A method for batch production of large-aspect-ratio ordered metal nanowires

Abstract

The present application belongs to the field of micro-nano structure manufacturing, and proposes a method for batch preparation of large aspect ratio ordered metal nanowires. The method uses metal salts as metal source, prepares metal precursor solution suitable for electrospinning conditions, uses low-pressure near-field electrospinning technology to batch prepare large aspect ratio ordered micron-level metal precursor fibers, and through heat treatment, the solvent and additives in the metal precursor fibers are pyrolyzed and volatilized, the metal precursor is reduced to metal element, the fiber volume is significantly reduced, the diameter is reduced from micron level to nanometer level, and ordered metal nanowires are obtained. The spinning process is continuous, and a batch of ordered metal nanowires with large aspect ratio can be prepared at a time. The method solves the problems of low aspect ratio of nanowires and disordered morphology in the existing preparation method of metal nanowires.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of micro-nano structure manufacturing, and particularly relates to a method for batch preparing large-aspect-ratio ordered metal nanowires. BACKGROUND

[0002] One-dimensional (1D) metal nanostructure materials as potential key elements of next-generation nano-electronic devices, the preparation and characterization of which have shown exponential growth.

[0003] Electrospinning is a simple and easy method for preparing one-dimensional nanomaterials. The principle is to use a high-voltage electrostatic field to drive the functional liquid to form a Taylor cone and eject a fine jet. The jet is stretched in the electric field and continuously thinned, and finally deposited on the receiving substrate to form continuous ultra-fine fibers with diameters in the nanometer to micrometer range. By changing the physical property parameters (viscosity, conductivity, surface tension, etc.) of the functional liquid and the spinning process parameters (inner diameter of the needle, applied electric field strength, spinning height, etc.), micro-nano structures of different requirements can be prepared.

[0004] In the electrospinning process, by reducing the spinning distance and spinning voltage, the electrospun fibers can be deposited at a fixed point or in a predetermined trajectory in a two-dimensional plane. The document "Long Zhu, Junsheng Liang, Xiaojian Li, Shijie Su, Huaan Wang, Jianping Xiao, Lujing Sun, Dazhi Wang. Preparation of high positioning accuracy lattice patterns with polymeric microfibers derived from near-field electrospinning [J]. Journal of Applied Polymer Science, 2023; 140: e54370." uses low-voltage near-field electrospinning technology to prepare high-precision and uniformly arranged micro-sized polyethylene oxide (PEO) fiber arrays by optimizing the printing parameters and printing order. Although low-voltage near-field electrospinning can batch prepare large-aspect-ratio ordered fibers, the functional liquid used needs to be an electrode material with poor conductivity. When using a metal slurry with good conductivity, a breakdown phenomenon occurs and a stable jet cannot be formed, so nanoscale metal conductive fibers cannot be directly spun.

[0005] There are many methods for preparing metal nanowires at present, such as the preparation method of ordered metal nanowire array disclosed in Chinese patent document CN 112481660 A. The method makes the metal nanowire array grow in the porous anodic aluminum oxide template through electrochemical deposition, and then removes the template to obtain the metal nanowire. However, the method and the commonly used metal nanowire preparation method have the problems of low length-diameter ratio of the prepared nanowire, disordered morphology, poor controllability in the preparation process, etc. There are still certain difficulties in batch preparation of metal nanowires with large length-diameter ratio and ordered arrangement. SUMMARY

[0006] The purpose of the present application is to overcome the defects of the prior art and to provide a method for batch preparation of ordered metal nanowires with large length-diameter ratio. Metal salts are used as the metal source to prepare a metal precursor solution suitable for electrospinning conditions. The solid content of the metal in the precursor solution is about 1% to 30%. Low-pressure near-field electrospinning technology is used to batch prepare micro-sized metal precursor fibers with large length-diameter ratio and ordered arrangement. Through heat treatment, the solvent and additives in the metal precursor fibers are pyrolyzed and volatilized, the metal precursor is reduced to metal element, the fiber volume shrinks, the diameter is reduced from microns to nanometers, and ordered metal nanowires are obtained. This method solves the problems of low length-diameter ratio and disordered morphology of the nanowires in the existing metal nanowire preparation methods.

