SiCnw / Ni composite material and preparation method and application thereof

Abstract

The invention discloses a SiCnw / Ni composite material as well as a preparation method and application thereof. The preparation method of the SiCnw / Ni composite material comprises the following steps: putting a substrate material into a deposition cavity of laser chemical vapor deposition equipment, vacuumizing the deposition cavity to 10Pa or below, introducing H2 and carrier gas carrying a precursor, adjusting the deposition pressure to a target value, and stabilizing the deposition pressure; and starting laser to heat the substrate material, raising the temperature of the substrate material to a deposition temperature and starting deposition, after deposition is completed, sequentially stopping introduction of the precursor and the carrier gas, closing the laser, then stopping introduction of H2, vacuumizing the reaction chamber to 20 Pa or below, taking out the substrate material after the substrate material is cooled to the room temperature, and electroplating nickel on the surface of the substrate material. The shielding effectiveness of the prepared SiCnw / Ni composite material reaches 69 dB (8-12 GHz) when the thickness is 0.39 mm, and the SiCnw / Ni composite material is good in flexibility, high in stability and wide in application prospect.

Description

Technical Field

[0001] This invention belongs to the field of electromagnetic shielding materials technology, and particularly relates to a SiCnw / Ni composite material, its preparation method, and its application. Background Technology

[0002] With the rapid development of 5G mobile communication, the Internet of Things, and intelligent interaction technologies, the complexity of the electromagnetic environment is increasing daily. The secondary pollution problem caused by the high reflectivity of traditional electromagnetic shielding materials has become a core bottleneck restricting the industry's development. Especially in the field of wearable electronics, where devices are densely deployed around the human body, electromagnetic interference (EMI) not only affects the stability of device performance but may also pose a potential threat to human health. Therefore, developing electromagnetic shielding materials with low reflectivity and high absorption characteristics, and achieving efficient electromagnetic energy conversion through synergistic innovation in material systems and structural design, has become a crucial direction that urgently needs breakthroughs in this field.

[0003] The strong electromagnetic wave reflection caused by impedance mismatch in current electromagnetic shielding fabrics stems from the over-reliance on highly conductive networks in traditional designs, which lack active control over the electromagnetic wave energy conversion path. While the concept of constructing Schottky barriers has yielded initial results in other materials, its mechanism of action in electromagnetic wave reflection and absorption loss remains insufficiently understood. More importantly, existing technologies have not yet proposed an effective method for constructing semiconductor nanoframework structures on flexible fabric substrates, resulting in a lack of theoretical support and practical exploration for the electromagnetic interference (EMI) absorption loss mechanism based on Schottky barriers in this field.

[0004] In conclusion, developing flexible composite materials that combine excellent shielding performance with strong absorption capacity has become the key to promoting the development of high-performance electromagnetic shielding fabrics. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the present invention aims to provide a SiCnw / Ni composite material, its preparation method, and its application, in order to solve the problems of strong electromagnetic wave reflection and insufficient absorption capacity caused by impedance mismatch in existing electromagnetic shielding fabrics.

[0006] The objective of this invention is achieved through the following technical solution: A method for preparing a SiCnw / Ni composite material includes the following steps: S1. Place the substrate material into the deposition chamber of the laser chemical vapor deposition equipment, evacuate the deposition chamber to below 10Pa, introduce H2 and carrier gas carrying the precursor, adjust the deposition pressure to the target value and stabilize it. The precursor contains a silicon source and a carbon source; S2. Turn on the laser to heat the substrate material until its temperature reaches the deposition temperature and deposition begins. After deposition is complete, stop the supply of precursor and carrier gas in sequence, turn off the laser, then stop the supply of H2, evacuate the reaction chamber to below 20 Pa, and remove the substrate material after it has cooled to room temperature. S3. Electroplating nickel onto the surface of the sample after cooling in step S2 yields the SiCnw / Ni composite material.

