A carbon-based composite material and its preparation method and application

Abstract

The present invention discloses a carbon-based composite material and its preparation method and application, which belong to the technical field of composite material preparation. The preparation of the carbon-based composite material includes: placing a carbon-based material and a reaction precursor in a reaction chamber; applying electricity to the carbon-based material, rapidly heating it to a high temperature and then keeping it warm for a period of time, and then rapidly cooling it; in the above process, the reaction precursor undergoes an in-situ chemical reaction on the surface of the carbon-based material to achieve the preparation of the carbon-based composite material. The in-situ high-temperature preparation method provided by the present invention has the characteristics of low energy consumption, high efficiency, safety and environmental protection; the reaction temperature is precise and highly controllable, and the equipment cost is low; at the same time, in the method of the present invention, since the injection of the reaction gas and the heating of the material to be treated are periodic, different gas sources can be combined to achieve the in-situ synthesis of the multi-component heterojunction coating composite material. The obtained carbon-based composite material has good high-temperature resistance and oxidation resistance and excellent electrochemical properties.

Description

Technical Field

[0001] The present invention belongs to the technical field of composite material preparation, and in particular relates to a carbon-based composite material and a preparation method and application thereof. Background Art

[0002] Carbon-based materials are widely used in aerospace, automobile manufacturing, energy catalysis and other fields due to their advantages such as light weight, high strength, good electrical conductivity and low thermal expansion coefficient. However, they begin to oxidize when the temperature exceeds 400°C in air, which greatly limits their application value. Based on reasonable structure and composition design, the heterogeneous composite of carbon-based materials and other functional materials (i.e., carbon-based composite materials) can be achieved through material composite technology. This is an effective strategy to improve the performance of carbon-based materials and is of great significance to expanding their application areas.

[0003] The synthesis methods of carbon-based composite materials include traditional furnace sintering methods (tubular and muffle furnaces, such as patent document CN109678133A) and microwave sintering methods (such as patent document CN101792331B). Among them, the traditional furnace sintering method uses an external heat source to heat the reaction chamber to a set temperature, induces the carbon-based material substrate in the cavity and the introduced reaction gas to undergo a chemical reaction to form a carbon-based composite material, which has the advantages of uniform and controllable temperature and low equipment cost. However, the traditional furnace sintering method has the disadvantages of slow heating and cooling rates (5-10°C / min), high temperature limitations (<1200°C), high energy consumption, and low efficiency. In contrast, the microwave sintering method utilizes the wave-absorbing properties of carbon-based materials and uses high-energy microwave irradiation to generate hot spots / arc plasma between carbon-based materials to heat the carbon-based materials as a whole to a high temperature and react with the reaction precursor; this method has the advantages of fast heating speed and high thermal efficiency. However, in the initial heating phase, the formation of ultra-high temperature hot spots or arc plasma results in uneven microscopic heat generation, resulting in localized hot spots that are detrimental to reaction uniformity. Furthermore, microwave heating equipment is complex and expensive, and poses the risk of ionizing radiation during operation. Therefore, finding a preparation method that combines low energy consumption, low cost, high efficiency, good temperature controllability, and safety and reliability to achieve the production of high-performance carbon-based composites has become an urgent issue to be addressed. Summary of the Invention

[0004] In view of the shortcomings of the existing technology, the purpose of the present invention is to provide a carbon-based composite material and its preparation method and application. The preparation method of the present invention can realize the controllable preparation of various carbon-based composite materials, which has the advantages of high efficiency, low cost, low energy consumption, strong temperature controllability, safety and environmental protection.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] In a first aspect, the present invention provides an in-situ high-temperature preparation method for carbon-based composite materials, comprising: placing a carbon-based material and a reaction precursor in a reaction chamber; applying electricity to the carbon-based material, rapidly heating it to a high temperature, keeping it warm for a period of time, and then rapidly cooling it; during the above process, the reaction precursor undergoes an in-situ chemical reaction on the surface of the carbon-based material to achieve the preparation of the carbon-based composite material.

[0007] As a preferred embodiment of the present invention, the carbon-based material is selected from one or more of carbon fiber, graphene, graphite, carbon nanotubes, carbon cloth, and carbonized wood. It is understood that the use of the above carbon-based materials is only exemplary, and the specific type can be flexibly selected according to the needs of use.

