Heteroatom-doped porous flower-like zinc oxide microsphere infrared smoke screen interference material and preparation method thereof

Abstract

The invention belongs to the field of new materials, particularly relates to the technical field of infrared smoke screen interference, and particularly provides a heteroatom-doped porous flower-shaped zinc oxide microsphere infrared smoke screen interference material and a preparation method thereof.The heteroatom-doped porous flower-shaped zinc oxide microsphere infrared smoke screen interference material is of a flower-shaped structure and is formed by self-assembly of a large number of porous nanosheets; the preparation raw materials of the infrared smoke screen material are low in price and easy to obtain, the preparation process is easy to operate, the yield is high, and industrial production is easy. The material is relatively high in infrared shielding performance and has a relatively great application prospect in the field of infrared smoke screen interference materials in the future.

Description

Technical Field

[0001] The present invention belongs to the field of new materials, and particularly relates to the field of infrared smoke interference technology. Specifically, it provides a heteroatom-doped porous flower-like zinc oxide microsphere infrared smoke interference material and a preparation method thereof. Background Art

[0002] Infrared guidance technology poses a severe threat to the safety of battlefield targets and personnel due to its advantages such as all-weather combat adaptability, high cost-effectiveness, strong anti-interference ability, and high guidance accuracy. Therefore, there is an urgent need to develop effective optoelectronic countermeasure means to enhance target protection capabilities. Smoke interference materials can effectively reduce the contrast between the target and the background through absorption, scattering, etc., thereby achieving signal interference and shielding of the infrared guidance system and enhancing the battlefield survivability of the target. It is a relatively effective optoelectronic countermeasure means.

[0003] Zinc oxide has excellent optoelectronic properties, and its preparation raw materials are cheap and easily available, the preparation process is simple to operate, and the yield is high. It is an ideal material for studying infrared smoke interference. At the same time, relevant research shows that reasonable microstructural design and selective construction of heteroatom defects are beneficial to improving the signal interference and shielding ability of zinc oxide against the infrared guidance system. In terms of microstructural design, the porous structure can not only enhance the absorption of incident infrared waves but also reduce its own density and increase its suspension ability. According to the analysis of the microstructural shielding interference mechanism of materials in the optical band, constructing heteroatom defects in porous zinc oxide can cause the migration of surface carriers in porous zinc oxide, generating a local surface plasmon resonance effect on the surface of the material particles, converting the energy of infrared photons into heat energy, thereby achieving the absorption of infrared waves. However, in existing heteroatom-doped materials, the heteroatoms come from the synthesis raw materials themselves, and the doping types and ratios are fixed, and the types and amounts of heteroatoms cannot be selectively doped.

[0004] Therefore, whether more effective microstructural materials can be constructed to obtain better effective interference and shielding of the infrared guidance system signal has become one of the key research points of the inventors. Summary of the Invention

[0005] To solve the problems existing in the above-mentioned prior art, the present invention provides a heteroatom-doped porous flower-like zinc oxide microsphere infrared smoke interference material and a preparation method thereof. The heteroatom-doped porous flower-like zinc oxide microsphere infrared smoke interference material has a flower-like structure and is composed of a large number of porous nanosheets self-assembled. The particle size is 2 - 15 μm. The preparation raw materials of this infrared smoke material are cheap and easily available, the preparation process is simple to operate, and the yield is high, which is easy for industrial production. This material has strong infrared shielding performance and has great application prospects in the field of infrared smoke interference materials in the future.

[0006] The heteroatom-doped porous flower-like zinc oxide microsphere infrared smoke interference material provided by the present invention has a flower-like structure and is composed of a large number of porous nanosheets self-assembled, with a particle size of 2-15 μm and a specific surface area of 350-420 m 3 ·g −1 , where the proportion of zinc oxide is 70-75 wt% and the proportion of heteroatoms is 25-30 wt%.