[0007] In this invention, SiC nanowhiskers (SiCnw) are prepared using laser chemical vapor deposition. The structure of the SiC nanowhiskers is controlled by adjusting the supersaturation of the precursor through deposition process parameters, and the loading of Ni nanoparticles is controlled by electroplating. The SiCnw / Ni composite material prepared by this invention forms a large number of nanoscale Schottky heterostructures. The multiple reflections and interfacial polarization at the interface improve the electromagnetic absorption efficiency, while its porous structure significantly enhances the multiple reflections of electromagnetic waves. Therefore, the composite material has excellent electromagnetic shielding performance.

[0008] Preferably, the flow rate of H2 in step S1 is 200~2000 sccm; more preferably, the flow rate of H2 is 500 sccm.

[0009] Preferably, the flow rate of the precursor in step S1 is 3~9 sccm; the flow rate of the carrier gas is 25~100 sccm; and the flow rate of the carrier gas is 6 sccm.

[0010] Preferably, the deposition pressure in step S1 is 500~3000 Pa.

[0011] Preferably, in the precursor composition of step S1, the carbon source is at least one selected from hexamethyldisilane (HMDS), methyltrichlorosilane, methane, and propane.

[0012] Preferably, in the precursor composition of step S1, the silicon source is at least one of hexamethyldisilane, methyltrichlorosilane, and silicon chloride.

[0013] Preferably, the substrate material in step S1 is one of carbon cloth, graphite paper, and graphite felt.

[0014] Preferably, the carrier gas in step S1 is Ar.

[0015] Preferably, the deposition temperature in step S2 is 1000~1300℃ and the deposition time is 10~60min; more preferably, the deposition temperature is 1050℃ and the deposition time is 20min.

[0016] Preferably, in step S2, after the laser is turned off, H2 is stopped when the temperature of the substrate material drops to 120~200℃.

[0017] Preferably, step S2 further includes treating the sample, which has been cooled to room temperature, in concentrated nitric acid for 15-60 minutes, followed by rinsing several times with deionized water. The concentrated nitric acid treatment is used to activate the sample surface.

[0018] Preferably, the specific operation steps for electroplating nickel in step S3 are as follows: The cooled sample was used as the cathode, and the nickel plate as the anode. The electrode size was 20 mm × 30 mm, and the electrode spacing was 1.5 ~ 3 cm. Electroplating was carried out at an electrolyte temperature of 25 ~ 35 °C and a pH of 2 ~ 5, with a current density of 0.03 ~ 0.15 A / cm² and an electroplating time of 0.5 ~ 10 min. The electrolyte composition was as follows: NiSO4·6H2O 50 ~ 150 g / L, NiCl2·6H2O 15 ~ 50 g / L, H3BO3 15 ~ 50 g / L.

[0019] The SiCnw / Ni composite material prepared by the above method is an example of a SiCnw / Ni composite material.

[0020] The aforementioned SiCnw / Ni composite material has applications as electromagnetic interference shielding fabrics. For example, it can be used as a shielding layer for aircraft electronic systems or in aerospace protective clothing. Simultaneously, it can also be used to develop smart medical textiles with multiple functions such as body temperature regulation and motion monitoring.

[0021] Compared with the prior art, the beneficial effects of the present invention include: (1) The SiCnw / Ni composite material provided by the present invention has an electromagnetic shielding effectiveness of 69dB at 8~12GHz with a thickness of 0.39mm, and has good flexibility and long-term stability, and has broad application prospects in the field of electromagnetic shielding.

[0022] (2) The preparation method of the present invention is simple, has a short cycle and good repeatability. Attached Figure Description

[0023] Figure 1 The XRD diffraction patterns are of the final products obtained from carbon cloth, Example 1, Comparative Example 1, and Comparative Example 2.

[0024] Figure 2 Field emission scanning electron microscope images of the final products obtained from carbon cloth, Example 1, Comparative Example 1, and Comparative Example 2.

[0025] Figure 3 Field emission scanning electron microscope (FESEM) image and EDS elemental mapping image of the SiCnw / Ni composite material prepared in Example 2.

