A ABX3 perovskite composite electromagnetic wave absorbing material and preparation method

Abstract

The present invention discloses an ABX3 perovskite composite electromagnetic wave absorption material and a preparation method, which belongs to the field of electromagnetic wave absorption material preparation. The first step is to prepare ABX3 perovskite by dry grinding, and then dry and heat treat it. The second step is to uniformly mix and compound the prepared ABX3 perovskite with carbon nanotube materials according to different mass ratios. The present invention adopts a solvent-free method to prepare ABX3 perovskite-type absorption material, which is in the form of irregular nanoparticles and forms a conductive network structure with carbon nanotubes. The suitable structure constructed in this way has a strong absorption effect on electromagnetic waves and has a wide absorption band. The material preparation method does not require toxic solvents, has simple synthesis equipment, low cost, few processes, high yield, and is suitable for large-scale preparation.

Description

Technical Field

[0001] The present invention relates to the technical field of electromagnetic wave absorbing materials, and in particular to an ABX3 perovskite-type composite electromagnetic wave absorbing material, and also to a method for preparing the electromagnetic wave absorbing material. Background Art

[0002] With the advancement of modern communications technology, the 5G era has ushered in new opportunities for information exchange within various communication devices. Currently, the application of various electronic instruments and equipment has become widespread across various fields. Electronic devices continuously generate electromagnetic radiation during use, and many precision instruments struggle to perform efficient and accurate calculations due to electromagnetic interference. Consequently, absorbing materials have emerged. When electromagnetic waves are transmitted to absorbing materials, some of the waves are reflected back, while some enter the absorbing material. The absorbing material dissipates the incoming electromagnetic energy by converting it into heat and other forms of energy, thereby achieving effective electromagnetic wave protection. Therefore, the ultimate goal is to develop an absorbing material with high absorption efficiency, a wide effective absorption bandwidth, a thin size, and a low weight.

[0003] Perovskite materials, as dielectric lossy materials, exhibit unique responses in electromagnetic wave environments due to their excellent physicochemical properties and crystal structure. Consequently, recent progress in the field of electromagnetic wave absorption has been made in perovskite materials. Current research on perovskite-type absorbers primarily focuses on perovskite oxides, which can achieve excellent absorption performance through temperature, element doping, and oxygen vacancies. Organic-inorganic lead halide perovskites, a promising semiconductor material, offer simpler and more cost-effective preparation techniques compared to perovskite oxides and possess excellent inherent properties, such as a tunable direct optical bandgap, long carrier lifetime, and high carrier mobility. Theoretically, they should exhibit superior dielectric loss capabilities in electromagnetic wave absorption. Previous reports have also highlighted other dielectric absorbers, such as carbon nanotubes, due to their high surface area and high electrical conductivity. However, these individual materials exhibit relatively limited electromagnetic wave loss mechanisms and narrow effective absorption bandwidths, making them difficult to achieve the broad absorption bandwidth required for absorbers. Currently, introducing other materials has become an important means of enriching its loss modes and broadening its effective absorption bandwidth. However, most current hybrid methods suffer from slow production speeds, low yields, and complex manufacturing processes. Combining perovskite materials with carbon nanotubes leverages their strengths and weaknesses, synergizing their dielectric properties and fully utilizing their electromagnetic loss capabilities. Therefore, the dry-process preparation of organic-inorganic lead halide perovskite materials and carbon nanotubes is conducive to the development of a low-cost, highly absorptive absorber.

[0004] Currently, perovskite-based absorbers require compounding through high-temperature calcination, solvents, and vapor deposition. While these methods yield good absorbers, they are relatively complex and require a high processing environment, making large-scale production difficult. Therefore, the development of new perovskite-based absorbers and their preparation technologies is urgent.

