A device and method for rapidly preparing metal nanowires by coupling joule heat with high-voltage electrostatic field

Abstract

The application discloses a device and method for rapidly preparing metal nanowires by utilizing Joule heat coupling high-voltage electrostatic field, wherein a Joule heat component utilizes heated carbon paper to rapidly generate Joule heat, and the heat is conducted to a T-shaped conductive base of a loaded metal material through a ceramic heat conduction sheet which is high in heat conduction and electrically insulated, a dielectric barrier is constructed to realize decoupling of a Joule heat loop and a high-voltage electrostatic field loop; a high-voltage electrostatic field component constructs a high-strength electrostatic field above the T-shaped conductive base through a sharp cone-shaped high-voltage anode, under the protection of a sealed inert gas, the metal material is controlled to reach a molten state by adjusting the Joule heat, so that the metal material overcomes surface tension and occurs tensile deformation along the direction of the electric field line under the action of the strong electrostatic force, and then water cooling circulation is started to realize superfast cooling and solidification. The application completes the reaction in a second level time through two field coupling, is high in preparation efficiency, is free of solvent pollution in the process, and is high in product purity and excellent in one-dimensional crystal orientation, and has good industrial amplification potential.

Description

Technical Field

[0001] This invention belongs to the technical field of one-dimensional micro / nano structure metal material preparation device and method, and relates to the preparation of metal nanowires, specifically to a device and method for rapidly preparing metal nanowires using a Joule thermally coupled high-voltage electrostatic field. Background Technology

[0002] With the rapid development of nanoscience and technology, metallic nanomaterials have attracted widespread attention from academia and industry due to their unique physical and chemical properties. Among them, metallic nanowires, as a typical one-dimensional nanomaterial, not only possess extremely high specific surface area but also exhibit excellent electron transport capabilities, thermal conductivity, and good macroscopic mechanical flexibility. These outstanding properties make them promising for applications in many cutting-edge fields such as catalysis, flexible electronics, photoelectric detection, and high-sensitivity sensors. For example, in the field of electrocatalysis, metallic nanowires, with their continuous conductive network, abundant highly active edge / step sites, and structural stability that prevents aggregation, can significantly reduce reaction energy barriers, improve mass transfer efficiency, and enhance mass activity, making them an important catalytic material with great potential for industrialization.

[0003] Currently, the main methods for synthesizing metal nanowires include hydrothermal / solvothermal methods, hard template methods, seed-mediated growth methods, and chemical vapor deposition methods. Among them, the hydrothermal method typically uses high temperature and high pressure conditions in a closed reactor to induce the reduction of the metal precursor and achieve anisotropic growth with the assistance of specific surfactants. The hard template method relies on a template with regular nanopores (such as porous anodic alumina) to fill the pores with metal through electrochemical deposition or physical methods, and then uses strong acid or strong base etching to remove the template, thereby releasing the metal nanowires.

[0004] However, existing metal nanowire preparation technologies still face many insurmountable technical bottlenecks and defects in practical applications and large-scale production, as follows: (1) The preparation cycle is long. Traditional wet chemical synthesis methods (such as hydrothermal method and seed method) or template method usually require complex solution preparation, long-term isothermal reaction (often lasting several hours to several days) and cumbersome subsequent cleaning and purification steps, resulting in extremely low production efficiency; (2) The reaction reagents are not green and environmentally friendly. In the chemical reduction process, a large amount of organic solvents, strong reducing agents (such as sodium borohydride and hydrazine hydrate) and surfactants used often have high toxicity and corrosiveness, which can easily cause serious pollution to the environment. At the same time, the organic ligands remaining on the surface of metal nanowires are extremely difficult to completely remove, which will seriously mask the catalytic active sites of the material; (3) There is a high pressure safety risk. Hydrothermal method or solvothermal method must be carried out in a specially made closed reaction vessel. As the temperature rises, huge steam pressure will be generated inside the system. When the equipment is aged or the operation is improper, there are significant safety hazards such as explosion.

