A method for coating two-dimensional materials on the surface of non-metallic particles based on a high-temperature growth process

Abstract

This invention relates to the preparation technology of two-dimensional material composites, specifically a method for coating two-dimensional materials onto the surface of non-metallic particles based on a high-temperature growth process. This method is suitable for the large-scale preparation of continuously coated non-metallic particulate materials. The invention employs a three-step method to form continuously coated two-dimensional materials on the surface of non-metallic particles: First, a continuous metal catalyst coating layer with a nanometer-thickness is formed on the surface of the non-metallic particles; then, the coated non-metallic particles are mixed with micron-sized powder of the same metal catalyst composition; next, a continuously coated two-dimensional material film is grown on the surface of the non-metallic particles using a high-temperature catalytic reaction; finally, the metal catalyst is removed, yielding the two-dimensional coated non-metallic particulate material. This invention can achieve the formation of two-dimensional material coating layers on the surface of a large number of non-metallic particles. The two-dimensional materials exhibit continuous, non-overlapping microstructures, high coating rates, and high crystallinity. Furthermore, this method is easily scalable.

Description

Technical Field

[0001] This invention relates to the preparation technology of two-dimensional material composites, 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 the mass production of non-metallic particle materials with continuous two-dimensional material coating. Background Technology

[0002] Developing controllable methods for preparing high-quality two-dimensional (2D) composite materials is fundamental to realizing the applications of 2D materials. Among these methods, high-temperature metal-catalyzed growth offers significant advantages, including high-quality 2D materials with continuous microstructures. However, this method faces several challenges in growing 2D materials on non-metallic particle surfaces. The most prominent issue is the discontinuous metal coating caused by dewetting of the metal catalyst on the non-metallic particle surface at high temperatures, resulting in a discontinuous structure and low coating efficiency in the metal-catalyzed 2D material. To fundamentally solve this problem, it is necessary to develop methods that maintain continuous coating and sufficient uniform contact between the metal catalyst and the non-metallic particles at high temperatures, and these methods should be easily scalable. Achieving large-scale preparation of high-quality, continuously coated 2D non-metallic particle materials would significantly promote the application of 2D composite materials in fields such as thermal management, energy, and transportation. Summary of the Invention

[0003] The purpose of this 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 achieve the mass production of high-quality non-metallic particle materials continuously coated with two-dimensional materials.

[0004] The technical solution of this invention is:

[0005] A method for coating two-dimensional materials onto the surface of non-metallic particles based on a high-temperature growth process is disclosed. The method employs a three-step process to form a continuously coated two-dimensional material on the surface of non-metallic particles. 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. Then, the coated non-metallic particles are mixed with micron-sized powder of the same metal catalyst. Next, a continuous two-dimensional material film is grown on the surface of the non-metallic particles using a high-temperature catalytic reaction. Finally, the metal catalyst is removed to obtain non-metallic particle material coated with 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 nanometer-thickness is formed on the surface of the non-metallic particles. Then, the precursor is infiltrated into the metal catalyst coating layer by low-temperature heating. Next, the coated non-metallic particles are mixed with micron-sized powder of the same metal catalyst, and a continuous two-dimensional material film is grown on the surface of the non-metallic particles by high-temperature catalytic reaction. Finally, the metal catalyst is removed to obtain non-metallic particle material coated with two-dimensional material.

[0008] The method for coating two-dimensional materials on the surface of non-metallic particles based on a high-temperature growth process is applicable to two-dimensional materials grown by means of high-temperature metal catalytic reaction. 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] The method for coating two-dimensional materials on the surface of non-metallic particles based on a high-temperature growth process, wherein the morphology of the non-metallic particles includes, but is not limited to, granular, sheet-like, fibrous, or porous structures.

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

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

[0012] The method for coating two-dimensional materials on the surface of non-metallic particles based on a high-temperature growth process includes, but is not limited to, mixing non-metallic particles coated with metal catalysts with catalyst powder of the same composition; the typical mixing volume ratio is 1:1 to 1:3.

[0013] The method for coating two-dimensional materials on the surface of non-metallic particles based on a high-temperature growth process, wherein the particle size of the non-metallic particles is larger than the particle size of the catalyst powder mixed with them.

[0014] The method for coating two-dimensional materials on the surface of non-metallic particles based on a high-temperature growth process typically involves a low-temperature heating temperature of 300–600°C and a high-temperature heating temperature of 800–1200°C.

