Preparation method of porous nitrogen-doped hollow carbon sphere loaded copper-nickel double monatomic electrocatalytic material and application thereof

Abstract

The present application relates to the field of electrochemical energy materials, and particularly relates to a preparation method of porous nitrogen-doped hollow carbon sphere loaded copper-nickel double monatomic electrocatalytic material, which comprises the following steps: (1) preparing nitrogen-doped carbon-coated silica spheres; (2) preparing nitrogen-doped hollow carbon spheres; (3) preparing porous nitrogen-doped hollow carbon sphere loaded copper-nickel double monatomic electrocatalytic material. The present application utilizes the silica template method to prepare the porous nitrogen-doped hollow carbon sphere, and further utilizes the liquid nitrogen freezing and thermal decomposition method to prepare the porous nitrogen-doped hollow carbon sphere loaded copper-nickel double monatomic electrocatalytic material. The synthesized double monatomic electrocatalytic material has atomically dispersed bimetallic active sites and high specific surface area, inhibits the hydrogen evolution reaction, exhibits 98% carbon dioxide to carbon monoxide conversion efficiency, and simultaneously exhibits excellent long-term stability.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of electrochemical energy materials, in particular to a preparation method of a porous nitrogen-doped hollow carbon sphere loaded copper-nickel double monatomic electrocatalytic material and application thereof. BACKGROUND

[0002] The electrocatalytic carbon dioxide reduction reaction as an electrochemical method for producing chemical substances in the process of carbon neutralization has been widely concerned. The reduction product carbon monoxide is the main component of synthesis gas and various gases and fuels. However, the selectivity of the electrocatalytic carbon dioxide reduction product depends on the type of electrocatalytic material used. Since the electrochemical carbon dioxide reduction reaction system is an aqueous solution, so far, no electrocatalytic material has 100% selectivity for a single product due to its high overpotential and competitive hydrogen evolution reaction. At the same time, *COOH and *CO species are generally considered to be key intermediates for selective carbon monoxide production. Therefore, it is of great significance to improve the selectivity of *COOH, *CO, increase the adsorption strength, promote electrochemical carbon dioxide reduction and inhibit the hydrogen evolution reaction.

[0003] Metal-nitrogen-carbon monatomic catalysts have been widely studied as an effective electrocatalytic carbon dioxide reduction catalyst. Among these monatomic catalysts, nickel-nitrogen-carbon catalysts have shown considerable carbon monoxide faradic efficiency and current density, but the selectivity and adsorption strength of reaction intermediates such as *COOH and *CO are still limited. In addition, it has been reported that double monatomic support on carbon-based materials is an effective way to improve electrochemical performance, especially nitrogen-doped carbon, which has attracted attention due to its change in electronic structure, thereby serving as a carbon dioxide adsorption activation site. Incorporating double monatomic metals into a nitrogen-doped mesoporous hollow carbon sphere carrier not only reduces metal content and metal agglomeration, but also facilitates the establishment of active sites such as metal-nitrogen groups. SUMMARY

[0004] In order to solve the existing technical problems, the present application proposes a preparation method of a porous nitrogen-doped hollow carbon sphere loaded copper-nickel double monatomic electrocatalytic material. The porous nitrogen-doped hollow carbon sphere loaded copper-nickel double monatomic electrocatalytic material proposed by the present application is prepared by a silica template method to prepare a porous nitrogen-doped hollow carbon sphere, and further prepared by a liquid nitrogen freezing and thermal decomposition method to prepare a porous nitrogen-doped hollow carbon sphere loaded copper-nickel double monatomic electrocatalytic material, thereby improving the carbon dioxide adsorption activity. Through the uniform loading of copper-nickel double monatomic on the porous nitrogen-doped hollow carbon sphere and the electronic interaction between nitrogen, the hydrogen evolution reaction is reduced, and the selectivity of the porous nitrogen-doped hollow carbon sphere loaded copper-nickel double monatomic electrocatalytic material for carbon dioxide reduction is greatly improved.

[0005] The application aims to provide a preparation method of a porous nitrogen-doped hollow carbon sphere loaded copper-nickel double monatomic electrocatalytic material.

[0006] The application aims to provide a preparation method of a porous nitrogen-doped hollow carbon sphere loaded copper-nickel double monatomic electrocatalytic material.

[0007] S1, nitrogen-doped carbon-coated silica sphere preparation: a certain amount of tetraethyl orthosilicate, ammonia water, deionized water and ethanol are stirred and mixed, a dopamine hydrochloride solution is added to obtain a composite solution, the composite solution is fully stirred, and carbonization treatment is performed to obtain a nitrogen-doped carbon-coated silica sphere;

[0008] S2, nitrogen-doped hollow carbon sphere preparation: the nitrogen-doped carbon-coated silica sphere obtained in S1 is added to a hydrofluoric acid solution, fully stirred, centrifuged and washed, and dried to obtain a nitrogen-doped hollow carbon sphere;

[0009] S3, porous nitrogen-doped hollow carbon sphere loaded copper-nickel double monatomic electrocatalytic material preparation: the nitrogen-doped hollow carbon sphere obtained in S2 is uniformly dispersed in deionized water, copper salt and nickel salt are added, and stirring, freezing, drying and calcination are sequentially performed to obtain a porous nitrogen-doped hollow carbon sphere loaded copper-nickel double monatomic electrocatalytic material.

[0010] Further, in S1, the stirring time of tetraethyl orthosilicate, ammonia water, deionized water and ethanol is 20-40 min, the stirring time of adding the dopamine hydrochloride solution is 24-48 h, and the carbonization treatment temperature is 700-1000℃, and the carbonization time is 3h.

[0011] Further, in S1, the volume ratio of tetraethyl orthosilicate, ammonia water, deionized water and ethanol is 2:3:100:30, and the volume ratio of the tetraethyl orthosilicate solution to the dopamine hydrochloride solution is 1:5.

[0012] Further, in S2, the mass ratio of the nitrogen-doped carbon-coated silica sphere to the hydrofluoric acid is 1:1000.

[0013] Further, in S2, the concentration of the hydrofluoric acid solution is 20-40wt%, and the hydrofluoric acid etching time is 0.5-2h.