[0005] In summary, traditional methods for synthesizing metal nanowires struggle to simultaneously address issues of high efficiency, environmental friendliness, and safety. Therefore, there is an urgent need to develop novel ultrafast physical or thermochemical synthesis strategies to overcome the limitations of liquid-phase mass transfer and growth kinetics in traditional chemical methods. Summary of the Invention

[0006] The purpose of this invention is to provide an apparatus and method for rapidly preparing metal nanowires using a Joule thermally coupled high-voltage electrostatic field, thereby solving the problems of low efficiency, reagent contamination, and safety hazards in the preparation of metal nanowires from a new perspective.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: A device for rapidly fabricating metal nanowires using Joule heating coupled with a high-voltage electrostatic field includes a base and a sealing cover that are sealed together, and a Joule heating assembly and a high-voltage electrostatic field assembly disposed on a support platform of the base and located in a sealed cavity between the base and the sealing cover. The Joule heating assembly mainly consists of a water-cooled copper tube, conductive copper blocks, a voltage-conducting plate, a ceramic heat-conducting plate, and heating carbon paper. Two sets of oppositely arranged conductive copper blocks are supported and fixed to the support platform of the base by the water-cooled copper tube. The heating carbon paper is pressed and fixed between the two sets of oppositely arranged conductive copper blocks by the voltage-conducting plate and a fixing nut. The ceramic heat-conducting plate is disposed on the heating carbon paper. One side of the conductive copper block is electrically connected to the positive terminal of the power supply through the water-cooled copper tube, and the other side of the conductive copper block is electrically connected to the negative terminal of the power supply through the water-cooled copper tube. At the same time, the end of the water-cooled copper tube is connected to a circulating water pipeline to achieve heat exchange and cooling. The water-cooled copper tube also serves as a heat exchange cooling system. The Joule heating circuit includes a current input channel and a circulating water cooling channel. The high-voltage electrostatic field assembly mainly consists of a high-voltage anode, a high-voltage cathode, a U-shaped fixing clamp, and a T-shaped conductive substrate. The T-shaped conductive substrate, loaded with metal material, is placed on a ceramic heat-conducting sheet, and its bottom end is fixed to the U-shaped fixing clamp at the front end of the high-voltage cathode by a clamping screw to achieve electrical connection with the high-voltage cathode. The pointed bottom end of the high-voltage anode is suspended directly above the T-shaped conductive substrate. The high-voltage anode and high-voltage cathode are respectively connected to the positive and negative terminals of an external high-voltage generator through lines to form a high-voltage electric field on the T-shaped conductive substrate. By adjusting the Joule heating assembly, the metal material on the T-shaped conductive substrate is controlled to reach a molten state, so that it overcomes the surface tension and undergoes tensile deformation along the direction of the electric field lines under the action of strong electrostatic force. Then, the water cooling cycle is turned on to achieve rapid cooling and solidification to obtain metal nanowires.

[0008] Furthermore, the base is provided with an annular sealing groove, in which a sealing ring is installed. The sealing cover is sealed and fastened to the base by pressing the sealing ring. An air inlet pipe and an air outlet pipe are installed through the sealing support platform of the base. The air inlet pipe and the air outlet pipe extend into the base cavity and pass through the through hole on the side wall of the base cavity to connect with a protective gas source or vacuum equipment. This is used to introduce protective gas into the reaction cavity formed by the sealing cover and the base to achieve an oxygen-free atmosphere reaction environment or to draw a vacuum to achieve a vacuum reaction environment. This suppresses the oxidation reaction of the metal material during heating and stretching, thereby preventing the metal material from oxidizing and improving the stability of the metal nanowire formation. By suppressing the oxidation reaction that occurs in the metal material during heating, melting and stretching, the influence of oxidation on its melting behavior and stretching process is reduced.

[0009] Furthermore, the conductive copper block is provided with through holes, and the middle part of the U-shaped water-cooled copper pipe passes through the through holes on the conductive copper block to realize the function of supporting, cooling and conducting electricity for the conductive copper block. The two ends of the U-shaped water-cooled copper pipe are respectively sealed and pass through the base support platform and extend into the base cavity. The U-shaped water-cooled copper pipe in the base cavity is electrically connected to an external power supply through a connecting wire, and the end of the U-shaped water-cooled copper pipe in the base cavity is connected to circulating water through a pipeline.