[0008] As a preferred embodiment of the technical solution of the present invention, the reaction precursor is one or more of a gas, liquid or solid precursor; the gas precursor is selected from one or more of methane, dichlorosilane, borane, nitrogen, and ammonia; the liquid precursor includes one or more of titanium tetrachloride and silicon tetrachloride; the solid precursor is selected from one or more of tellurium, selenium, SiO, TiO2, WO3, MoO3, and Cr2O3. Obviously, the types of reaction precursors mentioned above are only exemplary, and their specific types can be selected accordingly as needed; accordingly, the surface of the carbon-based material can be coated with a variety of materials such as silicon carbide, titanium carbide, tungsten carbide, molybdenum carbide, zirconium carbide, boron nitride, carbon nitride, etc., greatly enriching the types of carbon-based composite materials.

[0009] As a preferred embodiment of the technical solution of the present invention, the electric heating is direct heating by Joule heat, and constant current or constant pressure heating can be used; preferably, the electric voltage is 100V; the electric current is 5-30A.

[0010] As a preferred embodiment of the technical solution of the present invention, the heating rate of rapid heating is 100-10 5 ℃ / s.

[0011] As a preferred embodiment of the technical solution of the present invention, the temperature for rapid heating to a high temperature is 1500-3000° C. It is understandable that the above temperature can be a specific value among 1500° C., 1600° C., 1700° C., 1800° C., 1900° C., 2000° C., 2100° C., 2200° C., 2300° C., 2400° C., 2500° C., 2600° C., 2700° C., 2800° C., 2900° C., and 3000° C., or any value within the range of 1500-3000° C.

[0012] As a preferred embodiment of the technical solution of the present invention, the holding time is 10 ms to 5 min. It is understandable that the holding time can be a specific value of 10 ms, 20 ms, 50 ms, 100 ms, 500 ms, 1000 ms, 10 s, 30 s, 60 s, 90 s, 120 s, 150 s, 180 s, 210 s, 240 s, 270 s, 300 s, or any value within the range of 10 ms to 5 min.

[0013] As the preferred embodiment of the technical solution of the present invention, the cooling rate of rapid cooling is 100~10 5 ℃ / s.

[0014] As a preferred embodiment of the technical solution of the present invention, one or more electrical heating processes may be performed after the rapid cooling. That is, the process of "applying electrical current to the carbon-based material, rapidly heating it to a high temperature, then maintaining the temperature for a period of time, and then rapidly cooling it" may be repeated once or multiple times as needed, using a periodic pulse heating method.

[0015] As a preferred embodiment of the technical solution of the present invention, the rapid cooling method is one or more of natural cooling, air cooling, and water cooling.

[0016] In a second aspect, the present invention seeks to protect the carbon-based composite material prepared by the above method.

[0017] Thirdly, the present invention also seeks to protect the application of carbon-based composite materials in the fields of electrochemical catalysis, high-temperature catalysis, electrically driven high-temperature catalysis or high-temperature resistance and antioxidant.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] (1) The in-situ high-temperature preparation method provided by the present invention has the characteristics of low energy consumption, high efficiency, safety and environmental protection. In the method of the present invention, the high temperature is directly generated by the carbon-based material after the power is applied, and the high temperature is limited to the carbon-based material and the surrounding limited area; and the heating rate of the carbon-based material is fast, up to about 10 5 ℃ / s. This method precisely controls the spatial distribution of temperature and the rapid heating rate, reducing energy dissipation and overall energy consumption. Furthermore, the extremely high reaction temperature accelerates the reaction kinetics, significantly shortening the reaction time and improving reaction efficiency. Furthermore, the localized high temperature confines the chemical reaction to the surface of the material to be treated, preventing side reactions of the reaction gases in other areas of the reaction chamber. This not only avoids the large-scale deposition of toxic and harmful byproducts, but also improves the utilization efficiency of the reaction gases, facilitates the recycling of excess reaction gases, and reduces waste gas emissions.

[0020] (2) The in-situ high-temperature preparation method provided by the present invention has a precise and highly controllable reaction temperature. Utilizing the Joule heating principle, electric current is used to directly heat the carbon substrate. By programming the current waveform and precisely controlling the current magnitude, precise control of reaction parameters such as the heating rate, holding temperature, holding time, cooling rate, and number of pulses during the heating process can be achieved.

