Method for preparing carbon nanomaterial / cellulose composite material in bridge manner

Abstract

The invention discloses a method for preparing a carbon nanomaterial / cellulose composite material in a'bridge 'mode, and belongs to the field of carbon nanomaterial / cellulose composite materials. According to the invention, a polypeptide nanofiber'bridge 'material is synthesized; cellulose surface modification; magnetically stirring, mixing and reacting the synthesized amphiphilic polypeptide nanofiber'bridge 'material, surface-modified cellulose and a carbon nanomaterial at room temperature, and drying a precipitate obtained by centrifugation at room temperature to prepare the carbon nanomaterial / cellulose composite material. According to the method for preparing the carbon nanomaterial / cellulose composite material in a'bridge 'mode, amphiphilic polypeptide molecules or polypeptide nanofibers are introduced to serve as a'bridge' for combining the carbon nanomaterial and cellulose, firm connection is formed between the carbon nanomaterial and the cellulose, combination of the carbon nanomaterial and the cellulose is effectively promoted, the method is simple and easy to implement, and the method is suitable for industrial production. And more excellent stability and mechanical properties can be obtained.

Description

Technical Field

[0001] The present invention belongs to the field of carbon nanomaterial / cellulose composite materials, and particularly relates to a "bridge" method for preparing a carbon nanomaterial / cellulose composite material. Background Art

[0002] High-performance carbon nanomaterial / cellulose composites have broad applications across various fields and are of great significance to the development of energy, environment, medicine, and materials science. For example, in the energy sector, carbon nanomaterial / cellulose composites can be used in lithium-ion batteries, solar cells, and supercapacitors. In environmental protection, carbon nanomaterial / cellulose composites can be used for sewage treatment, heavy metal adsorption, and soil remediation. In healthcare, carbon nanomaterial / cellulose composites can also be used in medical applications such as medical imaging, drug delivery systems, and biosensors.

[0003] Cellulose is commonly used as a bio-based matrix for composite materials, enhancing their biodegradability and sustainability. Carbon nanomaterials are primarily used as reinforcing agents to improve the mechanical and electrical properties of composite materials. However, due to differences in the physical and chemical properties of carbon nanomaterials and cellulose, the bonding between them is often unstable. The reasons for this are: first, the high surface and chemical activity of carbon nanomaterials, which is mismatched by the surface chemical properties of cellulose, results in an unstable bond between the two and a difficulty in forming a good composite system; second, carbon nanomaterials are highly crystalline, while cellulose has a low degree of crystallinity, resulting in an uneven composite structure or prone to phase separation; third, the interaction between carbon nanomaterials and cellulose is influenced by interfacial regulation. Without appropriate interfacial regulation methods, the bond between the two is unstable and prone to uneven dispersion or aggregation. Therefore, it is highly necessary to develop a method that can promote the bonding of carbon nanomaterials and cellulose to improve the stability and mechanical properties of the composite.

[0004] Methods commonly used to promote the binding of carbon nanomaterials and cellulose include surface modification, interface regulation, selection of appropriate solvents, suitable processing techniques, or the use of additives. These methods primarily enhance the interaction between the two by physically or covalently adsorbing hydrophilic groups or other functional groups onto the surfaces of carbon nanomaterials and cellulose. Alternatively, mechanical grinding, ultrasonic treatment, high-temperature heat treatment, and other processing techniques can be used to improve the binding stability of the composite material. By introducing amphiphilic polypeptide molecules or polypeptide nanofibers as a "bridge" between the carbon nanomaterial and cellulose, a strong connection is formed between the two, effectively promoting their binding. This method is simple and easy to implement, and can achieve superior stability and mechanical properties. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a "bridge" method for preparing a carbon nanomaterial / cellulose composite material.

[0006] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0007] A "bridge" method for preparing a carbon nanomaterial / cellulose composite material comprises the following steps:

[0008] Step a, synthesis of polypeptide nanofiber "bridge" material: selecting amphiphilic polypeptide molecules as precursor materials, and synthesizing polypeptide nanofiber "bridge" material by molecular self-assembly method;

[0009] Step b, cellulose surface modification: cellulose or cellulose nanocrystals are subjected to surface modification treatment to make their surface have better hydrophilicity or reactive sites;

[0010] Step c, preparation of carbon nanomaterial / cellulose composite material: the amphiphilic polypeptide nanofiber "bridge" material synthesized in step a, the cellulose surface-modified in step b, and the carbon nanomaterial are mixed and reacted under magnetic stirring at room temperature, and the precipitate obtained by centrifugation is dried at room temperature to obtain a carbon nanomaterial / cellulose composite material.

