Cu2O nanomaterial, and preparation method and application thereof
Cu2O nanomaterials were prepared by reacting copper salts with reducing sugars in the presence of alcohol solvents and bases, which solved the problems of poor C2+ product selectivity and severe hydrogen evolution side reactions of copper-based catalysts and achieved high-efficiency CO2RR performance.
Patent Information
- Application Number
- CN202310079447.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2023-01-16
- Publication Date
- 2025-12-12
- Estimated Expiration
- 2043-01-16
AI Technical Summary
Existing copper-based catalysts exhibit poor selectivity for C2+ products and severe hydrogen evolution side reactions during electrocatalytic CO2 reduction, hindering their industrial application.
Cu2O nanomaterials were prepared by reacting copper salts with reducing sugars in the presence of alcohol solvents and alkali. By controlling the reaction conditions and without adding additional reducing agents or surfactants, spherical nanoparticles with reducing sugar molecules on their surface were formed.
It improves the selectivity of C2+ products in the CO2RR reaction and suppresses the hydrogen evolution side reaction. The Faraday efficiency of C2+ products can reach 82.39%, while the Faraday efficiency of hydrogen evolution side reaction is less than 13%.
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Figure CN116254564B_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application belongs to the field of electrochemical functional materials, and particularly relates to a Cu2O nanomaterial, a preparation method and application thereof. BACKGROUND
[0002] The combustion of fossil energy emits a large amount of CO2, causing a series of problems such as global greenhouse effect, climate warming, sea level rise, etc. Electro-catalytic reduction of CO2 (CO2RR) can convert intermittent energy such as solar energy and wind energy into fuels and high-value chemicals under normal temperature and pressure conditions, and is an effective way to realize carbon cycle and storage and conversion of electrical energy into chemical energy. In the field of electro-catalytic reduction of CO2 on metal electrodes, copper is the only metal catalyst that can reduce CO2 into multi-carbon products (i.e. C 2+ products), which can obtain two-electron (2e - ) transfer products (such as CO and HCOOH), eight-electron (8e - ) transfer products (such as CH4) and more than 16 different products. From the perspective of thermodynamics and economic benefits, C 2+ products have higher market value and energy density. For example, typical C 2+ product C2H4 is a key chemical raw material for various chemical industries (such as polyethylene material production), in addition, C2H4 can also be directly used as a welding fuel or a mixed component in natural gas.
[0003] Although copper-based catalysts can electro-catalytically reduce CO2 to obtain C 2+ products, the copper-based catalysts prepared by the existing technical means have poor selectivity for C 2+ products, which makes it difficult to separate the final product. At the same time, C 2+ products are often generated at a higher potential, and the hydrogen evolution side reaction is serious, which is not conducive to the generation of C 2+ products. For example, the existing technical document "Highly Selective CO2 Electroreduction to CH4 by In Situ Generated Cu2O Single-Type Sites on a Conductive MOF: Stabilizing Key Intermediates with Hydrogen Bonding" (J. Yi et al., Angew. Chem. Int. Ed. 2020) reports a Cu2O@HHTP catalyst with Cu2O unit points generated in situ on a conductive MOF, which is used for electro-catalytic reduction of CO2, and the Faraday efficiency of the hydrogen evolution reaction reaches 21.0%. Therefore, the problems of poor product selectivity and serious hydrogen evolution reaction seriously hinder the production of C 2+Industrial application of the product and development of the corresponding copper-based catalyst. Modifying the catalyst surface with small molecules is an effective strategy to improve the electrochemical performance of CO2RR. By changing the microenvironment near the catalyst surface, the surface modification molecules interact with the reaction intermediates or molecules, thereby making the C 2+ The reaction path is more advantageous.
[0004] Therefore, it is urgent to develop a preparation method that is economical and environmentally friendly, and has higher C 2+ There is an urgent need for CO2RR molecular modification of copper-based nanocatalysts to improve product selectivity. SUMMARY
[0005] The technical problem to be solved by the present application is to overcome the problems of low product selectivity and serious hydrogen evolution side reaction in the existing copper-based catalyst for CO2RR to obtain C 2+ The present application provides a Cu2O nanomaterial and a preparation method and application thereof.
[0006] The present application solves the above technical problems by the following technical solutions:
[0007] The present application provides a preparation method of Cu2O nanomaterial, which comprises the following steps: mixing copper salt and reducing sugar in the presence of alcohol solvent and base, wherein the molar ratio of the copper salt to the reducing sugar is preferably 1:(0.5-8).
