Preparation method of modified nickel foam

Abstract

The present invention provides a method for preparing a modified nickel foam, step S1: pre-treating the nickel foam; step S2: placing the pre-treated nickel foam in a 1-butyl-3-methylimidazole bis (trifluoromethanesulfonyl) imide salt solvent, heating at a set temperature for a certain time under a nitrogen environment, and preparing a modified nickel foam. By placing the pre-treated nickel foam in a 1-butyl-3-methylimidazole bis (trifluoromethanesulfonyl) imide salt solvent, reacting under certain conditions, the 1-butyl-3-methylimidazole bis (trifluoromethanesulfonyl) imide salt solvent can provide elements such as C, O, F, and S, causing a layer of modified substances to grow on the surface of the modified nickel foam, which is beneficial to increase the surface area of ​​the nickel foam and promote the progress of the catalytic reaction. O, F, S ternary doped carbon coated on the surface of the nickel foam can make the nickel foam more adaptable to catalysis under acidic conditions, so that the nickel foam has higher acid resistance and higher catalytic performance.

Description

Technical Field

[0001] The present invention relates to the field of metal materials, and particularly to a preparation method of modified nickel foam. Background Art

[0002] Nickel foam is a sound-absorbing material with excellent performance and has a high sound absorption coefficient at high frequencies; the sound absorption performance at low frequencies can be improved through the design of the sound absorption structure. Nickel foam itself is composed of metallic nickel and has characteristics such as a three-dimensional porous structure, high tensile strength, and weldability. It is widely used in the fields of electrocatalysis, photocatalysis, photoelectrocatalysis, batteries, etc. However, since metallic nickel undergoes a slow chemical reaction in a dilute acidic environment, pure nickel foam has defects such as poor acid resistance and limited catalytic performance.

[0003] In view of this, it is necessary to improve the nickel foam in the prior art to solve the above problems. Summary of the Invention

[0004] The purpose of the present invention is to disclose a preparation method of modified nickel foam, which is used to solve the defects of poor acid resistance and limited catalytic performance of nickel foam in the prior art. Therefore, it is necessary to modify or improve the nickel foam in order to obtain nickel foam with high acid resistance and high catalytic performance.

[0005] To achieve the above purpose, the present invention provides a preparation method of modified nickel foam, including the following steps:

[0006] Step S1: Pretreat the nickel foam;

[0007] Step S2: Place the pretreated nickel foam in a 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt solvent, and heat it at a set temperature for a certain time in a nitrogen environment to prepare the modified nickel foam.

[0008] As a further improvement of the present invention, the pretreatment of the nickel foam in step S1 includes:

[0009] Take nickel foam of a preset size and place it in an HCl solution for ultrasonic washing for a certain time to remove the oxides on the surface of the nickel foam;

[0010] Wash the ultrasonically washed nickel foam with deionized water and absolute ethanol to remove the HCl solution on the surface of the nickel foam, and place it under vacuum conditions for drying.

[0011] As a further improvement of the present invention, the concentration of the HCl solution is 1.0 mol / L.

[0012] As a further improvement of the present invention, the relative vacuum degree of the vacuum condition is 0 - 1 KPa.

[0013] As a further improvement of the present invention, the 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt solvent containing nickel foam is placed in a tube furnace and heated at 280-380 °C for 2-5 h.

[0014] As a further improvement of the present invention, the modified nickel foam is washed with absolute ethanol to remove impurities on the surface of the modified nickel foam;

[0015] The washed modified nickel foam is placed in a vacuum drying oven and dried for 12 h.

[0016] As a further improvement of the present invention, the temperature of the vacuum drying oven is 25 °C and the relative vacuum degree is 0-1 KPa.

[0017] As a further improvement of the present invention, the 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt is of analytical purity.

[0018] As a further improvement of the present invention, the pretreated nickel foam is placed in an excessive amount of 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt solvent.