[0011] The method for preparing a carbon nanomaterial / cellulose composite material in a "bridge" manner according to the present invention comprises the following steps:

[0012] Step a1: Weigh 2-5 mg of 95% pure polypeptide solid powder in a beaker and dissolve it in 10 mL of ultrapure water under stirring to obtain a uniform polypeptide solution for later use.

[0013] Step a2: Place the polypeptide solution obtained in step a1 in a water bath at 80°C for self-assembly of polypeptide monomers, and maintain the reaction for 24 hours to obtain a polypeptide nanofiber "bridge" material solution.

[0014] Furthermore, the polypeptide sequence of the polypeptide solid powder described in the present invention is lysine-isoleucine-isoleucine-isoleucine-isoleucine-lysine-tyrosine-tryptophan-tyrosine-alanine-phenylalanine.

[0015] The novel feature of this invention is the introduction of amphiphilic polypeptide molecules or polypeptide nanofibers as a "bridge" between carbon nanomaterials and cellulose. These polypeptide molecules or polypeptide nanofibers possess hydrophilic or carbon nanomaterial-affinity properties at one end and cellulose-affinity properties at the other, and possess a high number of active sites.

[0016] The "bridge" method for preparing a carbon nanomaterial / cellulose composite material according to the present invention, step b comprises the following steps:

[0017] Step b1, under magnetic stirring, adding 5 mL each of a 50 mg / mL 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride morpholineethanesulfonic acid solution and a 25 mg / mL N-hydroxysuccinimide ethanesulfonic acid solution to 5 mL of a 1-3% mass fraction cellulose nanofiber or cellulose nanocrystal solution, and maintaining the reaction for 24 hours to obtain a mixed solution for standby use;

[0018] Step b2: After centrifuging and washing the mixed solution obtained in step b1 three times, the final precipitate was collected and dispersed in 10 mL of ultrapure water to obtain an activated cellulose nanomaterial solution.

[0019] Furthermore, the cellulose nanofibers of the present invention are selected from one or more of cellulose and its derivatives and hybrids.

[0020] Furthermore, the cellulose nanofibers described in the present invention refer to fibers having a minor axis diameter in the nanometer range.

[0021] Furthermore, the minor axis diameter of the cellulose nanofibers described in the present invention can be 10nm to 400nm, 10nm to 350nm, 10nm to 300nm, 20nm to 300nm, 20nm to 250nm, 30nm to 250nm, 30nm to 200nm, 40nm to 200nm, 40nm to 150nm, 50nm to 150nm, or 50nm to 100nm.

[0022] Preferably, the minor axis diameter of the cellulose nanofibers described in the present invention is 10 nm to 300 nm.

[0023] The present invention discloses a method for preparing a carbon nanomaterial / cellulose composite material in a "bridge" manner. In step c, the amphiphilic polypeptide nanofiber "bridge" material synthesized in step a with a mass concentration of 0.2-0.5 mg / mL, the activated cellulose nanomaterial solution with a mass concentration of 1-5 mg / mL surface-modified in step b, and the carbon nanomaterial solution with a mass concentration of 1-4 mg / mL are mixed under magnetic stirring at room temperature for 24 hours, centrifuged three times, and the final precipitate is collected and dried at room temperature to obtain a carbon nanomaterial / cellulose composite material with a stable structure.

[0024] Furthermore, the carbon nanomaterials described in the present invention are selected from one or more of graphene, carbon nanotubes, carbon nitride, and carbon nanofibers.

[0025] Compared with the existing known technologies, the technical solution provided by the present invention has the following beneficial effects:

[0026] 1. The present invention discloses a "bridge" method for preparing carbon nanomaterial / cellulose composite materials. Amphiphilic polypeptide molecules or polypeptide nanofibers are introduced as "bridges" between carbon nanomaterials and cellulose to form chemical bonds or physical adsorption, forming a stable "bridge" and network structure, effectively achieving a strong bond between carbon nanomaterials and cellulose. The reaction mechanism is as follows: Figure 1 shown.

[0027] 2. The "bridge" method for preparing carbon nanomaterial / cellulose composite materials described in the present invention is simple and easy to implement, and is applicable to the preparation of composite materials of various types of carbon nanomaterials and cellulose.