[0008] In the present application, the alcohol solvent can be C1-C5 aliphatic alcohol, preferably one or more of methanol, ethanol, ethylene glycol, n-butanol and glycerol, more preferably ethanol, ethylene glycol, n-butanol or glycerol.
[0009] In the present application, the molar ratio of the copper salt to the reducing sugar can be 1:0.6, 1:2, 1:3, 1:4 or 1:7, preferably 1:(1-5), more preferably 1:(3-4.5).
[0010] In the present application, the molar ratio of the copper salt to the base is preferably 1:(8-12), for example 1:10.
[0011] In the present application, the copper salt can be a copper precursor commonly used in the art for preparing cuprous oxide nanomaterial, for example one or more of copper acetylacetonate, copper chloride, copper nitrate, copper acetate and copper sulfate, preferably copper acetylacetonate, copper chloride or copper nitrate, more preferably copper acetylacetonate.
[0012] In the present application, the reducing sugar can be one or more of glucose, fructose, mannose, maltose, lactose and galactose, preferably glucose, fructose or mannose.
[0013] In the present application, the base can be one or more of sodium hydroxide, potassium hydroxide and ammonia water, preferably sodium hydroxide or potassium hydroxide.
[0014] In the present application, preferably, the copper salt and the reducing sugar are first dissolved in the alcohol solvent to form a mixed solution, and then the base is added to the mixed solution to perform the mixing reaction. The above specific mixing order helps to form spherical particles with uniform size.
[0015] In the mixed solution, the concentration of the copper salt is preferably 0.005-0.1 mol / L, for example 0.0077 mol / L, 0.0083 mol / L, 0.053 mol / L, 0.063 mol / L or 0.087 mol / L.
[0016] In the mixed solution, the concentration of the reducing sugar is preferably 0.005-0.1 mol / L, for example 0.005 mol / L, 0.017 mol / L, 0.033 mol / L, 0.047 mol / L, 0.058 mol / L, 0.065 mol / L, 0.089 mol / L or 0.097 mol / L.
[0017] Preferably, the base is first prepared into a base solution and then added to the mixed solution. The solvent in the base solution can be a conventional solvent that can dissolve the base, for example water. The concentration of the base solution is preferably 1-10 mol / L, for example 5 mol / L.
[0018] In the present application, no additional strong reducing agent needs to be added during the preparation of the Cu2O nanomaterial. The strong reducing agent can be conventional in the art, for example hydrazine hydrate or sodium borohydride.
[0019] In the present application, no additional surfactant needs to be added during the preparation of the Cu2O nanomaterial. The surfactant can be conventional in the art, for example polyvinylpyrrolidone, cetyltrimethylammonium bromide or sodium dodecyl sulfate.
[0020] In the present application, the mixing reaction is generally performed under magnetic stirring.
[0021] In the present application, the mixing reaction is generally performed under magnetic stirring.
[0022] In the present application, the mixing reaction can be performed for 0-360 min and not 0, preferably 20-120 min, for example 30 min, 60 min or 90 min.
[0023] In the present application, the temperature of the mixing reaction can be 15-180℃, preferably 60-100℃, for example 65℃, 85℃ or 95℃.
[0024] In the present application, the mixing reaction is generally followed by washing and drying operations.
[0025] The washing can be performed by conventional methods in the art, and generally includes solid-liquid separation of the mixture obtained after the mixing reaction by centrifugation, re-dispersing the solid product in the solvent, and solid-liquid separation by centrifugation after sufficient stirring, repeating the above operations 3-5 times, and washing away the impurities remaining on the surface of the solid product.
[0026] The solid-liquid separation device can be a conventional centrifuge in the art.
[0027] The rotation speed of the centrifugation can be 5000-10000 rpm, preferably 6000-8000 rpm, for example 6500 rpm, 7500 rpm or 8000 rpm.
[0028] The centrifugation time can be 5-20 min, preferably 6-10 min, for example 6 min, 8 min or 10 min.
[0029] The solvent used in the washing process can be an alcohol solvent, for example isopropanol.
[0030] The drying method can be a conventional drying method in the art, for example freeze-drying or vacuum drying, preferably freeze-drying.
[0031] The drying time can be 12-24 h, for example 16 h, 18 h or 24 h.
[0032] The present application provides a Cu2O nanomaterial prepared by the above method.
