A method for rapidly preparing aluminum nitride nanowires by electrothermal shock

Abstract

The application provides a method for rapidly preparing aluminum nitride nanowires by electrothermal shock, and belongs to the technical field of inorganic nonmetal material preparation. The method uses aluminum alloy powder and chloride additives as raw materials to prepare aluminum nitride nanowires by electrothermal shock in one step. The method comprises the following steps: (1) uniformly mixing aluminum alloy powder and chloride additives according to a certain ratio to prepare a suspension; (2) coating the prepared suspension on a carbon substrate module and drying; (3) performing electrothermal shock on the carbon substrate module loaded with the raw materials in a nitrogen environment; the temperature and time of the electrothermal shock are accurately controlled by adjusting the voltage and current intensity, so that the nanocrystallization treatment of the material is realized; (4) using a carbon collector module to collect the product in a heterotopic manner; after the electrothermal shock process is completed, a layer of white product, i.e. aluminum nitride nanowires, is collected on the surface of the carbon collector module. The method has the advantages of simplicity and rapidness, and harmful defects caused by the introduction of metal catalysts are avoided. The method for preparing aluminum nitride nanowires has a wide application prospect in the fields of optoelectronic devices and functional composite materials.

Description

Technical Field

[0001] This invention belongs to the technical field of inorganic non-metallic material preparation, and relates to an aluminum nitride nanowire and its rapid preparation method. Background Technology

[0002] Aluminum nitride (AlN) is an excellent thermal shock resistant material due to its good thermal conductivity and low coefficient of thermal expansion. Its good dielectric properties also make it suitable for a range of applications, including integrated circuits and multi-chip modules, ceramic substrates, and hydrogen storage. Compared to aluminum nitride nanoparticles, aluminum nitride nanowires possess unique low dimensionality, which can effectively improve the field emission enhancement factor, making them promising for novel magnetic materials, molecular electronics and optoelectronic devices, and functional composite materials.

[0003] Since aluminum nitride powder can only produce aluminum nitride nanocones directly in nitrogen and cannot directly produce one-dimensional aluminum nitride nanowire structures [Liu C, Hu Z, Wu Q, et al. Vapor-solid growth and characterization of aluminum nitride nanocones[J]. Journal of the American Chemical Society, 2005, 127(4): 1318-1322.], the current methods for synthesizing aluminum nitride nanowires mainly include the following two: one is chemical vapor deposition (CVD), which uses a metal catalyst to first form Me-N-Al molten droplets on a substrate. Then, during the chemical vapor deposition process, the N and Al in the droplets become supersaturated, thereby forming initial AlN nuclei that accumulate continuously. Subsequently, under the guidance of the metal catalyst, they are directionally generated into nanowire structures. 109264678A proposes a method for growing aluminum nitride nanowires using Ti catalysis. However, the use of Ti metal catalyst in this method may introduce harmful defects into the generated aluminum nitride nanowires, thus affecting the material properties. Another method is the carbothermal reduction method, which generates aluminum nitride by carbothermal reduction of Al2O3 under a nitrogen atmosphere. CN 103539087 B proposes an improved carbothermal reduction method to grow aluminum nitride nanowires on a silicon substrate. However, this method has the disadvantages of long time consumption, high energy consumption, and serious pollution.

[0004] This invention proposes a novel method for rapidly preparing aluminum nitride nanowires in a very short time using aluminum alloy powder and chloride auxiliaries via electrothermal shock. Compared with other preparation methods, this method uses chloride-assisted synthesis of aluminum nitride nanowires, avoiding the harmful defects caused by the introduction of metal catalysts, and also has the advantages of simple and rapid preparation process (~1s). Summary of the Invention

[0005] This invention provides a method for rapidly preparing aluminum nitride nanowires using electrothermal shock, overcoming the drawbacks of traditional aluminum nitride nanowire growth methods, such as reliance on metal catalysts and long growth times.