[0010] Furthermore, both the high-voltage anode and the high-voltage cathode are covered with insulating sleeves, and the high-voltage anode and the high-voltage cathode are sealed through the insulating sleeves, penetrating the base support platform and extending into the base cavity. Their positions are far from the high-temperature center to prevent electrode ablation. The bottom end of the high-voltage anode faces the central reaction area of ​​the T-shaped conductive substrate. The vertical distance between the tip of the high-voltage anode and the surface of the T-shaped conductive substrate is set to 10-30 mm to achieve a high electrostatic field strength. The end of the high-voltage anode has a highly anisotropic pointed cone structure with a tip curvature radius of less than 50 μm, used to construct a highly focused electric field line distribution and a high-intensity electrostatic field in the space directly above the T-shaped conductive substrate. The working voltage between the high-voltage anode and the high-voltage cathode is set by adjusting the high-voltage generator, and this working voltage is less than the maximum breakdown voltage of the introduced inert gas to provide the maximum electrostatic field strength.

[0011] A method for rapidly preparing metal nanowires using a Joule thermocoupled high-voltage electrostatic field is disclosed. Based on the aforementioned apparatus for rapidly preparing metal nanowires using a Joule thermocoupled high-voltage electrostatic field, the specific preparation steps are as follows: The bottom end of a T-shaped conductive substrate loaded with metal material is fixed to a high-voltage cathode using a U-shaped clamp. After fixing, the sealing ring is sealed by the compression of the sealing cap and base. Inert gas is introduced into the reaction chamber between the base and the sealing cap through the inlet and outlet pipes to replace residual air. First, the Joule thermocouple is activated to reduce the metal material on the T-shaped conductive substrate into nano-metal particles. Then, the high-voltage generator is activated to generate an electrostatic field. In the presence of the electrostatic field… During the process, the external power supply is turned on again to generate Joule heating for the carbon paper. This heat is then conducted to the T-shaped conductive substrate through the ceramic heat-conducting sheet, causing the metal material on it to heat up to a molten state. Under the action of electrostatic force generated by the high-voltage electrostatic field, the metal material overcomes the surface tension and undergoes tensile deformation along the electric field lines pointing towards the high-voltage anode. After the Joule heating is completed, water cooling is turned on to remove heat through water circulation, achieving rapid cooling and ultimately obtaining one-dimensional metal nanowires. By adjusting the input voltage and duration of Joule heating, the heating rate and melting degree of the metal material can be controlled, and its surface tension can be adjusted, thereby achieving the regulation of the size and morphology of the metal nanowires.

[0012] Furthermore, the ceramic heat-conducting sheet is a highly thermally conductive and electrically insulating ceramic sheet with a thickness of less than 1 mm. While serving as an intermediate medium for heat conduction, it also forms a dielectric barrier to block crosstalk of the Joule heating current to the high-voltage electrostatic field component, thereby constructing two independent current conduction paths and achieving decoupling between the external Joule heating circuit and the high-voltage electrostatic field circuit.

[0013] Furthermore, the ceramic heat-conducting sheet is made of aluminum nitride (AlN), boron nitride (BN), alumina (Al2O3), or silicon carbide (SiC) ceramic.

[0014] Furthermore, the metal material is a low-melting-point metal or its alloy, specifically tin, indium, lead, bismuth and their alloy systems. By forming an alloy system, the melting temperature of the metal material is reduced and its fluidity and stability during the stretching process are improved.

[0015] Compared with the prior art, the beneficial effects and advantages of the present invention are: This invention achieves ultrafast preparation of metal nanowires through the coupling effect of Joule heating and a high-voltage electrostatic field, completing the reaction within seconds, significantly improving the preparation efficiency compared to traditional chemical synthesis methods. It adopts a purely physical preparation process, eliminating the need for any liquid solvents or organic surfactants, thus eliminating the problems of residual chemical reagents and post-processing purification of the product from the source. The device has a simple structure, is easy to operate, and is applicable to a variety of metals and alloys. The obtained product has high purity and good potential for industrial scale-up. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the preparation device in this invention.