[0014] Further, in S3, the total mass fraction of copper and nickel in the nitrogen-doped hollow carbon sphere is 0.3-1wt%, the mass ratio of the copper salt to the nickel salt is Cu:Ni=0.1:0.9-0.9:0.1, the calcination temperature is 500-900℃, and the calcination time is 3h.

[0015] The preparation method of the porous nitrogen-doped hollow carbon sphere loaded copper-nickel double monatomic electrocatalytic material can prepare the porous nitrogen-doped hollow carbon sphere loaded copper-nickel double monatomic electrocatalytic material.

[0016] The application of the porous nitrogen-doped hollow carbon sphere loaded copper-nickel double-atom electrocatalytic material in electrocatalytic carbon dioxide production carbon monoxide.

[0017] The application of the porous nitrogen-doped hollow carbon sphere loaded copper-nickel double-atom electrocatalytic material is carried out under the condition of electrocatalytic carbon dioxide production carbon monoxide under normal temperature, and the electrolyte is 0.5 mol / L potassium hydroxide solution.

[0018] Compared with the prior art, the application has the following advantages:

[0019] 1. By wrapping hydrochloric acid hydrochloric acid dopamine with silicon dioxide as a template to provide a nitrogen source and a carbon source, high specific surface area porous nitrogen-doped hollow carbon spheres are obtained by carbonization etching, so that high carbon dioxide adsorption activity is obtained.

[0020] 2. By uniformly loading copper-nickel double-atom on the porous nitrogen-doped hollow carbon sphere, and the electronic effect between the doped nitrogen, the hydrogen evolution reaction is reduced, and the selectivity of the porous nitrogen-doped hollow carbon sphere loaded copper-nickel double-atom electrocatalytic material for carbon dioxide reduction is greatly improved.

[0021] 3. The preparation method does not require expensive high-precision equipment, the synthesis process is simple, easy to operate, the reaction time is relatively short, the repeatability is reliable, the production cost is low, and it is very suitable for large-scale industrial production. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 The scanning electron microscope image of the porous nitrogen-doped hollow carbon sphere prepared in this embodiment 1.

[0023] Figure 2 The specific surface area graph of the porous nitrogen-doped hollow carbon sphere prepared in this embodiment 1.

[0024] Figure 3 The scanning electron microscope image of the porous nitrogen-doped hollow carbon sphere loaded copper-nickel double-atom electrocatalytic material prepared in this embodiment 1.

[0025] Figure 4 The electrocatalytic Faraday efficiency graph of the porous nitrogen-doped hollow carbon sphere loaded copper-nickel double-atom electrocatalytic material prepared in this embodiment 1.

[0026] Figure 5 The X-ray diffraction graph of the catalyst material prepared in this embodiment 1.

[0027] Figure 6 The Faraday efficiency comparison graph of the catalyst material electrocatalytic carbon dioxide reduction to produce carbon monoxide prepared in this embodiment 1 and comparative example 1 and comparative example 2.

[0028] Figure 7A comparison chart of the faradic efficiency of the catalyst materials prepared in Examples 1-10 for electrocatalytic reduction of carbon dioxide to produce carbon monoxide. DETAILED DESCRIPTION

[0029] The technical solutions of the present application will be apparently and completely described below in combination with the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without creative work belong to the protection scope of the present application. Unless specifically stated, the equipment and reagents used in the present application are the commonly commercially available products in the technical field.

[0030] The present application provides a preparation method of a porous nitrogen-doped hollow carbon sphere loaded copper-nickel double-atomic electrocatalytic material. Silica is used as a template to wrap hydrochloric acid and dopamine hydrochloride to provide a nitrogen source and a carbon source. Carbonization etching is further used to obtain a porous nitrogen-doped hollow carbon sphere with high specific surface area and high carbon dioxide adsorption activity. A certain mass fraction of copper salt and nickel salt is added at a constant speed. Freeze-drying and high-temperature calcination are used to uniformly load copper-nickel double-atomic on the surface of the porous nitrogen-doped hollow carbon sphere, so as to fully contact and react with carbon dioxide, reduce the hydrogen evolution reaction, and greatly improve the selectivity of the porous nitrogen-doped hollow carbon sphere loaded copper-nickel double-atomic electrocatalytic material for carbon dioxide reduction. In addition, the synthesis process of the nitrogen-doped porous carbon loaded copper-nickel double-atomic electrocatalytic material is simple and easy to operate.

[0031] Comparative Example 1

[0032] A preparation method of a nitrogen-doped porous carbon loaded copper single-atomic catalyst, comprising the following steps:

[0033] (1) Preparation of nitrogen-doped carbon-coated silica spheres: 2 mL of tetraethyl orthosilicate, 3 mL of ammonia water, 100 mL of deionized water, and 30 mL of ethanol are stirred and mixed. After stirring, 10 mL of a dopamine hydrochloride solution is added to obtain a composite solution. The composite solution is stirred to form polydopamine hydrochloride-coated silica spheres. The silica spheres are calcined at 900 DEG C under a nitrogen atmosphere for 3 h to obtain nitrogen-doped carbon-coated silica spheres.

[0034] (2) Preparation of nitrogen-doped hollow carbon spheres: 1000 mg of the nitrogen-doped carbon-coated silica spheres obtained in S1 are mixed with 30 mL of a 30wt% hydrofluoric acid solution. The mixture is stirred for 1.5 h to remove the silica template. After centrifugation, washing, and drying, nitrogen-doped hollow carbon spheres are obtained.

[0035] (3) Preparation of porous nitrogen-doped hollow carbon sphere supported copper monatomic electrocatalytic material: the nitrogen-doped hollow carbon spheres obtained in S2 are uniformly dispersed in deionized water, a Cu(NO3)2 solution with a total mass of copper accounting for 0.7wt% of the nitrogen-doped hollow carbon spheres is added to the aqueous solution containing 40mg of nitrogen-doped hollow carbon spheres, after uniform stirring, freeze-drying, calcination at 900℃ for 3h, a nitrogen-doped porous carbon supported copper monatomic catalyst is prepared.

