Method for coating two-dimensional material on surfaces of nonmetal particles based on high-temperature growth process

Abstract

The invention relates to a preparation technology of a two-dimensional composite material, in particular to a method for coating a two-dimensional material on the surface of a non-metal particle based on a high-temperature growth process, which is suitable for preparing a large number of non-metal particle materials continuously coated with the two-dimensional material. A continuously coated two-dimensional material is formed on the surfaces of non-metal particles by adopting a three-step method: firstly, a continuous metal catalyst coating layer with nanoscale thickness is formed on the surfaces of the non-metal particles, and then the coated non-metal particles are mixed with micron-sized powder of a metal catalyst with the same component; secondly, growing a continuously coated two-dimensional material film on the surfaces of the non-metal particles by adopting a high-temperature catalytic reaction; and finally, removing the metal catalyst to obtain the nonmetal particle material coated with the two-dimensional material. According to the method, a two-dimensional material coating layer can be formed on the surfaces of a large number of non-metal particles, and the two-dimensional material has the characteristics of continuous microstructure, no lap joint, high coating rate and high crystallization quality; in addition, the method is easy to realize large-scale amplification.

Description

Technical Field

[0001] The present invention relates to a preparation technology of two-dimensional material composite materials, specifically a method for coating two-dimensional materials on the surface of non-metallic particles based on a high-temperature growth process, which is suitable for mass preparation of non-metallic particle materials continuously coated with two-dimensional materials. Background Art

[0002] The development of controllable preparation methods for high-quality two-dimensional material composites is the basis for realizing the application of two-dimensional materials. Among them, the preparation method based on high-temperature metal catalytic growth process has outstanding advantages such as high quality of the obtained two-dimensional materials and continuous microstructure. However, the use of this method to grow two-dimensional materials on the surface of non-metallic particles faces a series of difficulties. Among them, the most prominent problem is that the dewetting of metal catalysts on the surface of non-metallic particles at high temperatures causes the metal coating layer to be discontinuous, which leads to the discontinuous structure and low coverage of the two-dimensional materials grown by metal catalysis. In order to fundamentally solve this problem, it is necessary to develop a method to keep the metal catalyst on the surface of non-metallic particles continuously coated with metal catalysts at high temperatures and in sufficient and uniform contact with the non-metallic particles, and the method needs to be easy to scale up. If it is possible to prepare a large number of non-metallic granular materials with continuous coating of high-quality two-dimensional materials, it will strongly promote the application of two-dimensional material composites in thermal management, energy, transportation and other fields. Summary of the invention

[0003] The purpose of the present invention is to provide a method for coating two-dimensional materials on the surface of non-metallic particles based on a high-temperature growth process. This method can realize the large-scale preparation of non-metallic particle materials continuously coated with high-quality two-dimensional materials.

[0004] The technical solution of the present invention is:

[0005] A method for coating a two-dimensional material on the surface of a non-metallic particle based on a high temperature growth process, using a three-step method to form a continuously coated two-dimensional material on the surface of a non-metallic particle, the specific process is as follows:

[0006] For non-metallic particles containing two-dimensional material precursors: first, a continuous metal catalyst coating layer with a nanometer thickness is formed on the surface of the non-metallic particles, and then the coated non-metallic particles are mixed with micrometer-sized powders of metal catalysts of the same composition; then, a continuous two-dimensional material film is grown on the surface of the non-metallic particles by a high-temperature catalytic reaction; finally, the metal catalyst is removed to obtain a non-metallic particle material coated with a two-dimensional material;

[0007] For non-metallic particles that do not contain two-dimensional material precursors: first, a continuous metal catalyst coating layer with a thickness of nanometers is formed on the surface of the non-metallic particles, and then the precursor is infiltrated into the metal catalyst coating layer by low-temperature heating; then, the coated non-metallic particles are mixed with micron-sized powders of metal catalysts of the same composition, and a high-temperature catalytic reaction is used to grow a continuously coated two-dimensional material film on the surface of the non-metallic particles; finally, the metal catalyst is removed to obtain a non-metallic particle material coated with a two-dimensional material.

