Plasmon polariton copper-based nano material, preparation method thereof and application of plasmon polariton copper-based nano material in carbon dioxide capture-conversion system

Abstract

The invention provides a plasmon copper-based nano material, a preparation method thereof and application of the plasmon copper-based nano material in a carbon dioxide capture-conversion system.The preparation method comprises the steps that a copper nanowire modified by polytetrafluoroethylene is adopted as a plasmon catalyst, carbon dioxide is efficiently adsorbed and captured through organic amine, and under excitation of polarized light with the specific wavelength, the carbon dioxide is converted into the plasmon copper-based nano material. And efficient carbon dioxide electroreduction is realized. Compared with the prior art, carbon dioxide capture and photoelectrocatalysis carbon dioxide conversion of the plasmon copper-based nano material are combined, rapid capture and release of carbon dioxide are achieved, and the Faraday efficiency of reducing carbon dioxide into methane reaches up to 90% or above. The invention constructs a carbon dioxide capture-conversion system with industrial application potential, and provides a new path for realizing energy conservation and emission reduction.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of nanocatalysis and carbon dioxide capture, and particularly relates to a plasmonic copper-based nanomaterial, a preparation method thereof and application thereof in a carbon dioxide capture-conversion system. BACKGROUND

[0002] The overconsumption of non-renewable fossil energy has triggered a series of severe environmental problems and energy crises. Therefore, it is urgent to develop carbon dioxide emission reduction and resource utilization technologies. Carbon dioxide conversion technology driven by renewable electricity can convert carbon dioxide into high-value fuels and chemicals at room temperature and pressure, which is an effective way to achieve carbon cycle, solve global environmental problems and alleviate energy crisis. However, the low solubility of carbon dioxide in aqueous electrolyte solution seriously restricts the industrial application of electrochemical carbon dioxide reduction technology. Therefore, it is urgent to develop efficient electrocatalytic carbon dioxide reduction systems to overcome the limitation of low carbon dioxide concentration on conversion efficiency.

[0003] Current research shows that copper-based catalysts are one of the most effective catalysts for deep reduction of carbon dioxide. However, due to the low solubility of carbon dioxide in aqueous electrolyte, the electrocatalytic reduction efficiency is low, and it is easy to cause serious competitive hydrogen evolution reaction. On the other hand, current researches mostly use high-purity carbon dioxide as the reaction gas, and the purification and enrichment process of high-purity carbon dioxide usually accompanies high energy consumption and high cost, which reduces the economic feasibility of electrochemical reduction of carbon dioxide. The combination of carbon dioxide capture and electrocatalytic conversion technology is an effective way to overcome the above challenges. However, the commonly used organic amine solution capture method in industry needs to consume a large amount of energy to desorb carbon dioxide and regenerate the adsorption site. Therefore, it is urgent to develop catalysts and low-energy carbon dioxide capture-conversion integrated systems to achieve efficient capture and conversion of carbon dioxide.

[0004] CN108560018A discloses a nano-copper electrode material, which comprises a conductive substrate and a surface super-gas-attractive copper nanowire aggregate attached to the conductive substrate. The surface of the copper nanowire has multiple grain boundaries. In the preparation process, the copper hydroxide nanowire array material is immersed in a polytetrafluoroethylene dispersion liquid, taken out and calcined at high temperature, and then electro-reduced in an electrolyte solution for a certain time to obtain a nano-copper electrode material, which is used as an electrochemical reduction electrode. However, this method can only improve the mass transfer rate of carbon dioxide at the interface between the material and water, but cannot overcome the fundamental limitation of low solubility of carbon dioxide in aqueous electrolyte solution. Therefore, the effective solubility of carbon dioxide in the carbon dioxide reduction reaction process is still insufficient, which ultimately restricts the further improvement of the overall reaction efficiency.