[0036] <Comparative Example 2>

[0037] A method for preparing a nitrogen-doped porous carbon supported nickel monatomic catalyst, comprising the following steps:

[0038] (1) Preparation of nitrogen-doped carbon-coated silica spheres: 2mL of tetraethyl orthosilicate, 3mL of ammonia water, 100mL of deionized water, 30mL of ethanol are stirred and mixed, after stirring, 10mL of dopamine hydrochloride solution is added to obtain a composite solution, the above composite solution is fully stirred to form polydopamine hydrochloride coated silica spheres, and then calcination is carried out at 900℃ under nitrogen atmosphere for 3h to obtain nitrogen-doped carbon-coated silica spheres;

[0039] (2) Preparation of nitrogen-doped hollow carbon spheres: 1000mg of nitrogen-doped carbon-coated silica spheres obtained in S1 and 30mL of 30wt% hydrofluoric acid solution are mixed, stirred for 1.5h to remove the silica template, and after centrifugal washing and drying, nitrogen-doped hollow carbon spheres are obtained;

[0040] (3) Preparation of porous nitrogen-doped hollow carbon sphere supported nickel monatomic electrocatalytic material: the nitrogen-doped hollow carbon spheres obtained in S2 are uniformly dispersed in deionized water, a Ni(NO3)2 solution with a total mass of nickel accounting for 0.7wt% of the nitrogen-doped hollow carbon spheres is added to the aqueous solution containing 40mg of nitrogen-doped hollow carbon spheres, after uniform stirring, freeze-drying, calcination at 900℃ for 3h, a nitrogen-doped porous carbon supported nickel monatomic catalyst is prepared. 10 H 14 O4 solution, added to the aqueous solution containing 40mg of nitrogen-doped hollow carbon spheres, after uniform stirring, freeze-drying, high-temperature calcination at 900℃ for 3h, a nitrogen-doped porous carbon supported nickel monatomic catalyst is prepared.

[0041] <Example 1>

[0042] A method for preparing a porous nitrogen-doped hollow carbon sphere supported copper-nickel double monatomic electrocatalytic material, comprising the following steps:

[0043] (1) Preparation of nitrogen-doped carbon-coated silica spheres: 2mL of tetraethyl orthosilicate, 3mL of ammonia water, 100mL of deionized water, 30mL of ethanol are stirred and mixed, after stirring, 10mL of dopamine hydrochloride solution is added to obtain a composite solution, the above composite solution is fully stirred to form polydopamine hydrochloride coated silica spheres, and then calcination is carried out at 900℃ under nitrogen atmosphere for 3h to obtain nitrogen-doped carbon-coated silica spheres;

[0044] (2) Preparation of nitrogen-doped hollow carbon spheres: 1000 mg of nitrogen-doped carbon-coated silica spheres obtained from S1 were mixed with 30 mL of 30 wt% hydrofluoric acid solution, stirred for 1.5 h to remove silica template, centrifuged, washed and dried to obtain nitrogen-doped hollow carbon spheres.

[0045] (3) Preparation of porous nitrogen-doped hollow carbon spheres supported on copper-nickel dual-monoatom electrocatalytic material: The nitrogen-doped hollow carbon spheres obtained in S2 were uniformly dispersed in deionized water, and Cu(NO3)2 and NiC, with a total copper-nickel content of 0.7 wt% of the nitrogen-doped hollow carbon spheres, were added. 10 H 14 O4 was mixed with Cu:Ni in a mass ratio of 0.5:0.5 and added to an aqueous solution containing 40 mg of nitrogen-doped hollow carbon spheres. After stirring evenly, the mixture was freeze-dried and calcined at 900 °C for 3 h to prepare a porous nitrogen-doped hollow carbon sphere-supported copper-nickel dual single-atom electrocatalytic material.

[0046] Scanning electron microscope (SEM) images of the porous nitrogen-doped hollow carbon spheres (prepared by S2) prepared in Example 1 were obtained, and the results are as follows: Figures 1-2 As shown in the figure, the preparation method of Example 1 can produce hollow carbon spheres with uniform size, and the resulting porous nitrogen-doped hollow carbon spheres have a porous structure and a diameter as high as 861 μm. 2 / g -1 High specific surface area.

[0047] Scanning electron microscope (SEM) images of the porous nitrogen-doped hollow carbon sphere-supported copper-nickel dual single-atom electrocatalytic material prepared in Example 1 were obtained, and the results are as follows: Figure 3 As shown in the figure, the porous nitrogen-doped hollow carbon sphere-supported copper-nickel dual single-atom electrocatalytic material prepared in Example 1 has a morphology of uniformly sized hollow carbon spheres.

[0048] Figure 4 The figure shows the electrocatalytic Faraday efficiency of the porous nitrogen-doped hollow carbon sphere-supported copper-nickel dual-single-atom electrocatalytic material prepared in Example 1. As can be seen from the figure, the porous nitrogen-doped hollow carbon sphere-supported copper-nickel dual-single-atom electrocatalytic material prepared in Example 1 has extremely high electrocatalytic efficiency for carbon monoxide reduction from carbon dioxide and high selectivity for carbon dioxide reduction, reaching as high as 98%.

[0049] Figure 5 The image shows the X-ray diffraction pattern of Example 1. As can be seen from the image, the porous nitrogen-doped hollow carbon sphere-supported copper-nickel dual-single-atom electrocatalytic material prepared in Example 1 does not exhibit characteristic peaks of metallic copper and nickel, which means that copper and nickel nanoparticles are not present. This proves the successful preparation of the porous nitrogen-doped hollow carbon sphere-supported copper-nickel dual-single-atom electrocatalytic material.

[0050] Figure 6The faradic efficiency of the electrocatalytic reduction of carbon dioxide to produce carbon monoxide for Example 1 and Comparative Examples 1 and 2 can be seen from the figure, and it can be seen that the electrocatalytic reduction of carbon dioxide to produce carbon monoxide of Example 1 has the highest efficiency, reaching 98%.

[0051] Figure 7 The faradic efficiency of the electrocatalytic reduction of carbon dioxide to produce carbon monoxide for Example 1 and Examples 2-10 can be seen from the figure, and it can be seen that the electrocatalytic reduction of carbon dioxide to produce carbon monoxide of Example 1 has the highest efficiency, reaching 98%.