[0005] A wide variety of microwave-absorbing materials are now flourishing. Perovskite materials are thriving in optoelectronics, energy storage, sensors, and other fields. Perovskite oxides have demonstrated significant potential in electromagnetic wave absorption. Halogen perovskites, due to their wavelength tunability, high optical absorption coefficients, and ultra-long carrier diffusion lengths, offer superior electrical properties compared to perovskite oxides and have been actively developed in various optoelectronic fields. However, research on organic-inorganic lead halide perovskite-based microwave-absorbing materials is limited. Summary of the Invention

[0006] The purpose of the present invention is to provide an ABX3 perovskite-type composite electromagnetic wave absorption material. Given that the current perovskite-type oxide wave absorption performance is difficult to meet the technical requirements of "thin, light, wide, and strong", ABX3 has greater dielectric loss control advantages than perovskite-type oxides. By adjusting the composite ratio of ABX3 halogen perovskite and carbon nanotubes, the conductivity of the composite material is changed to achieve efficient absorption of electromagnetic waves at a low thickness.

[0007] Another object of the present invention is to provide a method for preparing an ABX3 perovskite-type composite electromagnetic wave absorbing material. The ABX3 perovskite-type composite electromagnetic wave absorbing material produced by this method exhibits irregularly shaped nanoparticles. The material utilizes inexpensive raw materials, requires minimal equipment, and has a simple preparation process. The method eliminates the need for chemical solvents, resulting in a high product yield. The overall preparation method adheres to the principles of energy conservation and green chemistry.

[0008] The object of the present invention is achieved like this:

[0009] A method for preparing an ABX3 perovskite composite electromagnetic wave absorbing material comprises the following steps:

[0010] (1) Pre-treating the perovskite precursor powders of each component in ABX3, wherein the precursors include a precursor 1 and a precursor 2, wherein the component of the precursor 1 is a mixture of one or more of MACl, MABr, MAI, FACl, FABr, and FAI, and the component of the precursor 2 is one or more of PbCl2, PbBr2, and PbI2 powders, and the obtained powders are first dried by a drying method of vacuum drying, freeze drying, or direct drying;

[0011] (2) weighing and mixing the two components of the dried precursor powder in a 1:1 molar ratio, grinding them by ball milling or grinding under low humidity conditions for no less than 30 minutes to obtain the corresponding ABX3 perovskite powder;

[0012] (3) ABX3 is heated, A is MA + When the heating temperature is 60-80℃, A is FA + When the heating temperature is 150℃-200℃, the A-site ion is (MA x FA 1-x ) + When 0≤x≤1, it needs to be heated at 60-200°C for 10-30 minutes;

[0013] (4) Weighing and mixing the ABX3 perovskite powder and carbon nanotubes in a mass ratio of 1:1 to 5:1 in step (3), stirring and grinding the mixture in a low humidity environment for no more than 20 minutes; or adding n-hexane or cyclohexane, mechanically stirring and mixing the mixture in a micro-solution environment for no more than 30 minutes, and then heating to 40-80° C. and continuing to stir for 10-20 minutes to volatilize the n-hexane or cyclohexane, and finally obtaining an ABX3 perovskite-type composite electromagnetic wave absorbing material.

[0014] A-site ion is (MA + , FA + ), the B-site ion is Pb 2+ , X-site ion is (CL - , Br - , I - ).

[0015] An ABX3 perovskite-type composite electromagnetic wave absorbing material is prepared by the above method.

[0016] Carbon nanotubes are adsorbed and wrapped on the surface of the synthesized perovskite. The carbon nanotubes cross each other and are arranged throughout the synthesized irregular perovskite material to form a carbon chain network and construct a three-dimensional network structure.

[0017] The microscopic morphology of the material is irregular nanoparticles with a particle size of 200nm-1μm.

[0018] The ABX3 perovskite composite electromagnetic wave absorbing material of the present invention is an ABX3 perovskite carbon nanotube composite (A=MA + , FA + ,B=Pb 2+ , X=Cl - Br - , I -), wherein the composite mass ratio of ABX3 to carbon nanotubes is (1:1 to 5:1), the electromagnetic wave absorbing material is irregularly shaped nanoparticles, and the carbon nanotubes are tubular and cover the surface of the particles or run through the middle thereof.