[0007] Technical scheme of the present application:

[0008] A method for batch preparation of ordered metal nanowires with large length-diameter ratio, comprising the following steps:

[0009] First, a metal precursor solution is prepared, and then a low-pressure near-field electrospinning device is used to spin on a receiving substrate 7-1 according to a predetermined trajectory. The spun metal precursor fibers 7-2 are arranged in order on the receiving substrate 7-1 or across the grooves of the receiving substrate 7-1. The diameter of the spun metal precursor fibers 7-2 is controlled by adjusting the electrospinning parameters. The receiving substrate 7-1 and the metal precursor fibers 7-2 thereon are placed in a high-temperature furnace 9 for heat treatment. The solvent and additives in the metal precursor fibers 7-2 are pyrolyzed and volatilized, the metal precursor is reduced to metal element, the fiber volume shrinks to 1 / 10 of the original volume, the diameter is reduced from microns to nanometers, and metal nanowires with large length-diameter ratio and ordered arrangement are obtained. The specific steps are as follows:

[0010] 1) Inject the metal precursor solution into the syringe 1, install the syringe 1 on the micro pump 2, and connect the needle of the syringe 1 to the positive electrode of the high-voltage power supply 8;

[0011] 2) Fix the receiving substrate 7-1 on the X-Y axis moving platform 6, and connect it to the negative electrode of the high-voltage power supply 8;

[0012] 3) Adjusting the Z-axis moving platform 3 to drive the injector 1 to the spinning distance and adjusting the X-Y-axis moving platform 6 to drive the receiving substrate 7-1 to the spinning starting position through the control system 5;

[0013] 4) Setting the liquid flow of the micro pump 2, suspending a stable precursor solution droplet at the needle of the injector 1, setting the working voltage of the high-voltage power supply 8, setting the movement speed and trajectory of the X-Y-axis moving platform 6, and starting to spin on the receiving substrate 7-1 according to the predetermined trajectory under the observation of the high-power camera 4;

[0014] 5) Placing the receiving substrate 7-1 and the metal precursor fiber 7-2 thereon prepared in step 4 into the high-temperature furnace 9 for heat treatment to obtain the large-aspect-ratio ordered metal nanowire.

[0015] In the above preparation method, the metal precursor solution is a mixed solution of metal salts, high-molecular complexing agents and organic solvents; the metal salts are silver salts, platinum salts, gold salts, etc.; the high-molecular complexing agents are polyether ketone type high-molecular compounds, polystyrene type high-molecular compounds, polyethylene type high-molecular compounds, polypropylene type high-molecular compounds, etc.; and the organic solvents are alcohol solvents, alicyclic hydrocarbon solvents, ester solvents, etc.; the metal solid content in the precursor solution accounts for 1% to 30%.

[0016] In the above preparation method, the low-pressure near-field electrospinning device includes an injector 1, a micro pump 2, a Z-axis moving platform 3, a high-power camera 4, a computer control system 5, an X-Y-axis moving platform 6 and a high-voltage power supply 8; the micro pump 2 is installed on the Z-axis moving platform 3, the injector 1 is vertically installed on the micro pump 2, the positive electrode of the high-voltage power supply 8 is connected with the metal needle of the injector 1, the X-Y-axis moving platform 6 and the Z-axis moving platform 3 are controlled by the computer control system 5, and the working process is observed by the high-power camera 4.

[0017] In the above preparation method, the receiving substrate 7-1 in step 2) is a conductive substrate such as a silicon wafer or a stainless steel sheet, which can have an array of 20 to 1000 μm wide grooves.

[0018] In the above preparation method, the spinning distance in step 3) is 1 to 4 mm.

[0019] In the above preparation method, the liquid flow of the micro pump 2 in step 4) is 0.1 to 0.5 μL / min.