[0052] <Example 2>

[0053] A method for preparing a porous nitrogen-doped hollow carbon sphere loaded copper-nickel double-atom electrocatalytic material, comprising the following steps:

[0054] (1) Preparation of nitrogen-doped carbon-coated silica spheres: 2 mL of tetraethyl orthosilicate, 3 mL of ammonia water, 100 mL of deionized water, 30 mL of ethanol are stirred and mixed, and after stirring, 10 mL of dopamine hydrochloride solution is added to obtain a composite solution, and the composite solution is stirred to form poly-dopamine hydrochloride-coated silica spheres, which are calcined at 900°C under a nitrogen atmosphere for 3 h to obtain nitrogen-doped carbon-coated silica spheres;

[0055] (2) Preparation of nitrogen-doped hollow carbon spheres: 1000 mg of the nitrogen-doped carbon-coated silica spheres obtained in S1 are mixed with 30 mL of a 30 wt% hydrofluoric acid solution, and stirred for 1.5 h to remove the silica template, and after centrifugal washing and drying, nitrogen-doped hollow carbon spheres are obtained;

[0056] (3) Preparation of a porous nitrogen-doped hollow carbon sphere loaded copper-nickel double-atom electrocatalytic material: the nitrogen-doped hollow carbon spheres obtained in S2 are uniformly dispersed in deionized water, and Cu(NO3)2 and NiCO4 with a total mass of copper and nickel accounting for 0.7 wt% of the nitrogen-doped hollow carbon spheres are mixed in a mass ratio of Cu:Ni=0.1:0.9, and added to an aqueous solution containing 40 mg of the nitrogen-doped hollow carbon spheres, and after stirring uniformly, freeze-drying is performed, and calcination is performed at a temperature of 900°C for 3 h, thereby obtaining a porous nitrogen-doped hollow carbon sphere loaded copper-nickel double-atom electrocatalytic material. 10 H 14 O4, and the mass ratio of Cu:Ni is 0.1:0.9, and the mixture is added to an aqueous solution containing 40 mg of the nitrogen-doped hollow carbon spheres, and after stirring uniformly, freeze-drying is performed, and calcination is performed at a temperature of 900°C for 3 h, thereby obtaining a porous nitrogen-doped hollow carbon sphere loaded copper-nickel double-atom electrocatalytic material.

[0057] <Example 3>

[0058] A method for preparing a porous nitrogen-doped hollow carbon sphere loaded copper-nickel double-atom electrocatalytic material, comprising the following steps:

[0059] (1) Preparation of nitrogen-doped carbon-coated silica spheres: 2 mL of tetraethyl orthosilicate, 3 mL of ammonia water, 100 mL of deionized water, 30 mL of ethanol were stirred and mixed, after stirring, 10 mL of dopamine hydrochloride solution was added to obtain a composite solution, the above composite solution was fully stirred to form poly-dopamine hydrochloride coated silica spheres, and then calcined at 900°C under nitrogen atmosphere for 3h to obtain nitrogen-doped carbon-coated silica spheres;

[0060] (2) Preparation of nitrogen-doped hollow carbon spheres: 1000 mg of nitrogen-doped carbon-coated silica spheres obtained in S1 and 30 mL of 30wt% hydrofluoric acid solution were mixed, stirred for 1.5h to remove the silica template, and then centrifuged, washed and dried to obtain nitrogen-doped hollow carbon spheres;

[0061] (3) Preparation of porous nitrogen-doped hollow carbon sphere supported copper-nickel double monatomic electrocatalytic material: the nitrogen-doped hollow carbon spheres obtained in S2 were uniformly dispersed in deionized water, Cu(NO3)2 and NiC 10 H 14 O4 with a total mass of copper and nickel accounting for 0.7wt% of the nitrogen-doped hollow carbon spheres were mixed in a mass ratio of Cu:Ni=0.3:0.7, added to an aqueous solution containing 40 mg of nitrogen-doped hollow carbon spheres, uniformly stirred, and then freeze-dried and calcined at 900°C for 3h to obtain a porous nitrogen-doped hollow carbon sphere supported copper-nickel double monatomic electrocatalytic material.

[0062] <Example 4>

[0063] A method for preparing a porous nitrogen-doped hollow carbon sphere supported copper-nickel double monatomic electrocatalytic material, comprising the following steps:

[0064] (1) Preparation of nitrogen-doped carbon-coated silica spheres: 2 mL of tetraethyl orthosilicate, 3 mL of ammonia water, 100 mL of deionized water, 30 mL of ethanol were stirred and mixed, after stirring, 10 mL of dopamine hydrochloride solution was added to obtain a composite solution, the above composite solution was fully stirred to form poly-dopamine hydrochloride coated silica spheres, and then calcined at 900°C under nitrogen atmosphere for 3h to obtain nitrogen-doped carbon-coated silica spheres;

[0065] (2) Preparation of nitrogen-doped hollow carbon spheres: 1000 mg of nitrogen-doped carbon-coated silica spheres obtained in S1 and 30 mL of 30wt% hydrofluoric acid solution were mixed, stirred for 1.5h to remove the silica template, and then centrifuged, washed and dried to obtain nitrogen-doped hollow carbon spheres;

[0066] (3) Preparation of porous nitrogen-doped hollow carbon sphere supported copper-nickel double monatomic electrocatalytic material: the nitrogen-doped hollow carbon spheres obtained in S2 were uniformly dispersed in deionized water, Cu(NO3)2 and NiC10 H 14 O4, mixed in a mass ratio of Cu:Ni=0.7:0.3, was added to an aqueous solution containing 40 mg of nitrogen-doped hollow carbon spheres, stirred uniformly, freeze-dried, calcined at a temperature of 900°C for 3 h, thereby obtaining a porous nitrogen-doped hollow carbon sphere loaded copper-nickel double monatomic electrocatalytic material.