[0019] The electromagnetic wave absorbing material comprises a three-dimensional conductive network structure, with the ABX3 structures being irregularly shaped and clustered together. Carbon nanotubes (CNTs) coat this structure to form a conductive network. When electromagnetic waves enter the material, they refract back and forth along its irregular surfaces, enhancing interfacial polarization and increasing electromagnetic wave losses. Furthermore, when electromagnetic waves enter the absorbing material, the CNTs within the conductive network are transferred to various regions, resulting in multiple losses that are superimposed and beneficial to electromagnetic wave loss.

[0020] Compared with the prior art, the present invention has the following advantages:

[0021] The effective ABX3 perovskite composite electromagnetic wave absorbing material provided by the present invention has excellent dielectric properties and a conductive network structure. Compared with other perovskite oxide absorbing materials, the carbon nanotube composite ABX3 has carbon nanotubes wrapped around the surface of the perovskite material and connected in series with the perovskite materials to form a three-dimensional conductive network, which greatly improves its conductivity and dielectric loss capacity. Therefore, the material has a high reflection loss value, a wide bandwidth, and a low matching thickness. The carbon nanotube and ABX3 composite can achieve excellent wave absorption effects when combined at different mass ratios, realizing the adjustment of the wave absorption band.

[0022] The preparation method of the present invention is simple, the raw materials are easily available and inexpensive, the requirements for preparation equipment are low, and the preparation process is simple. No large amounts of chemical solvents are required, and the product yield is high, reaching over 95%. The overall preparation method conforms to the concepts of energy conservation and consumption reduction and green chemistry, and is suitable for large-scale production. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is the scanning electron microscope image of MAPbI3;

[0024] Figure 2 : is the reflection loss curve of the absorbing material in Examples 1-4 at different thicknesses at frequencies of 2 to 18 GHz;

[0025] Figure 3 Graph showing the maximum effective absorption bandwidth of the absorbing materials in Examples 1-4 at frequencies of 2 to 18 GHz;

[0026] Figure 4 is the reflection loss curve of the absorbing material in Example 5 at a frequency of 2 to 18 GHz;

[0027] Figure 5: is the reflection loss curve of the absorbing material in Example 6 at a frequency of 2 to 18 GHz;

[0028] Figure 6 : is the reflection loss curve of the absorbing material in Example 7 at a frequency of 2 to 18 GHz;

[0029] Figure 7 This is the scanning electron microscope image of MAPbBr3 and CNTS after compounding;

[0030] Figure 8 This is a scanning electron microscope image of FAPbI3 and CNTS after compounding. DETAILED DESCRIPTION

[0031] The present invention is further described below with reference to the examples. All chemicals and reagents used in the examples are commercially available unless otherwise specified.

[0032] Example 1

[0033] (1) Take 158.97 mg of MAI and 461 mg of PbI2, both with a purity of 98% or higher, and dry the PbI2 at 60°C for 10 min. Place the MAI and PbI2 in a mortar and stir until evenly combined. Grind for 30-40 min to obtain a black MAPbI3 powder.

[0034] (2) Place the MAPbI3 powder from step (1) into a container, set the heating temperature in an oven to 60-80°C, and heat for 10-30 minutes. Take out the dried MAPbI3 powder and place it in a container. Then, according to the requirement that the mass ratio of MAPbI3:CNTS is 1:1, weigh the corresponding mass of CNTS and place it in the container. Add 2-3 ml of cyclohexane or n-hexane and stir at room temperature for 30 minutes. Then place it on a heating table, set the heating temperature to 40-80°C, and stir for 10-20 minutes to allow the cyclohexane or n-hexane to completely evaporate, thereby obtaining the final product, an ABX3 perovskite-type composite absorber with a MAPbI3:CNTS ratio of (1:1).

[0035] (3) The obtained absorbing material is filled into the wave-transmitting material at a mass ratio of 20%, and the absorbing sample is measured at a frequency of 2 to 18 GHz using a vector network analyzer. Figure 2 As shown in the figure, when the material thickness is 1.38mm, the reflection loss value is -24.0dB, and the absorption peak center frequency is at 16.8GHz. Figure 3 As shown in the figure, when the material thickness is 1.45 mm, it has a maximum absorption bandwidth of 4.4 GH.