[0033] In the present application, the Cu2O nanomaterial can be spherical nanoparticles.
[0034] In the present application, the particle size of the Cu2O nanomaterial can be 100-200 nm.
[0035] In the present application, the surface of the Cu2O nanomaterial can be adsorbed with a reducing sugar molecule.
[0036] The present application provides a use of the above Cu2O nanomaterial as a catalyst in a carbon dioxide electro-reduction reaction.
[0037] The above preferred conditions can be arbitrarily combined based on common sense in the art, i.e. to obtain various preferred examples of the present application.
[0038] The reagents and raw materials used in this invention are all commercially available.
[0039] The positive and progressive effects of this invention are as follows:
[0040] (1) The method for preparing Cu2O nanomaterials of the present invention, under alkaline conditions, uses an alcohol solvent with surface-active function as the reaction solvent, utilizes reducing sugars as reducing agents and modifying molecules, and, with the synergistic effect of other features, promotes the reaction of Cu2O nanomaterials. 2+ The precursor is reduced to Cu2O nanomaterials with reducing sugar molecules on the surface. The process is simple, the conditions are mild, it is environmentally friendly, and it is easy to achieve large-scale production.
[0041] The Cu2O nanomaterial of the present invention can be uniform nanoscale spherical particles with a particle size range of 100-200 nm.
[0042] (2) When the Cu2O nanomaterial of the present invention is applied to the CO2RR reaction, it can promote the adsorption and activation of CO2, preferentially adsorb CO, which is beneficial to CC coupling, thereby improving C 2+ It not only improves the selectivity of the product, but also helps to suppress hydrogen evolution side reactions.
[0043] (3) In a preferred embodiment of the present invention, Cu2O nanomaterials are applied to the C2RR reaction. 2+ Faraday efficiency of product FE C2+ The efficiency can reach up to 82.39%, and it also controls the hydrogen evolution side reaction to a certain extent. The Faraday efficiency of the hydrogen evolution reaction is FE. H2 The lowest possible rate is 7.79%. Attached Figure Description
[0044] Figure 1 This is a transmission electron microscope (TEM) image of the Cu2O nanomaterials in Example 3.
[0045] Figure 2 This is a transmission electron microscope (TEM) image of Cu2O nanomaterials in Comparative Example 1.
[0046] Figure 3 The image shows the X-ray diffraction (XRD) pattern of the Cu2O nanomaterial in Example 3.
[0047] Figure 4 The image shows the X-ray photoelectron spectrum (XPS) of the Cu2O nanomaterial in Example 3, wherein... Figure 4 (a) is the Cu 2P electron energy spectrum. Figure 4 (b) is the Cu LMN Auger electron spectrum.
[0048] Figure 5The infrared spectrum (FTIR) of the Cu2O nanomaterial of Examples 1-4.
[0049] Figure 6 The Faraday efficiency of the Cu2O nanomaterial of Examples 1-4 for electrocatalysis of carbon dioxide to generate hydrogen as a byproduct at different potentials. 2+ The Faraday efficiency of the product.
[0050] Figure 7 The Faraday efficiency of the Cu2O nanomaterial of Examples 1-4 for electrocatalysis of carbon dioxide to generate hydrogen as a byproduct at different potentials. DETAILED DESCRIPTION
[0051] The application will be further described in the following examples without limiting the application to the examples. The experimental methods in the following examples, if not otherwise specified, are selected according to the conventional methods and conditions, or according to the instructions of the commercial products.
[0052] The application will be further described in the following examples without limiting the application to the examples. The experimental methods in the following examples, if not otherwise specified, are selected according to the conventional methods and conditions, or according to the instructions of the commercial products.
[0053] Example 1
[0054] A method for preparing a Cu2O nanomaterial, comprising the following steps:
[0055] 0.001 mol of copper acetylacetonate (i.e., Cu(acac)2) and 0.0006 mol of glucose were added to 118 mL of ethylene glycol, and stirred for 10 min to prepare a mixed solution, and the volume of the mixed solution was 120 mL.
[0056] 0.01 mol of KOH was dissolved in 2 mL of deionized water, and then added to the above mixed solution, and stirred to form a blue reaction solution. The reaction solution was placed in an oil bath at a temperature of 95 ℃, and stirred for 30 min. The stirring was magnetic stirring, and the stirring speed was 1500 rpm.
