Preparation method and application of low-aspect-ratio Cu microwire
By using surfactants and reducing agents in an alcohol-containing solution to synthesize Cu microwires with low aspect ratios, the problem of difficult preparation by existing technologies has been solved, and the high efficiency of Cu microwires in the electrocatalytic reduction of CO2 has been achieved.
Patent Information
- Application Number
- CN202510210816.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-25
- Publication Date
- 2025-11-04
- Estimated Expiration
- 2045-02-25
AI Technical Summary
Existing technologies cannot effectively prepare Cu microwires with low aspect ratios, which limits their application in fields such as conductive coatings, high-temperature power devices, transparent/flexible electrodes, optoelectronic devices, and catalytic materials.
Cu microwires were synthesized in an alcohol-containing solution using surfactants and reducing agents. By controlling the reaction temperature and time, the morphology and structure of the product were adjusted to prepare Cu microwires with a diameter of about 1 to 3 micrometers and a length of about 90 to 150 micrometers.
The prepared Cu microwires exhibited good catalytic performance in the electrocatalytic reduction of CO2, with ethylene as the main product. The preparation method was simple and the reaction conditions were mild.
Smart Images
Figure CN120038336B_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The application belongs to the technical field of low-dimensional functional materials. BACKGROUND
[0002] Due to its high reserves and good electrical conductivity, thermal conductivity and ductility, copper metal has an important position in commercial applications. When copper and copper-based structures are reduced to the low-dimensional field, they exhibit different optical, electrical, magnetic and other properties from bulk or large-size particles, making them widely used in electronics, catalysis, sensing and biomedical fields, and their main performance often depends on the size and morphology of Cu materials.
[0003] In recent years, one-dimensional copper materials (copper nanowires, copper microwires) have received more and more attention due to their high electrical conductivity, low cost and other advantages. The excellent electrical conductivity makes them a potential alternative to indium tin oxide (ITO) and an important candidate material for manufacturing transparent and flexible electrodes. In addition, due to their special morphology and exposed crystal faces, copper nanowires / microwires often exhibit different activity and catalytic selectivity in catalytic processes than nanoparticles, nanosheets and other structures. As an important research object, they are used in thermal catalysis, electrocatalysis, photocatalysis and photo-thermal catalysis, involving important chemical processes such as CO2 conversion, hydrogenation reaction, coupling reaction, etc.
[0004] Currently, researchers have developed various synthesis methods for one-dimensional copper nanomaterials, including but not limited to oil phase thermal reduction method, hydrothermal synthesis method and one-step reduction method, etc. However, most of the Cu nanowires obtained by the disclosed methods have a small diameter (mostly below 100 nm) and a large aspect ratio. Cu microwires can be applied to conductive coatings / high-temperature power components, transparent / flexible electrodes, optoelectronic devices and catalytic materials. However, the existing technology has relatively few studies on Cu microwires, and it is difficult to prepare Cu microwires with a low aspect ratio. Therefore, to some extent, the selection range of the market demand end is limited. SUMMARY
[0005] The present application aims to solve the problem that the prior art cannot prepare Cu microwires with a low aspect ratio, and further provides a preparation method and application of Cu microwires with a low aspect ratio.
[0006] A preparation method of Cu microwires with a low aspect ratio, which is carried out according to the following steps:
[0007] I. Preparation of precursor salt solution:
[0008] Dissolve the sodium halide salt in an alcohol-containing organic solution, then add the copper salt and stir to mix uniformly to obtain the precursor salt solution;
[0009] II. Preparation of reducing agent solution:
[0010] Dissolving the reducing agent and the surfactant in an alcohol-containing organic solution to obtain a reducing agent solution;
[0011] III. Reduction:
[0012] Heating the precursor salt solution to 100-150 DEG C, then adding the reducing agent solution and mixing uniformly, under the condition of temperature 100-150 DEG C, reacting for 0.5-1 h, after reaction, cooling to room temperature, finally centrifuging, washing and vacuum drying to obtain low aspect ratio Cu microwires.
[0013] Application of the low aspect ratio Cu microwires, as raw materials to prepare gas diffusion electrodes, for electrocatalytic reduction of CO2.
[0014] The beneficial effects of the present application are:
[0015] The present application relates to a synthesis method of copper microwires, using surfactants, reducing agents, reaction solvents (complexing agents), and adding a certain amount of sodium halide to adjust the morphology of the product structure to obtain Cu microwires.
[0016] I. The diameter of the Cu microwires prepared by the present application is about 1-3 microns, the length is about 90-150 microns, the preparation method is simple, and the reaction conditions are mild.
