A method for eliminating electromagnetic radiation based on graphene oxide

Abstract

The electromagnetic radiation elimination method based on graphene oxide of the present invention dopes layered iron cobalt nickel hydroxide into graphene oxide, resulting in a richer interface between graphene oxide and layered iron cobalt nickel hydroxide; enhancing interface polarization; and the rich interface between layered iron cobalt nickel hydroxide and graphene oxide can provide multiple scattering and reflection. After doping, lattice distortion will occur, resulting in enhanced dielectric loss; and when the matching thickness of LDH / G is 4.5 mm, the minimum reflection loss reaches -46.1 dB at 14.38 GHz, and the effective absorption band is 5.9 GHz, thus possessing excellent electromagnetic radiation elimination ability; at the same time, it has the advantages of thin thickness, light weight, wide absorption frequency band, high absorption intensity, and meets the performance requirements of high temperature resistance and acid and alkali resistance.

Description

Technical Field

[0001] The present invention relates to the technical field of electromagnetic radiation elimination, and particularly to an electromagnetic radiation elimination method based on graphene oxide. Background Art

[0002] In the past decade, under the influence of Moore's Law, the performance of chips has been rapidly improved, and modern electronic technology has entered a new era of development. Electronic devices such as mobile phones, televisions, and computers have entered the daily lives of the general public. These electronic devices have greatly improved the production and living efficiency of mankind. However, wireless electronic devices will radiate electromagnetic waves (EMW) during operation, causing electromagnetic interference (EMI). The electromagnetic radiation generated during their operation has an adverse impact on the human body. High-intensity electromagnetic radiation, on the one hand, inhibits the proliferation of immune cells in the body, and on the other hand, accelerates the carcinogenesis of cells, thus increasing the probability of humans getting cancer. Research shows that electromagnetic radiation will, to a certain extent, affect the development of fetuses and cause fetal deformities. People's living environment is filled with electromagnetic waves everywhere, and then electromagnetic pollution has become a new type of pollution source. At the same time, electromagnetic radiation and electromagnetic interference also pose severe challenges to information security and the normal operation of electronic devices.

[0003] Therefore, in order to address the above-mentioned electromagnetic radiation problems, people have accelerated the research on electromagnetic wave absorption materials and electromagnetic radiation elimination methods.

[0004] The existing electromagnetic radiation elimination methods mainly use electromagnetic shielding materials to address the increasingly serious problems of electromagnetic interference and pollution. The existing technologies use traditional metals such as steel, copper, and aluminum, as well as alloys. Due to their high electrical conductivity, they are widely used in electromagnetic radiation elimination. However, the defects of high density, high rigidity, and susceptibility to corrosion and oxidation of traditional metals and alloys have greatly limited their application scenarios.

[0005] In addition, the most reported in the existing technologies are related to graphene and carbon nanotubes. Among them, graphene oxide (GO) is a two-dimensional carbon nanomaterial. The co-oriented structure of GO is partially repaired, a large number of defects are introduced on the surface of GO due to the reduction of oxygen-containing functional groups, and there are still some residual oxygen-containing functional groups on the surface and edges of GO, such as carboxyl groups, hydroxyl groups, and epoxy groups. Therefore, GO can generate polarization centers through a large number of defects and residual oxygen-containing functional groups on its surface, and attenuate the incident electromagnetic waves through dielectric loss. However, when a single GO material is used as an electromagnetic wave absorption material, there are problems such as poor impedance matching, narrow wave absorption band, and weak absorption of electromagnetic waves. The existing electromagnetic radiation elimination methods mentioned in the existing technologies cannot simultaneously meet the performance requirements of being thin, light in weight, having a wide absorption frequency band, high absorption intensity, and being resistant to high temperatures and acids and alkalis.