[0067] <Embodiment 5>

[0068] A preparation method of a porous nitrogen-doped hollow carbon sphere loaded copper-nickel double monatomic electrocatalytic material, comprising the following steps:

[0069] (1) Preparation of nitrogen-doped carbon-coated silica spheres: 2 mL of tetraethyl orthosilicate, 3 mL of ammonia water, 100 mL of deionized water, 30 mL of ethanol were stirred and mixed, and then 10 mL of dopamine hydrochloride solution was added to obtain a composite solution. The composite solution was stirred to form poly-dopamine hydrochloride coated silica spheres, which were calcined at 900°C under nitrogen atmosphere for 3 h to obtain nitrogen-doped carbon-coated silica spheres;

[0070] (2) Preparation of nitrogen-doped hollow carbon spheres: 1000 mg of nitrogen-doped carbon-coated silica spheres obtained in S1 were mixed with 30 mL of 30wt% hydrofluoric acid solution, stirred for 1.5 h to remove the silica template, and then centrifuged, washed and dried to obtain nitrogen-doped hollow carbon spheres;

[0071] (3) Preparation of a porous nitrogen-doped hollow carbon sphere loaded copper-nickel double monatomic electrocatalytic material: the nitrogen-doped hollow carbon spheres obtained in S2 were uniformly dispersed in deionized water, Cu(NO3)2 and Ni(NO3)2 with a total mass of 0.7wt% of the nitrogen-doped hollow carbon spheres were added, and the mixture was stirred uniformly, freeze-dried, and calcined at a temperature of 900°C for 3 h, thereby obtaining a porous nitrogen-doped hollow carbon sphere loaded copper-nickel double monatomic electrocatalytic material. 10 H 14 O4, mixed in a mass ratio of Cu:Ni=0.9:0.1, was added to an aqueous solution containing 40 mg of nitrogen-doped hollow carbon spheres, stirred uniformly, freeze-dried, calcined at a temperature of 900°C for 3 h, thereby obtaining a porous nitrogen-doped hollow carbon sphere loaded copper-nickel double monatomic electrocatalytic material.

[0072] <Embodiment 6>

[0073] A preparation method of a porous nitrogen-doped hollow carbon sphere loaded copper-nickel double monatomic electrocatalytic material, comprising the following steps:

[0074] (1) Preparation of nitrogen-doped carbon-coated silica spheres: 2 mL of tetraethyl orthosilicate, 3 mL of ammonia water, 100 mL of deionized water, and 30 mL of ethanol were stirred and mixed, and then 10 mL of dopamine hydrochloride solution was added to obtain a composite solution. The above composite solution was stirred to form polydopamine hydrochloride-coated silica spheres, which were calcined at 900°C under a nitrogen atmosphere for 3 h to obtain nitrogen-doped carbon-coated silica spheres.

[0075] (2) Preparation of nitrogen-doped hollow carbon spheres: 1000 mg of nitrogen-doped carbon-coated silica spheres obtained in S1 and 30 mL of 30 wt% hydrofluoric acid solution were mixed and stirred for 1.5 h to remove the silica template. After centrifugal washing and drying, nitrogen-doped hollow carbon spheres were obtained.

[0076] (3) Preparation of porous nitrogen-doped hollow carbon sphere supported copper-nickel double-atom electrocatalytic material: The nitrogen-doped hollow carbon spheres obtained in S2 were uniformly dispersed in deionized water. Cu(NO3)2 and NiC 10 H 14 O4 with a total mass of 0.7 wt% of the nitrogen-doped hollow carbon spheres were mixed in a mass ratio of Cu:Ni=0.5:0.5 and added to an aqueous solution containing 40 mg of nitrogen-doped hollow carbon spheres. After stirring uniformly, freeze-drying and calcination at 500°C for 3 h, a porous nitrogen-doped hollow carbon sphere supported copper-nickel double-atom electrocatalytic material was obtained.

[0077] <Example 7>

[0078] A method for preparing a porous nitrogen-doped hollow carbon sphere supported copper-nickel double-atom electrocatalytic material, comprising the following steps:

[0079] (1) Preparation of nitrogen-doped carbon-coated silica spheres: 2 mL of tetraethyl orthosilicate, 3 mL of ammonia water, 100 mL of deionized water, and 30 mL of ethanol were stirred and mixed, and then 10 mL of dopamine hydrochloride solution was added to obtain a composite solution. The above composite solution was stirred to form polydopamine hydrochloride-coated silica spheres, which were calcined at 900°C under a nitrogen atmosphere for 3 h to obtain nitrogen-doped carbon-coated silica spheres.

[0080] (2) Preparation of nitrogen-doped hollow carbon spheres: 1000 mg of nitrogen-doped carbon-coated silica spheres obtained in S1 and 30 mL of 30 wt% hydrofluoric acid solution were mixed and stirred for 1.5 h to remove the silica template. After centrifugal washing and drying, nitrogen-doped hollow carbon spheres were obtained.

[0081] (3) Preparation of porous nitrogen-doped hollow carbon sphere supported copper-nickel double-atom electrocatalytic material: The nitrogen-doped hollow carbon spheres obtained in S2 were uniformly dispersed in deionized water. Cu(NO3)2 and NiC 10H 14 O4, mixed according to the mass ratio of Cu:Ni=0.5:0.5, was added to a water solution containing 40 mg of nitrogen-doped hollow carbon spheres, stirred uniformly, freeze-dried, and calcined at 700°C for 3 h, thereby obtaining a porous nitrogen-doped hollow carbon sphere loaded copper-nickel double-atom electrocatalytic material.

[0082] <Embodiment 8>

[0083] A method for preparing a porous nitrogen-doped hollow carbon sphere loaded copper-nickel double-atom electrocatalytic material, comprising the following steps:

[0084] (1) Preparation of nitrogen-doped carbon-coated silica spheres: 2 mL of tetraethyl orthosilicate, 3 mL of ammonia water, 100 mL of deionized water, and 30 mL of ethanol were stirred and mixed, and then 10 mL of a dopamine hydrochloride solution was added to obtain a composite solution. The composite solution was stirred to form polydopamine hydrochloride-coated silica spheres, which were calcined at 900°C under a nitrogen atmosphere for 3 h to obtain nitrogen-doped carbon-coated silica spheres;

[0085] (2) Preparation of nitrogen-doped hollow carbon spheres: 1000 mg of the nitrogen-doped carbon-coated silica spheres obtained in S1 were mixed with 30 mL of a 30 wt% hydrofluoric acid solution, and stirred for 1.5 h to remove the silica template. After centrifugal washing and drying, nitrogen-doped hollow carbon spheres were obtained;