[0026] Figure 4The graph shows the comparison of the resistance change and electromagnetic shielding performance of the SiCnw / Ni composite material prepared in Example 2 before and after 1000 repeated bending cycles.

[0027] Figure 5 This is a transmission electron microscope image of the SiCnw / Ni composite material prepared in Example 3.

[0028] Figure 6 The XRD diffraction patterns are those of the SiCnw / Ni composite materials prepared in Examples 1-4.

[0029] Figure 7 The graphs show the comparison of dielectric constant and electromagnetic shielding performance of the SiCnw / Ni composite materials prepared in Examples 1-4.

[0030] Figure 8 for Figure 1 The graph shows a comparison of the conductivity and electromagnetic shielding performance of the final products obtained from carbon cloth, Example 2, Comparative Example 1, and Comparative Example 2. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0032] Example 1 A method for preparing SiCnw / Ni composite material, the specific steps of which are as follows: (1) Place the cleaned carbon cloth substrate (30mm×20mm×0.3mm) into the deposition chamber of the laser chemical vapor deposition equipment and adjust the position of the substrate so that it is within the laser coverage area; evacuate the deposition chamber to below 10Pa, introduce H2 and Ar carrying the precursor HMDS, the purity of H2 is 99.999 vol%, the flow rate of H2 is 500 sccm, the purity of Ar is 99.999 vol%, the flow rate of Ar is 25 sccm, the flow rate of HMDS is 6 sccm, adjust the deposition pressure to 2000Pa and stabilize for 5min; (2) Turn on the laser to irradiate the carbon cloth substrate. The laser wavelength is 1000nm. The substrate surface is heated to 1050℃ for deposition. The deposition time is 20min. After deposition, turn off HMDS, carrier gas Ar and laser in sequence. When the substrate temperature shows 150℃, turn off H2 and evacuate to below 20Pa to cool the substrate to room temperature. Take out the substrate material. Place the sample that has been cooled to room temperature in concentrated nitric acid for 30min and then wash it several times with deionized water. (3) The sample after being washed several times with deionized water was used as the cathode and the nickel plate as the anode. The electrode size was 20mm×30mm and the electrode spacing was 2cm. Electroplating was carried out at an electrolyte temperature of 30℃ and pH=3, with a current density of 0.09 A / cm² and an electroplating time of 5min. The electrolyte composition was as follows: NiSO4·6H2O 75g / L, NiCl2·6H2O 25g / L, H3BO3 25g / L. After electroplating, SiCnw / Ni composite material was obtained with a total thickness of 0.39mm.

[0033] Example 2 A method for preparing SiCnw / Ni composite material, the specific steps of which are as follows: (1) Place the cleaned carbon cloth substrate (30mm×20mm×0.3mm) into the deposition chamber of the laser chemical vapor deposition equipment and adjust the position of the substrate so that it is within the laser coverage area; evacuate the deposition chamber to below 10Pa, introduce H2 and Ar carrying the precursor HMDS, the purity of H2 is 99.999 vol%, the flow rate of H2 is 500 sccm, the purity of Ar is 99.999 vol%, the flow rate of Ar is 25 sccm, the flow rate of HMDS is 6 sccm, adjust the deposition pressure to 2000Pa and stabilize for 5min; (2) Turn on the laser to irradiate the carbon cloth substrate. The laser wavelength is 1000nm. The substrate surface is heated to 1050℃ for deposition. The deposition time is 20min. After deposition, turn off HMDS, carrier gas Ar and laser in sequence. When the substrate temperature shows 150℃, turn off H2 and evacuate to below 20Pa to cool the substrate to room temperature. Take out the substrate material. Place the sample that has been cooled to room temperature in concentrated nitric acid for 30min and then wash it several times with deionized water. (3) The sample after being washed several times with deionized water was used as the cathode and the nickel plate as the anode. The electrode size was 20mm×30mm and the electrode spacing was 2cm. Electroplating was carried out at an electrolyte temperature of 30℃ and pH=3, with a current density of 0.09 A / cm² and an electroplating time of 3min. The electrolyte composition was as follows: NiSO4·6H2O 75g / L, NiCl2·6H2O 25g / L, H3BO3 25g / L. After electroplating, SiCnw / Ni composite material was obtained with a total thickness of 0.37mm.