[0008] The method of coating two-dimensional materials on the surface of non-metallic particles based on a high-temperature growth process is suitable for two-dimensional materials grown by means of high-temperature metal catalytic reactions. The types of two-dimensional materials include but are not limited to graphene, two-dimensional boron nitride, two-dimensional transition metal chalcogenides, silicene or phosphorene.

[0009] In the method of coating the two-dimensional material on the surface of non-metallic particles based on a high-temperature growth process, the morphology of the non-metallic particles includes but is not limited to granular, flaky, fibrous or porous structures.

[0010] The method of coating two-dimensional materials on the surface of non-metallic particles based on a high-temperature growth process, the components of the non-metallic particles include but are not limited to silicon, silicon oxide, aluminum oxide, silicon nitride, boron nitride, diamond, silicon carbide, silicate or their composite materials, and the typical particle size range of the non-metallic particles is 4 to 400 mesh.

[0011] The method of coating two-dimensional materials on the surface of non-metallic particles based on a high-temperature growth process, the method of forming a continuous metal catalyst coating layer on the surface of non-metallic particles includes but is not limited to chemical plating, electrochemical plating or physical vapor deposition, the components of the metal catalyst include but are not limited to iron, cobalt, nickel, copper, platinum, gold or their alloys, the typical metal catalyst coating layer thickness is 50nm to 200nm, and the typical metal catalyst particle size is 5μm to 50μm.

[0012] The method of coating two-dimensional materials on the surface of non-metallic particles based on a high-temperature growth process, and the method of mixing non-metallic particles coated with metal catalysts with catalyst powders of the same component include but are not limited to stirring or ball milling; the typical mixing volume ratio is 1:1 to 1:3.

[0013] In the method of coating the two-dimensional material on the surface of non-metallic particles based on a high-temperature growth process, the particle size of the non-metallic particles is larger than the particle size of the catalyst powder mixed therewith.

[0014] The method of coating the two-dimensional material on the surface of non-metallic particles based on a high-temperature growth process has a typical low-temperature heating temperature of 300 to 600°C and a typical high-temperature heating temperature of 800 to 1200°C.

[0015] In the method for coating two-dimensional materials on the surface of non-metallic particles based on a high-temperature growth process, the atmosphere during the low-temperature and high-temperature heating processes is a reducing, inert or weakly oxidizing atmosphere.

[0016] The method of coating two-dimensional materials on the surface of non-metallic particles based on a high-temperature growth process uses chemical etching to remove metal catalysts. Typical etchants include but are not limited to aqueous solutions of one of ferric chloride, cupric chloride, hydrochloric acid, nitric acid, and hydrogen peroxide, or a mixture of two or more.

[0017] The design concept of the present invention is:

[0018] The present invention uses a three-step process to form a continuously coated two-dimensional material on the surface of non-metallic particles. For non-metallic particles containing a two-dimensional material precursor: first, a continuous metal catalyst coating layer is formed on the surface of the non-metallic particles, and then the non-metallic particles are mixed with a powder of a catalyst of the same component; then, a high-temperature catalytic reaction is used to grow a continuously coated two-dimensional material film on the surface of the non-metallic particles; finally, the metal catalyst is removed to obtain a non-metallic particle material coated with the two-dimensional material. For non-metallic particles that do not contain a two-dimensional material precursor: first, a continuous metal catalyst coating layer is formed on the surface of the non-metallic particles, and then the precursor is infiltrated into the metal catalyst layer by low-temperature heating; then, the non-metallic particles are mixed with a powder of a catalyst of the same component, and a high-temperature catalytic reaction is used to grow a continuously coated two-dimensional material film on the surface of the non-metallic particles; finally, the metal catalyst is removed to obtain a non-metallic particle material coated with the two-dimensional material. In the above process, the two methods of metal catalyst coating and direct mixing of metal catalyst powder are combined: forming a continuous metal catalyst coating layer on the surface of non-metallic particles ensures sufficient and continuous contact between the metal catalyst and the surface of non-metallic particles, while mixing non-metallic particles with metal powder can avoid the problem of discontinuity of the metal coating layer caused by dewetting at high temperature.