[0086] (3) Preparation of a porous nitrogen-doped hollow carbon sphere loaded copper-nickel double-atom electrocatalytic material: the nitrogen-doped hollow carbon spheres obtained in S2 were uniformly dispersed in deionized water, and Cu(NO3)2 and Ni(NO3)2 with a total mass of 0.3 wt% of the nitrogen-doped hollow carbon spheres were added. After stirring uniformly, freeze-drying, and calcination at 700°C for 3 h, a porous nitrogen-doped hollow carbon sphere loaded copper-nickel double-atom electrocatalytic material was obtained. 10 H 14 O4, mixed according to the mass ratio of Cu:Ni=0.5:0.5, was added to a water solution containing 40 mg of nitrogen-doped hollow carbon spheres, stirred uniformly, freeze-dried, and calcined at 900°C for 3 h, thereby obtaining a porous nitrogen-doped hollow carbon sphere loaded copper-nickel double-atom electrocatalytic material.

[0087] <Embodiment 9>

[0088] A method for preparing a porous nitrogen-doped hollow carbon sphere loaded copper-nickel double-atom electrocatalytic material, comprising the following steps:

[0089] (1) Preparation of nitrogen-doped carbon-coated silica spheres: 2 mL of tetraethyl orthosilicate, 3 mL of ammonia water, 100 mL of deionized water, and 30 mL of ethanol were stirred and mixed, and then 10 mL of a dopamine hydrochloride solution was added to obtain a composite solution. The composite solution was stirred to form polydopamine hydrochloride-coated silica spheres, which were calcined at 900°C under a nitrogen atmosphere for 3 h to obtain nitrogen-doped carbon-coated silica spheres;

[0090] (2) Preparation of nitrogen-doped hollow carbon spheres: 1000 mg of nitrogen-doped carbon-coated silica spheres obtained in S1 and 30 mL of a hydrofluoric acid solution with a concentration of 30 wt% were mixed, stirred for 1.5 h to remove the silica template, and then centrifuged, washed, and dried to obtain nitrogen-doped hollow carbon spheres;

[0091] (3) Preparation of a porous nitrogen-doped hollow carbon sphere loaded copper-nickel double monatomic electrocatalytic material: the nitrogen-doped hollow carbon spheres obtained in S2 were uniformly dispersed in deionized water, Cu(NO3)2 and NiCO4 with a total mass of 0.5 wt% of the nitrogen-doped hollow carbon spheres were mixed according to a mass ratio of Cu:Ni = 0.5:0.5, added to an aqueous solution containing 40 mg of nitrogen-doped hollow carbon spheres, uniformly stirred, freeze-dried, and calcined at a temperature of 900°C for 3 h, thereby obtaining a porous nitrogen-doped hollow carbon sphere loaded copper-nickel double monatomic electrocatalytic material. 10 H 14 O4, according to a mass ratio of Cu:Ni = 0.5:0.5, was added to an aqueous solution containing 40 mg of nitrogen-doped hollow carbon spheres, uniformly stirred, freeze-dried, and calcined at a temperature of 900°C for 3 h, thereby obtaining a porous nitrogen-doped hollow carbon sphere loaded copper-nickel double monatomic electrocatalytic material.

[0092] <Example 10>

[0093] A method for preparing a porous nitrogen-doped hollow carbon sphere loaded copper-nickel double monatomic electrocatalytic material, comprising the following steps:

[0094] (1) Preparation of nitrogen-doped carbon-coated silica spheres: 2 mL of tetraethyl orthosilicate, 3 mL of ammonia water, 100 mL of deionized water, and 30 mL of ethanol were stirred and mixed, and then 10 mL of a dopamine hydrochloride solution was added after stirring to obtain a composite solution. The composite solution was stirred to form poly-dopamine hydrochloride-coated silica spheres, which were calcined at 900°C for 3 h under a nitrogen atmosphere to obtain nitrogen-doped carbon-coated silica spheres;

[0095] (2) Preparation of nitrogen-doped hollow carbon spheres: 1000 mg of nitrogen-doped carbon-coated silica spheres obtained in S1 and 30 mL of a hydrofluoric acid solution with a concentration of 30 wt% were mixed, stirred for 1.5 h to remove the silica template, and then centrifuged, washed, and dried to obtain nitrogen-doped hollow carbon spheres;

[0096] (3) Preparation of a porous nitrogen-doped hollow carbon sphere loaded copper-nickel double monatomic electrocatalytic material: the nitrogen-doped hollow carbon spheres obtained in S2 were uniformly dispersed in deionized water, Cu(NO3)2 and NiCO4 with a total mass of 1 wt% of the nitrogen-doped hollow carbon spheres were mixed according to a mass ratio of Cu:Ni = 0.5:0.5, added to an aqueous solution containing 40 mg of nitrogen-doped hollow carbon spheres, uniformly stirred, freeze-dried, and calcined at a temperature of 900°C for 3 h, thereby obtaining a porous nitrogen-doped hollow carbon sphere loaded copper-nickel double monatomic electrocatalytic material. 10 H 14 O4, according to a mass ratio of Cu:Ni = 0.5:0.5, was added to an aqueous solution containing 40 mg of nitrogen-doped hollow carbon spheres, uniformly stirred, freeze-dried, and calcined at a temperature of 900°C for 3 h, thereby obtaining a porous nitrogen-doped hollow carbon sphere loaded copper-nickel double monatomic electrocatalytic material.