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

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

[0017] The design concept of this invention is:

[0018] This invention employs 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; then, the non-metallic particles are mixed with a catalyst powder of the same composition. Next, a continuously coated two-dimensional material film is grown on the surface of the non-metallic particles using a high-temperature catalytic reaction. Finally, the metal catalyst is removed to obtain the two-dimensional coated non-metallic particle material. For non-metallic particles not containing a two-dimensional material precursor: First, a continuous metal catalyst coating layer is formed on the surface of the non-metallic particles; then, the precursor is infiltrated into the metal catalyst layer through low-temperature heating. Next, the non-metallic particles are mixed with a catalyst powder of the same composition, and a continuously coated two-dimensional material film is grown on the surface of the non-metallic particles using a high-temperature catalytic reaction. Finally, the metal catalyst is removed to obtain the two-dimensional coated non-metallic particle material. In the above process, two methods are combined: metal catalyst coating and direct mixing of metal catalyst powder. 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. 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 this invention are:

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

[0021] 2. This invention can avoid the problem of discontinuous metal catalyst coating caused by high temperature dewetting, and the prepared two-dimensional material has the characteristics of continuous microstructure and high coating rate. Attached Figure Description

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

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

[0024] Figure 3 This is a morphology diagram of the multilayer graphene-coated silicon oxide particles obtained in Example 3. Detailed Implementation

[0025] In its specific implementation, this invention employs 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; then, the non-metallic particles are mixed with a catalyst powder of the same composition (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); next, a continuously coated two-dimensional material film is grown on the surface of the non-metallic particles using a high-temperature catalytic reaction; finally, the metal catalyst is removed to obtain the two-dimensional material-coated non-metallic particle material. In this invention, "a large number of non-metallic particles" means that the amount of non-metallic particles used in a single application reaches hundreds of grams or more.

[0026] The present invention will be further described in detail below through embodiments.

[0027] Example 1

[0028] In this embodiment, diamond particles coated with multilayer graphene are prepared.

[0029] First, nickel is electroless plated onto the surface of diamond particles (200 mesh, 100 grams). The process is as follows:

[0030] (1) Degreasing: Boil the diamond particles in a 10wt% NaOH aqueous solution for 30 minutes and rinse them three times with distilled water to remove grease and other contaminants from the diamond surface.

[0031] (2) Roughening: Boil in 1M dilute nitric acid for 20 minutes and wash with distilled water 3 times.

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

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

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

[0035] (6) Chemical plating: Stir the plating solution (Ni2SO4·6H2O 30g / L, NaH2PO4·2H2O 30g / L, water balance, temperature 88℃) ultrasonically for 30 seconds to complete the nickel plating. The thickness of the nickel plating layer is 100nm.

[0036] Then, nickel-plated diamond particles and nickel powder (average particle size 20 μm) were 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 under an argon atmosphere (flow rate 500 sccm) for 10 minutes to transform the diamond surface into multilayered graphene. Finally, the sample, cooled to room temperature, was immersed in an aqueous solution of nitric acid (2 M molar concentration) for 12 hours to dissolve and remove the nickel catalyst. After washing and drying, graphene-coated diamond particles (average 3–9 layers in this example) were obtained, see [link to relevant documentation]. 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 alumina particles are prepared, which differs from Example 1 in that:

[0039] First, nickel-plated alumina particles (300 mesh) with a thickness of 200 nm were placed in a horizontal tube furnace for nitriding and boronizing. Approximately 100 mg of solid boric acid was placed upstream of the quartz tube in the furnace. The inner cavity of the quartz tube was evacuated and then filled with argon gas, maintaining an internal pressure of approximately 20 Torr. The tube furnace was heated to 600 °C, and the solid boric acid precursor was heated to 300 °C. Simultaneously, the argon gas flow rate was adjusted to 250 sccm, and 50 sccm of ammonia gas was introduced to nitrid and boronize the nickel-plated alumina particles. After 10 minutes, the sample was removed for rapid cooling. Then, the cooled sample was mixed with nickel powder (average particle size of 5 μm) at 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. Heating was performed at 1000°C under 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 (1 M molar concentration) for 8 hours to dissolve and remove the nickel catalyst. After washing and drying, diamond particles coated with multilayer boron nitride (3–10 layers on average in this example) were obtained. See [link to relevant documentation]. Figure 2 .Depend on Figure 2 It can be seen that boron nitride forms a continuous coating layer on the surface of alumina particles.