[0017] II. The Cu microwires prepared by the present application exhibit good catalytic performance when applied to the electrocatalytic reduction of CO2 reaction, and the main product is ethylene. BRIEF DESCRIPTION OF DRAWINGS
[0018] Figure 1 Scanning electron microscope image of the Cu microwires prepared in Example 1;
[0019] Figure 2 X-ray diffraction spectrum of the Cu microwires prepared in Example 1;
[0020] Figure 3 Scanning electron microscope image of the Cu microparticles prepared in the comparative experiment;
[0021] Figure 4 Catalytic product distribution diagram of the Cu microwires prepared in Example 1 for electrocatalytic reduction of CO2;
[0022] Figure 5 Catalytic product distribution diagram of the Cu microparticles prepared in the comparative experiment for electrocatalytic reduction of CO2. DETAILED DESCRIPTION
[0023] Detailed implementation I: The present embodiment is a preparation method of low aspect ratio Cu microwires, which is carried out according to the following steps:
[0024] I. Preparation of a precursor salt solution:
[0025] The sodium halide salt is dissolved in an alcohol-containing organic solution, then a copper salt is added and stirred to mix uniformly to obtain a precursor salt solution;
[0026] II. Preparation of a reducing agent solution:
[0027] The reducing agent and the surfactant are dissolved in an alcohol-containing organic solution to obtain a reducing agent solution;
[0028] III. Reduction:
[0029] The precursor salt solution is heated to 100-150°C, then the reducing agent solution is added and mixed uniformly, and the reaction is carried out at a temperature of 100-150°C for 0.5-1 h. After the reaction, the mixture is cooled to room temperature, and then centrifuged, washed, and vacuum dried to obtain Cu microwires with a low aspect ratio.
[0030] The beneficial effects of the present embodiment are:
[0031] The present embodiment relates to a method for synthesizing copper microwires, which uses a surfactant, a reducing agent, a reaction solvent (complexing agent), and a certain amount of sodium halide to adjust the morphology and structure of the product to obtain Cu microwires.
[0032] I. The Cu microwires prepared in the present embodiment have a diameter of about 1-3 microns and a length of about 90-150 microns, and the preparation method is simple and the reaction conditions are mild.
[0033] II. The Cu microwires prepared in the present embodiment exhibit good catalytic performance when applied to the electrocatalytic reduction of CO2, and the main product is ethylene.
[0034] Specific embodiment II: The difference between the present embodiment and specific embodiment I is that the sodium halide salt in step I is sodium chloride or sodium bromide, and the copper salt in step I is copper nitrate, copper acetate, copper chloride, or copper sulfate. The other aspects are the same as in specific embodiment I.
[0035] Specific embodiment III: The difference between the present embodiment and one of specific embodiments I or II is that the alcohol-containing organic solvent in steps I and II is ethylene glycol or triethylene glycol. The other aspects are the same as in specific embodiments I or II.
[0036] Specific embodiment IV: The difference between the present embodiment and one of specific embodiments I to III is that the molar ratio of the sodium halide salt to the alcohol-containing organic solution in step I is (0.02-0.2) mmol:20 mL, and the molar ratio of the sodium halide salt to the copper salt in step I is 1:(1-10). The other aspects are the same as in specific embodiment III.
[0037] Specific embodiment five: different from one of specific embodiments one to four is that: the reducing agent in step two is ascorbic acid or sodium borohydride; the surfactant in step two is PVP K30. The others are the same as specific embodiments one to four.
[0038] Specific embodiment six: different from one of specific embodiments one to five is that: the ratio of the amount of substance of the reducing agent to the volume of the alcohol-containing organic solution in step two is (0.5-1) mmol:5 mL; the ratio of the amount of substance of the surfactant to the volume of the alcohol-containing organic solution in step two is (1-2) mmol:5 mL. The others are the same as specific embodiments one to five.
[0039] Specific embodiment seven: different from one of specific embodiments one to six is that: the reducing agent solution is added in step three at an adding speed of 0.25 mL / min-1 mL / min; the volume ratio of the reducing agent solution to the precursor salt solution in step three is 1:(2-3). The others are the same as specific embodiments one to six.
[0040] Specific embodiment eight: different from one of specific embodiments one to seven is that: the centrifugation, washing and vacuum drying in step three are specifically under the condition of a rotation speed of 5000 rpm-12000 rpm, centrifugation for 3 min-10 min, separation to obtain a solid, then washing the solid with anhydrous ethanol or n-hexane for 3-5 times, and finally vacuum drying at a temperature of 40℃-60℃ for 10 h-12 h. The others are the same as specific embodiments one to seven.
[0041] Specific embodiment nine: different from one of specific embodiments one to eight is that: the low aspect ratio Cu microwire prepared in step three has a diameter of 1 μm-3 μm and a length of 90 μm-150 μm. The others are the same as specific embodiments one to eight.