[0006] Therefore, those skilled in the art are committed to developing an electromagnetic radiation elimination method based on graphene oxide, aiming to solve the defect problems existing in the prior art. Summary of the Invention

[0007] In view of the above-mentioned defects of the prior art, the technical problem to be solved by the present invention is that in the current prior art, in the elimination of electromagnetic radiation, traditional metals and alloys have the defects of high density, high rigidity, and susceptibility to corrosion and oxidation, which greatly limit the application scenarios of traditional metals and alloys; and when the existing single GO material is used as an electromagnetic wave absorption material, there are problems such as poor impedance matching, narrow wave absorption frequency band, and weak absorption of electromagnetic waves; it is impossible to achieve the performance requirements of being thin in thickness, light in weight, wide in absorption frequency band, high in absorption intensity, and at the same time having high temperature resistance and acid and alkali resistance.

[0008] To achieve the above object, an electromagnetic radiation elimination method based on graphene oxide of the present invention includes the following steps:

[0009] Step 1: Mix graphite and sodium nitrate, and then add concentrated sulfuric acid while stirring and mixing the three to make them evenly stirred and mixed.

[0010] Step 2: Place the product obtained in Step 1 under the condition of an ice-water bath, gradually add potassium permanganate, and after complete addition, maintain the ice-water bath and continuously stir and react for 1 - 2 h.

[0011] Step 3: After the stirring in Step 2 is completed, carry out a medium-temperature water bath heating reaction, and continue to maintain stirring, keep the medium-temperature water bath temperature, and continuously stir and react for 1 - 2 h.

[0012] Step 4: After the stirring in Step 3 is completed, add deionized water, then carry out a high-temperature water bath heating reaction, and continue to maintain stirring, keep the high-temperature water bath temperature, and continuously stir and react for 1 - 2 h to obtain graphene oxide colloid.

[0013] Step 5: Preheat the layered iron-cobalt-nickel hydroxide under vacuum conditions to remove impurities and obtain pure layered iron-cobalt-nickel hydroxide.

[0014] Step 6: Mix the graphene oxide colloid, pure layered iron-cobalt-nickel hydroxide and coupling agent and carry out ball milling.

[0015] In Step 1, the molar ratio of graphite to sodium nitrate is 1:1 - 2:1.

[0016] In Step 1, the molar ratio of graphite to concentrated sulfuric acid is 1:22 - 1:32.

[0017] Step 2: Under the condition of an ice-water bath, add a certain amount of potassium permanganate to a beaker. After complete addition, maintain the ice-water bath and continuously stir and react for 1 - 2 h.

[0018] The molar ratio of potassium permanganate added in step 2 to graphite added in step 1 is 3:1 to 5:1;

[0019] The addition process time of potassium permanganate in step 2 is not less than 30 min;

[0020] Step 3: After the stirring in step 2 is completed, carry out medium-temperature water bath heating reaction, and continue to maintain stirring, keep the medium-temperature water bath temperature, and continuously stir and react for 1 - 2 h;

[0021] The medium-temperature water bath temperature in step 3 is controlled at 34 - 38 °C;

[0022] Step 4: After the stirring in step 3 is completed, measure a certain amount of deionized water and pour it into a beaker, then carry out high-temperature water bath heating reaction, and continue to maintain stirring, keep the high-temperature water bath temperature, and continuously stir and react for 1 - 2 h;

[0023] The molar ratio of deionized water in step 4 to concentrated sulfuric acid added in step 1 is 3:1 to 2:1;

[0024] The high-temperature water bath temperature in step 4 is controlled at 96 - 98 °C;

[0025] After the high-temperature water bath heating in step 4 is completed, graphene oxide colloid is obtained;

[0026] Step 5: Preheat the layered iron cobalt nickel hydroxide under vacuum conditions;

[0027] The preheating temperature in step 5 is 100 °C;

[0028] The preheating time in step 5 is 2 - 3 h;

[0029] Step 6: Add the product obtained in step 4, the product obtained in step 5, and a certain amount of coupling agent into the ball milling tank body, and perform high-energy ball milling preparation;

