Preparation method of graphene oxide and nickel synergistically optimized carbon nanohelix and application thereof

Abstract

This invention discloses a method for preparing carbon nanotube spirals synergistically optimized with graphene oxide and nickel, as well as the resulting products and applications. The steps are as follows: first, Ni nanoparticles are grown in situ on the surface of carbon nanotube spirals (CNCs) by cation exchange method to obtain Ni / CNCs; then, annealing is carried out at 450°C for 2 h in an argon atmosphere, and graphene oxide (GO) is electrostatically self-assembled onto the surface of Ni / CNCs to obtain GO / Ni / CNCs; then, GO / Ni / CNCs are filled into polytetrafluoroethylene (PTFE) by blending and rolling method to obtain PTFE / GO / Ni / CNCs composite film; finally, films with filling amounts of 20% and 50% are pressed together to form a bilayer film. The composite material obtained by this invention is a corn-like structure of Ni / CNCs coated with GO. Using CNCs as the framework, PTFE / GO / Ni / CNCs composite material is prepared by cation exchange and electrostatic self-assembly. The process is simple, can precisely control the number and size of Ni nanoparticles, and solves the shortcomings of Ni nanoparticles being of different sizes and unevenly distributed. It has good electrical conductivity, electromagnetic wave absorption, electromagnetic shielding, and photothermal properties, and has wide application value in fields such as light-driven heating and electromagnetic protection.

Description

Technical Field

[0001] This invention relates to a method for preparing carbon nanospirals synergistically optimized by graphene oxide and nickel, and also to the product obtained by the method and its application in electromagnetic wave protection and photothermal fields, belonging to the field of nanomaterial preparation and application technology. Background Technology

[0002] Innovations in electronic information technology have driven the rapid development of the Internet of Things (IoT) era, enabling the interconnection of everything. However, under the impact of this global digital wave, traditional electromagnetic protection devices with single functions can no longer meet the needs of increasingly complex electromagnetic application environments. Therefore, the development of multifunctional materials that can solve the core problem of electromagnetic pollution is particularly urgent. Among these, electromagnetic protection materials deployed in complex environments need to have excellent durability and stability to ensure long-term stable operation.

[0003] Among numerous materials, polytetrafluoroethylene (PTFE) exhibits great application potential due to its unique chemical inertness, mechanical toughness, and electrical insulation properties. However, as a good electromagnetic wave (EMW) transmissive material, it has inherent limitations in electromagnetic protection and thermal management, necessitating the exploration of composite materials to improve its performance. One effective approach is to introduce carbon materials modified with metal nanoparticles (such as carbon nanotubes (CNC) and graphene oxide (GO)) into PTFE. First, carbon nanotubes possess high conductivity, thus exhibiting excellent electromagnetic interference (EMI) shielding performance. Simultaneously, their unique three-dimensional chiral structure can induce multiple reflections and scattering, enriching loss mechanisms and inducing new cross-polarization losses. Then, GO, with its two-dimensional structure and abundant oxygen-containing functional groups, effectively prevents corrosion and oxidation due to its high density. This functionality can compensate for the shortcomings of PTFE, forming a dual-protective structure and thereby improving the overall durability of the material. However, high conductivity is an inherent characteristic of pure carbon materials, which may become an obstacle to its application in the field of electromagnetic wave absorption (EWA). Specifically, the impedance mismatch caused by high conductivity significantly increases the reflectivity of electromagnetic waves. The introduction of metal nanoparticles creates conductive paths between carbon materials, increasing interfacial polarization and improving impedance matching. The addition of carbon materials and metal nanoparticles also endows PTFE with photo-driven heating properties. Therefore, optimizing the structure of PTFE / C composites is a crucial research direction for improving their electromagnetic wave attenuation and photothermal conversion performance. Summary of the Invention

[0004] To address the shortcomings of CNCs, this invention provides a method for preparing carbon nanotubes and the resulting product through the synergistic optimization of graphene oxide and nickel. This method is simple, and by optimizing the structure of graphene oxide, the resulting composite material has a stable structure and good electrical conductivity, electromagnetic wave absorption, electromagnetic shielding, and photothermal properties, making it widely applicable in the fields of photothermal and electromagnetic wave protection.