[0019] The advantages and beneficial effects of the present invention are:

[0020] 1. The present invention utilizes a metal catalytic reaction at high temperature to form a two-dimensional material on the surface of non-metallic particles. The prepared two-dimensional material has the characteristic of high crystal quality.

[0021] 2. The present invention can avoid the problem of discontinuity of the metal catalyst coating layer caused by high-temperature dewetting, and the prepared two-dimensional material has the characteristics of continuous microstructure and high coverage. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a morphology image of the multi-layer graphene-coated diamond particles obtained in Example 1.

[0023] Figure 2This is the morphology of the multilayer boron nitride-coated aluminum oxide particles obtained in Example 2.

[0024] Figure 3 This is the morphology of the multilayer graphene-coated silicon oxide particles obtained in Example 3. DETAILED DESCRIPTION

[0025] In the specific implementation process, the present invention adopts a three-step method to form a continuously coated two-dimensional material on the surface of non-metallic particles: first, a continuous metal catalyst coating layer is formed on the surface of the non-metallic particles, and then the non-metallic particles are mixed with the powder of the catalyst of the same component (for non-metallic particles that do not contain a two-dimensional material precursor, the precursor is infiltrated into the metal catalyst layer by low-temperature heating before mixing); then, a high-temperature catalytic reaction is used to grow a continuously coated two-dimensional material film on the surface of the non-metallic particles; finally, the metal catalyst is removed to obtain a non-metallic particle material coated with a two-dimensional material. In the present invention, a large amount of non-metallic particles means that the amount of non-metallic particles used in a single time reaches more than 100 grams.

[0026] Below, the present invention is further described in detail by examples.

[0027] Example 1

[0028] In this embodiment, multi-layer graphene-coated diamond particles are prepared.

[0029] First, nickel is plated on the surface of diamond particles (200 mesh, weight 100 grams) by chemical plating. The process flow is as follows:

[0030] (1) Degreasing: The diamond particles were boiled in a 10 wt% NaOH aqueous solution for 30 minutes and rinsed with distilled water for 3 times to remove grease and other dirt on the diamond surface.

[0031] (2) Roughening: Boil in 1 M dilute nitric acid for 20 minutes and wash three times with distilled water.

[0032] (3) Sensitization: Soak in sensitizing solution (SnCl2 10 g / L, HCl 20 mL / L, balance water) for 4 minutes, take out and rinse with water until neutral.

[0033] (4) Activation: Soak in activation solution (PdCl2 0.5 g / L, HCl 10 mL / L, balance water) for 4 minutes, take out and rinse with water.

[0034] (5) Reduction: Soak in a 30 g / L NaH2PO4 aqueous solution at room temperature for 3 minutes.

[0035] (6) Chemical plating: Nickel plating was completed by ultrasonic stirring in a plating solution (Ni2SO4·6H2O 30 g / L, NaH2PO4·2H2O 30 g / L, balance water, temperature 88°C) for 30 seconds. The thickness of the nickel plating layer was 100 nm.

[0036] Then, the nickel-plated diamond particles and nickel powder (average particle size of 20 μm) were stirred and mixed at a volume ratio of 1:2 for 30 minutes to obtain a mixed powder. The mixed powder was placed in a horizontal tube furnace to grow graphene, and heated at 850°C in an argon atmosphere (flow rate of 500 sccm) for 10 minutes to convert the diamond surface into multilayer graphene. Finally, the sample cooled to room temperature was immersed in an aqueous solution of nitric acid (molar concentration of 2M) for 12 hours to dissolve and remove the nickel catalyst. After washing and drying, diamond particles coated with graphene (an average of 3 to 9 layers in this embodiment) were obtained. Figure 1 .Depend on Figure 1 It can be seen that graphene forms a continuous coating layer on the surface of diamond particles.