[0017] Figure 2 This is a schematic diagram of the preparation device in this invention.

[0018] Figure 3 This is a schematic diagram of the preparation device in this invention.

[0019] Figure 4 This is an exploded view of the preparation apparatus in this invention.

[0020] Figure 5 This is a physical reference diagram of the preparation apparatus in this invention.

[0021] Figure 6 This is a scanning electron microscope image of the metal nanowires prepared in Example 1.

[0022] Figure 7 This is a scanning electron microscope image of the metal nanowires prepared in Example 2.

[0023] In the diagram: 1-base, 2-sealing cover, 3-water-cooled copper pipe, 4-conductive copper block, 5-voltage conductive sheet, 6-ceramic heat-conducting sheet, 7-heating carbon paper, 8-high-voltage anode, 9-high-voltage cathode, 10-U-shaped fixing clip, 11-T-shaped conductive base, 12-sealing ring, 13-air inlet pipe, 14-air outlet pipe. Detailed Implementation

[0024] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] Combination Figures 1-5The technical solution of the preparation device in this invention is described in detail. A device for rapidly preparing metal nanowires using Joule heating coupled with a high-voltage electrostatic field includes a base 1 and a sealing cover 2 that are sealed together, and a Joule heating component and a high-voltage electrostatic field component disposed on a base support platform and located within a sealed cavity between the base 1 and the sealing cover 2. The Joule heating component mainly consists of a water-cooled copper tube 3, conductive copper blocks 4, a voltage-conducting plate 5, a ceramic heat-conducting plate 6, and heating carbon paper 7. Two sets of opposing conductive copper blocks 4 are supported and fixed on the base support platform by the water-cooled copper tube 3. The heating carbon paper 7 is pressed and fixed between the two sets of opposing conductive copper blocks 4 by the voltage-conducting plate 5 and a fixing nut. The ceramic heat-conducting plate 6 is disposed on the heating carbon paper 7. One side of the conductive copper block 4 is electrically connected to the positive terminal of the power supply through the water-cooled copper tube 3, and the other side of the conductive copper block 4 is electrically connected to the negative terminal of the power supply through the water-cooled copper tube 3. Simultaneously, the end of the water-cooled copper tube 3 is connected to a circulating water pipeline for heat exchange and cooling. The water-cooled copper tube 3 also serves as the Joule heating element. The Joule heating circuit includes a current input channel and a circulating water cooling channel. The high-voltage electrostatic field assembly mainly consists of a high-voltage anode 8, a high-voltage cathode 9, a U-shaped fixing clip 10, and a T-shaped conductive substrate 11. The T-shaped conductive substrate 11, which carries metal material, is placed on a ceramic heat-conducting sheet 6, and the bottom end of the T-shaped conductive substrate 11 is fixed to the U-shaped fixing clip 10 at the front end of the high-voltage cathode 9 by a clamping screw to achieve electrical connection with the high-voltage cathode 9. The pointed bottom end of the high-voltage anode 8 is suspended directly above the T-shaped conductive substrate 11. The high-voltage anode 8 and the high-voltage cathode 9 are respectively connected to the positive and negative terminals of an external high-voltage generator through lines to form a high-voltage electric field on the T-shaped conductive substrate 11. By adjusting the Joule heating assembly, the metal material on the T-shaped conductive substrate 11 is controlled to reach a molten state, so that it overcomes the surface tension and undergoes tensile deformation along the direction of the electric field lines under the action of strong electrostatic force. Then, the water cooling cycle is turned on to achieve rapid cooling and solidification to obtain metal nanowires.

[0026] The base is provided with an annular sealing groove, in which a sealing ring 12 is installed. The sealing cover 2 is sealed and fastened to the base 1 by pressing the sealing ring 12. An air inlet pipe 13 and an air outlet pipe 14 are sealed and installed through the base support platform. The air inlet pipe 13 and the air outlet pipe 14 extend into the base cavity and pass through the through hole on the side wall of the base cavity to connect with a protective gas source or vacuum equipment. This is used to introduce protective gas into the reaction cavity formed by the sealing cover 2 and the base 1 to achieve an oxygen-free atmosphere reaction environment or to draw a vacuum to achieve a vacuum reaction environment. This suppresses the oxidation reaction of the metal material during heating and stretching, thereby preventing the metal material from oxidizing and improving the stability of the metal nanowire formation. By suppressing the oxidation reaction that occurs during the heating, melting and stretching of the metal material, the influence of oxidation on its melting behavior and stretching process is reduced.