[0007] In addition, the inventor also provides a preparation method of the above-mentioned heteroatom-doped porous flower-like zinc oxide microsphere infrared smoke interference material, and the specific steps are as follows: (1)Preparation of porous flower-like zinc oxide microspheres: Add zinc oxysalt and cetyltrimethylammonium bromide into a beaker containing ethylene glycol and deionized water, and mechanically stir for 2-4 h to form a uniform transparent solution; then transfer the above solution to a stainless steel autoclave containing urea and mechanically stir for 1-3 h; After that, the autoclave is maintained at 100-140 °C for 16-24 h. After the reaction is completed, take out the zinc oxide precursor, naturally cool it to room temperature, wash it alternately with deionized water and ethanol five times each, and then vacuum dry it at 80 °C for 12 h; finally, heat the sample in a sintering furnace to 300-700 °C at a heating rate of 10 °C / min, keep it for 1-4 h, and then naturally cool it to room temperature. A large number of pores are formed in the zinc oxide microsphere nanosheets, and porous flower-like zinc oxide microspheres (Porous flower-like ZnO microspheres, ZnO) are obtained, with a particle size of 2-15 μm and a specific surface area of 350-420 m 3 ·g −1 ; In the above step (1), the zinc oxysalt is selected from one of zinc acetate, zinc nitrate or zinc sulfate; the molar ratio of the amounts of zinc oxysalt, cetyltrimethylammonium bromide and urea is 0.6-1:1:0.6-1.67.

[0008] Further, the molar amount of any one of zinc oxysalt, cetyltrimethylammonium bromide or urea to the volume of the mixture of ethylene glycol and deionized water is 3-5 mol:12 L; the volume ratio of ethylene glycol to deionized water is 0.5-1:1, and more preferably 0.7-0.75:1.

[0009] The rotation speed of mechanical stirring in the above steps is 400-1000 revolutions per minute.

[0010] (2)Preparation of heteroatom-doped porous flower-like zinc oxide microspheres: Place the heteroatom doping source and the porous flower-like zinc oxide microspheres obtained in step (1) on two separate porcelain boats in a tube furnace, with the former upstream and the latter downstream. Under a protective atmosphere, heat at 300-500 °C for 1-3 h to obtain heteroatom-doped porous flower-like zinc oxide microspheres.

[0011] In the above step (2), the doped heteroatoms are any one or more of the three elements N, S, and P; the sources of N, S, and P elements are urea, sublimed sulfur, and sodium hypophosphite, respectively; the protective atmosphere is selected from one or more of inert gases such as nitrogen and argon; the mass ratio of the total mass of the heteroatom doping source to the mass of the porous flower-like zinc oxide microspheres is 1-3:1, and more preferably 1:1.

[0012] Compared with undoped zinc oxide, constructing heteroatom defects in porous zinc oxide can cause the migration of surface carriers in porous zinc oxide, generate local surface plasmon resonance effects on the surface of material particles, convert infrared photon energy into heat energy, and thus achieve the absorption of infrared waves. At the same time, as the doping types increase, the defect types also increase, and the polarization centers further increase, thereby further enhancing the material's surface plasmon resonance effect and improving the material's infrared wave loss ability.

[0013] In this application, the preferably doped heteroatoms are the three elements N, S, and P. The above elements are from urea, sublimed sulfur, and sodium hypophosphite, which have wide sources and low prices; their sublimation temperatures are close, and they can be vapor-deposited simultaneously without affecting each other's deposition effects due to large differences in their sublimation temperatures. Finally, the vapor deposition of urea, sublimed sulfur, and sodium hypophosphite is simple in operation and easy to scale up production and promotion. Other elements can also be doped on this basis, but too many types of doped heteroatoms may lead to losses in other properties of the material, such as lattice stress co-induced by too many heteroatoms; when too many heteroatoms coexist, the doping sites may repel each other; too many heteroatoms doped blur the heterointerfaces and weaken the space charge accumulation effect; by-products generated during the reaction of too many heteroatom precursors block the mesoporous structure, etc. Therefore, the inventor preferably selects the above three-element scheme.

[0014] At the same time, the mass of heteroatom doping needs to be appropriate. Excessive doping leads to overly dense polarization centers, resulting in dispersed relaxation times, broadened and weakened dielectric loss peaks; at the same time, excessive doping is equivalent to coating a layer on the surface of zinc oxide, which will instead affect the migration of carriers. Therefore, the total mass of the above heteroatom doping source is controlled.

[0015] The doping ratio of each heteroatom in the finally obtained zinc oxide microspheres is random, but zinc oxide accounts for 70-75 wt%, and heteroatoms account for 25-30 wt%.