[0042] Specific embodiment ten: an application of a low aspect ratio Cu microwire, which is used as a raw material to prepare a gas diffusion electrode for electrocatalytic reduction of CO2.
[0043] The beneficial effects of the present application are verified by the following examples:
[0044] Example one:
[0045] A preparation method of a low aspect ratio Cu microwire, which is carried out according to the following steps:
[0046] I. Preparation of a precursor salt solution:
[0047] Dissolve the sodium halide salt in the alcohol-containing organic solution, then add the copper salt and stir to mix uniformly, to obtain a precursor salt solution;
[0048] The sodium halide salt is sodium chloride; the alcohol-containing organic solvent is ethylene glycol; the copper salt is copper nitrate;
[0049] The mass amount of the sodium halide salt to the volume of the alcohol-containing organic solution is 0.2 mmol:20 mL; the molar ratio of the sodium halide salt to the copper salt is 1:10;
[0050] II. Preparation of a reducing agent solution:
[0051] Dissolve the reducing agent and the surfactant in the alcohol-containing organic solution to obtain a reducing agent solution;
[0052] The reducing agent is ascorbic acid; the surfactant is PVP K30; the alcohol-containing organic solvent is ethylene glycol;
[0053] The mass amount of the reducing agent to the volume of the alcohol-containing organic solution is 0.75 mmol:5 mL; the mass amount of the surfactant to the volume of the alcohol-containing organic solution is 1.5 mmol:5 mL;
[0054] III. Reduction:
[0055] Heat the precursor salt solution to 140°C, then add the reducing agent solution at a rate of 0.25 mL / min and mix uniformly, react for 1 h at a temperature of 140°C, cool to room temperature after the reaction, and finally centrifuge, wash, and vacuum dry to obtain Cu microwires;
[0056] The volume ratio of the reducing agent solution to the precursor salt solution is 1:2.
[0057] The centrifugation, washing, and vacuum drying in step three are specifically centrifuging at a speed of 8000 rpm for 5 min, separating the solid, washing the solid with anhydrous ethanol 3 times, and finally vacuum drying at a temperature of 60°C for 12 h.
[0058] The Cu microwires prepared in step three have a diameter of 1 μm-3 μm and a length of 90 μm-150 μm.
[0059] The application of the Cu microwires prepared above is that the Cu microwires are used as raw materials to prepare a gas diffusion electrode for electrocatalytic reduction of CO2;
[0060] The gas diffusion electrode is specifically prepared according to the following steps:
[0061] ①Add the Cu microwires to a mixed solution of Nafion and isopropanol, ultrasonically mix at a power of 100 W for 30 min to obtain a catalyst ink;
[0062] The volume ratio of the Nafion solution to isopropyl alcohol in the mixed solution of Nafion and isopropyl alcohol is 1:30; the concentration of Cu microwires in the catalyst ink is 8 mg / mL;
[0063] ②According to the loading amount of Cu microwires, 1 mg / cm 2 The catalyst ink is sprayed on the carbon paper at room temperature, and finally dried to obtain a gas diffusion electrode;
[0064] The carbon paper is Sigracet 28BC;
[0065] The electrocatalytic CO2 reduction is specifically performed according to the following steps:
[0066] ① Assembly: A gas diffusion electrode is arranged between a CO2 gas flow chamber and a cathode chamber, an anion exchange membrane is arranged between the cathode chamber and an anode chamber, a counter electrode is arranged in the anode chamber, a reference electrode is arranged in the cathode chamber, and a cathode liquid flow tank is connected to the cathode chamber through a conduit, and an anode liquid flow tank is connected to the anode chamber through a conduit, electrolyte is poured into the cathode liquid flow tank and the anode liquid flow tank, and finally a positive electrode of a power supply is connected to the counter electrode, and a negative electrode of the power supply is connected to the gas diffusion electrode;
[0067] The electrolyte is a 1M KOH electrolyte, the flow rate of the electrolyte is 5 mL / min; the material of the CO2 gas flow chamber is polyether ether ketone (PEEK); the counter electrode is a nickel foam; the reference electrode is an Ag / AgCl electrode; and the anion exchange membrane is fumasep FAA-3-PK-130;
[0068] ② Electro-catalytic CO2 reduction: CO2 gas is introduced into the CO2 gas flow chamber at a flow rate of 30 sccm, and the CO2 is continuously introduced to maintain the current density of the gas diffusion electrode at 50 mA·cm -2 ~ 500 mA·cm -2 , and the gas products are collected, the electrolyte after the reaction is separated and purified, and the electro-catalytic CO2 reduction is completed.