[0057] After the reaction was completed, the reaction solution was cooled to room temperature, and the solid product was separated by centrifugation. The solid product was washed with isopropanol for 3 times, the centrifugation speed was 8000 rpm, and the centrifugation time was 10 min. The washed solid product was freeze-dried to obtain the final product, and the drying time was 24 h.
[0058] Example 2
[0059] In Example 2, the amount of glucose in Example 1 was replaced by 0.002 mol, and the other steps and conditions were the same as those in Example 1.
[0060] Example 3
[0061] The amount of glucose in Example 1 is replaced with 0.004 mol, and the remaining steps and conditions are the same as in Example 1.
[0062] Example 4
[0063] The amount of glucose in Example 1 is replaced with 0.007 mol, and the remaining steps and conditions are the same as in Example 1.
[0064] Example 5
[0065] The ethylene glycol in Example 1 is replaced with glycerol, and the remaining steps and conditions are the same as in Example 1.
[0066] Example 6
[0067] The ethylene glycol in Example 1 is replaced with n-butanol, and the remaining steps and conditions are the same as in Example 1.
[0068] Example 7
[0069] The glucose in Example 1 is replaced with fructose, and the remaining steps and conditions are the same as in Example 1.
[0070] Example 8
[0071] The glucose in Example 1 is replaced with mannose, and the remaining steps and conditions are the same as in Example 1.
[0072] Example 9
[0073] The glucose in Example 1 is replaced with galactose, and the remaining steps and conditions are the same as in Example 1.
[0074] Example 10
[0075] The glucose in Example 1 is replaced with lactose, and the remaining steps and conditions are the same as in Example 1.
[0076] Example 11
[0077] The glucose in Example 1 is replaced with maltose, and the remaining steps and conditions are the same as in Example 1.
[0078] Comparative Example 1
[0079] The copper salt in Example 1 is replaced with copper chloride, and the ethylene glycol is replaced with water, and the remaining steps and conditions are the same as in Example 1.
[0080] Effect Example 1
[0081] (1) Morphology characterization
[0082] The products prepared in Example 3 and Comparative Example 1 were subjected to TEM microscopic morphology characterization using a JEM-1400 instrument, and the results were respectively as follows:Figure 1 and Figure 2 As shown. By Figure 1 It can be seen that the product prepared using Example 3 is a uniformly sized spherical nanoparticle with a particle size between 100 and 200 nm. Figure 2 It can be seen that the product prepared using Comparative Example 1 has irregular particle shape and a wide particle size distribution range.
[0083] (2) Phase characterization
[0084] The product obtained in Example 3 was characterized by XRD phase analysis using a D8 ADVANCE (Bruker) X-ray diffractometer. The results are as follows: Figure 3 As shown. By Figure 3 It can be seen that the main diffraction peaks correspond to the (111), (200) and (220) crystal planes of Cu2O (JCPDS 78-2076), proving that the product obtained in Example 3 is Cu2O nanocrystals.
[0085] The product obtained in Example 3 was characterized by X-ray photoelectron spectroscopy (XPS) using a Thermo Scientific ESCALAB 250Xi. The results are as follows: Figure 4 As shown. By Figure 4 The Cu 2P electronic spectrum results in (a) show that Cu2O (Cu2O) appears at 932.4 eV. + ) or Cu(Cu 0 The characteristic peak of ) is composed of Figure 4 (b) The Cu LMM Auger electron spectroscopy (AES) shows that the Cu element in the product is mainly in the monovalent oxidation state (Cu at 570 eV). + Characteristic peaks). Cu 2+ The formation is due to Cu during the XPS test. + It is formed by oxidation upon exposure to air. XPS characterization results indicate that the product obtained in Example 3 is Cu2O.
[0086] (3) Surface modification molecular characterization
[0087] The products obtained in Examples 1-4 were subjected to Fourier Transmission Infrared (FTIR) spectroscopy, and the results are as follows: Figure 5 As shown. Figure 5 The infrared spectrum shows peaks at 3384, 2920, 2890, 1590, and 1378 cm⁻¹. -1 The peaks correspond to the -OH stretching vibration, n(CH) vibration, C=O, and OCH bending vibration, respectively, which are the infrared characteristic peaks of glucose, proving that the Cu2O nanomaterials prepared in Examples 1 to 4 are modified with hydroxyl-containing glucose molecules.