[0021] (3) The in-situ high-temperature preparation method provided by the present invention has the advantage of low equipment cost. The carbon-based material self-heating high-temperature induced in-situ reaction strategy integrates the heating, cooling, and reaction systems into one, which helps to simplify the equipment structure, reduce the equipment volume, and reduce the equipment weight, thereby significantly reducing the equipment cost.

[0022] (4) The in-situ high-temperature preparation method provided by the present invention enables in-situ synthesis of multi-component heterojunction coating composite materials. Because the injection of the reaction gas and the heating of the material to be treated are cyclical in the present method, different gas sources can be combined to achieve in-situ synthesis of multi-component heterojunction coating composite materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a microscopic morphology photograph of the silicon carbide-carbon fiber composite material of Example 1 of the present invention.

[0024] Figure 2 This is a microscopic morphology photograph of the silicon carbide-carbon fiber composite material of Example 2 of the present invention.

[0025] Figure 3 This is a microscopic morphology photograph of the silicon carbide-carbon fiber composite material of Example 3 of the present invention.

[0026] Figure 4 This is a photo of an oxygen combustion experiment of a carbon fiber composite material carbon cloth and a carbon fiber carbon cloth in Example 3 of the present invention.

[0027] Figure 5 This is a thermogravimetric test curve of the carbon fiber composite material and the carbon fiber in Example 3 of the present invention.

[0028] Figure 6 3 is the current-time curve of the oxygen evolution reaction of the carbon fiber composite material loaded with iridium (Ir) nanoparticles and the carbon fiber in Example 3 of the present invention. DETAILED DESCRIPTION

[0029] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0030] Unless otherwise specified, all commodities or reagents in this invention were purchased through market channels.

[0031] Example 1

[0032] A method for in-situ high-temperature preparation of carbon-based composite materials, the specific steps are as follows: fix a 5 cm long and 1 cm wide carbon cloth horizontally 1 mm above the silicon monoxide powder, and connect both ends of the carbon cloth to a constant current power supply in an argon atmosphere glove box. Set the power supply voltage to 100V and the current to 15A. After the power is turned on, the temperature of the carbon cloth rises rapidly to 1700°C within 150ms, and then cools naturally after keeping warm for 1s. In the above process, the evaporation of silicon monoxide is induced and its in-situ reaction with carbon fiber generates silicon carbide, realizing the coaxial coating of the ultra-thin silicon carbide layer. The micromorphology of the ultra-thin silicon carbide shell coated carbon fiber is as follows Figure 1 shown.

[0033] Example 2

[0034] A method for in-situ high-temperature preparation of carbon-based composite materials, the specific steps are as follows: fix a 5 cm long and 1 cm wide carbon cloth horizontally 1 mm above the silicon monoxide powder, and connect both ends of the carbon cloth to a constant current power supply in an argon atmosphere glove box. Set the power supply voltage to 100V and the current to 20A. After the power is turned on, the temperature of the carbon cloth rises rapidly to 2100°C within 250ms, and then cools naturally after keeping warm for 5s. In the above process, the evaporation of silicon monoxide is induced and its in-situ reaction with carbon fiber generates silicon carbide, achieving coaxial coating of a 100nm thick silicon carbide layer. The micromorphology of the silicon carbide shell coated carbon fiber is as follows Figure 2 shown.

[0035] Example 3

[0036] A method for in-situ high-temperature preparation of carbon-based composite materials, the specific steps are as follows: take a 5 cm long and 1 cm wide carbon cloth, fix it horizontally 1 mm above the silicon monoxide powder, and connect the two ends of the carbon cloth to a constant current power supply in a low-pressure reaction chamber. Set the power supply voltage to 100V and the current to 25A. After the power is turned on, the temperature of the carbon cloth rises rapidly to 2400°C within 300ms, and then cools naturally after keeping warm for 30s. In the above process, the evaporation of silicon monoxide is induced and its in-situ reaction with carbon fiber generates silicon carbide, realizing a composite structure of silicon carbide nanowires coated with carbon fiber. The morphology of the carbon fiber micro-composite material is as follows Figure 3 shown.