[0020] In the above preparation method, the working voltage of the high-voltage power supply 8 in step 4) is 0.2 to 1 kV.

[0021] In the above preparation method, the movement speed of the X-Y-axis moving platform 6 in step 4) is 10 to 100 mm / s.

[0022] In the above preparation method, the electrospinning process in step 4) controls the diameter of the spun metal precursor fiber 7-2 by controlling the movement speed of the X-Y axis moving platform 6, and the spun metal precursor fiber 7-2 is deposited in order on the receiving substrate 7-1 according to the movement path of the X-Y axis moving platform 6, or across the groove of the receiving substrate 7-1.

[0023] In the above preparation method, the heating reduction temperature in step 5) is 800°C, and the heating time is 30 minutes.

[0024] In the above preparation method, the metal nanowire in step 5) has a diameter of 100-1000 nm, a length of several millimeters or even several centimeters, and a large aspect ratio.

[0025] The present application has the advantages of being able to mass-produce large-aspect-ratio ordered metal nanowires. Metal salts are used as the metal source, and a metal precursor solution suitable for electrospinning is prepared, with the metal solid content in the precursor solution being about 1%-30%. By reducing the spinning distance and the spinning voltage, the spun metal precursor fiber is deposited at a fixed point or in an ordered manner according to a predetermined trajectory in a two-dimensional plane, the spinning process is continuous, and a large number of large-aspect-ratio ordered metal precursor fibers can be prepared at a time. By controlling the movement speed of the receiving substrate, the diameter of the spun metal precursor fiber can be controlled. By heat treating the metal precursor fiber, the solvent and additives in the metal precursor fiber are pyrolyzed and volatilized, the metal precursor is reduced to metal, the fiber volume shrinks, the diameter is reduced from microns to nanometers, and large-aspect-ratio ordered metal nanowires are obtained. This method solves the problems of low aspect ratio and disordered morphology of nanowires in existing metal nanowire preparation methods, and has a wide application prospect in the field of one-dimensional (1D) metal nanostructure material preparation. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 is a schematic diagram of a low-pressure near-field electrospinning device;

[0027] Fig. 2(a) is a schematic diagram of a receiving substrate such as a silicon wafer or a stainless steel sheet;

[0028] Fig. 2(b) is a schematic diagram of a receiving substrate with an array of grooves;

[0029] Figure 3 is an image of a jet formed during the electrospinning process of a platinum precursor solution;

[0030] Figure 4 is a schematic diagram of a high-temperature furnace for heat treating metal nanowires;

[0031] Figure 5 is a schematic diagram of ordered platinum precursor fibers;

[0032] Figure 6is a schematic diagram of patterned platinum precursor fiber;

[0033] Figure 7 is a schematic diagram of suspended platinum precursor fiber across the groove;

[0034] Figure 8 is an energy dispersive spectrometer image of prepared platinum nanowire;

[0035] Figure 9 is an X-ray diffraction image of prepared platinum nanowire;

[0036] Wherein: 1-syringe, 2-micro pump, 3-Z-axis moving platform, 4-high power microscope, 5-control system, 6-X-Y-axis moving platform, 7-receiving substrate with electrospun fiber, 7-1-receiving substrate, 7-2-electrospun fiber, 8-high voltage power supply, 9-high temperature furnace. DETAILED DESCRIPTION

[0037] The specific embodiments of the present application are described in detail below in conjunction with the technical solutions and drawings.

[0038] Specific embodiment 1, taking the preparation of ordered platinum nanowire as an example.