[0028] 3. The carbon nanomaterial / cellulose composite material prepared by the "bridge" type method for preparing carbon nanomaterial / cellulose composite material described in the present invention has excellent stability and mechanical properties and is suitable for many fields such as energy engineering, environmental protection, and biomedicine. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 Schematic diagram of peptide nanofiber "bridge" material promoting the composite of carbon nanomaterials and cellulose;

[0030] Figure 2 This is the atomic force microscopy image of the polypeptide nanofiber "bridge" material obtained in Example 1;

[0031] Figure 3 Atomic force microscopy images of the cellulose nanofibers, oxidized cellulose nanofibers, and activated cellulose nanofibers obtained in Example 1;

[0032] Figure 4 : This is a transmission electron microscopy image of the graphene oxide / cellulose composite material obtained in Example 1;

[0033] Figure 5 This is a scanning electron microscope image of the carbon nanotube / cellulose composite material obtained in Example 2;

[0034] Figure 6 : This is a transmission electron microscopy image of the graphite-like carbon nitride / cellulose composite material obtained in Example 2; DETAILED DESCRIPTION

[0035] The present invention will be further described below with reference to specific embodiments.

[0036] The technical solutions in the embodiments of the present invention are clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments; based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0037] In the present invention, unless otherwise specified, the raw materials used are commercially available products in the art.

[0038] In the present invention, the main experimental equipments are: FM-Nanoview6800 atomic force microscope (Suzhou Feishiman Precision Instrument Co., Ltd.), Regulus 8100 scanning electron microscope (Hitachi, Japan), Tecnai G2 F20 transmission electron microscope (FEI, USA).

[0039] Example 1

[0040] This embodiment provides a "bridge" method for preparing a carbon nanomaterial / cellulose composite material, comprising the following steps:

[0041] Step a, synthesis of polypeptide nanofiber "bridge" material: selecting amphiphilic polypeptide molecules as precursor materials, and synthesizing polypeptide nanofiber "bridge" material by molecular self-assembly method;

[0042] Step b, cellulose surface modification: cellulose or cellulose nanocrystals are subjected to surface modification treatment to make their surface have better hydrophilicity or reactive sites;

[0043] Step c, preparation of carbon nanomaterial / cellulose composite material: the amphiphilic polypeptide nanofiber "bridge" material synthesized in step a, the cellulose surface-modified in step b, and the carbon nanomaterial are mixed and reacted under magnetic stirring at room temperature, and the precipitate obtained by centrifugation is dried at room temperature to obtain a carbon nanomaterial / cellulose composite material.

[0044] In the method for preparing a carbon nanomaterial / cellulose composite material in a "bridge" manner described in this embodiment, step a comprises the following steps:

[0045] Step a1: Weigh 2 mg of 95% pure peptide solid powder (Nanjing Jiepeptide Biotechnology Co., Ltd.) in a beaker and dissolve it in 10 mL of ultrapure water under stirring to obtain a uniform peptide solution for later use.

[0046] Step a2: Place the polypeptide solution obtained in step a1 in a water bath at 80°C for self-assembly of polypeptide monomers, and keep the reaction for 24 hours to obtain a 0.2 mg / mL polypeptide nanofiber "bridge" material solution. Figure 2As shown, this embodiment can obtain polypeptide nanofibers with a length of 1-5 μm and a diameter of 2-10 nm.

[0047] Preferably, the polypeptide sequence of the polypeptide solid powder described in this embodiment is lysine-isoleucine-isoleucine-isoleucine-isoleucine-lysine-tyrosine-tryptophan-tyrosine-alanine-phenylalanine.

[0048] In the method for preparing a carbon nanomaterial / cellulose composite material in a "bridge" manner described in this embodiment, step b comprises the following steps:

[0049] Step b1: Under magnetic stirring (stirring speed of 200 rpm), 5 mL each of a 50 mg / mL solution of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride in morpholinoethanesulfonic acid (Shanghai Luoen Reagent Co., Ltd.) and a 25 mg / mL solution of N-hydroxysuccinimide ethanesulfonic acid (Shanghai Luoen Reagent Co., Ltd.) were added to 5 mL of a 1% by mass solution of oxidized cellulose nanofibers (Beijing North Century Cellulose Materials Co., Ltd., China). The reaction was maintained for 24 hours to obtain a mixed solution for later use.

[0050] Step b2: centrifuge the mixed solution obtained in step b1 (centrifugal speed: 15000 rpm, centrifugal time: 15 min) for 3 times, collect the final precipitate, and disperse it in 10 mL of ultrapure water to obtain an activated cellulose nanomaterial solution.