[0005] CN120054552A discloses a kind of plasmonic copper-based nanomaterial and its preparation method and application in photoelectrocatalytic carbon dioxide, using nickel single atom supported copper phosphide nanowire as plasmonic catalyst, under the condition of ultra-low reaction potential and simulated sunlight irradiation, efficient carbon dioxide conversion is realized.But this material and method in the process of photoelectrocatalytic carbon dioxide reduction, product variety is numerous and distribution is complex, single product selectivity is low.This not only increases the difficulty and cost of product separation, also significantly reduces the energy efficiency and practical application value of the whole process. SUMMARY

[0006] The purpose of the present application is to provide a kind of plasmonic copper-based nanomaterial and its preparation method and application in carbon dioxide capture-conversion system, adopt organic amine adsorption capture carbon dioxide, and utilize the plasmonic local thermal effect generated by copper nanostructure under the excitation of specific wavelength polarized light to accelerate the release of carbon dioxide adsorbed by organic amine.In addition, by surface modification of polytetrafluoroethylene, the hydrophilic-hydrophobic property of the material surface is regulated, providing a local hydrophobic environment for the rapid activation of carbon dioxide, while inhibiting the competitive hydrogen evolution reaction, ultimately increasing the local carbon dioxide concentration on the surface of the catalyst and accelerating the carbon dioxide mass transfer rate, thereby realizing efficient photoelectrocatalytic reduction of carbon dioxide to methane.

[0007] The purpose of the present application is achieved by the following technical solutions:

[0008] The first object of the present application is to provide a kind of plasmonic copper-based nanomaterial, which is polytetrafluoroethylene modified copper nanowire.The plasmonic copper-based nanomaterial serves as a plasmonic catalyst, which realizes efficient carbon dioxide electro-reduction under the excitation of specific wavelength polarized light.

[0009] Further, the plasmonic catalyst is used as a working electrode, and an organic amine solution is used as an electrolyte to adsorb and capture carbon dioxide in raw gas, and efficient carbon dioxide electro-reduction is realized under the excitation of specific wavelength polarized light.

[0010] Further, the organic amine solution is a mixed solution of an organic amine compound and potassium chloride.

[0011] Further, the mass percentage of the organic amine compound and potassium chloride solution in the organic amine solution is 1% to 20%.

[0012] Further, the organic amine is a compound in which the hydrogen atom of the amine group is replaced by a non-hydrogen substituent.

[0013] Further, the non-hydrogen substituent is one or more of alkyl, alkenyl, alkynyl, aryl, cycloalkyl, halogenated alkyl, -ROH, -RSH, -OR, and -OC(O)R, etc.

[0014] Preferably, the polytetrafluoroethylene modified copper nanowire morphology is linear, and the diameter of the polytetrafluoroethylene modified copper nanowire is 50-200 nm.

[0015] Further preferably, the diameter of the polytetrafluoroethylene modified copper nanowire is 70-130 nm.

[0016] Preferably, in the plasmonic copper-based nanomaterial, the polytetrafluoroethylene is uniformly dispersed on the surface of the copper nanowire, and the mass percentage of fluorine to copper is 0.01%-1%.

[0017] Further preferably, the mass percentage of fluorine to copper on the surface of the polytetrafluoroethylene modified copper nanowire is 0.01%-0.2%.

[0018] A second object of the present application is to provide a preparation method of a plasmonic copper-based nanocatalyst, the preparation method comprising the following steps:

[0019] 1) placing metallic copper in an oxidant solution to perform an oxidation reaction to obtain a precursor, and then placing the precursor in a tube furnace to perform a heat treatment in an inert atmosphere to obtain copper nanowires;

[0020] 2) dropping a polytetrafluoroethylene solution on the surface of the copper nanowires obtained in step 1), and placing the copper nanowires in a tube furnace to perform a heat treatment in an inert atmosphere to obtain polytetrafluoroethylene modified copper nanowires, i.e. the plasmonic copper-based nanomaterial, i.e. the plasmonic copper-based nanomaterial.