[0039] First, prepare a platinum precursor solution, then use a low-pressure near-field electrospinning device to spin on the receiving substrate 7-1 according to the predetermined trajectory, and the spun metal precursor fiber 7-2 is arranged in order on the receiving substrate 7-1. Put the receiving substrate 7-1 and the platinum precursor fiber 7-2 thereon into the high temperature furnace 9 for heat treatment, so that the solvent and auxiliary agents in the platinum precursor fiber 7-2 are pyrolyzed and volatilized, the platinum precursor is reduced to platinum, the fiber volume shrinks, the diameter is reduced from microns to nanometers, and large aspect ratio ordered platinum nanowire is obtained. The specific steps are as follows:

[0040] 1) First, prepare a platinum precursor solution, mix platinum salts, high molecular compounds and organic solvents at room temperature with magnetic stirring, seal the solution preparation process with plastic film to prevent solvent evaporation loss, stir for 2 hours to obtain a uniform viscous electrospinning platinum precursor solution, and the platinum solid content in the precursor solution is about 10%. As shown in Figure 1 The prepared solution is injected into the syringe 1, the syringe 1 is installed on the micro pump 2, and the piston of the syringe 1 is pushed by the micro pump 2 during spinning to uniformly and quantitatively discharge the precursor solution. The needle of the syringe 1 is connected to the positive electrode of the high voltage power supply 8;

[0041] 2) As shown in Figure 2(a), the receiving substrate 7-1 is a silicon wafer substrate. The receiving substrate 7-1 is fixed on the predetermined position of the X-Y-axis moving platform 6, and the receiving substrate 7-1 is moved according to the predetermined trajectory by the X-Y-axis moving platform 6 during spinning. The receiving substrate 7-1 is connected to the negative electrode of the high voltage power supply 8;

[0042] 3) Adjust the Z-axis moving platform 3 to move the syringe 1 to the appropriate spinning distance, so that the needle of the syringe 1 is 4 mm away from the surface of the receiving substrate 7-1. Adjust the X-Y-axis moving platform 6 to move the receiving substrate 7-1 to the spinning starting position;

[0043] 4) Set the liquid inlet flow rate of the micro pump 2 to 0.1 μL / min, so that a stable droplet of precursor solution is suspended at the needle of the syringe 1. Set the spinning voltage of the high-voltage power supply 8 to 1 kV. Set the movement speed of the X-Y-axis moving platform 6 to 100 mm / s. Start the electrospinning process under the observation of the high-power camera 4. As shown in Figure 3 , under the action of the electric field of the high-voltage power supply 8, the functional liquid at the needle of the syringe 1 overcomes the surface tension and viscous force of the liquid film, and is further deformed, focused and sharpened to form a Taylor cone at the bottom of the needle droplet, and a jet is "pulled" out. As shown in Figure 5 , the spun fibers are deposited in order on the receiving substrate 7-1 along the movement path of the X-Y-axis moving platform 6;

[0044] 5) As shown in Figure 4 , place the receiving substrate and the electrospun fibers thereon prepared in step 4) into the high-temperature furnace 9 for heating reduction. The heating temperature is 800℃, and the heating time is 30 minutes. The solvent and the auxiliary agent in the platinum precursor fiber 7-2 are pyrolyzed and volatilized, and the platinum precursor is reduced to platinum metal. The fiber volume shrinks, and the diameter is reduced from microns to nanometers. The large-aspect-ratio ordered platinum nanowires with a diameter of 100 nm and a length of several centimeters are obtained. The prepared platinum nanowires are characterized, as shown in Figure 8 , Figure 9 , the main component of the platinum nanowires is platinum, and exhibits a face-centered cubic characteristic peak, which is consistent with the bulk platinum, proving that the solvent and the auxiliary agent in the platinum precursor fiber have been pyrolyzed and volatilized, and the platinum precursor has been completely reduced to platinum metal.

[0045] Specific embodiment 2, taking the preparation of patterned ordered platinum nanowires as an example.