[0006] To achieve the above objectives, the present invention provides a method for rapidly preparing aluminum nitride nanowires using electrothermal shock, the method comprising the following steps:

[0007] Step 1: After uniformly mixed aluminum alloy powder and chloride additive in a certain mass ratio, the mixture is dispersed in a solvent to form a suspension.

[0008] Step 2: Apply a small amount of suspension to the carbon-based module and then dry it to remove excess moisture.

[0009] Step 3: For the carbon substrate module loaded with raw materials obtained in Step 2, electrothermal shock is performed in a nitrogen environment. The temperature and time of the electrothermal shock are precisely controlled by modulating the voltage and current intensity, thereby achieving nano-scale processing of the material.

[0010] Step 4: While performing electrothermal shock in step 3, the product is collected in situ using a carbonaceous collector module. After the thermal shock process is completed, a layer of white product, namely aluminum nitride nanowires, is collected on the surface of the carbonaceous collector module.

[0011] Preferably, the aluminum alloy powder particle size in step (1) is 1-10 μm.

[0012] Preferably, the chloride auxiliary in step (1) is one or any combination of two or more of the following: ammonium chloride, aluminum chloride hexahydrate, ferric chloride, and potassium chloride, with a purity of analytical grade or higher.

[0013] Preferably, the mass ratio of aluminum alloy powder and chloride additive in step (1) is in the range of 1:5 to 5:1.

[0014] Preferably, the solvent in step (1) is one or any combination of two or more of the following: carbon tetrachloride, benzene, acetone, ethanol, ethylene glycol ethyl ether, and liquid paraffin.

[0015] Preferably, the material of the carbon substrate module in step (2) is one of the following: carbon cloth, carbon felt, graphene sheet, or graphite plate.

[0016] Preferably, the thermal shock temperature in step (3) is 1800-2500℃ and the thermal shock time is 0.1-1s.

[0017] Preferably, the material of the carbon collection module in step (4) is one of the following: carbon cloth, carbon felt, graphene sheet, or graphite plate.

[0018] The beneficial effects of this invention are: aluminum nitride nanowires are prepared simply and rapidly using aluminum alloy powder and chloride additives as raw materials and an electrothermal shock method. Compared with traditional preparation processes, this method is simple, has a short preparation cycle, and avoids the harmful defects caused by the introduction of metal catalysts. The obtained aluminum nitride nanowires have broad application prospects in optoelectronic devices and functional composite materials. Attached Figure Description

[0019] Figure 1 This is a scanning electron microscope (SEM) image of aluminum nitride nanowires prepared using the method of this invention.

[0020] Figure 2 This is an elemental distribution (EDS) diagram of aluminum nitride nanowires prepared using the method of this invention.

[0021] Figure 3 This is a high-resolution transmission electron microscope (HRTEM) image of aluminum nitride nanowires prepared using the method of this invention. Detailed Implementation

[0022] The present invention will be further described below with reference to specific embodiments, but the present invention is not limited to the following embodiments.

[0023] Unless otherwise specified, the experimental methods described in the following examples are conventional methods; the reagents and materials described are commercially available unless otherwise specified.

[0024] Example 1

[0025] (1) After mixing aluminum alloy powder and chloride additive NH4Cl at a mass ratio of 1:5, disperse them in ethanol solvent to form a suspension; (2) Take a small amount of suspension and apply it to the carbon cloth substrate module, and then dry it to remove excess moisture; (3) Perform electrothermal shock on the carbon cloth loaded with aluminum alloy powder and NH4Cl in a nitrogen environment. During the thermal shock process, the temperature is controlled at 1800℃ and the shock time is 1s by adjusting the voltage and current intensity; (4) At the same time as step (3), use a carbon cloth collecting module to place above the carbon cloth substrate module for off-site collection. After the thermal shock process, a layer of white substance appears on the surface of the carbon cloth collecting module, which is aluminum nitride nanowire.