[0037] Example 2

[0038] In this embodiment, multilayer boron nitride-coated aluminum oxide particles are prepared, which is different from that in Example 1 in that:

[0039] First, nickel-plated (thickness 200nm) alumina particles (300 mesh) were placed in a horizontal tube furnace for nitriding and boriding. About 100mg of solid boric acid was placed upstream of the quartz tube of the tube furnace, and the inner cavity of the quartz tube was evacuated to vacuum and filled with argon to keep the internal pressure of the quartz tube at about 20Torr. The tube furnace was heated to 600℃, the solid boric acid precursor was heated to 300℃, and the argon flow rate was adjusted to 250sccm and 50sccm of ammonia was introduced. The nickel-plated alumina particles were nitrided and borided. After 10 minutes, the sample was pushed out to achieve rapid cooling. Then, the cooled sample was stirred and mixed with nickel powder (average particle size 5μm) in a volume ratio of 1:1 for 30 minutes to obtain a mixed powder. The mixed powder was then placed in a horizontal tube furnace to grow boron nitride, and heated at 1000°C in an argon atmosphere (flow rate 500 sccm) for 10 minutes to form multilayer boron nitride on the surface of the alumina particles. Finally, the sample cooled to room temperature was immersed in an aqueous solution of ferric chloride (molar concentration 1M) for 8 hours to dissolve and remove the nickel catalyst, and after washing and drying, diamond particles coated with multilayer boron nitride (3 to 10 layers on average in this embodiment) were obtained. Figure 2 .Depend on Figure 2 It can be seen that boron nitride forms a continuous coating layer on the surface of the aluminum oxide particles.

[0040] Example 3

[0041] In this embodiment, multi-layer graphene-coated silicon oxide particles are prepared, which is different from that in Embodiment 1 in that:

[0042] First, the nickel-plated (thickness of 200nm) silicon oxide particles (300 mesh) were placed in a horizontal tube furnace for carburization. The tube furnace was heated to 600°C, and 400sccm of argon, 100sccm of hydrogen and 1sccm of ethylene were introduced at the same time to carburize the nickel-plated silicon oxide particles. After 30 minutes, the tube furnace was closed and cooled naturally. Then, the cooled sample was stirred and mixed with nickel powder (average particle size of 5μm) in a volume ratio of 1:1 for 30 minutes to obtain a mixed powder. The mixed powder was then placed in a horizontal tube furnace to grow graphene, heated at 1000°C and hydrogen atmosphere (flow rate 500sccm) for 10 minutes, and then the sample was quickly pushed out of the heating zone to cool down, and multilayer graphene was formed on the surface of the silicon oxide particles by the carbon deposition process. Finally, the sample cooled to room temperature was immersed in an aqueous solution of ferric chloride (molar concentration 1M) for 8 hours to dissolve and remove the nickel catalyst, and then washed and dried to obtain silicon oxide particles coated with multilayer graphene (3 to 10 layers on average in this embodiment). Figure 3 .Depend on Figure 3 It can be seen that graphene forms a continuous coating layer on the surface of silicon oxide particles.

[0043] The results of the embodiments show that the three-step method used in the present invention can be used to grow two-dimensional materials on a large scale on the surfaces of a large number of non-metallic particles. By combining the two methods of metal catalyst coating and metal catalyst powder mixing, it is possible to grow a coating layer of two-dimensional materials on the surfaces of a large number of non-metallic particles. The prepared two-dimensional materials have the characteristics of high crystallization quality. This method can avoid the problem of discontinuity of the nanoscale metal catalyst coating layer caused by high-temperature dewetting. The prepared two-dimensional materials have the characteristics of continuous microstructure and high coverage rate, and the method is easy to scale up.