[0040] Example 3

[0041] In this embodiment, the preparation of multilayer graphene-coated silicon oxide particles differs from that in Example 1 in that:

[0042] First, nickel-plated (200 nm thick) silicon oxide particles (300 mesh) were carburized in a horizontal tube furnace. The tube furnace was heated to 600 °C, and 400 sccm of argon, 100 sccm of hydrogen, and 1 sccm of ethylene were simultaneously introduced to carburize the nickel-plated silicon oxide particles. After 30 minutes, the tube furnace was turned off and allowed to cool naturally. Then, the cooled sample was mixed with nickel powder (average particle size 5 μm) at 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. It was heated at 1000 °C in a hydrogen atmosphere (flow rate 500 sccm) for 10 minutes, and then the sample was quickly removed from the heating zone to cool down, forming multilayer graphene on the surface of the silicon oxide particles through a carbon deposition process. Finally, the sample, cooled to room temperature, was immersed in an aqueous solution of ferric chloride (1 M molar concentration) for 8 hours to dissolve and remove the nickel catalyst. After washing and drying, multilayer graphene-coated silica particles (3-10 layers on average in this example) were obtained. 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 examples show that the three-step method of the present invention can grow two-dimensional materials on a large scale on the surface of a large number of non-metallic particles. By combining the two methods of metal catalyst coating and metal catalyst powder mixing, a coating layer of two-dimensional materials can be grown on the surface of a large number of non-metallic particles. The prepared two-dimensional materials have the characteristics of high crystal quality. This method can avoid the problem of discontinuity of nanoscale metal catalyst coating layer caused by high temperature dewetting. The prepared two-dimensional materials have the characteristics of continuous microstructure and high coating rate. Moreover, this method is easy to scale up.

Claims

1. A method for coating two-dimensional materials onto the surface of non-metallic particles based on a high-temperature growth process, characterized in that, A three-step method was used to form a continuous two-dimensional coating 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. Then, the coated non-metallic particles are mixed with micron-sized powder of the same metal catalyst by stirring or ball milling. Next, a continuous two-dimensional material film is grown on the surface of the non-metallic particles by high-temperature catalytic reaction. Finally, the metal catalyst is removed by chemical etching to obtain non-metallic particle material coated with two-dimensional material. For non-metallic particles that do not contain 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. Then, the precursor is infiltrated into the metal catalyst coating layer by low-temperature heating. Next, the coated non-metallic particles are mixed with micron-sized powder of the same metal catalyst by stirring or ball milling. A continuous two-dimensional material film is grown on the surface of the non-metallic particles by high-temperature catalytic reaction. Finally, the metal catalyst is removed by chemical etching to obtain non-metallic particle materials coated with two-dimensional materials. The metal catalyst coating has a thickness of 50 nm to 200 nm, the metal catalyst has a micron-sized powder particle size of 5 μm to 50 μm, the non-metallic particles have a particle size range of 4 to 400 mesh, and the particle size of the non-metallic particles is larger than the micron-sized powder particle size of the metal catalyst mixed with them; the low-temperature heating temperature is 300 to 600 °C, and the high-temperature catalysis temperature is 800 to 1200 °C.

2. The method for coating two-dimensional materials onto the surface of non-metallic particles based on a high-temperature growth process according to claim 1, characterized in that, This method is applicable to two-dimensional materials grown by means of high-temperature metal catalytic reaction, such as graphene, two-dimensional boron nitride, two-dimensional transition metal chalcogenides, silylene, or phosphorene.

3. The method for coating two-dimensional materials onto the surface of non-metallic particles based on a high-temperature growth process according to claim 1, characterized in that, Non-metallic particles can be granular, flaky, fibrous, or porous.

4. The method for coating two-dimensional materials onto the surface of non-metallic particles based on a high-temperature growth process according to claim 1, characterized in that, The non-metallic particles are composed of silicon, silicon oxide, aluminum oxide, silicon nitride, boron nitride, diamond, silicon carbide, silicates or composite materials thereof.

5. The method for coating two-dimensional materials onto the surface of non-metallic particles based on a high-temperature growth process according to claim 1, characterized in that, The method for forming a continuous metal catalyst coating layer on the surface of non-metallic particles is chemical plating, electrochemical plating, or physical vapor deposition. The metal catalyst is composed of iron, cobalt, nickel, copper, platinum, gold, or alloys thereof.

6. The method for coating two-dimensional materials onto the surface of non-metallic particles based on a high-temperature growth process according to claim 1, characterized in that, The volume ratio of non-metallic particles coated with metal catalyst to catalyst powder of the same composition is 1:1 to 1:

3.

7. The method for coating two-dimensional materials onto the surface of non-metallic particles based on a high-temperature growth process according to claim 1, characterized in that, The atmosphere used in low-temperature heating and high-temperature catalytic processes is a reducing, inert, or weakly oxidizing atmosphere.

8. The method for coating two-dimensional materials onto the surface of non-metallic particles based on a high-temperature growth process according to claim 1, characterized in that, The etching agent used in chemical etching is an aqueous solution of one or more of ferric chloride, copper chloride, hydrochloric acid, nitric acid, and hydrogen peroxide, or a mixture of two or more of them.

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