[0019] Compared with the prior art, the beneficial effects of the present invention are:

[0020] After pretreatment, the nickel foam reacts with the 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt solvent under certain conditions. The 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt solvent can provide elements such as C, O, F, and S, resulting in the growth of a layer of modified substance on the surface of the modified nickel foam. This modified substance has a porous structure, which is beneficial to increasing the surface area of the nickel foam and promoting the catalytic reaction. The carbon coated on the surface of the nickel foam doped with O, F, and S can make the nickel foam more adaptable to catalysis under acidic conditions, so that the nickel foam has higher acid resistance and higher catalytic performance. Description of the Drawings

[0021] Figure 1 is a flow chart of a preparation method of a modified nickel foam of the present invention;

[0022] Figure 2 is a low-magnification SEM image of the modified nickel foam;

[0023] Figure 3 is Figure 2 a high-magnification SEM image of a part of the modified nickel foam in

[0024] Figure 4 is an EDX test image of the modified nickel foam. Detailed Embodiments

[0025] The present invention will be described in detail below in conjunction with the embodiments shown in the accompanying drawings. It should be noted, however, that these embodiments are not intended to limit the present invention, and any equivalent transformation or substitution in terms of function, method, or structure made by those of ordinary skill in the art based on these embodiments shall fall within the protection scope of the present invention.

[0026] In the embodiments of the present application, the unit "g" is the weight unit "gram"; the unit "h" is the time unit "hour"; the unit "min" is the time unit "minute"; the unit "mol / L" is "moles per liter"; the unit "KPa" is the pressure unit "kilopascal"; the unit "°C" is the temperature unit "degree Celsius"; the unit "cm" is the length unit "centimeter"; "room temperature" is 25°C; the unit "KHZ" is "kilohertz".

[0027] Please refer Figure 1 as shown Figure 1 which is a flowchart of a preparation method of modified nickel foam provided by an embodiment of the present application. The method includes at least steps S1 to S2.

[0028] Step S1: Pretreat the nickel foam.

[0029] Step S2: Place the pretreated nickel foam in a 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt solvent (analytical pure), and heat it at a set temperature for a certain time in a nitrogen environment to obtain modified nickel foam.

[0030] Specifically, nickel foam of a set size is selected and added to a 1.0 mol / L HCl solution. The nickel foam is ultrasonically washed for 10 min to remove the oxides on the surface of the nickel foam. Subsequently, the nickel foam is first ultrasonically washed with deionized water and then ultrasonically cleaned with anhydrous ethanol (analytical pure). It is ultrasonically washed 3 times in the order of first using deionized water and then using anhydrous ethanol (analytical pure) to remove the hydrochloric acid on the surface of the nickel foam. Finally, the nickel foam is placed in a vacuum drying oven at room temperature and a relative vacuum of 0 to -1 KPa for drying for later use, where 0 KPa represents normal atmospheric pressure.

[0031] The dried nickel foam is placed in an excess of 1-butyl-3-methyl-imidazolium bis(trifluoromethanesulfonyl)imide salt solvent and placed in a tube furnace. It is heated at 280 to 380°C for 2 to 5 h in a nitrogen environment to obtain modified nickel foam. After the reaction, the modified nickel foam is naturally cooled to room temperature. The modified nickel foam is taken out of the tube furnace and washed 3 times with anhydrous ethanol (analytical pure) to remove the substances and dust that did not grow on the surface of the nickel foam. Subsequently, the washed modified nickel foam is placed in a vacuum drying oven at room temperature and a relative vacuum of 0 to -1 KPa for drying for 12 h to remove the ethanol on the surface of the modified nickel foam. Here, 0 KPa represents normal atmospheric pressure.

[0032] It should be noted that before placing the 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt solvent impregnated with nickel foam into the tube furnace, pure nitrogen with a purity of 99.99% needs to be introduced into the tube furnace for 30 h to expel the air in the tube furnace, so as to avoid mixing oxygen during the reaction of nickel foam with 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt and prevent affecting the reaction of nickel foam with 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt. Nitrogen with a purity of 99.99% is continuously introduced into the tube furnace during the reaction of the aforementioned nickel foam with 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt, and the nitrogen concentration in the tube furnace is always ensured to be maintained at 99.99%, so as to avoid oxidation on the surface of nickel foam. The ultrasonic model for ultrasonic cleaning is RQ3200DB, and the ultrasonic frequency is 100 KHZ. The model of the tube furnace is OTF-1200X. The model of the vacuum drying oven is DZF-6020.