[0016] Compared with the prior art, the method for preparing heteroatom-doped porous flower-like zinc oxide microspheres provided by the present invention has the following advantages: (1) The types and doping ratios of heteroatom doping can be selectively constructed. Heteroatom defects are constructed in porous zinc oxide, causing the migration of carriers on the surface of porous zinc oxide, generating a local surface plasmon resonance effect on the surface of the material particles, converting the energy of infrared photons into heat energy, and thus achieving the absorption of infrared waves. With the increase in the types of doping, the types of defects also increase, the polarization centers further increase, the plasma resonance effect of the material is improved, and the polarization loss ability is further enhanced. (2) The preparation method of the heteroatom-doped porous flower-like zinc oxide microspheres provided by the present invention has simple operation process, high yield, cheap and easily available raw materials for preparation, and is easy for industrial production. This material has strong infrared shielding performance and has great application prospects in the field of infrared smoke screen interference materials in the future. Description of the Drawings

[0017] Figure 1 SEM photograph of the nitrogen, sulfur, and phosphorus-doped porous flower-like zinc oxide microspheres (N,S,P-ZnO) prepared in Example 1; Figure 2 XRD pattern of the nitrogen, sulfur, and phosphorus-doped porous flower-like zinc oxide microspheres (N,S,P-ZnO) prepared in Example 1; Figure 3 Energy spectrum photograph of the nitrogen, sulfur, and phosphorus-doped porous flower-like zinc oxide microspheres (N,S,P-ZnO) prepared in Example 1. Specific Embodiments

[0018] The implementation schemes of the present invention will be further described in detail below through examples. It is necessary to point out that the following examples are only used to further illustrate the present invention, and the implementation modes of the present invention are not limited thereto. Some non-essential adjustments and improvements made by those familiar with the relevant fields according to the above invention scheme still fall within the protection scope of the present invention.

[0019] Example 1 Preparation method of an infrared smoke screen material of nitrogen, sulfur, and phosphorus-doped porous flower-like zinc oxide microspheres, the specific steps are as follows: (1) Preparation of porous flower-like zinc oxide microspheres: 3 mol of zinc acetate and 3 mol of cetyltrimethylammonium bromide were added to a beaker containing 4.5 L of ethylene glycol and 7.5 L of deionized water, and mechanically stirred for 2 h to form a homogeneous transparent solution. Subsequently, the above solution was transferred to a stainless-steel autoclave containing 3 mol of urea, and mechanically stirred for 1 h. The rotation speed of the above mechanical stirring was 800 revolutions per minute. Then, the autoclave was maintained at 110 °C for 16 h. After the reaction, the zinc oxide precursor was taken out, washed alternately with deionized water and ethanol five times each, and then vacuum dried at 80 °C for 12 h. Finally, the sample was annealed in air at 300 °C for 2 h to obtain porous flower-like zinc oxide microspheres (Porous flower-like ZnO microspheres, ZnO).

[0020] (2) Preparation of nitrogen, sulfur, phosphorus-doped porous flower-like zinc oxide microspheres (N,S,P-ZnO): N,S,P-ZnO was prepared by chemical vapor deposition in an argon atmosphere at 400 °C for 2 h. Urea, sublimed sulfur, sodium hypophosphite and ZnO obtained in step (1) were placed on two separate porcelain boats in a tube furnace, with the former upstream and the latter downstream. The mass ratio of urea, sublimed sulfur, sodium hypophosphite and porous flower-like zinc oxide microspheres was 1:1:1:3.

[0021] The finally prepared nitrogen, sulfur, phosphorus-doped porous flower-like zinc oxide microspheres had a flower-like structure, which was self-assembled by a large number of porous nanosheets, with a particle size of about 14 μm and a specific surface area of 401 m 3 ·g −1 . Zn, O, N, S, P were 57.1 wt%, 17.0 wt%, 4.6 wt%, 11.5 wt% and 9.8 wt% respectively.

[0022] Figure 1 The scanning electron microscope images of the nitrogen, sulfur, phosphorus-doped porous flower-like zinc oxide microspheres (N,S,P-ZnO) prepared in Example 1 were given. It can be seen from the scanning electron microscope that the nitrogen, sulfur, phosphorus-doped porous flower-like zinc oxide microspheres had a flower-like structure, which was self-assembled by a large number of porous nanosheets, with a particle size of about 14 μm.