[0030] Before use, the ball milling tank body and ball milling steel balls are cleaned with absolute ethanol;

[0031] The product obtained in step 4 needs to be washed to neutral and dried before being put into the ball milling tank body;

[0032] The addition amount of the coupling agent in step 6 is 2% - 3% of the total weight of the overall raw materials;

[0033] In step 6, the mass ratio of ball milling steel balls to raw materials is 1:10; and an appropriate amount of absolute ethanol needs to be added to submerge the raw materials and steel balls;

[0034] In step 6, after stirring evenly with a glass rod, it is hermetically loaded into a swing vibration ball mill for ball milling treatment;

[0035] The ball milling time in step 6 is 1 h to 2 h. After ball milling is completed, the obtained slurry needs to be placed in a vacuum drying oven for drying.

[0036] Further, when pouring concentrated sulfuric acid into the beaker in step 1, it needs to be slowly poured along the inner wall of the beaker.

[0037] Further, the graphite in step 1 is flake graphite, and the mesh number of the flake graphite is 325 mesh.

[0038] Further, the temperature of the ice-water bath in step 2 should be controlled at 3 to 5 °C.

[0039] Further, the purpose of preheating in step 5 is to eliminate the possible low-melting-point impurities on the surface of the layered iron cobalt nickel hydroxide.

[0040] Further, the coupling agent in step 6 is specifically calcium stearate.

[0041] Further, the material of the ball milling steel balls in step 6 is cemented carbide, and the diameter is 6 mm.

[0042] Further, the drying temperature of the vacuum drying oven in step 6 is 50 to 55 °C.

[0043] Further, after obtaining the dried product in step 6, the obtained product can be subjected to relevant electromagnetic radiation absorption performance tests.

[0044] Adopting the above solution, the electromagnetic radiation elimination method based on graphene oxide disclosed by the present invention has the following advantages:

[0045] (1) In the electromagnetic radiation elimination method based on graphene oxide of the present invention, layered iron cobalt nickel hydroxide is doped into graphene oxide, so that richer interfaces are generated between graphene oxide and layered iron cobalt nickel hydroxide; interfacial polarization usually occurs in a heterojunction structure with rich interfacial charge accumulation, and the huge difference in conductivity between layered iron cobalt nickel hydroxide and graphene oxide and the rich interfaces make the interfacial polarization enhanced; and the rich interfaces between layered iron cobalt nickel hydroxide and graphene oxide can provide multiple scattering and reflection, and lattice distortion will occur after doping, resulting in enhanced dielectric loss; thus, it has excellent electromagnetic radiation elimination ability.

[0046] (2) For the electromagnetic radiation elimination method based on graphene oxide of the present invention, when the matching thickness of LDH / G is 4.5 mm, the minimum reflection loss reaches -46.1 dB at 14.38 GHz, and the effective absorption band is 5.9 GHz. Compared with the prior art, the present invention has excellent electromagnetic radiation elimination ability, and at the same time, it has the advantages of thin thickness, light weight, wide absorption frequency band, high absorption intensity, and meets the performance requirements of high temperature resistance and acid and alkali resistance;

[0047] In summary, for the electromagnetic radiation elimination method based on graphene oxide disclosed in the present invention, layered iron cobalt nickel hydroxide is doped in graphene oxide, which makes the interface between graphene oxide and layered iron cobalt nickel hydroxide richer; the interface polarization is enhanced; and the rich interface between layered iron cobalt nickel hydroxide and graphene oxide can provide multiple scattering and reflection. After doping, lattice distortion will occur, resulting in enhanced dielectric loss; thus, it has excellent electromagnetic radiation elimination ability; at the same time, it has the advantages of thin thickness, light weight, wide absorption frequency band, high absorption intensity, and meets the performance requirements of high temperature resistance and acid and alkali resistance.