[0021] Further, the metallic copper in step 1) includes but is not limited to one or more of foam copper, copper sheet, copper mesh or copper block.

[0022] Further preferably, the metallic copper in step 1) is foam copper.

[0023] Further, the oxidant solution in step 1) includes an oxidant, sodium hydroxide and a solvent; wherein the solvent is deionized water.

[0024] Further, in the oxidant solution, the concentration of sodium hydroxide is 1-5 M, and the concentration of the oxidant is 0.05-1 M.

[0025] Further, the oxidant in step 1) includes but is not limited to one or more of ammonium persulfate, potassium persulfate, sodium persulfate, potassium hydrogen peroxymonosulfate and sodium hydrogen peroxymonosulfate.

[0026] Further preferably, the oxidant in step 1) is ammonium persulfate.

[0027] Further, the oxidation reaction time in step 1) is 10-80 min.

[0028] Further, the oxidation reaction time in step 1) is 20-40 min.

[0029] Further, the heat treatment temperature in step 1) is 100-500℃, and the heat treatment time is 1-6 h.

[0030] Further preferably, the heat treatment temperature in step 1) is 250-400℃, and the time is 2-4 h.

[0031] Further, the polytetrafluoroethylene in step 2) comprises polytetrafluoroethylene powder and a solvent; wherein the solvent is deionized water.

[0032] Further, the mass percentage of polytetrafluoroethylene powder to solvent in step 2) is 0.05%-2%.

[0033] Further preferably, the mass percentage of polytetrafluoroethylene powder to solvent in step 2) is 0.1%-1%.

[0034] Further, the heat treatment temperature in step 2) is 200-400℃, and the time is 0.5-5 h.

[0035] Further preferably, the heat treatment temperature in step 2) is 250-350℃, and the time is 1-3 h.

[0036] A third object of the present application is to provide an application of the plasmonic copper-based nanocatalyst in a carbon dioxide capture-conversion system, which comprises using polytetrafluoroethylene modified copper nanowires as a plasmonic catalyst, and using organic amines to efficiently adsorb and capture carbon dioxide, and realizing efficient carbon dioxide electro-reduction under the excitation of polarized light of a specific wavelength.

[0037] Further, the carbon dioxide capture-conversion system uses plasmonic copper-based nanomaterials as a working electrode, a silver-silver chloride electrode as a reference electrode, a platinum sheet as a counter electrode, and an organic amine and potassium chloride mixed solution as an electrolyte; through the carbon dioxide capture-conversion system, photoelectrocatalytic reaction is carried out under the excitation of polarized light of a specific wavelength and an applied potential, and carbon dioxide conversion is realized.

[0038] Further, the application method comprises the following steps:

[0039] The plasmonic copper-based nanomaterials are used as a working electrode, a platinum sheet is used as a counter electrode, a silver-silver chloride electrode is used as a reference electrode, an organic amine and potassium chloride mixed solution is used as an electrolyte, an applied potential of-0.2 to-1 V (vs. RHE) and an intensity of 100-1500 mW / cm 2The photoelectrocatalytic reaction is carried out under the excitation of specific wavelength polarized light, and the rapid capture and release of carbon dioxide are realized, and the faraday efficiency of carbon dioxide reduction to methane is up to 90% and above.

[0040] Further, the polytetrafluoroethylene modified copper nanowire is used as a plasmonic catalyst to photoelectrocatalyze the conversion of carbon dioxide into methane.

[0041] Further, the organic amine is a compound in which the hydrogen atom of the amine group is replaced by a non-hydrogen substituent, and the non-hydrogen substituent is one or more of an alkyl group (R) having 1-10 carbon atoms, an alkenyl group, an alkynyl group, an aryl group, a cycloalkyl group, a halogenated alkyl group, -ROH, -RSH, -OR, and -OC(O)R.

[0042] Further preferably, the organic amine is diethanolamine.