[0036] Example 2

[0037] (1) The steps are the same as step (1) of Example 1.

[0038] (2) Place the MAPbI3 powder from step (1) into a container, set the heating temperature in an oven to 60-80°C, and heat for 10-30 minutes. Take out the dried MAPbI3 powder and place it in a container. Then, according to the requirement that the mass ratio of MAPbI3:CNTS is 2:1, weigh the corresponding mass of CNTS and place it in the container. Add 2-3 ml of cyclohexane or n-hexane and stir at room temperature for 30 minutes. Then place it on a heating table, set the heating temperature to 40-80°C, and stir for 10-20 minutes to allow the cyclohexane or n-hexane to completely evaporate, thereby obtaining the final product, an ABX3 perovskite-type composite absorber with a MAPbI3:CNTS ratio of (2:1).

[0039] (3) The obtained absorbing material is filled into the wave-transmitting material at a mass ratio of 25%, and the absorbing sample is measured at a frequency of 2 to 18 GHz using a vector network analyzer. Figure 2 As shown in the figure, when the material thickness is 1.96mm, the reflection loss value is -56.4dB, and the absorption peak center frequency is at 12.6GHz. Figure 3 As shown in Figure 1, when the material thickness is 1.65 mm, it has a maximum absorption bandwidth of 4.76 GHz.

[0040] Example 3

[0041] (1) The steps are the same as step (1) of Example 1.

[0042] (2) Place the MAPbI3 powder from step (1) into a container, set the heating temperature in an oven to 60-80°C, and heat for 10-30 minutes. Take out the dried MAPbI3 powder and place it in a container. Then, according to the requirement that the mass ratio of MAPbI3:CNTS is 4:1, weigh the corresponding mass of CNTS and place it in the container. Add 2-3 ml of cyclohexane or n-hexane and stir at room temperature for 30 minutes. Then place it on a heating table, set the heating temperature to 40-80°C, and stir for 10-20 minutes to allow the cyclohexane or n-hexane to completely evaporate, thereby obtaining the final product, an ABX3 perovskite-type composite absorber with a MAPbI3:CNTS ratio of (4:1).

[0043] (3) The obtained absorbing material is filled into the wave-transmitting material at a mass ratio of 30%, and the absorbing sample is measured at a frequency of 2 to 18 GHz using a vector network analyzer. Figure 2 As shown in Figure 1, when the material thickness is 3.04 mm, the reflection loss value is -58.6 dB and the absorption peak center frequency is at 8.08 GHz. Figure 3 As shown in Figure 1, when the material thickness is 1.73 mm, it has a maximum absorption bandwidth of 4.72 GHz.

[0044] Example 4

[0045] (1) The steps are the same as step (1) of Example 1.

[0046] (2) Place the MAPbI3 powder from step (1) into a container, set the heating temperature in an oven to 60-80°C, and heat for 10-30 minutes. Take out the dried MAPbI3 powder and place it in a container. Then, according to the requirement that the mass ratio of MAPbI3:CNTS is 5:1, weigh the corresponding mass of CNTS and place it in the container. Add 2-3 ml of cyclohexane or n-hexane and stir at room temperature for 30 minutes. Then place it on a heating table, set the heating temperature to 40-80°C, and stir for 10-20 minutes to allow the cyclohexane or n-hexane to completely evaporate, thereby obtaining the final product, an ABX3 perovskite-type composite absorber with a MAPbI3:CNTS ratio of (5:1).

[0047] (3) The obtained absorbing material is filled into the wave-transmitting material at a mass ratio of 35%, and the absorbing sample is measured at a frequency of 2 to 18 GHz using a vector network analyzer. Figure 2 As shown in the figure, when the material thickness is 2.69 mm, the reflection loss value is -51.9 dB and the absorption peak center frequency is at 8.96 GHz. Figure 3 As shown in Figure 1, when the material thickness is 1.64 mm, it has a maximum absorption bandwidth of 4 GHz.