[0033] Example 1.

[0034] Select 1×1 cm nickel foam and add it to 1.0 mol / L HCl solution. The nickel foam is ultrasonically washed for 10 min to remove the oxides on the surface of the nickel foam. Subsequently, the nickel foam is ultrasonically washed with deionized water first, and then ultrasonically cleaned with anhydrous ethanol (analytical pure). Ultrasonic washing is carried out 3 times in the order of first using deionized water and then using anhydrous ethanol (analytical pure) to remove the hydrochloric acid on the surface of the nickel foam. Finally, the nickel foam is placed in a vacuum drying oven at room temperature and a relative vacuum degree of -0.85 KPa for drying for later use.

[0035] The dried nickel foam is placed in 0.5 g of 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt solvent, and the 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt solvent impregnating the nickel foam is placed in a tube furnace, heated to 330 °C and continuously heated for 3 h. The tube furnace is filled with inert gases such as nitrogen to obtain modified nickel foam. After the reaction is completed, the modified nickel foam is naturally cooled to room temperature, taken out from the tube furnace and washed 3 times with anhydrous ethanol (analytical pure) to remove the substances and dust that have not grown on the surface of the nickel foam. Subsequently, the washed modified nickel foam is placed in a vacuum drying oven at room temperature and a relative vacuum degree of -0.85 KPa for drying for 12 h to remove the ethanol on the surface of the modified nickel foam.

[0036] Example 2

[0037] Select a 5×5 cm nickel foam and add it to a 1.0 mol / L HCl solution. Ultrasonically wash the nickel foam for 10 min to remove the oxides on the surface of the nickel foam. Subsequently, ultrasonically wash the nickel foam with deionized water first, and then ultrasonically clean the nickel foam with anhydrous ethanol (analytical grade). Ultrasonically wash it 3 times in the order of first using deionized water and then using anhydrous ethanol (analytical grade) to remove the hydrochloric acid on the surface of the nickel foam. Finally, place the nickel foam in a vacuum drying oven at room temperature and a relative vacuum of -0.8 KPa for drying and standby.

[0038] Place the dried nickel foam in 0.5 g of 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide solvent, and place the 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide solvent soaking the nickel foam in a tube furnace. Heat it to 330 °C and continuously heat for 3 h. The tube furnace is filled with inert gases such as nitrogen to obtain modified nickel foam. After the reaction is completed, naturally cool the modified nickel foam to room temperature, take out the modified nickel foam from the tube furnace and wash it 3 times with anhydrous ethanol (analytical grade) to remove the substances and dust that did not grow on the surface of the nickel foam. Subsequently, place the washed modified nickel foam in a vacuum drying oven at room temperature and a relative vacuum of -0.8 KPa for 12 h to remove the ethanol on the surface of the modified nickel foam.

[0039] Example 3

[0040] Select a 0.5×0.5 cm nickel foam and add it to a 1.0 mol / L HCl solution. Ultrasonically wash the nickel foam for 10 min to remove the oxides on the surface of the nickel foam. Subsequently, ultrasonically wash the nickel foam with deionized water first, and then ultrasonically clean the nickel foam with anhydrous ethanol (analytical grade). Ultrasonically wash it 3 times in the order of first using deionized water and then using anhydrous ethanol (analytical grade) to remove the hydrochloric acid on the surface of the nickel foam. Finally, place the nickel foam in a vacuum drying oven at room temperature and a relative vacuum of -1 KPa for drying and standby.

[0041] Place the dried nickel foam in 0.5 g of 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide solvent, and place the 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide solvent soaking the nickel foam in a tube furnace. Heat it to 330 °C and continuously heat for 3 h. The tube furnace is filled with inert gases such as nitrogen to obtain modified nickel foam. After the reaction is completed, naturally cool the modified nickel foam to room temperature, take out the modified nickel foam from the tube furnace and wash it 3 times with anhydrous ethanol (analytical grade) to remove the substances and dust that did not grow on the surface of the nickel foam. Subsequently, place the washed modified nickel foam in a vacuum drying oven at room temperature and a relative vacuum of -0.85 KPa for 12 h to remove the ethanol on the surface of the modified nickel foam.