[0097] <Example 11>

[0098] A preparation method of a porous nitrogen-doped hollow carbon sphere loaded copper-nickel double monatomic electrocatalytic material, comprising the following steps:

[0099] (1) Preparation of nitrogen-doped carbon-coated silica spheres: 2 mL of tetraethyl orthosilicate, 3 mL of ammonia water, 100 mL of deionized water, and 30 mL of ethanol are stirred and mixed, and after stirring, 10 mL of a dopamine hydrochloride solution is added to obtain a composite solution. The above-mentioned composite solution is fully stirred to form poly-dopamine hydrochloride-coated silica spheres, which are calcined at 900°C under a nitrogen atmosphere for 3 h to obtain nitrogen-doped carbon-coated silica spheres;

[0100] (2) Preparation of nitrogen-doped hollow carbon spheres: 1000 mg of the nitrogen-doped carbon-coated silica spheres obtained in S1 are mixed with 30 mL of a 30 wt% hydrofluoric acid solution, and stirred for 1.5 h to remove the silica template. After centrifugal washing and drying, nitrogen-doped hollow carbon spheres are obtained;

[0101] (3) Preparation of a porous nitrogen-doped hollow carbon sphere loaded copper-nickel double monatomic electrocatalytic material: the nitrogen-doped hollow carbon spheres obtained in S2 are uniformly dispersed in deionized water, and Cu(NO3)2 and NiCO4 with a total mass of copper and nickel accounting for 0.7 wt% of the nitrogen-doped hollow carbon spheres are mixed in a mass ratio of Cu:Ni=0.5:0.5, and then added to an aqueous solution containing 40 mg of the nitrogen-doped hollow carbon spheres. After uniform stirring, freeze-drying, and calcination at a temperature of 900°C for 3 h, a porous nitrogen-doped hollow carbon sphere loaded copper-nickel double monatomic electrocatalytic material is prepared. 10 H 14 O4, and the total mass of copper and nickel accounts for 0.7 wt% of the nitrogen-doped hollow carbon spheres, are mixed in a mass ratio of Cu:Ni=0.5:0.5, and then added to an aqueous solution containing 40 mg of the nitrogen-doped hollow carbon spheres. After uniform stirring, freeze-drying, and calcination at a temperature of 900°C for 3 h, a porous nitrogen-doped hollow carbon sphere loaded copper-nickel double monatomic electrocatalytic material is prepared.

[0102] <Example 12>

[0103] A preparation method of a porous nitrogen-doped hollow carbon sphere loaded copper-nickel double monatomic electrocatalytic material, comprising the following steps:

[0104] (1) Preparation of nitrogen-doped carbon-coated silica spheres: 2 mL of tetraethyl orthosilicate, 3 mL of ammonia water, 100 mL of deionized water, and 30 mL of ethanol are stirred and mixed, and after stirring, 10 mL of a dopamine hydrochloride solution is added to obtain a composite solution. The above-mentioned composite solution is fully stirred to form poly-dopamine hydrochloride-coated silica spheres, which are calcined at 900°C under a nitrogen atmosphere for 3 h to obtain nitrogen-doped carbon-coated silica spheres;

[0105] (2) Preparation of nitrogen-doped hollow carbon spheres: 1000 mg of the nitrogen-doped carbon-coated silica spheres obtained in S1 are mixed with 30 mL of a 30 wt% hydrofluoric acid solution, and stirred for 1.5 h to remove the silica template. After centrifugal washing and drying, nitrogen-doped hollow carbon spheres are obtained;

[0106] (3) Preparation of porous nitrogen-doped hollow carbon sphere supported copper-nickel double-atom electrocatalytic material: uniformly disperse the nitrogen-doped hollow carbon spheres obtained in S2 in deionized water, mix Cu(NO3)2 and Ni(NO3)2 to a total mass of 0.7wt% of the nitrogen-doped hollow carbon spheres, mix according to the mass ratio of Cu:Ni=0.5:0.5, add to the aqueous solution containing 40mg of nitrogen-doped hollow carbon spheres, stir uniformly, freeze-dry, and calcine at 900℃ for 3h to prepare the porous nitrogen-doped hollow carbon sphere supported copper-nickel double-atom electrocatalytic material. 10 H 14 O4, NiC 10 H 14 O4, mix according to the mass ratio of Cu:Ni=0.5:0.5, add to the aqueous solution containing 40mg of nitrogen-doped hollow carbon spheres, stir uniformly, freeze-dry, and calcine at 900℃ for 3h to prepare the porous nitrogen-doped hollow carbon sphere supported copper-nickel double-atom electrocatalytic material.

[0107] <Example 13>

[0108] A method for preparing a porous nitrogen-doped hollow carbon sphere supported copper-nickel double-atom electrocatalytic material, comprising the following steps:

[0109] (1) Preparation of nitrogen-doped carbon-coated silica spheres: stir and mix 2mL of tetraethyl orthosilicate, 3mL of ammonia water, 100mL of deionized water, and 30mL of ethanol, then add 10mL of dopamine hydrochloride solution to obtain a composite solution, fully stir the composite solution to form polydopamine hydrochloride-coated silica spheres, and calcine at 900℃ for 3h under a nitrogen atmosphere to obtain nitrogen-doped carbon-coated silica spheres;

[0110] (2) Preparation of nitrogen-doped hollow carbon spheres: mix 1000mg of nitrogen-doped carbon-coated silica spheres obtained in S1 with 30mL of 30wt% hydrofluoric acid solution, stir for 1.5h to remove the silica template, centrifuge, wash, and dry to obtain nitrogen-doped hollow carbon spheres;

[0111] (3) Preparation of porous nitrogen-doped hollow carbon sphere supported copper-nickel double-atom electrocatalytic material: uniformly disperse the nitrogen-doped hollow carbon spheres obtained in S2 in deionized water, mix Cu(NO3)2 and Ni(NO3)2 to a total mass of 0.7wt% of the nitrogen-doped hollow carbon spheres, mix according to the mass ratio of Cu:Ni=0.5:0.5, add to the aqueous solution containing 40mg of nitrogen-doped hollow carbon spheres, stir uniformly, freeze-dry, and calcine at 900℃ for 3h to prepare the porous nitrogen-doped hollow carbon sphere supported copper-nickel double-atom electrocatalytic material. 10 H 14 O4, NiC 10 H 14 O4, mix according to the mass ratio of Cu:Ni=0.5:0.5, add to the aqueous solution containing 40mg of nitrogen-doped hollow carbon spheres, stir uniformly, freeze-dry, and calcine at 900℃ for 3h to prepare the porous nitrogen-doped hollow carbon sphere supported copper-nickel double-atom electrocatalytic material.