[0051] Preferably, see Figure 3 The average minor axis diameter of the oxidized cellulose nanofibers described in this embodiment is 15 nm, and the average length is 384 nm.

[0052] The present embodiment describes a method for preparing a carbon nanomaterial / cellulose composite material in a "bridge" manner. In step c, the amphiphilic polypeptide nanofiber "bridge" material synthesized in step a with a mass concentration of 0.2 mg / mL, the activated cellulose nanomaterial solution with a mass concentration of 1.5 mg / mL surface-modified in step b, and a graphene oxide solution with a mass concentration of 1.5 mg / mL (Hangzhou Gaoxun Biotechnology Co., Ltd., with a diameter of 0.5-1 μm and a length of 1 nm) are mixed under magnetic stirring (stirring speed of 200 rpm) at room temperature for 24 hours, and then centrifuged (centrifugal speed of 15000 rpm, centrifugal time of 15 minutes) three times. The final precipitate is collected and dried at room temperature to obtain a carbon nanomaterial / cellulose composite material with a stable structure. Figure 4 shown.

[0053] Example 2

[0054] This embodiment provides a "bridge" method for preparing a carbon nanomaterial / cellulose composite material, comprising the following steps:

[0055] Step a, synthesis of polypeptide nanofiber "bridge" material: selecting amphiphilic polypeptide molecules as precursor materials, and synthesizing polypeptide nanofiber "bridge" material by molecular self-assembly method;

[0056] Step b, cellulose surface modification: cellulose or cellulose nanocrystals are subjected to surface modification treatment to make their surface have better hydrophilicity or reactive sites;

[0057] Step c, preparation of carbon nanomaterial / cellulose composite material: the amphiphilic polypeptide nanofiber "bridge" material synthesized in step a, the cellulose surface-modified in step b, and the carbon nanomaterial are mixed and reacted under magnetic stirring at room temperature, and the precipitate obtained by centrifugation is dried at room temperature to obtain a carbon nanomaterial / cellulose composite material.

[0058] In the method for preparing a carbon nanomaterial / cellulose composite material in a "bridge" manner described in this embodiment, step a comprises the following steps:

[0059] Step a1: Weigh 3 mg of 95% pure peptide solid powder (Nanjing Jiepeptide Biotechnology Co., Ltd.) in a beaker and dissolve it in 10 mL of ultrapure water under stirring to obtain a uniform peptide solution for later use.

[0060] Step a2: Place the polypeptide solution obtained in step a1 in a water bath at 80°C for self-assembly of polypeptide monomers, and maintain the reaction for 24 hours to obtain a 0.3 mg / mL polypeptide nanofiber "bridge" material solution.

[0061] Preferably, the polypeptide sequence of the polypeptide solid powder described in this embodiment is lysine-isoleucine-isoleucine-isoleucine-isoleucine-lysine-tyrosine-tryptophan-tyrosine-alanine-phenylalanine.

[0062] In the method for preparing a carbon nanomaterial / cellulose composite material in a "bridge" manner described in this embodiment, step b comprises the following steps:

[0063] Step b1: Under magnetic stirring (stirring speed of 200 rpm), 5 mL each of a 50 mg / mL 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride morpholineethanesulfonic acid solution (Shanghai Luoen Reagent Co., Ltd.) and a 25 mg / mL N-hydroxysuccinimide ethanesulfonic acid solution (Shanghai Luoen Reagent Co., Ltd.) were added to 5 mL of a 2% by mass cellulose nanofiber solution (Beijing North Century Cellulose Materials Co., Ltd., China, with an average minor axis diameter of 20 nm and an average length of 400 nm). The reaction was maintained for 24 hours to obtain a mixed solution for later use.

[0064] Step b2: centrifuge the mixed solution obtained in step b1 (centrifugal speed: 15000 rpm, centrifugal time: 15 min) for 3 times, collect the final precipitate, and disperse it in 10 mL of ultrapure water to obtain an activated cellulose nanomaterial solution.

[0065] The present embodiment describes a method for preparing a carbon nanomaterial / cellulose composite material in a "bridge" manner. In step c, the amphiphilic polypeptide nanofiber "bridge" material synthesized in step a with a mass concentration of 0.3 mg / mL, the activated cellulose nanomaterial solution with a mass concentration of 2.5 mg / mL surface-modified in step b, and a carbon nanotube solution with a mass concentration of 2.5 mg / mL (Jiangsu Pioneer Nanomaterial Technology Co., Ltd., with a diameter of 5-10 nm and a length of 1-10 μm) are mixed under magnetic stirring (stirring speed of 200 rpm) at room temperature for 24 hours, and then centrifuged (centrifugal speed of 15000 rpm, centrifugal time of 15 minutes) three times. The final precipitate is collected and dried at room temperature to obtain a carbon nanomaterial / cellulose composite material with a stable structure. Figure 5 shown.