[0048] The following will further illustrate the concept, specific technical solutions and technical effects of the present invention in combination with specific embodiments to fully understand the purpose, features and effects of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 is a schematic flow chart of the electromagnetic radiation elimination method based on graphene oxide of the present invention;

[0050] Figure 2 are the reflection loss curves of (a) LDH, (b) LDH / G, and (c) LDH+G samples in Example 1 of the present invention;

[0051] Figure 3 are the three-dimensional reflection loss diagrams of (a) LDH, (b) LDH / G, and (c) LDH+G samples in Example 1 of the present invention;

[0052] Figure 4 is a schematic diagram of the microwave attenuation mechanism of LDH / G in Example 1 of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0053] The following introduces multiple preferred embodiments of the present invention to make its technical content clearer and easier to understand. The present invention can be embodied in many different forms of embodiments, and these embodiments are described by way of example. The protection scope of the present invention is not limited to the embodiments mentioned in the text.

[0054] Example 1. Completing the electromagnetic radiation elimination based on graphene oxide by using the method of the present invention

[0055] As shown in the figure,Figure 1 It is a schematic flow diagram of the electromagnetic radiation elimination method based on graphene oxide of the present invention; First, perform Step 1: Weigh a certain amount of graphite and sodium nitrate and put them into a beaker, and measure a certain amount of concentrated sulfuric acid, pour it into the beaker, and stir and mix the three evenly;

[0056] In Step 1, the molar ratio of graphite to sodium nitrate is 1:1 to 2:1;

[0057] In Step 1, the molar ratio of graphite to concentrated sulfuric acid is 1:22 to 1:32;

[0058] In Step 1, the stirring and mixing speed of the three is medium speed;

[0059] Specifically in implementation, the graphite added in Step 1 of this Example 1 is 6g, sodium nitrate is 4.5g, and concentrated sulfuric acid is 200ml;

[0060] When pouring the concentrated sulfuric acid into the beaker in Step 1, it needs to be slowly poured along the inner wall of the beaker into the beaker;

[0061] The graphite in Step 1 is flake graphite, and the mesh number of the flake graphite is 325 mesh;

[0062] Subsequently, perform Step 2: Under the condition of an ice-water bath, add a certain amount of potassium permanganate to the beaker. After it is completely added, maintain the ice-water bath and continuously stir and react for 1 to 2 hours;

[0063] In Step 2, the molar ratio of the added potassium permanganate to the graphite added in Step 1 is 3:1 to 5:1;

[0064] The time for adding potassium permanganate in Step 2 is not less than 30 minutes;

[0065] Specifically in implementation, a total of 25g of potassium permanganate is added in Step 2 of this Example 1, and the process of adding potassium permanganate is also more than 30 minutes;

[0066] Specifically in implementation, the temperature of the ice-water bath in Step 2 is controlled at 4°C; the time for continuous stirring and reaction is 1 hour;

[0067] After the ice-water bath is completed, Step 3 can be started: Perform medium-temperature water bath heating reaction and continue to maintain medium-speed stirring, keep the medium-temperature water bath temperature, and continuously stir and react for 1 to 2 hours;

[0068] The medium-temperature water bath temperature in Step 3 is controlled at 34 to 38°C;

[0069] Specifically in implementation, the warm water bath temperature of this Example 1 is controlled at 35°C; the time for continuous stirring and reaction is 1 hour;

[0070] After the stirring in Step 3 is completed, then Step 4 is carried out. Measure a certain amount of deionized water and pour it into a beaker. Then, carry out a high-temperature water bath heating reaction and continue to maintain medium-speed stirring, keep the high-temperature water bath temperature, and continuously stir and react for 1 - 2 h;

[0071] The molar ratio of the deionized water in Step 4 to the concentrated sulfuric acid added in Step 1 is 3:1 - 2:1;

[0072] The high-temperature water bath temperature in Step 4 is controlled at 96 - 98 °C;

[0073] After the high-temperature water bath heating in Step 4 is completed, graphene oxide colloid is obtained;