[0069] Comparative experiment: The difference between the present comparative experiment and Example 1 is that the use of sodium halide salt is cancelled in step one; and Cu microparticles are obtained in step three. The others are the same as Example 1.
[0070] Figure 1 The scanning electron microscope image of the Cu microwires prepared in Example 1; as shown in the figure, the obtained Cu microwires have a diameter of about 1-3 microns and a length of about 90-150 microns, and are uniformly distributed.
[0071] Figure 2The image shows the X-ray diffraction pattern of the Cu microwires prepared in Example 1. As can be seen from the image, the obtained material is mainly pure Cu and has good crystallinity.
[0072] Figure 3 The image shows a scanning electron microscope image of Cu microparticles prepared for comparison. As can be seen from the image, the main product is Cu microparticles with a size of about 0.5 to 2 micrometers and a relatively uniform size distribution.
[0073] Figure 4 This is a catalytic product distribution diagram of the Cu microwire electrocatalysis of CO2 prepared in Example 1. As shown in the diagram, during the electrocatalytic CO2 reduction process, CO is the main catalytic product of the Cu microwire at low current densities, while C2H4 becomes the main catalytic product as the reaction current density increases. At 250 mA / cm², the catalytic product is... -2 The highest Faraday efficiency of C2H4 at the specified current density was 33.4%, and it exhibited good suppression of H2 products at 400 mA / cm². -2 Below the current density, the hydrogen Faraday efficiency is less than 20%.
[0074] Figure 5 To compare the catalytic product distribution of Cu microparticles used in the electrocatalytic reduction of CO2, the figure shows that under low current density, the main catalytic product of Cu microparticles is similar to that of Cu microparticles, which is CO. However, at high reaction rates, the selectivity for H2 and CH4 is relatively high, especially at 400 mA cm⁻¹. -2 At the given current density, CH4 exhibits a maximum Faradaic efficiency of 23.3%, significantly higher than the 11.5% of Cu microwires. However, the selectivity for the CC-coupled product ethylene is relatively low.
Claims
1. A method for preparing low aspect ratio Cu microwires, characterized in that It is carried out according to the following steps: I. Preparation of precursor salt solution: Dissolve the sodium halide salt in an alcohol-containing organic solution, then add the copper salt and stir to mix uniformly to obtain the precursor salt solution; The molar ratio of the sodium halide salt to the copper salt is 1:(1-10); II. Preparation of reducing agent solution: Dissolve the reducing agent and the surfactant in an alcohol-containing organic solution to obtain the reducing agent solution; The molar ratio of the reducing agent to the alcohol-containing organic solution is (0.5-1) mmol:5 mL; the molar ratio of the surfactant to the alcohol-containing organic solution is (1-2) mmol:5 mL; III. Reduction: Heat the precursor salt solution to 100-150°C, then add the reducing agent solution at a rate of 0.25-1 mL / min and mix uniformly, react at a temperature of 100-150°C for 0.5-1 h, cool to room temperature after the reaction, and finally centrifuge, wash, and vacuum dry to obtain low aspect ratio Cu microwires; The volume ratio of the reducing agent solution to the precursor salt solution is 1:(2-3); the diameter of the prepared low aspect ratio Cu microwires is 1-3 μm, and the length is 90-150 μm; The alcohol-containing organic solution in steps I and II is ethylene glycol or triethylene glycol.
2. The method for preparing a low aspect ratio Cu microwire according to claim 1, characterized in that... The sodium halide salt in step I is sodium chloride or sodium bromide; the copper salt in step I is copper nitrate, copper acetate, copper chloride, or copper sulfate. 3.The method of claim 1, wherein the low aspect ratio Cu microwire is prepared by the steps of: forming a Cu seed layer on a substrate; depositing a Cu layer on the Cu seed layer; and performing a thermal annealing process on the Cu layer. The reducing agent in step II is ascorbic acid or sodium borohydride; the surfactant in step II is PVP K30.
4. The method for preparing a low aspect ratio Cu microwire according to claim 1, characterized in that... The centrifugation, washing, and vacuum drying in step III are specifically centrifuging at a speed of 5000-12000 rpm for 3-10 min to separate the solid, then washing the solid with anhydrous ethanol or n-hexane 3-5 times, and finally vacuum drying at a temperature of 40-60°C for 10-12 h.
5. The use of the low aspect ratio Cu microwire prepared by the preparation method according to claim 1, wherein the low aspect ratio Cu microwire is used as a material for a conductive material of a semiconductor device. It is used as a raw material to prepare a gas diffusion electrode for electrocatalytic reduction of CO2.
Citation Information
Patent Citations
Preparation method of regular pentagonal prism-shaped copper micrometer wire
CN103498198A
Preparation method of diameter-controllable Cu nanowires
CN108393501A