[0027] The conductive copper block 4 has a through hole. The middle part of the U-shaped water-cooled copper pipe 3 passes through the through hole on the conductive copper block 4 to support, cool and conduct electricity for the conductive copper block 4. The two ends of the U-shaped water-cooled copper pipe 3 are sealed and pass through the base support platform and extend into the base cavity. The U-shaped water-cooled copper pipe 3 in the base cavity is electrically connected to an external power supply through a connecting wire. At the same time, the end of the U-shaped water-cooled copper pipe 3 in the base cavity is connected to the circulating water pipeline.

[0028] Both the high-voltage anode 9 and the high-voltage cathode 10 are covered with insulating sleeves, and the high-voltage anode 9 and the high-voltage cathode 10 are sealed through the insulating sleeves, penetrating the base support platform and extending into the base cavity. They are located away from the high-temperature center to prevent electrode ablation. The bottom end of the high-voltage anode 9 faces the central reaction area of ​​the T-shaped conductive substrate 11. The vertical distance between the tip of the high-voltage anode 9 and the surface of the T-shaped conductive substrate 11 is set to 10~30mm to achieve a high electrostatic field strength. The end of the high-voltage anode 9 has a highly anisotropic pointed cone structure with a radius of curvature of less than 50μm, which is used to construct a highly focused electric field line distribution and a high-intensity electrostatic field in the space directly above the T-shaped conductive substrate 11. The working voltage between the high-voltage anode 9 and the high-voltage cathode 10 is set by adjusting the high-voltage generator, and this working voltage is less than the maximum breakdown voltage of the inert gas to provide the maximum electrostatic field strength. Example 1

[0029] This embodiment provides an apparatus and method for rapidly preparing metal nanowires using a Joule thermally coupled high-voltage electrostatic field. In this embodiment, a T-shaped conductive substrate is selected as the carbon paper material. A tin precursor is loaded onto the surface of the T-shaped conductive substrate as the metal material to be processed. The two ends of the heated carbon paper are respectively clamped and fixed between opposing conductive copper blocks using voltage-conducting sheets and fixing nuts. A ceramic heat-conducting sheet is placed on the upper surface of the heated carbon paper, and the T-shaped conductive substrate is laid flat on the upper surface of the ceramic heat-conducting sheet. The bottom end of the T-shaped conductive substrate is fixed to a U-shaped fixing clamp at the front end of the high-voltage cathode with a clamping screw, forming a stable electrical connection between the T-shaped conductive substrate and the high-voltage cathode. The bottom conical structure of the high-voltage anode (with a tip curvature radius of approximately 40 μm), vertically sealed and installed on the base support platform, is suspended and precisely aligned above the reaction area of ​​the T-shaped conductive substrate. The vertical distance between the tip of the high-voltage anode and the surface of the T-shaped conductive substrate is 10 mm. A sealed reaction chamber is constructed by pressing and fastening the sealing ring between the sealing cap and the base. Argon gas is introduced into the reaction chamber through the inlet to replace residual air, thereby inhibiting the oxidation of metallic tin. The gas is then discharged through the outlet to maintain a constant working pressure. The external Joule heating power supply is activated, with the input voltage adjusted to 10V and maintained for 5 seconds to reduce the metallic tin precursor into tin nanoparticles. An external high-voltage generator is then activated, with its input voltage adjusted and fixed at 5.49V. This voltage represents the maximum non-breakdown voltage of argon gas at this pressure, thus creating a high-intensity electrostatic field directly above the reaction zone. While the electrostatic field persists, a 15V current is supplied to the conductive copper block and heated carbon paper through a water-cooled copper pipe. This causes the heated carbon paper to generate ultrafast Joule heating, which is conducted vertically upwards through a ceramic heat-conducting plate to the T-shaped conductive substrate. This causes the metallic tin (melting point approximately 232℃) to rapidly heat to approximately 600℃, melting and forming molten metal droplets. When metallic tin is in a molten state, under the strong electrostatic force generated by the high-voltage electrostatic field, the molten metal droplet overcomes surface tension and undergoes stretching deformation along the electric field lines pointing towards the high-voltage anode. One end, in contact with the T-shaped conductive substrate, forms an anchoring connection, while the other end extends along the electric field lines, forming a liquid neck structure that further refines. After 5 seconds, the external power supply is cut off to terminate heating. Simultaneously, an external water pump drives cooling water to circulate within a water-cooled copper pipe for forced heat dissipation, carrying away residual heat to achieve rapid cooling. This allows the extended one-dimensional liquid metal structure to quickly cool and solidify, resulting in one-dimensional tin nanowires with excellent crystalline orientation on the surface of the T-shaped conductive substrate. The size and morphology of the metal nanowires prepared by this method can be controlled by adjusting the Joule heating input voltage and heating time. Example 2