[0034] Figure 3 Figures 1-2 show the field emission scanning electron microscope (FESEM) image and EDS elemental mapping of the SiCnw / Ni composite material prepared in Example 2. (a) is the FESEM image, (b) shows the overall EDS analysis results, and (c)-(e) are the EDS elemental distribution maps of C, Si, and Ni, respectively. Figure 3As shown, the results indicate that C, Si, and Ni are uniformly distributed in this material.

[0035] Figure 4 The graphs show the changes in electrical resistance and electromagnetic shielding performance of the SiCnw / Ni composite material prepared in Example 2 before and after 1000 repeated bending cycles. (a) corresponds to the resistance change curve, and (b) corresponds to the electromagnetic shielding performance change curve. Figure 4 As shown, only a relatively small increase in resistance was observed after 1000 cycles of flexural release testing. Furthermore, the EMI shielding efficiency of this composite material remained almost unchanged, indicating that the SiCnw / Ni composite material prepared in this invention possesses excellent flexibility and long-term stability as an EMI shielding fabric.

[0036] Example 3 A method for preparing SiCnw / Ni composite material, the specific steps of which are as follows: (1) Place the cleaned carbon cloth substrate (30mm×20mm×0.3mm) into the deposition chamber of the laser chemical vapor deposition equipment and adjust the position of the substrate so that it is within the laser coverage area; evacuate the deposition chamber to below 10Pa, introduce H2 and Ar carrying the precursor HMDS, the purity of H2 is 99.999 vol%, the flow rate of H2 is 500 sccm, the purity of Ar is 99.999 vol%, the flow rate of Ar is 25 sccm, the flow rate of HMDS is 6 sccm, adjust the deposition pressure to 2000Pa and stabilize for 5min; (2) Turn on the laser to irradiate the carbon cloth substrate. The laser wavelength is 1000nm. The substrate surface is heated to 1050℃ for deposition. The deposition time is 20min. After deposition, turn off HMDS, carrier gas Ar and laser in sequence. When the substrate temperature shows 150℃, turn off H2 and evacuate to below 20Pa to cool the substrate to room temperature. Take out the substrate material. Place the sample that has been cooled to room temperature in concentrated nitric acid for 30min and then wash it several times with deionized water. (3) The sample after being washed several times with deionized water was used as the cathode and the nickel plate as the anode. The electrode size was 20mm×30mm and the electrode spacing was 2cm. Electroplating was carried out at an electrolyte temperature of 30℃ and pH=3, with a current density of 0.09 A / cm² and an electroplating time of 1min. The electrolyte composition was as follows: NiSO4·6H2O 75g / L, NiCl2·6H2O 25g / L, H3BO3 25g / L. After electroplating, SiCnw / Ni composite material was obtained with a total thickness of 0.35mm.

[0037] Figure 5 The image shown is a transmission electron microscope image of the SiCnw / Ni composite material prepared in Example 3. Figure 5As shown, the darker-contrast Ni grains cluster together and are randomly distributed on top of the brighter-contrast SiC nanocrystals (see (a)). The interlayer spacing of the lattice fringes circled in (b) is 0.204 nm, an estimate consistent with the estimated interlayer spacing of the (111) layer of metallic Ni, corresponding to the Ni (111) plane. In the bright contrast region corresponding to the SiC crystal phase, the interlayer spacing of the observable lattice fringes is approximately 0.252 nm, corresponding to the SiC (111) crystal plane.