[0046] First, prepare the platinum precursor solution, and then use the low-voltage near-field electrospinning device to spin on the receiving substrate 7-1 along the predetermined trajectory. The spun metal precursor fiber 7-2 is arranged in a patterned order on the receiving substrate 7-1. Place the receiving substrate 7-1 and the platinum precursor fiber 7-2 thereon into the high-temperature furnace 9 for heat treatment. The solvent and the auxiliary agent in the platinum precursor fiber 7-2 are pyrolyzed and volatilized, and the platinum precursor is reduced to platinum metal. The fiber volume shrinks, and the diameter is reduced from microns to nanometers. The patterned ordered platinum nanowires are obtained. The specific steps are as follows:

[0047] 1) First, the platinum precursor solution is prepared. The platinum salt, the polymer compound and the organic solvent are stirred magnetically at room temperature. The solution is prepared in a plastic film to prevent solvent evaporation. The stirring is continued for 2 hours to obtain a uniform viscous electrospinning platinum precursor solution. The platinum solid content in the precursor solution is about 10%. As shown in Fig. 1, the prepared solution is injected into the syringe 1. The syringe 1 is installed on the micro pump 2. The syringe 1 piston is pushed by the micro pump 2 to quantitatively discharge the precursor solution at a constant speed during spinning. The needle of the syringe 1 is connected to the positive pole of the high voltage power supply 8. Figure 1

[0048] 2) As shown in Fig. 2(a), the receiving substrate 7-1 is a silicon wafer substrate. The receiving substrate 7-1 is fixed on the predetermined position of the X-Y axis moving platform 6. The receiving substrate 7-1 is moved along the predetermined track by the X-Y axis moving platform 6 during spinning. The receiving substrate 7-1 is connected to the negative pole of the high voltage power supply 8.

[0049] 3) The Z axis moving platform 3 is adjusted to move the syringe 1 to the appropriate spinning distance by the control system 5, so that the needle of the syringe 1 is 2 mm away from the surface of the receiving substrate 7-1. The X-Y axis moving platform 6 is adjusted to move the receiving substrate 7-1 to the starting position of spinning.

[0050] 4) The liquid inlet flow rate of the micro pump 2 is set to 0.2 μL / min. A stable precursor solution droplet is suspended at the needle of the syringe 1. The spinning voltage of the high voltage power supply 8 is set to 0.5 kV. The movement speed of the X-Y axis moving platform 6 is set to 50 mm / s. The electrospinning process is started under the observation of the high-power camera 4. As shown in Fig. 4, under the action of the electric field of the high voltage power supply 8, the functional liquid at the needle of the syringe 1 overcomes the surface tension and viscous force of the liquid film, and is further deformed, focused and sharpened to form a Taylor cone at the bottom of the needle droplet, and the jet is "pulled" out. As shown in Fig. 5, the spun fibers are patterned and orderly deposited on the receiving substrate 7-1 along the movement path of the X-Y axis moving platform 6. Figure 3 Figure 6

[0051] 5) As shown in Fig. 6, the receiving substrate and the electrospun fibers thereon obtained in step 4) are placed in the high temperature furnace 9 for heating and reduction. The heating temperature is 800°C, and the heating time is 30 minutes. The solvent and the additive in the platinum precursor fiber 7-2 are pyrolyzed and volatilized. The platinum precursor is reduced to platinum metal. The fiber volume shrinks, and the diameter is reduced from microns to nanometers. The patterned and orderly platinum nanowires with a diameter of 500 nm are obtained. Figure 4

[0052] Specific embodiment 3, preparation of the suspended and orderly platinum nanowires is taken as an example.

[0053] ​​​​First, a platinum precursor solution is prepared, and then a low-pressure near-field electrospinning device is used to spin the solution in a predetermined trajectory on a receiving substrate 7-1, and the spun metal precursor fibers 7-2 are laid across the grooves on the receiving substrate 7-1. The receiving substrate 7-1 and the platinum precursor fibers 7-2 thereon are placed in a high-temperature furnace 9 for heat treatment, so that the solvent and auxiliary agents in the platinum precursor fibers 7-2 are pyrolyzed and volatilized, the platinum precursor is reduced to elemental platinum, the fiber volume shrinks, the fiber diameter decreases, and the suspended platinum nanowires across the grooves on the receiving substrate 7-1 are obtained. The specific steps are as follows:

[0054] 1) First, a platinum precursor solution is prepared, and platinum salts, high molecular compounds and organic solvents are magnetically stirred at room temperature. The solution preparation process is sealed with a plastic film to prevent the solvent from evaporating and being lost. Stirring lasts for 2 hours to obtain a uniform viscous electrospinning platinum precursor solution. The platinum solid content in the precursor solution is about 10%. As shown in FIG. 1(b), the prepared solution is injected into a syringe 1, and the syringe 1 is installed on a micro pump 2. During spinning, the piston of the syringe 1 is pushed by the micro pump 2 to uniformly and quantitatively discharge the precursor solution. The needle of the syringe 1 is connected to the positive electrode of a high-voltage power supply 8; Figure 1

[0055] 2) As shown in FIG. 2(b), the receiving substrate 7-1 is a stainless steel sheet substrate with an array of 500 μm wide grooves. The receiving substrate 7-1 is fixed at a predetermined position on an X-Y axis moving platform 6, and the receiving substrate 7-1 is moved along a predetermined trajectory by the X-Y axis moving platform 6 during spinning. The receiving substrate 7-1 is connected to the negative electrode of the high-voltage power supply 8;

[0056] 3) The Z-axis moving platform 3 is adjusted by the control system 5 to move the syringe 1 to an appropriate spinning distance, so that the needle of the syringe 1 is 1 mm away from the surface of the receiving substrate 7-1. The X-Y axis moving platform 6 is adjusted to move the receiving substrate 7-1 to the starting position of spinning;

[0057] 4) The liquid inlet flow rate of the micro pump 2 is set to 0.5 μL / min, a stable precursor solution droplet is suspended at the needle of the syringe 1, the spinning voltage of the high-voltage power supply 8 is set to 0.2 kV, and the movement speed of the X-Y axis moving platform 6 is set to 10 mm / s. The electrospinning process is started under the observation of a high-power camera 4. As shown in FIG. 3(a), under the action of the electric field of the high-voltage power supply 8, the functional liquid at the needle of the syringe 1 overcomes the surface tension and viscous force of the liquid film, is further deformed, focused and sharpened, and a Taylor cone is formed at the bottom of the needle droplet, and a jet is "pulled" out. As shown in FIG. 3(b), the spun fibers are laid across the grooves on the receiving substrate 7-1 along the movement path of the X-Y axis moving platform 6; Figure 3 Figure 7

[0058] 5) As shown in FIG. 4(a), the receiving substrate 7-1 with the platinum precursor fibers 7-2 thereon is placed in the high-temperature furnace 9 for heat treatment. As shown in FIG. 4(b), the solvent and auxiliary agents in the platinum precursor fibers 7-2 are pyrolyzed and volatilized, the platinum precursor is reduced to elemental platinum, the fiber volume shrinks, the fiber diameter decreases, and the suspended platinum nanowires across the grooves on the receiving substrate 7-1 are obtained; Figure 4 ​​​As shown, the receiving substrate and the electrically emitting fibers thereon prepared in step 4) are put into a high-temperature furnace 9 for heating reduction, the heating temperature is 800℃, and the heating time is 30 minutes, so that the solvent and the auxiliary agent in the platinum precursor fiber 7-2 are pyrolyzed and volatilized, the platinum precursor is reduced to platinum metal, the fiber volume shrinks, and the diameter is reduced, to obtain large-aspect-ratio suspended platinum nanowires with a diameter of 1000 nm and a length of 500 μm.