[0037] Example 4

[0038] A method for in-situ high-temperature preparation of a carbon-based composite material comprises the following steps: a 5-cm-long, 1-cm-wide carbon cloth is horizontally fixed 1 mm above silicon monoxide powder. A constant-current power supply is connected to both ends of the carbon cloth within a low-pressure reaction chamber. The power supply voltage is set to 100V and the current to 30A. Within 400ms of powering on, the carbon cloth temperature rapidly rises to 2200°C. The temperature is maintained for 60 seconds, followed by natural cooling, resulting in the carbon-based composite material.

[0039] Related performance tests:

[0040] (1) Resistance to high temperature oxidation. Compared with carbon fiber, the carbon fiber composite material of the present invention has excellent resistance to high temperature oxidation and strong acid (alkaline) corrosion. First, the results of the 900 ° C flame combustion test in air show that after burning for 30 seconds, the carbon fiber composite material carbon cloth has no obvious damage, while the carbon fiber carbon cloth has obvious defects (such as Figure 4 As shown). Further analysis by oxygen atmosphere thermogravimetric testing showed that the initial oxidation temperature of the carbon fiber composite material was about 360 degrees Celsius higher than that of the uncoated carbon fiber (as shown). Figure 5 It shows good resistance to high temperature oxidation.

[0041] (2) Electrochemical properties. The carbon fiber composite material of the present invention has the characteristic of large surface area and is an excellent catalyst carrier. The carbon fiber composite material of Example 2 of the present invention is impregnated with iridium trichloride ethanol solution and dried, and further heated to 1000°C and kept warm for 200ms to obtain a carbon fiber composite material (material A) loaded with precious metal iridium (Ir) nanoparticles. Compared with the carbon fiber material (material B) loaded with Ir nanoparticles by the same method, material A exhibits excellent electrochemical stability when applied to the electrochemical oxygen evolution reaction. A three-electrode electrolytic cell test system (platinum sheet as counter electrode, the above-mentioned carbon fiber as working electrode, calomel electrode as reference electrode, 1M KOH as electrolyte) is used, and the initial current density of materials A and B is set to 10mA / cm by the chronopotentiometry test method. 2 , we can get Figure 6 As shown in the figure, when the oxygen evolution performance decays by 20%, the service life of material A is 2.5 times that of material B.

[0042] While the present invention is illustrated by the aforementioned embodiments, the present invention is not limited to these embodiments, nor does it necessarily rely on these embodiments for implementation. Those skilled in the art will appreciate that any improvements to the present invention, equivalent replacements for individual raw materials in the present invention, additions of auxiliary ingredients, and selection of specific methods, etc., fall within the scope of protection and disclosure of the present invention.

Claims

1. A method for in-situ high-temperature preparation of a carbon-based composite material, characterized in that: include: A carbon-based material and a reaction precursor are placed in a reaction chamber; the carbon-based material is energized, rapidly heated to a high temperature, then kept warm for a period of time, and then rapidly cooled; during the above process, the reaction precursor undergoes an in-situ chemical reaction on the surface of the carbon-based material, thereby achieving the preparation of a carbon-based composite material; Wherein, the reaction precursor is a solid precursor, specifically SiO; The reaction precursor is carbon cloth, which is horizontally fixed 1 mm above the silicon monoxide powder.

2. The in-situ high-temperature preparation method of a carbon-based composite material according to claim 1, characterized in that: The heating rate of rapid heating is 100~10 5 ℃ / s; rapid heating to high temperature is 1500~3000℃.

3. The in-situ high-temperature preparation method of a carbon-based composite material according to claim 1, characterized in that: After rapid cooling, one or more power-on treatments can be performed.

4. The in-situ high-temperature preparation method of a carbon-based composite material according to claim 1, characterized in that: The holding time is 10ms~5min.

5. The in-situ high-temperature preparation method of a carbon-based composite material according to claim 1, characterized in that: The cooling rate of rapid cooling is 100~10 5 ℃ / s.

6. The in-situ high-temperature preparation method of a carbon-based composite material according to claim 5, characterized in that: The rapid cooling method is one or more of natural cooling, air cooling, and water cooling.

7. A carbon-based composite material prepared by the method according to any one of claims 1 to 6.

8. Application of the carbon-based composite material according to claim 7 in the fields of electrochemical catalysis, high-temperature catalysis, electrically driven high-temperature catalysis or high-temperature resistance and antioxidant.

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