[0042] Example 4

[0043] Select a 1×1 cm nickel foam and add it to a 1.0 mol / L HCl solution. Ultrasonically wash the nickel foam for 10 min to remove the oxides on the surface of the nickel foam. Subsequently, ultrasonically wash the nickel foam with deionized water first, and then ultrasonically clean the nickel foam with anhydrous ethanol (analytical grade). Ultrasonically wash it 3 times in the order of first using deionized water and then using anhydrous ethanol (analytical grade) to remove the hydrochloric acid on the surface of the nickel foam. Finally, place the nickel foam in a vacuum drying oven at room temperature and a relative vacuum of -0.85 KPa for drying and standby.

[0044] Place the dried nickel foam in 0.25 g of 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide solvent, and place the 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide solvent soaking the nickel foam in a tube furnace. Heat it to 330 °C and continue heating for 3 h. The tube furnace is filled with inert gases such as nitrogen to obtain modified nickel foam. After the reaction is completed, naturally cool the modified nickel foam to room temperature, take out the modified nickel foam from the tube furnace and wash it 3 times with anhydrous ethanol (analytical grade) to remove the substances and dust that have not grown on the surface of the nickel foam. Subsequently, place the washed modified nickel foam in a vacuum drying oven at room temperature and a relative vacuum of -0.85 KPa for drying for 12 h to remove the ethanol on the surface of the modified nickel foam.

[0045] Example 5

[0046] Select a 1×1 cm nickel foam and add it to a 1.0 mol / L HCl solution. Ultrasonically wash the nickel foam for 10 min to remove the oxides on the surface of the nickel foam. Subsequently, ultrasonically wash the nickel foam with deionized water first, and then ultrasonically clean the nickel foam with anhydrous ethanol (analytical grade). Ultrasonically wash it 3 times in the order of first using deionized water and then using anhydrous ethanol (analytical grade) to remove the hydrochloric acid on the surface of the nickel foam. Finally, place the nickel foam in a vacuum drying oven at room temperature and a relative vacuum of -0.6 KPa for drying and standby.

[0047] Place the dried nickel foam in 2 g of 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide solvent, and place the 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide solvent soaking the nickel foam in a tube furnace. Heat it to 330 °C and continue heating for 3 h. The tube furnace is filled with inert gases such as nitrogen to obtain modified nickel foam. After the reaction is completed, naturally cool the modified nickel foam to room temperature, take out the modified nickel foam from the tube furnace and wash it 3 times with anhydrous ethanol (analytical grade) to remove the substances and dust that have not grown on the surface of the nickel foam. Subsequently, place the washed modified nickel foam in a vacuum drying oven at room temperature and a relative vacuum of -0.6 KPa for drying for 12 h to remove the ethanol on the surface of the modified nickel foam.

[0048] Example 6

[0049] A 1×1 cm nickel foam was added to a 1.0 mol / L HCl solution, and the nickel foam was ultrasonically washed for 10 min to remove the oxides on the surface of the nickel foam. Subsequently, the nickel foam was first ultrasonically washed with deionized water and then ultrasonically cleaned with anhydrous ethanol (analytical grade). The nickel foam was ultrasonically washed 3 times in the order of first using deionized water and then using anhydrous ethanol (analytical grade) to remove the hydrochloric acid on the surface of the nickel foam. Finally, the nickel foam was placed in a vacuum drying oven at room temperature and a relative vacuum of -0.75 KPa for drying for later use.

[0050] The dried nickel foam was placed in 0.5 g of 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide solvent, and the 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide solvent soaking the nickel foam was placed in a tube furnace and heated to 280 °C and continuously heated for 3 h. The tube furnace was filled with inert gases such as nitrogen to obtain modified nickel foam. After the reaction, the modified nickel foam was naturally cooled to room temperature, and the modified nickel foam was taken out of the tube furnace and washed 3 times with anhydrous ethanol (analytical grade) to remove the substances and dust that did not grow on the surface of the nickel foam. Subsequently, the washed modified nickel foam was placed in a vacuum drying oven at room temperature and a relative vacuum of -0.75 KPa for drying for 12 h to remove the ethanol on the surface of the modified nickel foam.