[0030] This embodiment provides an apparatus and method for rapidly preparing metal nanowires using a Joule thermally coupled high-voltage electrostatic field. In this embodiment, a T-shaped conductive substrate is selected as the carbon paper material, and a copper precursor is loaded onto the surface of the T-shaped conductive substrate as the metal material to be processed. The two ends of the heated carbon paper are respectively clamped and fixed between opposing conductive copper blocks using voltage-conducting sheets and fixing nuts. A ceramic heat-conducting sheet is placed on the upper surface of the heated carbon paper, and the T-shaped conductive substrate is laid flat on the upper surface of the ceramic heat-conducting sheet. The bottom end of the T-shaped conductive substrate is fixed to a U-shaped fixing clamp at the front end of the high-voltage cathode using clamping screws, thus forming a stable electrical connection between the T-shaped conductive substrate and the high-voltage cathode. A vertically sealed, cone-shaped structure (with a tip curvature radius of approximately 30 μm) of the bottom end of the high-voltage anode, which is mounted on the base support platform, is suspended and precisely aligned above the reaction area of ​​the T-shaped conductive substrate. The vertical distance between the tip of the high-voltage anode and the surface of the T-shaped conductive substrate is 15 mm. A sealed reaction chamber is constructed by pressing and fastening the sealing cap and the sealing ring together with the base. Argon gas is introduced into the reaction chamber through the inlet to replace residual air, thereby inhibiting the oxidation of metallic copper. The gas is then discharged through the outlet to maintain a constant working pressure. The external Joule heating power supply is activated, with the input voltage adjusted to 20V and maintained for 5 seconds to reduce the metallic copper precursor into copper nanoparticles. An external high-voltage generator is then activated, with its input voltage adjusted and fixed at 5.49V. This voltage represents the maximum non-breakdown voltage of argon gas at this pressure, thus creating a high-intensity electrostatic field directly above the reaction zone. While the electrostatic field persists, a 20V current is supplied to the conductive copper block and heated carbon paper through a water-cooled copper pipe. This causes the heated carbon paper to generate ultrafast Joule heating, which is conducted vertically upwards through a ceramic heat-conducting plate to the T-shaped conductive substrate. This causes the metallic copper (melting point approximately 1083℃) to rapidly heat to approximately 1200℃, melting and forming molten metal droplets. When metallic copper is in a molten state, under the strong electrostatic force generated by the high-voltage electrostatic field, the molten metal droplet overcomes surface tension and undergoes stretching deformation along the electric field lines pointing towards the high-voltage anode. One end, in contact with the T-shaped conductive substrate, forms an anchoring connection, while the other end extends along the electric field lines, forming a liquid neck structure that further refines. After 10 seconds, the external power supply is cut off to terminate heating. Simultaneously, an external water pump drives cooling water to circulate within the water-cooled copper pipe for forced heat dissipation, carrying away residual heat to achieve rapid cooling. This allows the extended one-dimensional liquid metal structure to quickly cool and solidify, resulting in one-dimensional copper nanowires with excellent crystalline orientation on the surface of the T-shaped conductive substrate. The size and morphology of the metal nanowires prepared by this method can be controlled by adjusting the Joule heating input voltage and heating time.