[0048] Example 5

[0049] (1) Take 111.97 mg of MABr and 367.01 mg of PbBr2, both with a purity of 98% or greater, and dry the PbBr2 at 60°C for 10 min. Then, place the MABr and PbBr2 in a mortar and stir until evenly mixed. Grind for 30-40 min to obtain an orange-yellow MAPbBr3 powder.

[0050] (2) Place the MAPbBr3 powder from step (1) into a container, set the heating temperature in an oven to 60-80°C, and heat for 10-30 minutes. Take out the dried MAPbBr3 powder and place it in a container. Then, according to the requirement of a MAPbBr3:CNTS mass ratio of 5:1, weigh the corresponding mass of CNTS and place it in the container. Add 2-3 ml of cyclohexane or n-hexane and stir at room temperature for 30 minutes. Then place it on a heating table, set the heating temperature to 40-80°C, and stir for 10-20 minutes to allow the cyclohexane or n-hexane to completely evaporate, thereby obtaining the final product, an ABX3 perovskite-type composite absorber with a MAPbBr3:CNTS ratio of (2:1).

[0051] (3) The obtained absorbing material is filled into the wave-transmitting material at a mass ratio of 30%, and the absorbing sample is measured at a frequency of 2 to 18 GHz using a vector network analyzer. Figure 4 As shown in the figure, when the material thickness is 3.49mm, the reflection loss value is -50.2dB, and the absorption peak center frequency is located at 7.08GHz. And when the material thickness is 1.83mm, it has a maximum absorption bandwidth of 3.84GHz.

[0052] Example 6

[0053] (1) The steps are the same as step (1) of Example 1.

[0054] (2) Place the MAPbI3 powder from step (1) into a container and heat in an oven at 60-80°C for 10-30 minutes. Remove the dried MAPbI3 powder and place it in a mortar. Then, according to the requirement that the mass ratio of MAPbI3:CNTS is 3:1, weigh the corresponding mass of CNTS and place it in the mortar. Grind and stir in a low humidity environment for at least 20 minutes. Finally, the final product is obtained, an ABX3 perovskite-type composite absorber with a MAPbI3:CNTS ratio of (3:1).

[0055] (3) The obtained absorbing material is filled into the wave-transmitting material at a mass ratio of 40%, and the absorbing sample is measured at a frequency of 2 to 18 GHz using a vector network analyzer. Figure 5 As shown in the figure, when the material thickness is 2.19mm, the reflection loss value is -27.2dB, and the absorption peak center frequency is located at 8.4GHz. And when the material thickness is 1.23mm, the maximum absorption bandwidth is 3.84GHz.

[0056] Example 7

[0057] (1) Take 171.97 mg of FAI and 461 mg of PbI2, both with a purity of 98% or higher, and dry the PbI2 at 60°C for 10 min. Then, place the FAI and PbI2 in a mortar and stir until evenly mixed. Grind for 30-40 min to obtain a brownish-yellow FAPbI3 powder.

[0058] (2) Place the FAPbI3 powder from step (1) into a container, place it on a heating table, set the heating temperature to 150-200°C, stir continuously, and heat for 10-30 minutes. Take out the dried FAPbI3 powder and place it in a container. Then, according to the requirement that the mass ratio of FAPbI3:CNTS is 3:1, weigh the corresponding mass of CNTS and place it in the container. Add 2-3 ml of cyclohexane or n-hexane and stir at room temperature for 30 minutes. Place it on a heating table again, set the heating temperature to 40-80°C, and stir for 10-20 minutes to allow the cyclohexane or n-hexane to completely evaporate, thereby obtaining the final product, an ABX3 perovskite-type composite absorber with a FAPbI3:CNTS ratio of (3:1).