[0074] In specific implementation, the addition amount of deionized water in this Example 1 is 500 ml, the warm water bath temperature is controlled at 98 °C, and the continuous stirring reaction time is 1 h;

[0075] Step 5: Preheat the layered iron cobalt nickel hydroxide under vacuum conditions;

[0076] The molar ratio of the layered iron cobalt nickel hydroxide to the product in Step 5 is 1:1 - 2:1;

[0077] The preheating temperature in Step 5 is 100 °C;

[0078] The preheating time in Step 5 is 2 - 3 h;

[0079] In specific implementation, the addition amount of the layered iron cobalt nickel hydroxide in this Example 1 is 10 g and the preheating time is 2 h;

[0080] The purpose of the preheating in Step 5 is to eliminate the possible low-melting-point impurities on the surface of the layered iron cobalt nickel hydroxide;

[0081] After Step 5 is completed, Step 6 can be carried out. Add the product obtained in Step 4, the product obtained in Step 5, and a certain amount of coupling agent into the ball milling tank body and perform high-energy ball milling preparation;

[0082] Before the ball milling tank body and the ball milling steel balls are used, they need to be cleaned with absolute ethanol;

[0083] The product obtained in Step 4 needs to be washed to neutral and dried before being put into the ball milling tank body;

[0084] The addition amount of the coupling agent in Step 6 is 2% - 3% of the total weight of the overall raw materials;

[0085] In Step 6, the mass ratio of the ball milling steel balls to the raw materials is 1:10; and an appropriate amount of absolute ethanol needs to be added to submerge the raw materials and the steel balls;

[0086] In step 6, after stirring evenly with a glass rod, it is hermetically packed into a swing vibration ball mill for ball milling treatment;

[0087] The ball milling time in step 6 is 1h - 2h. After ball milling is completed, the obtained slurry needs to be put into a vacuum drying oven for drying;

[0088] The coupling agent in step 6 is specifically calcium stearate;

[0089] The material of the ball milling steel balls in step 6 is cemented carbide, and the diameter is 6mm;

[0090] The drying temperature of the vacuum drying oven in step 6 is 50 - 55°C;

[0091] Specifically in implementation, the ball milling time in this Example 1 is 1.5h, and the drying temperature of the vacuum drying oven is 55°C;

[0092] After obtaining the dried product in step 6, the obtained product can be tested for relevant electromagnetic radiation absorption performance;

[0093] The following is the performance result test of this Example 1 for the electromagnetic radiation elimination method using the method of the present invention: The product obtained after going through step 6 is the composite product of layered iron cobalt nickel hydroxide and graphene oxide (abbreviation LDH / G); The comparative examples for performance testing are layered iron cobalt nickel hydroxide (abbreviation LDH), the mixed product of layered iron cobalt nickel hydroxide and graphene oxide (abbreviation LDH + G);

[0094] The reflection loss tests of the above three materials are carried out for samples with different thicknesses, and the electromagnetic frequency for testing is in the range of 2 - 18 GHz; The test results are as follows Figure 2 shown;

[0095] As shown in the figure, Figure 2 a is the reflection loss test of LDH. It can be seen from Figure 2 a that when the matching thickness is 4.0mm and the effective absorption bandwidth is 6.0GHz, the minimum reflection loss at 16.6GHz is -35.2dB;

[0096] As shown in the figure, Figure 2 b is the reflection loss test of LDH / G. It can be seen from Figure 2 b that at 14.38GHz, the best reflection loss of LDH / G can reach -46.1dB, and when the thickness is 4.5mm, the effective absorption bandwidth can reach 5.9GHz;

[0097] As shown in the figure, Figure 2 c is the reflection loss test of LDH + G. When the thickness is 5.0mm, the value of LDH + G is -41.3dB, and the effective absorption bandwidth is 6.1GHz;

[0098] The common feature of the three samples is that as the thickness increases, the reflection loss values all shift to lower frequencies; this indicates that the electromagnetic wave absorption characteristics of the samples can be adjusted by changing the thickness of the absorption layer;