[0031] The foregoing has shown and described the basic principles, main features and advantages of the present invention. Various changes and modifications can be made to the present invention without departing from the spirit and scope thereof, and all such changes and modifications fall within the scope of the present invention as claimed.

Claims

1. A device for rapidly preparing metal nanowires using a Joule thermally coupled high-voltage electrostatic field, characterized in that... The device includes a mutually sealing base and a sealing cover, and a Joule heating assembly and a high-voltage electrostatic field assembly located on a base support platform within a sealed cavity between the base and the sealing cover. The Joule heating assembly mainly consists of a water-cooled copper tube, conductive copper blocks, a voltage-conducting plate, a ceramic heat-conducting plate, and heating carbon paper. Two sets of opposing conductive copper blocks are supported and fixed to the base support platform by the water-cooled copper tube. The heating carbon paper is pressed and fixed between the two sets of opposing conductive copper blocks by the voltage-conducting plate and a fixing nut. The ceramic heat-conducting plate is placed on the heating carbon paper. One side of the conductive copper block is electrically connected to the positive terminal of the power supply through the water-cooled copper tube, and the other side of the conductive copper block is electrically connected to the negative terminal of the power supply through the water-cooled copper tube. At the same time, the end of the water-cooled copper tube is connected to a circulating water pipeline to achieve heat exchange and cooling. The water-cooled copper tube also serves as the current input channel and circulation channel of the Joule heating circuit. The circulating water cooling channel and the high-voltage electrostatic field assembly mainly consist of a high-voltage anode, a high-voltage cathode, a U-shaped fixing clamp, and a T-shaped conductive substrate. The T-shaped conductive substrate, loaded with metal material, is placed on a ceramic heat-conducting sheet, and the bottom end of the T-shaped conductive substrate is fixed to the U-shaped fixing clamp at the front end of the high-voltage cathode by a clamping screw to achieve electrical connection with the high-voltage cathode. The pointed bottom end of the high-voltage anode is suspended directly above the T-shaped conductive substrate. The high-voltage anode and the high-voltage cathode are respectively connected to the positive and negative terminals of an external high-voltage generator through lines to form a high-voltage electric field on the T-shaped conductive substrate. By adjusting the Joule heating component, the metal material on the T-shaped conductive substrate is controlled to reach a molten state, so that it overcomes the surface tension and undergoes tensile deformation along the direction of the electric field lines under the action of strong electrostatic force. Then, the water cooling cycle is turned on to achieve rapid cooling and solidification to obtain metal nanowires.

2. The apparatus for rapid fabrication of metal nanowires using a Joule thermally coupled high-voltage electrostatic field according to claim 1, characterized in that: The base is provided with an annular sealing groove, in which a sealing ring is installed. The sealing cover is sealed and fastened to the base by pressing the sealing ring. An air inlet pipe and an air outlet pipe are installed through the sealing support platform of the base. The air inlet pipe and the air outlet pipe extend into the base cavity and pass through the through hole on the side wall of the base cavity to connect with a protective gas source or vacuum equipment. This is used to introduce protective gas into the reaction chamber formed by the sealing cover and the base to achieve an oxygen-free atmosphere reaction environment or to draw a vacuum to achieve a vacuum reaction environment. This inhibits the oxidation reaction of the metal material during heating and stretching, thereby preventing the metal material from oxidizing and improving the stability of the metal nanowire formation. By inhibiting the oxidation reaction that occurs in the metal material during heating, melting and stretching, the influence of oxidation on its melting behavior and stretching process is reduced.

3. The apparatus for rapid fabrication of metal nanowires using a Joule thermally coupled high-voltage electrostatic field according to claim 1, characterized in that: The conductive copper block has through holes, and the middle of the U-shaped water-cooled copper tube passes through the through holes on the conductive copper block to support, cool, and conduct electricity. The two ends of the U-shaped water-cooled copper tube are sealed and pass through the base support platform and extend into the base cavity. The U-shaped water-cooled copper tube in the base cavity is electrically connected to an external power source through a connecting wire, and the end of the U-shaped water-cooled copper tube in the base cavity is connected to circulating water through a pipeline.

