characteristic peaks related to Fe-Se and Ni-Se bonds, indicating that the nickel iron selenide compound was successfully synthesized.

[0034] like Figure 4 The figure shows the oxygen evolution performance curves; where (a) is the hollow iron-nickel selenide polyhedral material prepared in Example 1, and (b) is the hollow nickel selenide polyhedral material prepared by high-temperature selenization of nickel hydroxide. The results show that both the hollow iron-nickel selenide polyhedral material and the hollow nickel selenide polyhedral material exhibit excellent OER catalytic activity. When the current density reaches 10 mA / cm², -2 At that time, the overpotential of hollow nickel selenide polyhedron was only 250mV, while the overpotential of hollow nickel selenide polyhedron was as high as 350mV, which is significantly better than that of hollow nickel selenide polyhedron.

[0035] like Figure 5 The figure shows the oxygen evolution stability test diagram of the hollow iron-nickel selenide polyhedral material prepared in Example 1. The stability of the hollow iron-nickel selenide polyhedral catalyst was evaluated by the chronopotential (VT) method. When tested continuously for 100 hours under an applied voltage, the potential remained basically constant throughout the test, indicating that the catalyst has good stability.

[0036] Example 2:

[0037] A hollow iron-nickel selenide polyhedral material is prepared by changing the amount of nickel chloride in step 2) of Example 1 to 540 mg (the mass ratio of the two is 1:3), while the other steps are the same as in Example 1, to obtain the hollow iron-nickel selenide polyhedral material.

[0038] Example 3:

[0039] A hollow iron-nickel selenide polyhedral material is prepared by changing the amount of nickel chloride in step 2) of Example 1 to 1260 mg (the mass ratio of the two is 1:7), while the other steps are the same as in Example 1, to obtain the hollow iron-nickel selenide polyhedral material.

[0040] Example 4:

[0041] A hollow iron-nickel selenide polyhedral material is prepared by replacing nickel chloride in step 2) of Example 1 with nickel nitrate, while the other steps are the same as in Example 1, to obtain the hollow iron-nickel selenide polyhedral material.

[0042] Example 5:

[0043] A hollow iron-nickel selenide polyhedral material is prepared by replacing nickel chloride in step 2) of Example 1 with nickel sulfate, while the other steps are the same as in Example 1, to obtain the hollow iron-nickel selenide polyhedral material.

[0044] Example 6:

[0045] A hollow iron-nickel selenide polyhedral material is prepared by changing the amount of methanol in step 2) of Example 1 to 20 mL, while the other steps are the same as in Example 1, to obtain the hollow iron-nickel selenide polyhedral material.

[0046] Example 7:

[0047] A hollow iron-nickel selenide polyhedral material is prepared by changing the amount of methanol in step 2) of Example 1 to 40 mL, while the other steps are the same as in Example 1, to obtain the hollow iron-nickel selenide polyhedral material.

[0048] Example 8:

[0049] A hollow iron-nickel selenide polyhedral material is prepared by changing the temperature of 120°C in step 2) of Example 1 to 90°C, while the other steps are the same as in Example 1, to obtain the hollow iron-nickel selenide polyhedral material.

[0050] Example 9:

[0051] A hollow iron-nickel selenide polyhedral material is prepared by changing the temperature of 120°C to 150°C in step 2) of Example 1, while the other steps are the same as in Example 1, to obtain the hollow iron-nickel selenide polyhedral material.

[0052] Example 10:

[0053] A hollow iron-nickel selenide polyhedral material is prepared by changing the reaction time of step 2) in Example 1 from 1 h to 0.5 h, while the other steps are the same as in Example 1, to obtain the hollow iron-nickel selenide polyhedral material.

[0054] Example 11:

[0055] A hollow iron-nickel selenide polyhedral material is prepared by changing the reaction time of step 2) in Example 1 from 1 hour to 2 hours, while the other steps are the same as in Example 1, to obtain the hollow iron-nickel selenide polyhedral material.

[0056] Example 12:

[0057] A hollow iron-nickel selenide polyhedral material is prepared by replacing 40 mg of hollow nickel hydroxide polyhedral material in step 3) of Example 1 with 35 mg, while the other steps are the same as in Example 1, to obtain hollow iron-nickel selenide polyhedra.

[0058] Example 13:

[0059] A hollow iron-nickel selenide polyhedron is prepared by replacing the 40 mg of hollow nickel hydroxide polyhedron material in step 3) of Example 1 with 45 mg, while the other steps are the same as in Example 1, to obtain the hollow iron-nickel selenide polyhedron material.

[0060] Example 14:

[0061] A hollow iron-nickel selenide polyhedral material is prepared by replacing 36 mL of ethanol in step 3) of Example 1 with 34 mL, while the other steps are the same as in Example 1, to obtain the hollow iron-nickel selenide polyhedral material.

[0062] Example 15:

[0063] A hollow iron-nickel selenide polyhedral material is prepared by replacing 36 mL of ethanol in step 3) of Example 1 with 38 mL, while the other steps are the same as in Example 1, to obtain the hollow iron-nickel selenide polyhedral material.