[0038] Example 4 A method for preparing SiCnw / Ni composite material, the specific steps of which are as follows: (1) Place the cleaned carbon cloth substrate (30mm×20mm×0.3mm) into the deposition chamber of the laser chemical vapor deposition equipment and adjust the position of the substrate so that it is within the laser coverage area; evacuate the deposition chamber to below 10Pa, introduce H2 and Ar carrying the precursor HMDS, the purity of H2 is 99.999 vol%, the flow rate of H2 is 500 sccm, the purity of Ar is 99.999 vol%, the flow rate of Ar is 25 sccm, the flow rate of HMDS is 6 sccm, adjust the deposition pressure to 2000Pa and stabilize for 5min; (2) Turn on the laser to irradiate the carbon cloth substrate. The laser wavelength is 1000nm. The substrate surface is heated to 1050℃ for deposition. The deposition time is 20min. After deposition, turn off HMDS, carrier gas Ar and laser in sequence. When the substrate temperature shows 150℃, turn off H2 and evacuate to below 20Pa to cool the substrate to room temperature. Take out the substrate material. Place the sample that has been cooled to room temperature in concentrated nitric acid for 30min and then wash it several times with deionized water. (3) The sample after being washed several times with deionized water was used as the cathode and the nickel plate as the anode. The electrode size was 20mm×30mm and the electrode spacing was 2cm. Electroplating was carried out at an electrolyte temperature of 30℃ and pH=3, with a current density of 0.09 A / cm² and an electroplating time of 0.5min. The electrolyte composition was as follows: NiSO4·6H2O 75g / L, NiCl2·6H2O 25g / L, H3BO3 25g / L. After electroplating, SiCnw / Ni composite material was obtained with a total thickness of 0.34mm.

[0039] Comparative Example 1 A method for preparing a silicon carbide / carbon cloth composite material, the specific steps of which are as follows: (1) Place the cleaned carbon cloth substrate (30mm×20mm×0.3mm) into the deposition chamber of the laser chemical vapor deposition equipment and adjust the position of the substrate so that it is within the laser coverage area; evacuate the deposition chamber to below 10Pa, introduce H2 and Ar carrying the precursor HMDS, the purity of H2 is 99.999 vol%, the flow rate of H2 is 500 sccm, the purity of Ar is 99.999 vol%, the flow rate of Ar is 25 sccm, the flow rate of HMDS is 6 sccm, adjust the deposition pressure to 2000Pa and stabilize for 5min; (2) Turn on the laser to irradiate the carbon cloth substrate. The laser wavelength is 1000nm. The substrate surface is heated to 1200℃ for deposition. The deposition time is 20min. After the deposition is completed, turn off HMDS, carrier gas Ar and laser in sequence. When the substrate temperature shows 150℃, turn off H2 and evacuate to below 20Pa to cool the substrate to room temperature. The silicon carbide / carbon cloth composite material is obtained with a total thickness of 0.34mm.

[0040] Comparative Example 2 A method for preparing a Ni / carbon cloth composite material, the specific steps of which are as follows: (1) At room temperature, the cleaned carbon cloth substrate (30mm×20mm×0.3mm) sample was placed in concentrated nitric acid for 30min and then washed several times with deionized water; (2) The sample after being washed several times with deionized water was used as the cathode and the nickel plate as the anode. The electrode size was 20mm×30mm and the electrode spacing was 2cm. Electroplating was carried out at an electrolyte temperature of 30℃ and pH=3, with a current density of 0.09 A / cm² and an electroplating time of 3min. The electrolyte composition was as follows: NiSO4·6H2O 75g / L, NiCl2·6H2O 25g / L, H3BO3 25g / L. After electroplating, SiCnw / Ni composite material was obtained with a total thickness of 0.36mm.

[0041] Figure 1 The XRD diffraction patterns of the final products obtained from carbon cloth, Example 1, Comparative Example 1, and Comparative Example 2 are shown below. Figure 1 As shown, after SiC deposition, obvious XRD diffraction peaks appear at 2θ = 35.6°, 60.0°, and 71.8°, which are attributed to the (111), (220), and (311) crystal planes of SiC, respectively. The shoulder peak observed at 2θ = 33.8° is related to the formation of twins (TB), and the presence of TB helps promote the growth of one-dimensional SiC nanostructures. After Ni was electroplated on the SiC layer surface, new diffraction peaks appeared at 2θ = 44.5°, 51.8°, and 76.4°, corresponding to the (111), (200), and (220) crystal planes of Ni, respectively, indicating that the metallic phase dominates in the Ni nanoparticles.