4. The apparatus for rapid fabrication of metal nanowires using a Joule thermally coupled high-voltage electrostatic field according to claim 1, characterized in that: Both the high-voltage anode and the high-voltage cathode are covered with insulating sleeves, and the high-voltage anode and the high-voltage cathode are sealed through the insulating sleeves, penetrating the base support platform and extending into the base cavity. Their positions are far from the high-temperature center to prevent electrode ablation. The bottom end of the high-voltage anode faces the central reaction area of ​​the T-shaped conductive substrate. The vertical distance between the tip of the high-voltage anode and the surface of the T-shaped conductive substrate is set to 10-30 mm to achieve a high electrostatic field strength. The end of the high-voltage anode has a highly anisotropic pointed cone structure with a radius of curvature of less than 50 μm, used to construct a highly focused electric field line distribution and a high-intensity electrostatic field in the space directly above the T-shaped conductive substrate. The working voltage between the high-voltage anode and the high-voltage cathode is set by adjusting the high-voltage generator, and this working voltage is less than the maximum breakdown voltage of the introduced inert gas to provide the maximum electrostatic field strength.

5. A method for rapidly preparing metallic nanowires using a Joule thermally coupled high-voltage electrostatic field, characterized in that... The device for rapidly preparing metal nanowires using a Joule thermally coupled high-voltage electrostatic field, as described in any one of claims 1 to 4, is used. The specific preparation steps are as follows: the bottom end of a T-shaped conductive substrate loaded with metal material is fixed to a high-voltage cathode using a U-shaped clamp. After fixing, the sealing ring is sealed by the compression of the sealing cap and base. Inert gas is introduced into the reaction chamber between the base and the sealing cap through the inlet and outlet pipes to replace residual air. First, the Joule thermal assembly is activated to reduce the metal material on the T-shaped conductive substrate to nano-metal particles. Then, the high-voltage generator is activated to generate an electrostatic field. During the existence of the electrostatic field, the device is activated again... An external power source is activated to heat carbon paper, generating Joule heating. This heat is then conducted to a T-shaped conductive substrate via a ceramic heat-conducting sheet, causing the metal material on the substrate to heat up to a molten state. Under the electrostatic force generated by the high-voltage electrostatic field, the metal material overcomes surface tension and undergoes tensile deformation along the electric field lines pointing towards the high-voltage anode. After Joule heating is completed, water cooling is activated to rapidly cool the substrate by circulating water and removing heat, ultimately obtaining one-dimensional metal nanowires. By adjusting the input voltage and duration of Joule heating, the heating rate and melting degree of the metal material can be controlled, thereby regulating its surface tension and thus achieving the adjustment of the size and morphology of the metal nanowires.

6. The method for rapidly preparing metal nanowires using a Joule thermally coupled high-voltage electrostatic field according to claim 5, characterized in that: The ceramic heat-conducting sheet is a highly thermally conductive and electrically insulating ceramic sheet with a thickness of less than 1 mm. While serving as an intermediate medium for heat conduction, it also forms a dielectric barrier to block crosstalk of the Joule heating current to the high-voltage electrostatic field component, thereby constructing two independent current conduction paths and decoupling the external Joule heating circuit from the high-voltage electrostatic field circuit.

7. The method for rapidly preparing metal nanowires using a Joule thermally coupled high-voltage electrostatic field according to claim 5, characterized in that: The ceramic heat-conducting sheet is made of aluminum nitride, boron nitride, aluminum oxide, or silicon carbide ceramic.

8. The method for rapidly preparing metal nanowires using a Joule thermally coupled high-voltage electrostatic field according to claim 5, characterized in that: The metal material is a low-melting-point metal or its alloy, specifically tin, indium, lead, bismuth and their alloy systems. By forming an alloy system, the melting temperature of the metal material is reduced and its fluidity and stability during the stretching process are improved.

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