[0005] The specific technical solution of this invention is as follows: A method for preparing carbon nanospirals synergistically optimized by graphene oxide and nickel includes the following steps: (1) Ni nanoparticles were grown in situ on the surface of CNCs by cation exchange method to obtain Ni / CNCs; (2) Anneal the Ni / CNCs to remove excess organic solvent from the surface; (3) Coating GO onto the surface of Ni / CNCs to form a GO / Ni / CNCs composite material; (4) Fill GO / Ni / CNCs into PTFE, mix, stir and roll to make PTFE / GO / Ni / CNCs composite film.

[0006] Furthermore, the carbon nanospirals used in this invention can be prepared using methods disclosed in the prior art, and the diameter of the nanowires is generally 100 nm.

[0007] In a specific embodiment of the present invention, a method for preparing CNC is provided, comprising the following steps: reacting potassium sodium tartrate tetrahydrate with copper chloride to obtain copper tartrate sulfate powder, reducing it at 290 °C under an acetylene atmosphere for 30 min to obtain a precursor, and then carbonizing it at 800 °C under an argon atmosphere for 2 hours.

[0008] Furthermore, in step (1), CNC is dispersed in an organic solvent to form a dispersion, and then the dispersion is dropped into a three-necked flask and ultrasonically dispersed in an ultrasonic machine.

[0009] Furthermore, in step (1), the method for preparing Ni by cation exchange can be carried out with reference to methods disclosed in the prior art. Preferably, the cation exchange method uses the standard Schlenk line technique. The precursors for the cation exchange method are nickel chloride, triphenyl phosphite, 1-octadecene, and hexadecylamine, respectively. The reaction temperature is 210°C, and the reaction time is 1 hour. The density of Ni nanoparticles grown on the CNC surface is controlled by adjusting the mass of CNCs. Experiments show that the density of Ni nanoparticles has a significant impact on the morphology and properties of the final product and is key to the formation of the final product's composition and morphology. Preferably, the amount of CNCs used is 200 mg. In the above preparation method, the growth density of Ni nanoparticles can be adjusted by changing the amount of CNCs.

[0010] Furthermore, in step (2), the Ni / CNCs composite material is annealed in an argon atmosphere. Annealing can be performed in a tube furnace. The specific annealing method can refer to methods disclosed in the prior art, with an annealing temperature of 430-450 ℃, an annealing time of 1-5 h, and a heating rate of 2-5 ℃ / min. The preferred calcination temperature is 450 ℃, and the annealing time is 2 h. At this calcination temperature, a product with good morphology and excellent performance can be obtained.

[0011] Furthermore, in step (2), the argon gas flow rate is 35-45 mL / min.

[0012] Furthermore, in step (3), GO is coated onto the surface of Ni / CNCs by electrostatic self-assembly at a mass ratio of 1:200, and the coating is carried out at 80 °C for 10 h.

[0013] Furthermore, in step (4), a PTFE solution with a content of 60% is used, and GO / Ni / CNCs and PTFE are mixed and pressed at mass ratios of 1:4 and 1:1, respectively, to roll films of 20 wt.% and 50 wt.% and then physically bonded together.

[0014] This invention first grows Ni nanoparticles of a certain density on the surface of CNCs in situ using a cation exchange method, then anneals the Ni / CNCs. Next, GO is coated using an electrostatic self-assembly method to obtain GO / Ni / CNCs. Finally, the GO / Ni / CNCs are blended and rolled with PTFE emulsion to obtain a PTFE / GO / Ni / CNCs composite film with unique morphology and excellent performance. In the cation exchange method, nickel chloride and triphenyl phosphate are mixed and heated in an inert gas environment. Triphenyl phosphate decomposes nickel chloride into fine nanoparticles, but in an atmosphere of 210°C, it is insufficient to combine with nickel chloride to form phosphides; instead, it forms fine metallic Ni particles. Because the reaction system is uniformly mixed, the Ni nanoparticles are attracted by the ionic bonds on the surface of the CNCs, thus fixing them to the surface. In this composite material, Ni nanoparticles grow uniformly on the surface of the CNCs. The density of Ni nanoparticle growth can be precisely controlled by controlling the amount of CNCs, resulting in uniform Ni nanoparticle size and no agglomeration on the CNCs surface.

[0015] During chemical vapor deposition (CVD), NiO / TiO2 is calcined in an acetylene environment. Both NiO and TiO2 act as catalysts during calcination, causing the acetylene to form a uniform amorphous carbon layer on the surface of the TiO2 nanowires. Furthermore, NiO reacts with acetylene to form a nickel / carbon nanotube composite structure, which grows uniformly on the carbon-coated TiO2 nanowire surface. The entire product exhibits a layered nanobrush-like structure. In this composite material, nickel / carbon nanotubes grow uniformly on the carbon-coated TiO2 nanowire surface. By controlling the reaction conditions, the number of carbon nanotubes (CNTs) can be precisely controlled, resulting in uniformly sized CNTs on the TiO2 nanowire surface without agglomeration.