[0043] Further, the concentration of the potassium chloride solution is 0.5-2M;

[0044] Further preferably, the concentration of the potassium chloride solution is 1M.

[0045] Further, the mass ratio of the organic amine to the potassium chloride solution is (1-20):100;

[0046] Further preferably, the mass ratio of the organic amine to the potassium chloride solution is (2-10):100.

[0047] Further preferably, the intensity of the specific wavelength polarized light is 500-1500mW / cm 2 .

[0048] Further preferably, the wavelength of the specific wavelength polarized light is 550nm.

[0049] Further, the reaction potential is -0.4 to -1V (vs. RHE);

[0050] Further preferably, the reaction potential is -0.6V (vs. RHE).

[0051] Further, the faraday efficiency of the conversion of carbon dioxide into methane reaches 90% and above.

[0052] Compared with the prior art, the beneficial effects of the present application are reflected in the following aspects:

[0053] (1) The plasmonic copper-based nanocatalyst provided by the present application has a simple preparation process, is easy to control, has low cost of raw materials, and is environmentally friendly, and will not cause secondary pollution.

[0054] (2) The plasmonic copper-based nanocatalyst, the preparation method thereof and the application thereof in photoelectrocatalytic reduction of carbon dioxide are provided, the product has a faraday efficiency of methane of more than 90%, and has good stability.

[0055] (3) The plasmonic copper-based nanocatalyst, the preparation method thereof and the application thereof in a carbon dioxide capture-conversion system are provided, organic amine is used to adsorb and capture carbon dioxide, and the plasmonic local thermal effect generated under the excitation of polarized light of a specific wavelength is used to accelerate the release of the carbon dioxide adsorbed by the organic amine. In addition, the surface modification of polytetrafluoroethylene is used to control the hydrophilic-hydrophobic property of the material surface, a local hydrophobic environment is provided for the rapid activation of carbon dioxide, and the competitive hydrogen evolution reaction is inhibited, so that the local carbon dioxide concentration on the surface of the catalyst is increased, the mass transfer rate of carbon dioxide is accelerated, and finally the photoelectrocatalytic reduction of carbon dioxide to methane is realized, thereby providing a new path for energy saving and emission reduction. BRIEF DESCRIPTION OF DRAWINGS

[0056] Figure 1 XRD patterns of the copper nanowires and the polytetrafluoroethylene modified copper nanowires prepared in Example 1;

[0057] Figure 2 UV absorption spectrum of the copper nanowires and the polytetrafluoroethylene modified copper nanowires prepared in Example 1;

[0058] Figure 3 SEM (a) and TEM (b) patterns of the copper nanowires prepared in Example 1;

[0059] Figure 4 SEM (a) and TEM (b) patterns of the polytetrafluoroethylene modified copper nanowires prepared in Example 1;

[0060] Figure 5 Carbon dioxide reduction product distribution diagram of the polytetrafluoroethylene modified copper nanowires prepared in Example 1 in the carbon dioxide capture-conversion system in Example 2;

[0061] Figure 6 Carbon dioxide reduction product distribution diagram of the polytetrafluoroethylene modified copper nanowires prepared in Example 1 in the photoelectrocatalytic reduction of carbon dioxide in Comparative Example 1;

[0062] Figure 7 Carbon dioxide reduction product distribution diagram of the copper nanowires prepared in Example 1 in the carbon dioxide capture-conversion system in Comparative Example 2;

[0063] Figure 8 Carbon dioxide reduction product distribution diagram of the copper nanowires prepared in Example 1 in the photoelectrocatalytic reduction of carbon dioxide in Comparative Example 3. DETAILED DESCRIPTION

[0064] The present application will be described in detail below with specific examples, but is by no means limited to the present application. In the present technical solution, if the preparation means, materials, structure or composition ratio and other features are not explicitly described, they are considered as common technical features disclosed in the prior art.