[0066] Example 3

[0067] This embodiment provides a "bridge" method for preparing a carbon nanomaterial / cellulose composite material, comprising the following steps:

[0068] Step a, synthesis of polypeptide nanofiber "bridge" material: selecting amphiphilic polypeptide molecules as precursor materials, and synthesizing polypeptide nanofiber "bridge" material by molecular self-assembly method;

[0069] Step b, cellulose surface modification: cellulose or cellulose nanocrystals are subjected to surface modification treatment to make their surface have better hydrophilicity or reactive sites;

[0070] Step c, preparation of carbon nanomaterial / cellulose composite material: the amphiphilic polypeptide nanofiber "bridge" material synthesized in step a, the cellulose surface-modified in step b, and the carbon nanomaterial are mixed and reacted under magnetic stirring at room temperature, and the precipitate obtained by centrifugation is dried at room temperature to obtain a carbon nanomaterial / cellulose composite material.

[0071] In the method for preparing a carbon nanomaterial / cellulose composite material in a "bridge" manner described in this embodiment, step a comprises the following steps:

[0072] Step a1: Weigh 5 mg of 95% pure peptide solid powder (Nanjing Jiepeptide Biotechnology Co., Ltd.) in a beaker and dissolve it in 10 mL of ultrapure water under stirring to obtain a uniform peptide solution for later use.

[0073] Step a2: Place the polypeptide solution obtained in step a1 in a water bath at 80°C for self-assembly of polypeptide monomers, and maintain the reaction for 24 hours to obtain a 0.5 mg / mL polypeptide nanofiber "bridge" material solution.

[0074] Preferably, the polypeptide sequence of the polypeptide solid powder described in this embodiment is lysine-isoleucine-isoleucine-isoleucine-isoleucine-lysine-tyrosine-tryptophan-tyrosine-alanine-phenylalanine.

[0075] In the method for preparing a carbon nanomaterial / cellulose composite material in a "bridge" manner described in this embodiment, step b comprises the following steps:

[0076] Step b1: Under magnetic stirring (stirring speed of 200 rpm), 5 mL each of a 50 mg / mL 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride morpholineethanesulfonic acid solution (Shanghai Luoen Reagent Co., Ltd.) and a 25 mg / mL N-hydroxysuccinimide ethanesulfonic acid solution (Shanghai Luoen Reagent Co., Ltd.) were added to 5 mL of a 2% by mass cellulose nanofiber solution (Beijing North Century Cellulose Materials Co., Ltd., China, with an average minor axis diameter of 20 nm and an average length of 400 nm). The reaction was maintained for 24 hours to obtain a mixed solution for later use.

[0077] Step b2: centrifuge the mixed solution obtained in step b1 (centrifugal speed: 15000 rpm, centrifugal time: 15 min) for 3 times, collect the final precipitate, and disperse it in 10 mL of ultrapure water to obtain an activated cellulose nanomaterial solution.

[0078] The present embodiment describes a method for preparing a carbon nanomaterial / cellulose composite material in a "bridge" manner. In step c, the amphiphilic polypeptide nanofiber "bridge" material synthesized in step a with a mass concentration of 0.5 mg / mL, the activated cellulose nanomaterial solution with a mass concentration of 2.5 mg / mL surface-modified in step b, and a graphite-like carbon nitride solution (Jiangsu Pioneer Nanomaterial Technology Co., Ltd., multilayer structure, size 50-300 nm) with a mass concentration of 3.5 mg / mL are mixed under magnetic stirring (stirring speed of 200 rpm) at room temperature for 24 hours, and then centrifuged (centrifugal speed of 15000 rpm, centrifugal time of 15 minutes) 3 times, and the final precipitate is collected and dried at room temperature to obtain a carbon nanomaterial / cellulose composite material with a stable structure. Figure 6 shown.

[0079] The embodiments of the present invention disclosed above are intended only to illustrate the present invention. The embodiments do not describe all details in detail, nor do they limit the present invention to the specific embodiments described. Numerous modifications and variations are possible based on the contents of this specification. These embodiments are selected and described in detail in this specification to better explain the principles and practical applications of the present invention, thereby enabling those skilled in the art to better understand and utilize the present invention.