[0026] Scanning electron microscope (JSM-7800) and transmission electron microscope (JEM-2100F) were used to observe the aluminum nitride nanowires obtained under the above conditions. The test results are attached. Figures 1-3 As shown, the aluminum nitride nanowires are about 60 nm in diameter and have an aluminum oxide film on their surface.

[0027] Example 2

[0028] (1) After mixing aluminum alloy powder and chloride additive aluminum chloride hexahydrate at a mass ratio of 1:5, disperse them in ethanol solvent to form a suspension; (2) Take a small amount of suspension and apply it to the carbon cloth substrate module, and then dry it to remove excess moisture; (3) Perform electrothermal shock on the carbon cloth loaded with aluminum alloy powder and aluminum chloride hexahydrate in a nitrogen environment. During the thermal shock process, the temperature is controlled at 1800℃ and the shock time is 1s by adjusting the voltage and current intensity; (4) At the same time as step (3), use a carbon cloth collection module to place on the carbon cloth substrate module for off-site collection. After the thermal shock process, a layer of white substance appears on the surface of the carbon cloth collection module, which is aluminum nitride nanowire.

[0029] A scanning electron microscope (JSM-7800) and a transmission electron microscope (JEM-2100F) were used to observe the aluminum nitride nanowires obtained under the above conditions. The crystal structure, morphology, and composition of the products were the same as those in Example 1.

[0030] Example 3

[0031] (1) After mixing aluminum alloy powder and chloride additive NH4Cl at a mass ratio of 5:1, disperse them in ethanol solvent to form a suspension; (2) Take a small amount of suspension and apply it to the carbon cloth substrate module, and then dry it to remove excess moisture; (3) Perform electrothermal shock on the carbon cloth loaded with aluminum alloy powder and NH4Cl in a nitrogen environment. During the thermal shock process, the temperature is controlled at 1800℃ and the shock time is 1s by adjusting the voltage and current intensity; (4) At the same time as step (3), use a carbon cloth collection module to place on the carbon cloth substrate module for off-site collection. After the thermal shock process, a layer of white substance appears on the surface of the carbon cloth collection module, which is aluminum nitride nanowire.

[0032] A scanning electron microscope (JSM-7800) and a transmission electron microscope (JEM-2100F) were used to observe the aluminum nitride nanowires obtained under the above conditions. The crystal structure, morphology, and composition of the products were the same as those in Example 1.

[0033] Example 4

[0034] (1) After mixing aluminum alloy powder and chloride additive NH4Cl at a mass ratio of 1:5, disperse them in ethylene glycol ethyl ether solvent to form a suspension; (2) Take a small amount of suspension and apply it to the carbon cloth substrate module, and then dry it to remove excess moisture; (3) Perform electrothermal shock on the carbon cloth loaded with aluminum alloy powder and NH4Cl in a nitrogen environment. During the thermal shock process, the temperature is controlled at 1800℃ and the shock time is 1s by adjusting the voltage and current intensity; (4) At the same time as step (3), use a carbon cloth collection module to place on the carbon cloth substrate module for off-site collection. After the thermal shock process, a layer of white substance appears on the surface of the carbon cloth collection module, which is aluminum nitride nanowire.

[0035] A scanning electron microscope (JSM-7800) and a transmission electron microscope (JEM-2100F) were used to observe the aluminum nitride nanowires obtained under the above conditions. The crystal structure, morphology, and composition of the products were the same as those in Example 1.

[0036] Example 5

[0037] (1) After mixing aluminum alloy powder and chloride additive NH4Cl at a mass ratio of 1:5, disperse them in ethanol solvent to form a suspension; (2) Take a small amount of suspension and apply it to the carbon cloth substrate module, and then dry it to remove excess moisture; (3) Perform electrothermal shock on the carbon cloth loaded with aluminum alloy powder and NH4Cl in a nitrogen environment. During the thermal shock process, the temperature is controlled at 2500℃ and the shock time is 0.1s by adjusting the voltage and current intensity; (4) At the same time as step (3), use a carbon cloth collection module to place on the carbon cloth substrate module for off-site collection. After the thermal shock process, a layer of white substance appears on the surface of the carbon cloth collection module, which is aluminum nitride nanowire.