[0016] The PTFE / GO / Ni / CNCs composite film obtained by this invention possesses excellent electrical conductivity, electromagnetic wave absorption, electromagnetic shielding, and photothermal properties, and exhibits structural stability and strong thermal stability. It shows great promise for applications in electromagnetic wave absorption and photothermal fields, overcoming the shortcomings of pure PTFE in these areas. Therefore, the PTFE / GO / Ni / CNCs composite film prepared by this invention and its applications in electromagnetic wave protection and photothermal fields are also within the scope of protection of this invention.

[0017] This invention uses CNCs as a framework to prepare PTFE / GO / Ni / CNCs composite films through cation exchange and electrostatic self-assembly. Ni nanoparticles are uniformly grown on CNCs, which effectively solves the problem of Ni nanoparticle aggregation and greatly improves the electromagnetic wave protection and photothermal properties of PTFE.

[0018] Compared with the prior art, the advantages of the present invention are as follows: (1) The present invention combines cation exchange method and electrostatic self-assembly to prepare PTFE / GO / Ni / CNCs composite film, and the preparation process is simple and easy to implement; (2) The present invention prepared a corn-like GO / Ni / CNCs composite material. By changing the mass of CNCs, the growth density of Ni nanoparticles can be precisely controlled and the phenomenon of uneven growth size and easy agglomeration of Ni nanoparticles can be effectively solved. It also has a large specific surface area, many active sites, and excellent performance. (3) The PTFE / GO / Ni / CNCs composite material prepared by the present invention has good electrical conductivity and stable structure. Experiments have shown that its performance is significantly improved compared with pure PTFE. Due to its stable structure, carbon material acts as a bridge for absorbing light energy, and it has broad application prospects in the field of photothermal.

[0019] (4) The PTFE / GO / Ni / CNCs composite film prepared by the present invention has strong thermal stability, excellent electrical conductivity and electromagnetic wave protection performance, and has broad application prospects in electromagnetic wave protection. Attached Figure Description

[0020] Figure 1 The following are TEM images of the samples of the present invention: (a) Ni / CNCs-1, (b) Ni / CNCs-2, (c) Ni / CNCs-3, (d) multiple Ni / CNCs, (e) GO / Ni / CNCs, (f) high-resolution transmission of Ni / CNCs-2 and (g) EDS of Ni / CNCs-2.

[0021] Figure 2 The images show SEM images of the samples of this invention: (a) CNCs, (b) GO / Ni / CNCs, (c) cross-section of PTFE / GO / Ni / CNCs, and (d) surface of PTFE / GO / Ni / CNCs.

[0022] Figure 3 This is a diagram of the electromagnetic parameters of CNCs.

[0023] Figure 4 The electromagnetic parameters of GO / Ni / CNCs-1 are shown in the diagram.

[0024] Figure 5 The electromagnetic parameters of GO / Ni / CNCs-2 are shown in the diagram.

[0025] Figure 6 The electromagnetic parameters of GO / Ni / CNCs-3 are shown in the diagram.

[0026] Figure 7 This is a diagram showing the electromagnetic wave absorption performance of CNCs.

[0027] Figure 8 The diagram shows the electromagnetic wave absorption performance of GO / Ni / CNCs-1.

[0028] Figure 9 The diagram shows the electromagnetic wave absorption performance of GO / Ni / CNCs-2.

[0029] Figure 10 The diagram shows the electromagnetic wave absorption performance of GO / Ni / CNCs-3.

[0030] Figure 11 SE of PTFE / GO / Ni / CNCs in the X-band T SE R and SE A .

[0031] Figure 12 SE of PTFE / GO / Ni / CNCs in the Ku band T SE R and SE A .

[0032] Figure 13 The electromagnetic shielding performance of PTFE / GO / Ni / CNCs in the X-band is shown in the diagram.

[0033] Figure 14 The electromagnetic shielding performance of PTFE / GO / Ni / CNCs in the Ku band is shown in the diagram.