[0088] Example 2
[0089] Electrocatalytic CO2 reduction (CO2RR) performance was tested using an electrocatalytic testing system. The test was conducted in a standard three-electrode system using an Autolab 302N electrochemical workstation. Cu2O nanomaterials were added to a solution containing 5 mL methanol and 20 μL Nafion and sonicated for 30 min to prepare an ink solution. This ink solution was then uniformly sprayed onto a surface with a geometric area of 3 × 3 cm². 2 The working electrode (GDE) was fabricated using a GDL (Gas diffusion layer, model 29BC). The catalyst loading (i.e., the mass of catalyst loaded per unit area) on the GDL surface was 1.11 mg / cm². 2 Ag / AgCl was used as the reference electrode, and Ni foam (geometric area 0.8 × 1.7 cm²) was used as the counter electrode. 2 The reaction was carried out using a flow cell electrolysis cell. The cathode and anode chambers of the electrolysis cell were separated by an anion exchange membrane. The electrolytes in both the anode and cathode chambers were 1.0 mol / L potassium bicarbonate solutions. The gaseous products generated by the catalytic CO2RR reaction were quantitatively analyzed using an online gas chromatography system (Shanghai Ruimin, GC-2020) equipped with an FID detector. Proton nuclear magnetic resonance (NMR) spectroscopy was employed. 1 The liquid products in the electrolyte after CO2 electrolysis reduction were sampled and analyzed by ¹H NMR, with dimethyl sulfoxide (DMSO) as an internal standard. Spectra were acquired on a Bruker AM 400 spectrometer. Each Cu₂O nanomaterial sample was tested four times, with working electrode potentials of -0.62, -0.78, -0.94, and -1.1 V (vs RHE), and a test time (i.e., potential holding time) of 10 min.
[0090] Following the above method, the products obtained in Examples 1-4 were used as catalysts for CO2RR tests to obtain C 2+ Product Faraday efficiency, such as Figure 6 As shown, the Faraday efficiency of H2 is as follows: Figure 7 As shown.
[0091] Depend on Figure 6 It can be seen that the Cu2O nanomaterials prepared in Examples 1-4 exhibit better C content when used to catalyze the CO2RR reaction. 2+ Product selectivity, C 2+ The product's Faraday efficiency reached over 54%. Under optimal testing conditions, i.e., an overpotential of -0.94V, the Cu₂O nanomaterials prepared in Example 3 catalyzed the CO₂RR reaction. 2+ The product's Faraday efficiency can reach up to 82.39%.
[0092] Depend on Figure 7 It can be seen that the Cu2O nanomaterials prepared in Examples 1-4 can suppress the hydrogen evolution side reaction to a certain extent when used as catalysts for the CO2RR reaction. When the Cu2O nanomaterials in Example 3 catalyze CO2RR, the Faradaic efficiency of the H2 byproduct is less than 13%, and under the optimal test conditions, i.e., at an overpotential of -0.94V, the Faradaic efficiency of the hydrogen byproduct can be as low as 7.79%.
Claims
1. A method for preparing Cu2O nanomaterials, characterized in that, It comprises the following steps: mixing copper salt and reducing sugar in the presence of alcohol solvent and base, wherein the molar ratio of the copper salt to the reducing sugar is 1:(2-8); the copper salt is copper acetylacetonate; The mixing reaction process is as follows: first, the copper salt and the reducing sugar are dissolved in the alcohol solvent to form a mixed solution, then the base is prepared into a base solution and added to the mixed solution to carry out the mixing reaction; the molar ratio of the copper salt to the base is 1:(8-12); the reducing sugar is one or more of glucose, fructose, mannose, maltose, lactose and galactose; the base is one or more of sodium hydroxide, potassium hydroxide and ammonia water; the alcohol solvent is one or more of methanol, ethanol, ethylene glycol, n-butanol and glycerol; the concentration of the copper salt in the mixed solution is 0.005-0.1 mol / L; the solvent in the base solution is water; the concentration of the base solution is 1-10 mol / L; The Cu2O nanomaterial is applied to a carbon dioxide electro-reduction reaction.
2. The method for preparing Cu2O nanomaterials as described in claim 1, characterized in that, The molar ratio of the copper salt to the reducing sugar is 1:2, 1:3, 1:4 or 1:
7.
3. The method for preparing Cu2O nanomaterials as described in claim 1, characterized in that, The molar ratio of the copper salt to the reducing sugar is 1:(2-5); And / or, the reducing sugar is glucose, fructose or mannose; And / or, the base is sodium hydroxide or potassium hydroxide.