[0038] A scanning electron microscope (JSM-7800) and a transmission electron microscope (JEM-2100F) were used to observe the aluminum nitride nanowires obtained under the above conditions. The crystal structure, morphology, and composition of the products were the same as those in Example 1.

[0039] Example 6

[0040] (1) Aluminum alloy powder and chloride additive NH4Cl are mixed evenly at a mass ratio of 1:5 and then dispersed in ethanol solvent to form a suspension; (2) A small amount of suspension is applied to the graphene sheet substrate module and then dried to remove excess moisture; (3) The graphene sheet loaded with aluminum alloy powder and NH4Cl is subjected to electrothermal shock in a nitrogen environment. The temperature is controlled at 2500℃ and the shock time is 0.1s by adjusting the voltage and current intensity during the thermal shock process; (4) At the same time as step (3), a graphene sheet collection module is placed above the graphene sheet substrate module for off-site collection. After the thermal shock process, a layer of white substance appears on the surface of the graphene sheet collection module, which is aluminum nitride nanowire.

[0041] A scanning electron microscope (JSM-7800) and a transmission electron microscope (JEM-2100F) were used to observe the aluminum nitride nanowires obtained under the above conditions. The crystal structure, morphology, and composition of the products were the same as those in Example 1.

[0042] The applicant declares that the above-described embodiments are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the present invention to the above examples. It should be noted that those skilled in the art can make several simple substitutions or deductions without departing from the concept of the present invention, and these all fall within the scope of protection of the present invention.

Claims

1. A method for rapidly preparing aluminum nitride nanowires using electrothermal shock, characterized in that, Includes the following steps: Step 1: After uniformly mixed aluminum alloy powder and chloride additive in a certain mass ratio, the mixture is dispersed in a solvent to form a suspension. Step 2: Apply a small amount of suspension to the carbon-based module and then dry it to remove excess moisture. Step 3: For the carbonaceous substrate module loaded with raw materials obtained in Step 2, electrothermal shock is performed in a nitrogen environment. The temperature of the electrothermal shock is 1800-2500℃ and the time is 0.1-1s, thereby realizing the nano-processing of the material. Step 4: While performing electrothermal shock in step 3, the product is collected in situ using a carbonaceous collector module. After the thermal shock process is completed, a layer of white product, namely aluminum nitride nanowires, is collected on the surface of the carbonaceous collector module.

2. The method for rapid preparation of aluminum nitride nanowires as described in claim 1, characterized in that: The aluminum alloy powder in step (1) has a particle size of 1~10μm.

3. The method for rapid preparation of aluminum nitride nanowires as described in claim 1, characterized in that: The chloride additive in step (1) is one or any combination of two or more of the following: ammonium chloride, aluminum chloride hexahydrate, ferric chloride, and potassium chloride, with a purity of analytical grade or higher.

4. The method for rapid preparation of aluminum nitride nanowires as described in claim 1, characterized in that: In step (1), the mass ratio of aluminum alloy powder to chloride additive is in the range of 1:5 to 5:

1.

5. The method for rapid preparation of aluminum nitride nanowires as described in claim 1, characterized in that: The solvent in step 1 is one or any combination of two or more of the following: carbon tetrachloride, benzene, acetone, ethanol, ethylene glycol ethyl ether, and liquid paraffin.

6. The method for rapid preparation of aluminum nitride nanowires as described in claim 1, characterized in that: The material of the carbon substrate module in step (2) is one of the following: carbon cloth, carbon felt, graphene sheet, or graphite plate.

7. The method for rapid preparation of aluminum nitride nanowires as described in claim 1, characterized in that: The material of the carbon collection module in step (4) is one of the following: carbon cloth, carbon felt, graphene sheet, or graphite plate.

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