Claims

1. A "bridge" method for preparing a carbon nanomaterial / cellulose composite material, characterized by: The steps include: Step a: Synthesis of polypeptide nanofiber "bridge" material: Selecting amphiphilic polypeptide molecules as precursor materials, and synthesizing polypeptide nanofiber "bridge" material using molecular self-assembly method; Step b, cellulose surface modification: cellulose or cellulose nanocrystals are subjected to surface modification treatment to make their surface have better hydrophilicity or reactive sites; Step c, preparation of carbon nanomaterial / cellulose composite material: the amphiphilic polypeptide nanofiber "bridge" material synthesized in step a, the surface-modified cellulose in step b, and the carbon nanomaterial are mixed and reacted under magnetic stirring at room temperature, and the precipitate obtained by centrifugation is dried at room temperature to prepare a carbon nanomaterial / cellulose composite material.

2. The method for preparing a carbon nanomaterial / cellulose composite material in a "bridge" manner according to claim 1, characterized in that: Step a includes the following steps: Step a1: Weigh 2-5 mg of 95% pure polypeptide solid powder in a beaker and dissolve it in 10 mL of ultrapure water under stirring to obtain a uniform polypeptide solution for later use. Step a2: Place the polypeptide solution obtained in step a1 in a water bath at 80°C for self-assembly of polypeptide monomers, and maintain the reaction for 24 hours to obtain a polypeptide nanofiber "bridge" material solution.

3. The method for preparing a carbon nanomaterial / cellulose composite material in a "bridge" manner according to claim 2, characterized in that: The polypeptide sequence of the polypeptide solid powder in step a1 is lysine-isoleucine-isoleucine-isoleucine-isoleucine-lysine-tyrosine-tryptophan-tyrosine-alanine-phenylalanine.

4. The method for preparing a carbon nanomaterial / cellulose composite material in a "bridge" manner according to claim 1, characterized in that: Step b includes the following steps: Step b1, under magnetic stirring, adding 5 mL each of a 50 mg / mL 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride morpholineethanesulfonic acid solution and a 25 mg / mL N-hydroxysuccinimide ethanesulfonic acid solution to 5 mL of a 1-3% mass fraction cellulose nanofiber or cellulose nanocrystal solution, and maintaining the reaction for 24 hours to obtain a mixed solution for standby use; Step b2: After centrifuging and washing the mixed solution obtained in step b1 three times, the final precipitate was collected and dispersed in 10 mL of ultrapure water to obtain an activated cellulose nanomaterial solution.

5. The method for preparing a carbon nanomaterial / cellulose composite material in a "bridge" manner according to claim 4, characterized in that: The cellulose nanofibers described in step b1 are selected from one or more of cellulose and its derivatives and hybrids.

6. The method for preparing a carbon nanomaterial / cellulose composite material in a "bridge" manner according to claim 4, characterized in that: The cellulose nanofibers described in step b1 refer to fibers having a minor axis diameter in the nanometer range.

7. The method for preparing a carbon nanomaterial / cellulose composite material in a "bridge" manner according to claim 4, characterized in that: The minor axis diameter of the cellulose nanofibers described in step b1 is 10nm to 400nm, 10nm to 350nm, 10nm to 300nm, 20nm to 300nm, 20nm to 250nm, 30nm to 250nm, 30nm to 200nm, 40nm to 200nm, 40nm to 150nm, 50nm to 150nm, or 50nm to 100nm.

8. The cellulose nanofiber according to claim 7, wherein: The short axis diameter of the cellulose nanofiber is 10 nm to 300 nm.

9. The method for preparing a carbon nanomaterial / cellulose composite material in a "bridge" manner according to claim 1, characterized in that: In step c, the amphiphilic polypeptide nanofiber "bridge" material synthesized in step a with a mass concentration of 0.2-0.5 mg / mL, the activated cellulose nanomaterial solution with a mass concentration of 1-5 mg / mL surface-modified in step b, and the carbon nanomaterial solution with a mass concentration of 1-4 mg / mL are mixed under magnetic stirring at room temperature for 24 hours, centrifuged three times, and the final precipitate is collected and dried at room temperature to obtain a structurally stable carbon nanomaterial / cellulose composite material.

10. The method for preparing a carbon nanomaterial / cellulose composite material in a "bridge" manner according to claim 1, characterized in that: The carbon nanomaterial described in step c is selected from one or more of graphene, carbon nanotubes, carbon nitride, and carbon nanofibers.

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