4. The method of claim 1, wherein the Cu20 nanomaterial is prepared by the process of claim 1. The alcohol solvent is ethanol, ethylene glycol, n-butanol or glycerol; And / or, the molar ratio of the copper salt to the reducing sugar is 1:(3-4.5).
5. The method for preparing Cu2O nanomaterials as described in claim 1, characterized in that, The concentration of the reducing sugar in the mixed solution is 0.017-0.1 mol / L.
6. The method for preparing Cu₂O nanomaterials as described in claim 1, characterized in that, The concentration of the copper salt in the mixed solution is 0.0077 mol / L, 0.0083 mol / L, 0.053 mol / L, 0.063 mol / L or 0.087 mol / L.
7. The method for preparing Cu₂O nanomaterials as described in claim 1, characterized in that, The concentration of the reducing sugar in the mixed solution is 0.017 mol / L, 0.033 mol / L, 0.047 mol / L, 0.058 mol / L or 0.065 mol / L.
8. The method of claim 1, wherein the Cu2O nano-material is prepared by the process of claim 1. The concentration of the base solution is 5 mol / L.
9. The method for preparing Cu2O nanomaterials according to any one of claims 1 to 8, characterized in that, The preparation process of the Cu2O nanomaterial does not need to add a strong reducing agent additionally; And / or, the preparation process of the Cu2O nanomaterial does not need to add a surfactant additionally; And / or, the mixing reaction is carried out under magnetic stirring; And / or, the mixing reaction time is 0-360 min and not 0; And / or, the mixing reaction temperature is 15-180 ℃; And / or, after the mixing reaction, washing and drying operations are further included.
10. The method of claim 9, wherein the Cu20 nanomaterial is prepared by the process of claim 1, 2, 3, 4, 5, 6, 7, 8, or 9. The preparation process of the Cu2O nanomaterial does not need to add hydrazine hydrate or sodium borohydride additionally; And / or, the preparation process of the Cu2O nanomaterial does not need to add polyvinylpyrrolidone, cetyltrimethylammonium bromide or sodium dodecyl sulfate additionally; And / or, the magnetic stirring speed is 500-3000 rpm; And / or, the mixing reaction time is 20-120 min; And / or, the temperature of the mixing reaction is 60-100 ℃.
11. The method for preparing Cu₂O nanomaterials as described in claim 10, characterized in that, The rotating speed of the magnetic stirring is 1000-1500 rpm; And / or, the time of the mixing reaction is 30 min, 60 min or 90 min; And / or, the temperature of the mixing reaction is 65 ℃, 85 ℃ or 95 ℃.
12. The method for preparing Cu2O nanomaterials as described in claim 9, characterized in that, The solvent used in the washing is an alcohol solvent; And / or, the process of the washing further comprises a centrifugation operation; And / or, the drying mode is freeze-drying or vacuum drying; And / or, the time of the drying is 12-24 h.
13. The method for preparing Cu₂O nanomaterials as described in claim 12, characterized in that, The solvent used in the washing is isopropyl alcohol; and / or, the drying mode is freeze-drying; And / or, the time of the drying is 16 h, 18 h or 24 h.
14. The method for preparing Cu₂O nanomaterials as described in claim 12, characterized in that, The rotating speed of the centrifugation operation is 5000-10000 rpm; And / or, the time of the centrifugation operation is 5-20 min.
15. The method for preparing Cu₂O nanomaterials as described in claim 14, characterized in that, The rotating speed of the centrifugation operation is 6000-8000 rpm; And / or, the time of the centrifugation operation is 6-10 min.
16. The method for preparing Cu2O nanomaterials as described in claim 15, characterized in that, The rotating speed of the centrifugation operation is 6500 rpm, 7500 rpm or 8000 rpm; And / or, the time of the centrifugation operation is 6 min, 8 min or 10 min.
17. A Cu20 nano-material, characterized in that, The Cu2O nanomaterial is prepared by the preparation method of the Cu2O nanomaterial according to any one of claims 1-16.
18. The Cu2O nanomaterial of claim 17, wherein, The Cu2O nanomaterial is a spherical nanoparticle; And / or, the particle size of the Cu2O nanomaterial is 100-200 nm.
19. Use of the Cu2O nanomaterial according to claim 17 or 18 as a catalyst in a carbon dioxide electro-reduction reaction.