[0059] (3) The obtained absorbing material is filled into the wave-transmitting material at a mass ratio of 30%, and the absorbing sample is measured at a frequency of 2 to 18 GHz using a vector network analyzer. Figure 6 As shown in the figure, when the material thickness is 1.89mm, the reflection loss value is -60.13dB, and the absorption peak center frequency is located at 12.6GHz. And when the material thickness is 1.51mm, it has a maximum absorption bandwidth of 4.16GHz.

[0060] In summary, the present invention discloses an ABX3 perovskite composite electromagnetic wave absorbing material and a preparation method thereof, which belongs to the field of preparation of electromagnetic wave absorbing materials. The ABX3 perovskite composite electromagnetic wave absorbing material, wherein the A-site ion is (MA + , FA + ), the B-site ion is Pb 2+ , X-site ion is (CL - , Br - , I -), which is compounded with carbon nanotubes to prepare an absorbing material. The material exists in the form of black powder and has the characteristics of being solvent-free, pollution-free, easy to prepare, energy-saving and resource-saving, and environmentally friendly. Its main preparation method is mainly divided into the following two steps. The first step is to prepare ABX3 perovskite by dry grinding, and then dry and heat-treat it. The second step is to uniformly mix and compound the prepared ABX3 perovskite and carbon nanotube materials according to different mass ratios. The present invention adopts a solvent-free method to prepare ABX3 perovskite-type absorption material, which is in the shape of irregular nanoparticles and forms a conductive network structure with carbon nanotubes. The suitable structure constructed in this way has a strong absorption effect on electromagnetic waves and has a wide absorption band. The material preparation method does not require toxic solvents, has simple synthesis equipment, low cost, few processes, high yield, and is suitable for large-scale preparation.

Claims

1. A method for preparing an ABX3 perovskite composite electromagnetic wave absorbing material, characterized in that: The steps include: (1) Pre-treating the perovskite precursor powders of each component in ABX3, wherein the precursors include a precursor 1 and a precursor 2, wherein the component of the precursor 1 is a mixture of one or more of MACl, MABr, MAI, FACl, FABr, and FAI, and the component of the precursor 2 is one or more of PbCl2, PbBr2, and PbI2 powders, and the obtained powders are first dried by a drying method of vacuum drying, freeze drying, or direct drying; (2) weighing and mixing the two components of the dried precursor powder in a 1:1 molar ratio, grinding them by ball milling or grinding under low humidity conditions for no less than 30 minutes to obtain the corresponding ABX3 perovskite powder; (3) ABX3 is heated, A is MA + When the heating temperature is 60-80℃, A is FA + When the heating temperature is 150℃-200℃, the A-site ion is (MA x FA 1-x ) + hour, Wherein, 0≤x≤1, it needs to be heated at 60-200℃ for 10-30 minutes; (4) Weighing and mixing the ABX3 perovskite powder and carbon nanotubes in a mass ratio of 1:1 to 5:1 in step (3), stirring and grinding the mixture in a low humidity environment for no more than 20 minutes; or adding n-hexane or cyclohexane, mechanically stirring and mixing the mixture in a micro-solution environment for no more than 30 minutes, and then heating to 40-80° C. and continuing to stir for 10-20 minutes to volatilize the n-hexane or cyclohexane, and finally obtaining an ABX3 perovskite-type composite electromagnetic wave absorbing material.

2. The method for preparing the ABX3 perovskite composite electromagnetic wave absorbing material according to claim 1, characterized in that: A-site ion is (MA + , FA + ), the B-site ion is Pb 2+ , X-site ion is (CL - , Br - , I - ).

3. An ABX3 perovskite composite electromagnetic wave absorbing material, characterized in that: Prepared by the method according to any one of claims 1-2.

4. The ABX3 perovskite composite electromagnetic wave absorbing material according to claim 3, characterized in that: Carbon nanotubes are adsorbed and wrapped on the surface of the synthesized perovskite. The carbon nanotubes cross each other and are arranged throughout the synthesized irregular perovskite material to form a carbon chain network and construct a three-dimensional network structure.

5. The ABX3 perovskite composite electromagnetic wave absorbing material according to claim 3, characterized in that: The microscopic morphology is irregular nanoparticles with a particle size of 200nm-1μm.

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