[0064] Example 16:

[0065] A hollow iron-nickel selenide polyhedral material is prepared by replacing 20 mg of potassium ferricyanide in step 3) of Example 1 with 15 mg, while the other steps are the same as in Example 1, to obtain the hollow iron-nickel selenide polyhedral material.

[0066] Example 17:

[0067] A hollow iron-nickel selenide polyhedral material is prepared by replacing 20 mg of potassium ferricyanide in step 3) of Example 1 with 25 mg, while the other steps are the same as in Example 1, to obtain the hollow iron-nickel selenide polyhedral material.

[0068] Example 18:

[0069] A hollow iron-nickel selenide polyhedral material is prepared by replacing the 4 mL aqueous solution in step 3) of Example 1 with 2 mL, while the other steps are the same as in Example 1, to obtain the hollow iron-nickel selenide polyhedral material.

[0070] Example 19:

[0071] A hollow iron-nickel selenide polyhedral material is prepared by replacing the 4 mL aqueous solution in step 3) of Example 1 with 6 mL, while the other steps are the same as in Example 1, to obtain the hollow iron-nickel selenide polyhedral material.

[0072] Example 20:

[0073] A hollow iron-nickel selenide polyhedral material is prepared by replacing 150mg of selenium powder in step 4) of Example 1 with 75mg (the mass ratio of the two is 1g:5g), while the other steps are the same as in Example 1, to obtain the hollow iron-nickel selenide polyhedral material.

[0074] Example 21:

[0075] A hollow iron-nickel selenide polyhedral material is prepared by replacing 150mg of selenium powder in step 4) of Example 1 with 225mg (the mass ratio of the two is 1g:15g), while the other steps are the same as in Example 1, to obtain the hollow iron-nickel selenide polyhedral material.

[0076] In summary, this invention successfully prepared a hollow iron-nickel selenide polyhedral material (Example 1) using a sequential template strategy. This hollow iron-nickel selenide polyhedral material exhibits a stable structure due to the protection of nitrogen-doped carbon material, making it resistant to collapse. During continuous testing under an applied voltage for 100 hours, the potential remained essentially constant throughout the testing process, indicating good stability. Furthermore, when the current density reached 10 mA / cm², the material showed good stability. -2 At this time, the hollow iron-nickel selenide polyhedral material exhibits an overpotential as low as 250mV, demonstrating excellent OER catalytic activity.

[0077] Although the description of the invention has been quite detailed and particularly of several described embodiments, it is not intended to limit it to any of these details or embodiments or any particular embodiment, but should be considered as providing a broad possible interpretation of the claims by referring to the appended claims and taking into account the prior art, thereby effectively covering the intended scope of the invention. Furthermore, the invention has been described above with respect to embodiments foreseeable by the inventors in order to provide a useful description, and non-substantial modifications to the invention that have not yet been foreseen may still represent equivalent modifications.

Claims

1. A method for preparing a hollow iron-nickel selenide polyhedral material, characterized in that, Includes the following steps: First, the metal-organic framework ZIF 8. A nickel precursor was added to a methanol solution for a solvothermal reaction to obtain hollow nickel hydroxide polyhedral material. Then, potassium ferricyanide aqueous solution and the obtained hollow nickel hydroxide polyhedral material were added to an ethanol solution, stirred until homogeneous, centrifuged, washed, and dried to obtain hollow nickel-iron bimetallic organic framework polyhedral material. Finally, the obtained hollow nickel-iron bimetallic organic framework polyhedral material and selenium powder were heated at a heating rate of 3℃ / min. The reaction ended when the temperature reached 350℃, yielding hollow nickel-iron selenide polyhedral material. Among them, nickel precursors include at least one of nickel nitrate, nickel chloride, and nickel sulfate; Metal-Organic Framework (ZIF) 8. The ratio of nickel precursor to methanol is 180 mg: (540 mg) 1260mg): (20mL) 40mL); The ratio of potassium ferricyanide aqueous solution to hollow nickel hydroxide polyhedral material is (2 mL) 6mL): (35mg 45mg); The mass ratio of hollow nickel-iron bimetallic organic framework polyhedron material to selenium powder is 1g:(5g) 15g); The temperature of the solvothermal reaction is 90℃ 150℃.

2. The preparation method according to claim 1, characterized in that, Metal-Organic Framework (ZIF) 8. The ratio of nickel precursor to methanol is 180mg:900mg:30mL.

3. The preparation method according to claim 1, characterized in that, The solvothermal reaction time is 0.5 h. 2h.

4. The preparation method according to claim 1, characterized in that, Potassium ferricyanide aqueous solution is made by mixing potassium ferricyanide and water at a ratio of 15 mg / L. 25mg): (2mL) It is prepared in a ratio of 6 mL.

5. The preparation method according to claim 1, characterized in that, The mass ratio of hollow nickel-iron bimetallic organic framework polyhedron material to selenium powder is 1g:10g.

6. A hollow iron-nickel selenide polyhedral material, characterized in that, By claim 1 It is prepared by any one of the preparation methods described in item 5.

7. The application of the hollow iron-nickel selenide polyhedral material according to claim 6 in the preparation of oxygen evolution reaction catalysts.

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