[0034] Figure 15 The table shows the surface temperature of PTFE / GO / Ni / CNCs-2 over time under (a) different light intensities, and (b) the surface temperature over time under continuous heating and cooling at the same light intensity. Detailed Implementation

[0035] The present invention will be described in detail below through specific embodiments. However, the uses and purposes of these exemplary embodiments are only for illustrating the present invention and do not constitute any limitation on the actual protection scope of the present invention, nor are they intended to limit the protection scope of the present invention to these embodiments.

[0036] Example 1: Preparation of PTFE / GO / Ni / CNCs composite material (1) Synthesis of carbon nanospirals Weigh 1.41 g of potassium sodium tartrate tetrahydrate and place it in a beaker. Dissolve it in ultrapure water to prepare a 50 mL 0.1 M potassium sodium tartrate solution. Weigh 0.85 g of copper chloride dihydrate and place it in a beaker. Dissolve it in ultrapure water to prepare a 50 mL 0.1 M copper chloride solution. Under strong stirring, slowly add the prepared copper chloride solution dropwise to the potassium sodium tartrate solution. After standing for 5 min, vacuum filter the mixture to obtain a light blue filter cake. Wash the filter cake three times with anhydrous ethanol, dry it, and then transfer it to a vacuum drying oven at 80 °C for 30 min to obtain the catalyst precursor. Weigh a small amount of precursor powder and evenly place it at the bottom of a ceramic boat. Prepare carbon nanospirals using chemical vapor deposition. Hold at 290 °C for 30 min in an acetylene atmosphere and anneal at 800 °C for 2 h in an argon atmosphere to obtain carbon nanospirals.

[0037] (2) Preparation of Ni / CNCs by cation exchange method A cation exchange method was used to disperse a mixed solution containing nickel chloride (1 mmol), triphenyl phosphite (10 mmol), 1-octadecene (10 ml), hexadecylamine (10 mmol), and CNCs uniformly by ultrasonic stirring. The dispersion was then transferred to a three-necked flask and purified at 120 °C for 1 h. The reaction was then carried out using standard Schlenk line technology, with CNCs and nickel chloride as precursors. The reaction was carried out at 210 °C for 1 h. 300 mg, 200 mg, and 100 mg of CNCs were added, respectively, to obtain Ni / CNCs composite materials, named Ni / CNCs-1, Ni / CNCs-2, and Ni / CNCs-3. The composites were centrifuged with alcohol, naturally dried, and then annealed in a tube furnace at 450 °C under an argon atmosphere (argon flow rate of 35-45 mL / min).

[0038] (3) Preparation of GO / Ni / CNCs composite materials by electrostatic self-assembly The prepared Ni / CNCs composite material was placed in a beaker, and a GO dispersion diluted with ultrapure water (mass ratio 1:200) was poured in. The mixture was ultrasonically dispersed until the Ni / CNCs were uniformly distributed in the dispersion. The beaker was then placed in an oven at 80℃ for 10 h to obtain the GO / Ni / CNCs composite material. Based on the different amounts of CNCs added, they were named GO / Ni / CNCs-1, GO / Ni / CNCs-2, and GO / Ni / CNCs-3, respectively.

[0039] (4) PTFE / GO / Ni / CNCs composite films were prepared by blending and rolling method. GO / Ni / CNCs and PTFE emulsion were uniformly mixed at mass ratios of 1:4 and 1:1, and ultrasonically stirred for 30 min. An appropriate amount of ethanol was then added, and the mixture was stirred until it reached a cohesive state. The mixture was then rolled to a thickness of 1 mm to form PTFE / GO / Ni / CNCs. A 20% PTFE / GO / Ni / CNCs layer was used as the upper film, and a 50% PTFE / GO / Ni / CNCs layer was used as the lower film. These layers were then physically pressed together. Based on the different amounts of CNCs added, they were named PTFE / GO / Ni / CNCs-1, PTFE / GO / Ni / CNCs-2, and PTFE / GO / Ni / CNCs-3, respectively.

[0040] Figure 1The TEM images of the obtained Ni / CNCs show a small number of Ni nanoparticles on the CNCs surface. As the CNCs content decreases, the Ni nanoparticles gradually become denser, forming a corncob structure. Finally, they uniformly cover the surface of the CNCs. TEM images of PTFE / GO / Ni / CNCs-1, PTFE / GO / Ni / CNCs-2, and PTFE / GO / Ni / CNCs-3 reveal the process of granular formation on the CNCs surface and the change in the Ni / CNCs ratio as the CNCs content decreases. High-resolution images of the Ni / CNCs demonstrate the successful synthesis and loading of Ni nanoparticles onto the CNCs surface.