[0051] Example 7

[0052] A 1×1 cm nickel foam was added to a 1.0 mol / L HCl solution, and the nickel foam was ultrasonically washed for 10 min to remove the oxides on the surface of the nickel foam. Subsequently, the nickel foam was first ultrasonically washed with deionized water and then ultrasonically cleaned with anhydrous ethanol (analytical grade). The nickel foam was ultrasonically washed 3 times in the order of first using deionized water and then using anhydrous ethanol (analytical grade) to remove the hydrochloric acid on the surface of the nickel foam. Finally, the nickel foam was placed in a vacuum drying oven at room temperature and a relative vacuum of -0.75 KPa for drying for later use.

[0053] The dried nickel foam was placed in 0.5 g of 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide solvent, and the 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide solvent soaking the nickel foam was placed in a tube furnace, heated to 380 °C and continuously heated for 3 h. The tube furnace was filled with inert gases such as nitrogen to obtain modified nickel foam. After the reaction, the modified nickel foam was naturally cooled to room temperature, taken out from the tube furnace and washed 3 times with anhydrous ethanol (analytical grade) to remove the substances and dust that did not grow on the surface of the nickel foam. Subsequently, the washed modified nickel foam was placed in a vacuum drying oven at room temperature and a relative vacuum of -0.75 KPa for 12 h to remove the ethanol on the surface of the modified nickel foam.

[0054] Example 8

[0055] A 1×1 cm nickel foam was added to 1.0 mol / L HCl solution, and the nickel foam was ultrasonically washed for 10 min to remove the oxides on the surface of the nickel foam. Subsequently, the nickel foam was ultrasonically washed with deionized water first, and then ultrasonically cleaned with anhydrous ethanol (analytical grade). It was ultrasonically washed 3 times in the order of first using deionized water and then using anhydrous ethanol (analytical grade) to remove the hydrochloric acid on the surface of the nickel foam. Finally, the nickel foam was placed in a vacuum drying oven at room temperature and a vacuum of -0.65 KPa for drying for later use.

[0056] The dried nickel foam was placed in 0.5 g of 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide solvent, and the 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide solvent soaking the nickel foam was placed in a tube furnace, heated to 330 °C and continuously heated for 2 h. The tube furnace was filled with inert gases such as nitrogen to obtain modified nickel foam. After the reaction, the modified nickel foam was naturally cooled to room temperature, taken out from the tube furnace and washed 3 times with anhydrous ethanol (analytical grade) to remove the substances and dust that did not grow on the surface of the nickel foam. Subsequently, the washed modified nickel foam was placed in a vacuum drying oven at room temperature and a relative vacuum of -0.65 KPa for 12 h to remove the ethanol on the surface of the modified nickel foam.

[0057] Example 9

[0058] A 1×1 cm nickel foam was added to 1.0 mol / L HCl solution, and the nickel foam was ultrasonically washed for 10 min to remove the oxides on the surface of the nickel foam. Subsequently, the nickel foam was ultrasonically washed with deionized water first, and then ultrasonically cleaned with anhydrous ethanol (analytical grade). It was ultrasonically washed 3 times in the order of first using deionized water and then using anhydrous ethanol (analytical grade) to remove the hydrochloric acid on the surface of the nickel foam. Finally, the nickel foam was placed in a vacuum drying oven at room temperature and a relative vacuum of -0.8 KPa for drying for later use.

[0059] The dried nickel foam was placed in 0.5 g of 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide solvent, and the 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide solvent soaking the nickel foam was placed in a tube furnace, heated to 330 °C and continuously heated for 5 h. The tube furnace was filled with inert gases such as nitrogen to obtain modified nickel foam. After the reaction, the modified nickel foam was naturally cooled to room temperature, taken out of the tube furnace and washed 3 times with anhydrous ethanol (analytical grade) to remove the substances and dust that did not grow on the surface of the nickel foam. Subsequently, the washed modified nickel foam was placed in a vacuum drying oven at room temperature and a relative vacuum of -0.8 KPa for 12 h to remove the ethanol on the surface of the modified nickel foam.