[0065] Unless otherwise specified, the reagents, methods, instruments and equipment used in the present application are conventional reagents, methods, instruments and equipment in the art. Unless otherwise specified, the reagents and materials used in the following examples are commercially available.

[0066] Example 1:

[0067] The present embodiment provides a preparation of polytetrafluoroethylene modified copper nanowire (plasmonic copper-based nanomaterial), which comprises the following steps:

[0068] (1) Cut the commercial copper foam sheet into uniform electrode pieces of 2x2 cm (mass about 0.3 g), and ultrasonically clean it with dilute hydrochloric acid, deionized water and ethanol for 10 min respectively, then immerse it in 100 mL deionized water containing 10 g sodium hydroxide and 2.3 g ammonium persulfate solid, soak for 40 min, and then take it out to obtain the precursor.

[0069] (2) Put the precursor prepared in the above process into a tube furnace, heat treat it at 300℃ for 2h under high-purity argon atmosphere, and set the heating rate to 5℃ / min to obtain copper nanowire.

[0070] (3) Drop 1 mL of polytetrafluoroethylene solution (solvent is deionized water) with a mass fraction of 2% on the surface of the copper nanowire, then put it into a tube furnace, heat treat it at 350℃ for 2h under high-purity argon atmosphere, and set the heating rate to 2℃ / min to finally obtain polytetrafluoroethylene modified copper nanowire (plasmonic copper-based nanomaterial).

[0071] The copper nanowire prepared in the above process (2) is the control material.

[0072] Figure 1 XRD patterns of copper nanowire and polytetrafluoroethylene modified copper nanowire: From the XRD pattern, it can be known that the main component of the synthesized material is zero-valent copper.

[0073] Figure 2 UV absorption spectrum of copper nanowire and polytetrafluoroethylene modified copper nanowire: From the UV absorption spectrum, it can be known that both the copper nanowire and the polytetrafluoroethylene modified copper nanowire exhibit plasmonic characteristic absorption near 550 nm wavelength, i.e. the polytetrafluoroethylene modified copper nanowire is a plasmonic copper-based nanomaterial.

[0074] Figure 3 With Figure 4SEM and TEM images of copper nanowires and polytetrafluoroethylene modified copper nanowires, respectively: The SEM and TEM images confirm the linear structure of the synthesized copper nanowires and polytetrafluoroethylene modified copper nanowires material, and the diameter of the nanowires is about 100 nm.

[0075] Example 2

[0076] This example provides an application of polytetrafluoroethylene modified copper nanowires (plasmonic copper-based nanomaterials) in a carbon dioxide capture-conversion system:

[0077] The carbon dioxide capture-conversion was carried out in a three-electrode system H-type reaction cell, and the electrolytic cell was separated by an anion exchange membrane. The polytetrafluoroethylene modified copper nanowires obtained in Example 1 were used as the working electrode, silver-silver chloride was used as the reference electrode, and platinum was used as the counter electrode. The electrolyte was a 50 mL mixture of 1 M diethanolamine and 1 M potassium chloride. The constant voltage carbon dioxide reduction reaction was carried out under the irradiation of 550 nm wavelength polarized light with an intensity of 1000 mW / cm 2 Figure 5

[0078] The faradic efficiency of the photoelectrocatalytic reduction of carbon dioxide to methane by the polytetrafluoroethylene modified copper nanowires in Example 2 was 93% at -0.6 V (vs. RHE). The faradic efficiency of the photoelectrocatalytic reduction of carbon dioxide to methane by the polytetrafluoroethylene modified copper nanowires in Example 2 was all higher than 85% in the range of -0.5 to -0.9 V (vs. RHE).