[0042] Figure 2 Field emission scanning electron microscope (FESEM) images of the final products obtained from carbon cloth, Example 1, Comparative Example 1, and Comparative Example 2, where (a) corresponds to carbon cloth, (b) and (c) correspond to Comparative Example 1, (d) corresponds to Comparative Example 2, and (e) and (f) correspond to Example 1. Figure 2 As shown, the original carbon fiber surface is smooth. Subsequently, the deposited SiC encapsulates the carbon fiber, forming needle-like nanocrystals. In addition, when Ni particles are directly electroplated onto the carbon fiber, the Ni particles form a uniform and complete coating on the carbon fiber surface. By further electroplating Ni particles on top of SiCnw, the entire surface of the carbon fiber is covered by SiCnw / Ni, forming a composite material.

[0043] Figure 6 The XRD diffraction patterns of the SiCnw / Ni composite materials prepared in Examples 1-4 are shown below. Figure 6 As shown, with the increase of electroplating time, the diffraction peak intensity of Ni gradually increases, while the diffraction peak intensity of SiC gradually decreases, indicating that the porous SiC layer is covered by the Ni layer.

[0044] Figure 7 The graphs show the dielectric constant and electromagnetic shielding performance of the SiCnw / Ni composite materials prepared in Examples 1-4. (a) shows the real part of the dielectric constant as a function of frequency; (b) shows the imaginary part of the dielectric constant as a function of frequency; and (c) shows the electromagnetic shielding effectiveness (SE). T The curve of SE versus frequency, (d) is the SE curve. T SE R and SE A The change curve. For example... Figure 7 As shown, both the real and imaginary parts of the dielectric constant increase with increasing electroplating time. It is well known that the imaginary part of the dielectric constant reflects the dielectric loss capability of a material, mainly originating from mechanisms such as interface polarization and dipole relaxation. Therefore, in Example 1, due to the enhanced dielectric loss, the electromagnetic wave attenuation capability is significantly improved, and the improvement in its EMI shielding performance is mainly attributed to absorption loss (SE). A The significant increase in reflection loss (SE) and the significant increase in reflection loss (SE) R The SE of Example 1 remains almost unchanged. A Total shielding effectiveness (SE) TThe values ​​of both were the highest, which is closely related to the enhanced dielectric loss. With prolonged Ni plating time, more Ni nanoparticles were deposited on the carbon cloth surface, increasing the Schottky contacts and enhancing interfacial polarization and electromagnetic wave absorption capabilities. These results indicate that the Schottky junction plays a crucial role in electromagnetic shielding. By constructing a Schottky junction through interface engineering, this composite material achieved an excellent EMI shielding performance of 68.6 dB (8–12 GHz) with an ultrathin thickness of only 0.39 mm.

[0045] Figure 8 for Figure 1 The graphs show a comparison of the conductivity and electromagnetic shielding performance of the final products obtained from carbon cloth, Example 2, Comparative Example 1, and Comparative Example 2. (a) is a bar chart comparing conductivity, and (b) is a graph showing the electromagnetic shielding performance of the final products. A The curves showing the change of SE with frequency, (c) represents SE. T The curve showing the change of frequency, (d) represents SE. A / SE T SE R / SE T A comparison curve of de. For example... Figure 8 As shown, the original carbon cloth, a conductive network constructed from carbon fibers, exhibits a conductivity as high as 23.2 S·cm. -1 With its high conductivity, this material achieves a total electromagnetic shielding effectiveness (SE) of 43.6 dB without any coating. T ), reflection loss (SE) R ) accounts for SE T The proportion is approximately 35%, due to its lower skin depth for incident electromagnetic waves. The conductivity of the Comparative Example 1 sample, after SiC nanowhisk deposition, is slightly lower than that of the original carbon cloth. This is because the conductive network of the original carbon cloth may be interfered with by the SiC covering the top of each carbon fiber, limiting the transport of free electrons. Nevertheless, the absorption loss (SE) of Comparative Example 1 is... A ) and total shielding effectiveness (SE) T All of them have improved, and their SE R The reduction and SE A The enhancement may be related to the reduction in conductivity and the improvement of impedance mismatch through SiC deposition.