[0099] As Figure 3 shown, Figure 3 is the three-dimensional reflection loss diagram of the three samples. By selecting appropriate thickness and formulation, the LDH / G hybrid material has excellent electromagnetic radiation elimination ability;

[0100] As Figure 4 shown, Figure 4 is a schematic diagram of the microwave attenuation mechanism of LDH / G. The enhanced WMA performance of LDH / G hybridization is mainly because graphene oxide is an excellent dielectric loss material with abundant defects, hydroxyl groups, epoxy groups, carboxyl groups, and a large specific surface area. Secondly, neither pure LDH flakes nor graphene oxide flakes are suitable as ideal absorbers when the dielectric constant is too high or too low. The integration of LDH and graphene oxide can bring good electromagnetic compatibility and electromagnetic behavior; and the in-situ growth of LDH plates on the surface of graphene oxide generates more uniform contact and more interfaces; interfacial polarization usually occurs in heterojunction structures with rich interfacial charge accumulation. Considering the huge difference in conductivity between LDH and GO and the rich interfaces, there must be more interfacial polarization compared to pure candidates and LDH+G mixtures. Finally, the rich interfaces between LDH and GO can provide multiple scattering and reflection; at the same time, lattice distortion will occur after doping, resulting in enhanced dielectric loss;

[0101] Through the electromagnetic radiation elimination method of the present invention, the original characteristics of GO are maintained, and the skin effect and two-dimensional layer superposition are reduced; the binary hybrid structure also causes additional dipole polarization and interfacial polarization; when the matching thickness is 4.5 mm, the minimum reflection loss reaches -46.1 dB at 14.38 GHz, and the effective absorption band is 5.9 GHz.

[0102] Comparative Example 1: Using a single GO material as the electromagnetic wave absorption material to complete electromagnetic radiation elimination

[0103] In the said Comparative Example 1, only a single GO material commonly used in the prior art was used to complete electromagnetic wave absorption; the absorption results show that at the same matching thickness of 4.5 mm, the effective wave absorption bandwidth can reach 4.2 GHz, and the minimum reflection loss reaches -23.6 dB at 8.72 GHz;

[0104] The absorption material of Comparative Example 1 has problems of poor impedance matching, narrow wave absorption band, and weak absorption of electromagnetic waves in practical applications; its ability to eliminate electromagnetic radiation is also slightly weaker.

[0105] In summary, in the patented technical solution, layered iron cobalt nickel hydroxide is doped into graphene oxide, resulting in a richer interface between graphene oxide and layered iron cobalt nickel hydroxide. Interface polarization usually occurs in heterojunction structures with abundant interfacial charge accumulation. The large difference in conductivity between layered iron cobalt nickel hydroxide and graphene oxide and the rich interface enhance the interface polarization. Moreover, the rich interface between layered iron cobalt nickel hydroxide and graphene oxide can provide multiple scattering and reflection, and lattice distortion will occur after doping, leading to enhanced dielectric loss. And when the matching thickness of LDH / G is 4.5 mm, the minimum reflection loss reaches -46.1 dB at 14.38 GHz, and the effective absorption band is 5.9 GHz, thus possessing excellent electromagnetic radiation elimination ability. At the same time, it has the advantages of thin thickness, light weight, wide absorption frequency band, high absorption intensity, and meets the performance requirements of high temperature resistance and acid and alkali resistance.

[0106] The following will further illustrate the concept, specific technical solutions and technical effects of the present invention in combination with specific embodiments to fully understand the purpose, features and effects of the present invention.

[0107] The preferred specific embodiments of the present invention have been described in detail above. It should be understood that those of ordinary skill in the art can make many modifications and variations based on the concept of the present invention without creative work. Therefore, all technical solutions that can be obtained by those skilled in the art in the technical field of the present invention through logical analysis, reasoning or limited experiments based on the concept of the present invention on the basis of the prior art shall fall within the protection scope determined by the claims.