[0079] Comparative Example 1

[0080] This comparative example provides an application of polytetrafluoroethylene modified copper nanowires (plasmonic copper-based nanomaterials) in a photoelectrocatalytic carbon dioxide reduction system:

[0081] The photoelectrocatalytic carbon dioxide reduction reaction was carried out in a three-electrode system H-type reaction cell, and the electrolytic cell was separated by an anion exchange membrane. The polytetrafluoroethylene modified copper nanowires obtained in Example 1 were used as the working electrode, silver-silver chloride was used as the reference electrode, and platinum was used as the counter electrode. The electrolyte was a 50 mL 1 M potassium chloride aqueous solution. The constant voltage carbon dioxide reduction reaction was carried out under the irradiation of 550 nm wavelength polarized light with an intensity of 1000 mW / cm 2 Figure 6

[0082] ​​​​The Faraday efficiency of the polytetrafluoroethylene modified copper nanowires in Comparative Example 1 for photoelectrocatalytic reduction of carbon dioxide to methane at -0.6 V (vs. RHE) was 75%. The Faraday efficiency of the polytetrafluoroethylene modified copper nanowires in Comparative Example 1 for photoelectrocatalytic reduction of carbon dioxide to methane in the range of -0.5 to -0.9 V (vs. RHE) were all in the range of 70-80%.

[0083] Comparative Example 2

[0084] This comparative example provides an application of copper nanowires in a carbon dioxide capture-conversion system:

[0085] The carbon dioxide capture-conversion was performed in a three-electrode system H-type reaction cell, and the electrolytic cell was separated by an anion exchange membrane into the cathode and anode. The control material copper nanowires obtained in Example 1 were used as the working electrode, silver-silver chloride as the reference electrode, and platinum as the counter electrode, and the electrolyte was a 50 mL mixture solution of 1 M diethanolamine and 1 M potassium chloride. The constant voltage carbon dioxide reduction reaction was performed under irradiation of 550 nm wavelength polarized light with an intensity of 1000 mW / cm 2 , and carbon dioxide gas was continuously introduced during the reaction process. The experimental results are shown in Figure 7 .

[0086] The Faraday efficiency of the copper nanowires in Comparative Example 2 for photoelectrocatalytic reduction of carbon dioxide to methane at -0.8 V (vs. RHE) was 46%. The Faraday efficiency of the copper nanowires in Comparative Example 2 for photoelectrocatalytic reduction of carbon dioxide to methane in the range of -0.5 to -0.9 V (vs. RHE) were all less than 50%.

[0087] Comparative Example 3

[0088] This comparative example provides an application of copper nanowires in a photoelectrocatalytic carbon dioxide reduction system:

[0089] The photoelectrocatalytic carbon dioxide reduction reaction was performed in a three-electrode system H-type reaction cell, and the electrolytic cell was separated by an anion exchange membrane into the cathode and anode. The control material copper nanowires obtained in Example 1 were used as the working electrode, silver-silver chloride as the reference electrode, and platinum as the counter electrode, and the electrolyte was a 50 mL 1 M potassium chloride aqueous solution. The constant voltage carbon dioxide reduction reaction was performed under irradiation of 550 nm wavelength polarized light with an intensity of 1000 mW / cm 2 , and carbon dioxide gas was continuously introduced during the reaction process. The experimental results are shown in Figure 8 .

[0090] The Faraday efficiency of the photoelectrocatalytic reduction of carbon dioxide to methane by the copper nanowires in Comparative Example 3 at -0.8 V (vs. RHE) was 37%. The Faraday efficiency of the photoelectrocatalytic reduction of carbon dioxide to methane by the copper nanowires in Comparative Example 3 in the range of -0.5 to -0.9 V (vs. RHE) was less than 50%.

[0091] The foregoing description of the embodiments is for the purpose of enabling a person with ordinary skill in the art to make and use the invention. Various modifications to these embodiments can be readily apparent to those skilled in the art, and the generic principles defined herein can be applied to other embodiments without the use of inventive faculty. Thus, the present invention is not intended to be limited to the embodiments described herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A plasmonic copper-based nanomaterial, characterized in that, The plasmonic copper-based nanomaterial is used as a plasmonic catalyst; The plasmonic copper-based nanomaterial is polytetrafluoroethylene modified copper nanowire; The plasmonic catalyst is used as a working electrode, and an organic amine solution is used as an electrolyte to adsorb and capture carbon dioxide in raw gas, and carbon dioxide is reduced under excitation of a specific wavelength polarized light.