[0046] The specific embodiments of the present invention described above do not constitute a limitation on the scope of protection of the present invention. Any other corresponding changes and modifications made in accordance with the technical concept of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A method for preparing a SiCnw / Ni composite material, characterized in that, Includes the following steps: S1. Place the substrate material into the deposition chamber of the laser chemical vapor deposition equipment, evacuate the deposition chamber to below 10Pa, introduce H2 and carrier gas carrying the precursor, adjust the deposition pressure to the target value and stabilize it. The precursor contains a silicon source and a carbon source; S2. Turn on the laser to heat the substrate material until its temperature reaches the deposition temperature and deposition begins. After deposition is complete, stop the supply of precursor and carrier gas in sequence, turn off the laser, then stop the supply of H2, evacuate the reaction chamber to below 20 Pa, and remove the substrate material after it has cooled to room temperature. S3. Electroplating nickel onto the surface of the sample after cooling in step S2 yields the SiCnw / Ni composite material.

2. The method for preparing the SiCnw / Ni composite material according to claim 1, characterized in that, The flow rate of H2 in step S1 is 200~2000 sccm; and / or The flow rate of the precursor in step S1 is 3~9 sccm; the flow rate of the carrier gas is 25~100 sccm.

3. The method for preparing the SiCnw / Ni composite material according to claim 1, characterized in that, The deposition pressure in step S1 is 500~3000 Pa.

4. The method for preparing the SiCnw / Ni composite material according to claim 1, characterized in that, In step S1, the carbon source in the precursor composition is at least one selected from hexamethyldisilane, methyltrichlorosilane, methane, and propane; and / or In the precursor composition described in step S1, the silicon source is at least one of hexamethyldisilane, methyltrichlorosilane, and silicon chloride.

5. The method for preparing the SiCnw / Ni composite material according to claim 1, characterized in that, The substrate material in step S1 is one of carbon cloth, graphite paper, and graphite felt; and / or The carrier gas in step S1 is Ar.

6. The method for preparing the SiCnw / Ni composite material according to claim 1, characterized in that, The deposition temperature in step S2 is 1000~1300℃, and the deposition time is 10~60 min; and / or In step S2, after the laser is turned off, H2 is stopped when the temperature of the substrate material drops to 120~200℃.

7. The method for preparing the SiCnw / Ni composite material according to claim 1, characterized in that, Step S2 also includes placing the sample, which has been cooled to room temperature, in concentrated nitric acid for 15-60 minutes, followed by washing it several times with deionized water.

8. The method for preparing the SiCnw / Ni composite material according to claim 1, characterized in that, The specific steps for electroplating nickel in step S3 are as follows: The cooled sample was used as the cathode, and the nickel plate as the anode. The electrode size was 20 mm × 30 mm, and the electrode spacing was 1.5 ~ 3 cm. Electroplating was carried out at an electrolyte temperature of 25 ~ 35 °C and a pH of 2 ~ 5, with a current density of 0.03 ~ 0.15 A / cm² and an electroplating time of 0.5 ~ 10 min. The electrolyte composition was as follows: NiSO4·6H2O 50 ~ 150 g / L, NiCl2·6H2O 15 ~ 50 g / L, H3BO3 15 ~ 50 g / L.

9. A SiCnw / Ni composite material, characterized in that, It is prepared by the preparation method of SiCnw / Ni composite material according to any one of claims 1 to 8.

10. The application of the SiCnw / Ni composite material of claim 9 as an electromagnetic interference shielding fabric.

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