Claims

1. A method for coating a two-dimensional material on the surface of a non-metallic particle based on a high temperature growth process, characterized in that: A three-step method is used to form a continuously coated two-dimensional material on the surface of non-metallic particles. The specific process is as follows: For non-metallic particles containing two-dimensional material precursors: first, a continuous metal catalyst coating layer with a nanometer thickness is formed on the surface of the non-metallic particles, and then the coated non-metallic particles are mixed with micrometer-sized powders of metal catalysts of the same composition; then, a continuous two-dimensional material film is grown on the surface of the non-metallic particles by a high-temperature catalytic reaction; finally, the metal catalyst is removed to obtain a non-metallic particle material coated with a two-dimensional material; For non-metallic particles that do not contain two-dimensional material precursors: first, a continuous metal catalyst coating layer with a thickness of nanometers is formed on the surface of the non-metallic particles, and then the precursor is infiltrated into the metal catalyst coating layer by low-temperature heating; then, the coated non-metallic particles are mixed with micron-sized powders of metal catalysts of the same composition, and a high-temperature catalytic reaction is used to grow a continuously coated two-dimensional material film on the surface of the non-metallic particles; finally, the metal catalyst is removed to obtain a non-metallic particle material coated with a two-dimensional material.

2. The method for coating a two-dimensional material on the surface of a non-metallic particle based on a high temperature growth process according to claim 1, characterized in that: This method is applicable to two-dimensional materials grown by high-temperature metal catalytic reactions, and the types of two-dimensional materials include but are not limited to graphene, two-dimensional boron nitride, two-dimensional transition metal chalcogenides, silicene or phosphorene.

3. The method for coating a two-dimensional material on the surface of a non-metallic particle based on a high temperature growth process according to claim 1, characterized in that: The morphology of the non-metallic particles includes but is not limited to granular, flake, fibrous or porous structures.

4. The method for coating a two-dimensional material on the surface of a non-metallic particle based on a high temperature growth process according to claim 1, characterized in that: The components of the non-metallic particles include but are not limited to silicon, silicon oxide, aluminum oxide, silicon nitride, boron nitride, diamond, silicon carbide, silicate or composite materials thereof. The typical particle size range of the non-metallic particles is 4 to 400 meshes.

5. The method for coating a two-dimensional material on the surface of a non-metallic particle based on a high temperature growth process according to claim 1, characterized in that: Methods for forming a continuous metal catalyst coating layer on the surface of non-metallic particles include but are not limited to chemical plating, electrochemical plating or physical vapor deposition. The components of the metal catalyst include but are not limited to iron, cobalt, nickel, copper, platinum, gold or their alloys. The typical thickness of the metal catalyst coating layer is 50nm to 200nm, and the typical particle size of the metal catalyst is 5μm to 50μm.

6. The method for coating a two-dimensional material on the surface of a non-metallic particle based on a high temperature growth process according to claim 1, characterized in that: Methods for mixing the non-metallic particles coated with the metal catalyst with the catalyst powder of the same composition include but are not limited to stirring or ball milling; the typical mixing volume ratio is 1:1 to 1:

3.

7. The method for coating a two-dimensional material on the surface of a non-metallic particle based on a high temperature growth process according to claim 1, characterized in that: The particle size of the non-metallic particles is larger than the particle size of the catalyst powder mixed therewith.

8. The method for coating a two-dimensional material on the surface of a non-metallic particle based on a high temperature growth process according to claim 1, characterized in that: The typical temperature for low temperature heating is 300-600°C, and the typical temperature for high temperature heating is 800-1200°C.

9. The method for coating a two-dimensional material on the surface of a non-metallic particle based on a high temperature growth process according to claim 1, characterized in that: The atmosphere during the low-temperature and high-temperature heating process is a reducing, inert or weakly oxidizing atmosphere.

10. The method for coating a two-dimensional material on the surface of a non-metallic particle based on a high temperature growth process according to claim 1, characterized in that: The metal catalyst is removed by chemical etching, and typical etchants include but are not limited to an aqueous solution of one of ferric chloride, cupric chloride, hydrochloric acid, nitric acid, and hydrogen peroxide, or a mixture of two or more thereof.

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