Claims

1. A method for batch production of large aspect ratio ordered metal nanowires, characterized by, The steps are as follows: First, a metal precursor solution is prepared, and then a low-pressure near-field electrospinning device is used to spin the metal precursor fibers (7-2) on the receiving substrate (7-1) in a predetermined trajectory. The metal precursor fibers (7-2) are arranged in order on the receiving substrate (7-1) or across the grooves of the receiving substrate (7-1); by adjusting the electrospinning parameters to control the diameter of the spun metal precursor fibers (7-2), the receiving substrate (7-1) and the metal precursor fibers (7-2) thereon are placed in a high-temperature furnace (9) for heat treatment, so that the solvent and auxiliary agents in the metal precursor fibers (7-2) are pyrolyzed and volatilized, the metal precursor is reduced to elemental metal, the fiber volume shrinks to 1 / 10 of the original volume, and the diameter is reduced from microns to nanometers, obtaining large-aspect-ratio ordered metal nanowires; the specific steps are as follows: 1) The metal precursor solution is injected into the syringe (1), the syringe (1) is installed on the micro pump (2), and the needle of the syringe (1) is connected to the positive electrode of the high-voltage power supply (8); 2) The receiving substrate (7-1) is fixed on the X-Y axis moving platform (6) and connected to the negative electrode of the high-voltage power supply (8); 3) By controlling the system (5), the Z-axis moving platform (3) drives the syringe (1) to the spinning distance, and the X-Y axis moving platform (6) drives the receiving substrate (7-1) to the spinning starting position; 4) Set the liquid flow of the micro pump (2), hang a stable precursor solution droplet at the needle of the syringe (1), set the working voltage of the high-voltage power supply (8), set the movement speed and trajectory of the X-Y axis moving platform (6), and start spinning on the receiving substrate (7-1) in a predetermined trajectory under the observation of the high-power camera (4); 5) The receiving substrate (7-1) and the metal precursor fibers (7-2) thereon prepared in step 4) are placed in a high-temperature furnace (9) for heat treatment, and large-aspect-ratio ordered metal nanowires are obtained; The metal precursor solution is a mixed solution of metal salts, high-molecular complexing agents, and organic solvents; the metal salt is silver salt, platinum salt, or gold salt, the high-molecular complexing agent is polyether ketone type high-molecular compound, polystyrene type high-molecular compound, polyethylene type high-molecular compound, or polypropylene type high-molecular compound, the organic solvent is alcohol solvent, alicyclic hydrocarbon solvent, or ester solvent; the metal solid content in the metal precursor solution is 1% to 30%.

2. The method of claim 1, wherein, The low-pressure near-field electrospinning device includes a syringe (1), a micro pump (2), a Z-axis moving platform (3), a high-power camera (4), a computer control system (5), an X-Y axis moving platform (6), and a high-voltage power supply (8); the micro pump (2) is installed on the Z-axis moving platform (3), the syringe (1) is vertically installed on the micro pump (2), the positive electrode of the high-voltage power supply (8) is connected to the metal needle of the syringe (1), the X-Y axis moving platform (6) and the Z-axis moving platform (3) are controlled by the computer control system (5), and the working process is observed by the high-power camera (4).

3. The method of claim 1, wherein, The receiving substrate (7-1) in step 2) is a conductive substrate of silicon wafer or stainless steel sheet, on which an array of 20-1000 μm wide grooves is formed.

4. The method of claim 1, wherein, The spinning distance in step 3) is 1-4 mm.

5. The method of claim 1, wherein, The liquid inlet flow rate of the micro pump (2) in step 4) is 0.1-0.5 μL / min.

6. The method of claim 1, wherein, The movement speed of the X-Y axis moving platform (6) in step 4) is 10-100 mm / s.

7. The method of claim 1, wherein, In the electrospinning process in step 4), the diameter of the spun metal precursor fiber (7-2) is controlled by controlling the movement speed of the X-Y axis moving platform (6), and the spun metal precursor fiber (7-2) is deposited on the receiving substrate (7-1) along the movement path of the X-Y axis moving platform (6) in an orderly and neat manner, or across the grooves of the receiving substrate (7-1).

8. The method of claim 1, wherein, The heating reduction temperature in step 5) is 800°C, and the heating time is 30 minutes.

9. The method of claim 1, wherein, The metal nanowire in step 5) has a diameter of 100-1000 nm, a length of millimeter to centimeter, and a large aspect ratio.

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