[0041] Figure 2 The image shows a SEM image of the obtained PTFE / GO / Ni / CNCs. The CNCs obtained by chemical vapor deposition have high helicity, a diameter of about 100 nm, and obvious chiral structure. The Ni / CNCs are coated with a layer of GO, and the SEM image shows that the film is uniformly coated on its outer surface. The cross-sectional SEM image of the film shows that after being mixed with PTFE and rolled into a film, it is uniformly embedded inside the PTFE fibers, with a strong structure and a smooth surface.

[0042] As the amount of CNCs added increases, the surface-loaded Ni nanoparticles gradually decrease. When the amount increases to 300 mg, the Ni nanoparticles on the surface almost disappear, which leads to a decrease in performance.

[0043] Application Example 1 Applications of PTFE / GO / Ni / CNCs composite materials in electromagnetic wave absorption: (1) Add the sample (GO / Ni / CNCs-1, GO / Ni / CNCs-2, GO / Ni / CNCs-3) and PTFE to a beaker at a mass ratio of 1:4.

[0044] (2) Add alcohol and stir continuously to make the sample and PTFE wax evenly mixed.

[0045] (3) Place the well-mixed sample and PTFE in a mold to obtain a ring with an inner diameter of 3.04 mm, an outer diameter of 7.00 mm, and a thickness of 2.00 mm.

[0046] (4) Place each ring on a vector mesh analyzer to measure its electromagnetic parameters. The results are as follows: Figure 3-6 As shown.

[0047] (5) Take another sample and mix it with PTFE in a ratio of 1:4 and 1:1, press it into a 1 mm film, and press them together.

[0048] (6) The electromagnetic shielding performance of each film was measured on a vector grid analyzer, and the results are as follows: Figure 11-14 As shown As shown in the figure, the real part ε' and imaginary part ε" of the dielectric of CNCs exhibit a decreasing trend across the entire frequency range, with ε' reaching a maximum of 40, indicating that CNCs possess high conductivity. When the content of added CNCs gradually decreases, ε' and ε" change significantly, indicating that the addition of Ni nanoparticles has a substantial impact on dielectric properties. The changes in ε' and ε'' values ​​for GO / Ni / CNCs-1, GO / Ni / CNCs-2, and GO / Ni / CNCs-3 are very similar. Taking GO / Ni / CNCs-2 as an example, the ε' value decreases from 14.32 at 2 GHz to 9.15 at 18 GHz, and the ε" value decreases from 3.94 at 2 GHz to 18 GHz. The dielectric loss tangent of GO / Ni / CNCs is 3.54 at GHz, with several small peaks. This may be attributed to the large amount of charge carriers brought by excessive CNCs, which, due to their conductivity, cause a considerable amount of electromagnetic waves to be reflected into space under the action of alternating electromagnetic fields on the surface of the conductive current composite material. It is worth noting that GO / Ni / CNCs-2 has a higher dielectric loss tangent than GO / Ni / CNCs-1 and GO / Ni / CNCs-3, thus exhibiting higher electromagnetic wave absorption performance. This is mainly due to two key factors: good impedance matching capability and dissipation capability. The three-dimensional spatial network structure of CNCs, GO, and Ni nanoparticles with an appropriate ratio can produce good impedance matching with free space. The gap spaces in the network structure lead to multiple reflections and scatterings, which is very effective in improving electromagnetic wave absorption. The real and imaginary parts of the complex permeability are approximately 1 and 0, respectively. This result indicates that insufficient nickel nanoparticles have poor magnetic loss capability, but adjusting the impedance matching is useful.

[0049] The electromagnetic wave absorption performance of each sample is as follows: Figure 7-10 As shown in the figure, CNCs have virtually no electromagnetic wave absorption performance. As the amount of CNCs added decreases, the electromagnetic wave absorption performance of the GO / Ni / CNCs composite material first increases and then decreases, with GO / Ni / CNCs-3 exhibiting the best electromagnetic wave absorption performance.