Claims

1. An electromagnetic radiation elimination method based on graphene oxide, characterized in that, it includes the following steps: Step 1: Mix graphite and sodium nitrate, and then add concentrated sulfuric acid while stirring and mixing to make the three evenly stirred and mixed; Step 2: Place the product obtained in Step 1 under the condition of an ice-water bath, gradually add potassium permanganate, and after complete addition, maintain the ice-water bath and continuously stir and react for 1-2 h; Step 3: After the stirring in Step 2 is completed, carry out a medium-temperature water bath heating reaction and continue to maintain stirring, keep the medium-temperature water bath temperature, and continuously stir and react for 1-2 h; Step 4: After the stirring in Step 3 is completed, add deionized water, then carry out a high-temperature water bath heating reaction and continue to maintain stirring, keep the high-temperature water bath temperature, and continuously stir and react for 1-2 h to obtain a graphene oxide colloid; Step 5: Preheat the layered iron cobalt nickel hydroxide under vacuum conditions to remove impurities and obtain pure layered iron cobalt nickel hydroxide; Step 6: Mix the graphene oxide colloid, pure layered iron cobalt nickel hydroxide and a coupling agent for ball milling; The molar ratio of the layered iron cobalt nickel hydroxide to the product is 1:1 - 2:1; The coupling agent is calcium stearate; The addition amount of the coupling agent is 2% - 3% of the total weight of the overall raw materials; The mass ratio of the ball milling steel balls to the raw materials is 1:10; and anhydrous ethanol needs to be added to immerse the raw materials and the steel balls; The ball milling time is 1 h - 2 h, and after ball milling is completed, the obtained slurry needs to be placed in a vacuum drying oven for drying; After obtaining the dried product in Step 6, the obtained product can be tested for relevant electromagnetic radiation absorption performance.

2. The electromagnetic radiation elimination method according to claim 1, characterized in that, in Step 1, the molar ratio of graphite to sodium nitrate is 1:1 - 2:1; in Step 1, the molar ratio of graphite to concentrated sulfuric acid is 1:22 - 1:

32.

3. The electromagnetic radiation elimination method according to claim 1, characterized in that, in Step 2, the molar ratio of the added potassium permanganate to the added graphite in Step 1 is 3:1 - 5:1; the addition process time of potassium permanganate in Step 2 is not less than 30 min.

4. The electromagnetic radiation elimination method according to claim 1, characterized in that, the medium-temperature water bath temperature in Step 3 is controlled at 34 - 38 °C; in Step 4, the molar ratio of the deionized water to the concentrated sulfuric acid added in Step 1 is 3:1 - 2:1; the high-temperature water bath temperature in Step 4 is controlled at 96 - 98 °C; the preheating temperature in Step 5 is 100 °C; the preheating time in Step 5 is 2 - 3 h.

5. The electromagnetic radiation elimination method according to claim 1, characterized in that, before using the ball milling tank body and the ball milling steel balls, they are cleaned with anhydrous ethanol; the product obtained in Step 4 can be put into the ball milling tank body only after being washed to neutral and dried; in Step 6, it needs to be stirred evenly with a glass rod and then hermetically loaded into a swing vibration ball mill for ball milling treatment.

6. The electromagnetic radiation elimination method according to claim 1, characterized in that, the material of the ball milling steel balls in Step 6 is cemented carbide and the diameter is 6 mm; The drying temperature of the vacuum drying oven in step 6 is 50 to 55 °C.

7. The electromagnetic radiation elimination method according to claim 1, characterized in that when pouring concentrated sulfuric acid into the beaker in step 1, it needs to be slowly poured along the inner wall of the beaker; the graphite in step 1 is flake graphite, and the mesh number of the flake graphite is 325 mesh; the temperature of the ice-water bath in step 2 should be controlled at 3 to 5 °C.

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