[0112] <Example 14>

[0113] A method for preparing a porous nitrogen-doped hollow carbon sphere supported copper-nickel double-atom electrocatalytic material, comprising the following steps:

[0114] (1) Preparation of nitrogen-doped carbon-coated silica spheres: 2 mL of tetraethyl orthosilicate, 3 mL of ammonia water, 100 mL of deionized water, 30 mL of ethanol were stirred and mixed, after stirring, 10 mL of dopamine hydrochloride solution was added to obtain a composite solution, the above composite solution was stirred to form polydopamine hydrochloride coated silica spheres, and then calcined at 900°C for 3h under nitrogen atmosphere to obtain nitrogen-doped carbon-coated silica spheres;

[0115] (2) Preparation of nitrogen-doped hollow carbon spheres: 1000 mg of nitrogen-doped carbon-coated silica spheres obtained in S1 and 30 mL of 30wt% hydrofluoric acid solution were mixed and stirred for 1.5h to remove the silica template, and then centrifuged, washed and dried to obtain nitrogen-doped hollow carbon spheres;

[0116] (3) Preparation of porous nitrogen-doped hollow carbon sphere supported copper-nickel double monatomic electrocatalytic material: the nitrogen-doped hollow carbon spheres obtained in S2 were uniformly dispersed in deionized water, Cu(NO3)2 and Ni(NO3)2 with a total mass of 0.7wt% of the nitrogen-doped hollow carbon spheres were mixed in a mass ratio of Cu:Ni=0.5:0.5, and then added to an aqueous solution containing 40 mg of nitrogen-doped hollow carbon spheres, stirred uniformly, and then freeze-dried and calcined at 900°C for 3h to obtain a porous nitrogen-doped hollow carbon sphere supported copper-nickel double monatomic electrocatalytic material.

[0117] The porous nitrogen-doped hollow carbon sphere supported copper-nickel double monatomic electrocatalytic materials prepared in Examples 1-10 were tested for their activity in electrocatalytic reduction of carbon dioxide, wherein the mass ratio of copper-nickel double monatomic, high-temperature calcination deposition temperature and the total mass fraction of copper-nickel in nitrogen-doped hollow carbon spheres were different. Figure 7 The activity comparison chart of the porous nitrogen-doped hollow carbon sphere supported copper-nickel double monatomic electrocatalytic material tested at a voltage of -0.9V for electrocatalytic reduction of carbon dioxide showed that the electrocatalytic materials obtained under different mass ratios of copper-nickel double monatomic, different high-temperature calcination deposition temperatures and different total mass fractions of copper-nickel in nitrogen-doped hollow carbon spheres all had good performance, and the porous nitrogen-doped hollow carbon sphere supported copper-nickel double monatomic electrocatalytic material prepared in Example 1 had the highest activity in carbon dioxide reduction reaction.

[0118] The above examples are only used to help understand the technical solutions of the present application and its core idea. It should be pointed out that for those skilled in the art, without departing from the principles of the present application, the present application can be improved and modified in several ways, and these improvements and modifications also fall within the scope of protection of the claims of the present application.

Claims

1. A method for preparing a porous nitrogen-doped hollow carbon sphere-supported copper-nickel dual single-atom electrocatalytic material, characterized in that: The method comprises the following steps: S1, preparing nitrogen-doped carbon-coated silica spheres: a certain amount of tetraethyl orthosilicate, ammonia water, deionized water and ethanol are stirred and mixed, a dopamine hydrochloride solution is added to obtain a composite solution, the composite solution is fully stirred, and carbonization treatment is performed to obtain nitrogen-doped carbon-coated silica spheres; S2, preparing nitrogen-doped hollow carbon spheres: the nitrogen-doped carbon-coated silica spheres obtained in S1 are added to a hydrofluoric acid solution, fully stirred, centrifuged and washed, and dried to obtain nitrogen-doped hollow carbon spheres; S3, preparing a porous nitrogen-doped hollow carbon sphere loaded copper-nickel double-atom electrocatalytic material: the nitrogen-doped hollow carbon spheres obtained in S2 are uniformly dispersed in deionized water, and copper salt and nickel salt are added, and then stirring, freezing, drying and calcination are sequentially performed, and the copper-nickel double-atom electrocatalytic material is obtained by uniformly loading the copper-nickel double-atom on the porous nitrogen-doped hollow carbon spheres; specifically, the freezing method is liquid nitrogen freezing; the calcination temperature is 500-900°C, and the calcination time is 3h; Specifically, the total mass fraction of copper and nickel in the nitrogen-doped hollow carbon spheres is 0.3-1wt%, and the mass ratio of copper salt to nickel salt is Cu:Ni=0.5:0.

5.

2. The preparation method of the porous nitrogen-doped hollow carbon sphere loaded copper-nickel double monatomic electrocatalytic material according to claim 1, characterized in that, In S1, the stirring time of tetraethyl orthosilicate, ammonia water, deionized water and ethanol is 20-40min, the stirring time of adding the dopamine hydrochloride solution is 24-48h, and the carbonization treatment temperature is 700-1000°C, and the carbonization time is 3h.

3. The method of claim 1, wherein the method is characterized by: In S1, the volume ratio of tetraethyl orthosilicate, ammonia water, deionized water and ethanol is 2:3:100:30, and the mass ratio of tetraethyl orthosilicate to dopamine hydrochloride is 1:

5.

4. The method according to claim 1, wherein the method is characterized in that, In S2, the mass ratio of nitrogen-doped carbon-coated silica spheres to hydrofluoric acid is 100:

3.

5. The method of claim 1, wherein the method is characterized by: In S2, the concentration of the hydrofluoric acid solution is 20-40wt%, and the hydrofluoric acid etching time is 0.5-2h.

6. The porous nitrogen-doped hollow carbon sphere loaded copper-nickel double-atom electrocatalytic material is prepared by the method of any one of claims 1-5.

7. The application of the porous nitrogen-doped hollow carbon sphere loaded copper-nickel double-atom electrocatalytic material in electrocatalytic carbon dioxide to carbon monoxide.

8. The use of the porous nitrogen-doped hollow carbon sphere supported copper-nickel biatomic electrocatalytic material according to claim 7, characterized in that, Under the condition of normal temperature and 0.5mol / L potassium hydroxide solution as electrolyte, the yield of electrocatalytic carbon dioxide to carbon monoxide reaches 98%.

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