[0050] This film exhibits excellent EMI performance, demonstrating high EMI shielding effectiveness (SE) of 13.90 and 14.25 dB in the X and Ku bands, respectively. This superior performance is attributed to the dense interweaving of GO / Ni / CNCs, which enhances the skin effect and generates significant impedance mismatch. Conductivity testing further validates the significantly improved conductivity of the bilayer PTFE / GO / Ni / CNC film. This innovative design aims to meet the growing demand for advanced materials that can simultaneously provide EWA and shielding in practical applications. The bilayer PTFE / GO / Ni / CNC composite film prepared by laminating the above materials exhibits impressive EMI SE values ​​of 16.01 and 14.93 dB in the X and Ku bands, respectively, reflecting its excellent shielding performance. To understand how single-layer and multilayer structures achieve effective electromagnetic interference shielding, the total shielding effectiveness (SET), absorption shielding effectiveness (SEA), and reflection shielding effectiveness (SER) were analyzed. The SEA values ​​of PTFE / GO / Ni / CNCs-20%, PTFE / GO / Ni / CNCs-50%, and the stacked versions exceeded those of SER, indicating that absorption is the main mechanism of EMW degradation.

[0051] Application Example 2 Applications of PTFE / GO / Ni / CNCs composites in photothermal fields: (2) Each sample was attached to the heat insulation board with heat insulation tape. Under simulated sunlight, the temperature change was recorded every 15 seconds for 6 minutes using an infrared camera. The results are as follows: Figure 15 As shown in figure a, the surface temperature of the PTFE / GO / Ni / CNCs composite film reaches its maximum after 50 seconds.

[0052] (3) When the light source is turned off, it can be seen that the composite film cools down rapidly in a very short time. The results of the continuous heating and cooling test show that the material still has a stable heat absorption capacity after being irradiated by simulated sunlight, indicating that the material does not undergo obvious decomposition and damage after being heated by light.

Claims

1. A method for preparing polytetrafluoroethylene (PTFE) synergistically optimized from graphene oxide and nickel / carbon nanospirals, characterized in that, Includes the following steps: (1) Ni nanoparticles were grown in situ on the surface of CNCs by cation exchange method to obtain Ni / CNCs; In the cation exchange method, 200 mg carbon nanospiroles, 1 mmol nickel chloride, 10 mmol triphenyl phosphite, 10 ml 1-octadecene and 10 mmol hexadecylamine were added to a three-necked flask, and the mixture was purified at 120 °C for 1 h, and then the temperature was raised to 210 °C for 1 h. (2) Anneal the Ni / CNCs; (3) GO is coated onto the surface of Ni / CNCs by electrostatic self-assembly to form a GO / Ni / CNCs composite material; (4) Fill GO / Ni / CNCs into PTFE, mix, stir and roll to make PTFE / GO / Ni / CNCs composite film.

2. The method according to claim 1, characterized in that: In step (2), annealing is performed in an argon atmosphere with an argon flow rate of 35-45 mL / min.

3. The method according to claim 1, characterized in that: In step (2), the annealing temperature is 430-450 ℃, the annealing time is 1-5 h, and the heating rate is 2-5 ℃ / min.

4. The method according to claim 3, characterized in that: The annealing temperature was 450 ℃, the annealing time was 2 h, and the heating rate was 3 ℃ / min.

5. The method according to claim 1, characterized in that: In step (3), GO uses graphene oxide aqueous dispersion, which is diluted with ultrapure water at a mass ratio of 1:

200. The coating is carried out at 80 °C for 10 h.

6. The method according to claim 1, characterized in that: In step (4), GO / Ni / CNCs and PTFE emulsion are uniformly mixed at mass ratios of 1:4 and 1:1, respectively, and thin films with GO / Ni / CNCs contents of 20 wt.% and 50 wt.% are rolled and pressed together to form a bilayer film.

7. The method according to any one of claims 1-6, characterized in that: Carbon nanospirals were prepared by the following method: Potassium sodium tartrate tetrahydrate was reacted with copper chloride to obtain copper tartrate sulfate powder, which was then reduced at 290 °C under an acetylene atmosphere for 30 min to obtain the precursor, and then carbonized at 800 °C under an argon atmosphere for 2 hours.

8. A PTFE / GO / Ni / CNCs composite material prepared by the method of preparing polytetrafluoroethylene synergistically optimized by graphene oxide and nickel / carbon nanospirals as described in claim 7.

9. The PTFE / GO / Ni / CNCs composite material according to claim 8, characterized in that: In the PTFE / GO / Ni / CNCs composite material, Ni nanoparticles are uniformly grown on the surface of CNCs, and a GO layer is coated on the surface of the Ni nanoparticles. GO / Ni / CNCs are uniformly embedded inside the PTFE fiber.

10. The application of the PTFE / GO / Ni / CNCs composite material according to claim 8 or 9 in the fields of electromagnetic wave protection or photothermal protection.

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