[0060] In the prior art, the surface of nickel foam is smooth and has some patterns, with the defects of poor acid resistance and limited catalytic performance.

[0061] From the Figure 2 、 Figure 3 SEM images of the modified nickel foam prepared in Examples 1 to 9, it can be seen that the modified nickel foam 1 has a three-dimensional porous structure 10 and the surface becomes rough, indicating that a modified substance 20 has grown on the surface of the modified nickel foam. The modified substance 20 has a porous structure 10, which is beneficial to increasing the surface area of the nickel foam 1 and promoting the progress of the catalytic reaction. To further determine the composition of the modified substance 20 on the surface of the modified nickel foam 1, EDX test was carried out on the modified substance 20. As shown in Figure 4 , the EDX test shows that the atomic percentages of the modified substances C, O, F, and S are 58.19%, 18.69%, 13.4%, and 7.34% respectively, that is, the modified substance is a carbon material doped with O, F, and S. This experiment successfully proves that 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide can decompose at high temperature to provide elements such as C, O, F, and S. The carbon coated with O, F, and S on the surface of the nickel foam can make the nickel foam more adaptable to catalysis under acidic conditions. In addition, the incorporation of heteroatoms into the carbon skeleton will cause a redistribution of charges, thereby changing the chemisorption characteristics of the carbon material, being more conducive to adsorption and ensuring the efficient progress of catalysis; the porous structure 10 on the surface of the nickel foam can greatly increase the surface area; the oxygen-containing functional groups that may exist on the surface of the carbon material can not only improve the hydrophilicity of the material, but also disrupt the charge balance on the surface of the carbon atoms, enhancing the attraction of the material to anions. The obtained surface-modified nickel foam can be used for electrolysis of water, battery cathode materials, photocatalytic water splitting, etc.

[0062] The series of detailed descriptions listed above are only specific descriptions of the feasible implementation manners of the present invention, and they are not intended to limit the protection scope of the present invention. Any equivalent implementation manners or modifications made without departing from the technical spirit of the present invention should be included in the protection scope of the present invention.

[0063] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above-described exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be embraced within the present invention. Any reference signs in the claims should not be construed as limiting the claimed invention.

[0064] In addition, it should be understood that although this specification is described in terms of embodiments, not every embodiment only contains an independent technical solution. This narrative manner of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A preparation method of modified nickel foam, characterized in that, it comprises the following steps: Step S1: Pretreat the nickel foam; Step S2: Place the pretreated nickel foam in a 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt solvent, put it in a tubular furnace, and heat it at 280-380°C for 2-5 h in a nitrogen environment to obtain the modified nickel foam.

2. The preparation method of modified nickel foam according to claim 1, characterized in that, the pretreatment of the nickel foam in step S1 includes: Take nickel foam of a preset size and place it in an HCl solution for ultrasonic washing for a certain time to remove the oxides on the surface of the nickel foam; Wash the ultrasonically washed nickel foam with deionized water and absolute ethanol, and place it in a vacuum condition for drying.

3. The preparation method of modified nickel foam according to claim 2, characterized in that, the concentration of the HCl solution is 1.0 mol / L.

4. The preparation method of modified nickel foam according to claim 2, characterized in that, the relative vacuum degree of the vacuum condition is 0 to -1 KPa.

5. The preparation method of modified nickel foam according to claim 1, characterized in that, the modified nickel foam is washed with absolute ethanol to remove the impurities on the surface of the modified nickel foam; Place the washed modified nickel foam in a vacuum drying oven and dry it for 12 h.

6. The preparation method of modified nickel foam according to claim 5, characterized in that, the temperature of the vacuum drying oven is 25°C, and the relative vacuum degree is 0 to -1 KPa.

7. The preparation method of modified nickel foam according to claim 1, characterized in that, the 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt is of analytical purity.

8. The preparation method of modified nickel foam according to claim 1, characterized in that, Place the pretreated nickel foam in an excessive amount of 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt solvent.

Images