2. The plasmonic copper-based nanomaterial of claim 1, wherein, The polytetrafluoroethylene modified copper nanowire has a diameter of 50-200 nm.

3. The plasmonic copper-based nanomaterial of claim 1, wherein, In the polytetrafluoroethylene modified copper nanowire, polytetrafluoroethylene is uniformly modified on the surface of the copper nanowire, and the mass percentage of fluorine to copper is 0.01%-1%.

4. The plasmonic copper-based nanomaterial of claim 1, wherein, The organic amine solution is a mixed solution of an organic amine compound and potassium chloride. The mass ratio of the organic amine compound to the potassium chloride solution in the organic amine solution is (1-20):

100. The specific wavelength polarized light has a wavelength of 550 nm and an intensity of 100-1500 mW / cm 2 .

5. The plasmonic copper-based nanomaterial of claim 1, wherein, The organic amine is a compound in which the hydrogen atom of an amine group is replaced by a non-hydrogen substituent.

6. The plasmonic copper-based nanomaterial of claim 5, wherein, The non-hydrogen substituent is one or more of an alkyl group, an alkenyl group, an alkynyl group, an aryl group, a cycloalkyl group, a halogenated alkyl group, -ROH, -RSH, -OR and -OC(O)R having 1-10 carbon atoms.

7. A method of preparing the plasmonic copper-based nanomaterial according to any one of claims 1 to 6, characterized in that, The preparation method comprises the following steps: 1) copper metal is placed in an oxidant solution to perform an oxidation reaction to obtain a precursor, and then the precursor is heat-treated in an inert atmosphere to obtain copper nanowire; 2) polytetrafluoroethylene solution is drop-coated on the surface of the copper nanowire obtained in step 1), and the copper nanowire is heat-treated in an inert atmosphere to obtain polytetrafluoroethylene modified copper nanowire, i.e. the plasmonic copper-based nanomaterial.

8. The method of claim 7, wherein the plasmonic copper-based nanomaterial is prepared by a method comprising: depositing a copper layer on a substrate; and depositing a layer of silver on the copper layer. In step 1), the copper metal includes one of copper foam, copper sheet, copper mesh or copper block. In step 1), the oxidant includes one or more of ammonium persulfate, potassium persulfate, sodium persulfate, potassium hydrogen peroxymonosulfate and sodium hydrogen peroxymonosulfate. In step 1), the oxidation reaction time is 20-80 min. In step 1), the heat treatment temperature is 100-500°C, and the heat treatment time is 1-6 h. In step 1), the inert gas includes one of high-purity argon and high-purity nitrogen. In step 2), the inert gas includes one of high-purity argon and high-purity nitrogen. In step 2), the heat treatment temperature is 200-400°C, and the time is 0.5-5 h.

9. Use of the plasmonic copper-based nanomaterial according to any one of claims 1-6 in a carbon dioxide capture-conversion system, characterized in that, The carbon dioxide capture-conversion system uses the plasmonic copper-based nanomaterial as a working electrode, a silver-silver chloride electrode as a reference electrode, a platinum sheet as a counter electrode, and a mixed solution of an organic amine and potassium chloride as an electrolyte. The carbon dioxide capture-conversion system performs photoelectrocatalytic reaction under excitation of a specific wavelength polarized light and an applied potential to realize carbon dioxide conversion.

10. Use according to claim 9, characterized in that, The Faraday efficiency of carbon dioxide conversion to methane is 90%-96%. The wavelength of the specific wavelength polarized light is 550 nm, and the intensity is 100-1500 mW / cm 2 ; The applied potential is -0.2 to -1.2 V vs. RHE.

Images