[0023] Figure 2 The XRD pattern of the nitrogen, sulfur, phosphorus-doped porous flower-like zinc oxide microspheres (N,S,P-ZnO) prepared in Example 1 was given. It can be seen from the figure that the prepared ZnO had good crystallinity, and all the diffraction peaks corresponded well with the standard pattern of ZnO (JCPDS: 36-1451), indicating that the obtained samples were all hexagonal wurtzite zinc oxide structures.

[0024] Figure 3The EDS spectrum of the nitrogen, sulfur, and phosphorus co-doped porous flower-like zinc oxide microspheres (N,S,P-ZnO) prepared in Example 1 is presented, demonstrating the successful doping of N, S, and P elements.

[0025] Example 2 A preparation method of nitrogen and sulfur co-doped porous flower-like zinc oxide microsphere infrared smoke materials, the specific steps are as follows: (1) Preparation of porous flower-like zinc oxide microspheres: 3 mol of zinc acetate and 4 mol of cetyltrimethylammonium bromide were added to a beaker containing 4.0 L of ethylene glycol and 8.0 L of deionized water, and mechanically stirred for 3 h to form a homogeneous transparent solution. Subsequently, the above solution was transferred to a stainless steel autoclave containing 5 mol of urea, and mechanically stirred for 2 h. The rotation speed of the above mechanical stirring was 900 revolutions per minute. Then the autoclave was maintained at 120 °C for 18 h. After the reaction, the zinc oxide precursor was taken out, washed alternately with deionized water and ethanol five times each, and then vacuum dried at 80 °C for 12 h. Finally, the sample was annealed in air at 400 °C for 2 h to obtain porous flower-like zinc oxide microspheres (Porous flower-like ZnO microspheres, ZnO).

[0026] (2) Preparation of nitrogen and sulfur co-doped porous flower-like zinc oxide microspheres (N,S-ZnO): N,S-ZnO was prepared by chemical vapor deposition in an argon atmosphere at 500 °C for 1 h. Among them, urea / sublimed sulfur and ZnO obtained in step (1) were placed on two separate porcelain boats in a tube furnace, with the former upstream and the latter downstream. Urea and sublimed sulfur are the sources of N and S elements respectively, and the mass ratio of urea, sublimed sulfur, and porous flower-like zinc oxide microspheres is 1:1:2.

[0027] The finally prepared nitrogen and sulfur co-doped porous flower-like zinc oxide microspheres have a flower-like structure, which is self-assembled by a large number of porous nanosheets, with a particle size of about 14 μm and a specific surface area of 394 m 3 ·g −1 . Zn, O, N, and S are 57.7 wt%, 14.1 wt%, 8.8 wt%, and 19.4 wt% respectively.

[0028] Example 3 A preparation method of nitrogen and phosphorus co-doped porous flower-like zinc oxide microsphere infrared smoke materials, the specific steps are as follows: (1) Preparation of porous flower-like zinc oxide microspheres: 3 mol of zinc acetate and 4 mol of cetyltrimethylammonium bromide were added to a beaker containing 5.0 L of ethylene glycol and 7.0 L of deionized water, and mechanically stirred for 4 h to form a homogeneous transparent solution at a rotation speed of 800 revolutions per minute. Subsequently, the above solution was transferred to a stainless-steel autoclave containing 4 mol of urea, and mechanically stirred for 1 h at a rotation speed of 1000 revolutions per minute. Then, the autoclave was maintained at 140 °C for 16 h. After the reaction was completed, the zinc oxide precursor was taken out, washed alternately with deionized water and ethanol five times each, and then vacuum dried at 80 °C for 12 h. Finally, the sample was annealed in air at 300 °C for 3 h to obtain porous flower-like zinc oxide microspheres (Porous flower-like ZnO microspheres, ZnO).

[0029] (2)Preparation of nitrogen and phosphorus doped porous flower-like zinc oxide microspheres (N,P-ZnO): N,P-ZnO was prepared by chemical vapor deposition in an argon atmosphere at 500 °C for 2 h. Urea / sodium hypophosphite and ZnO obtained in step (1) were placed on two separate porcelain boats in a tube furnace, with the former upstream and the latter downstream. Urea and sodium hypophosphite are the sources of N and P elements respectively, and the mass ratio of urea, sodium hypophosphite and porous flower-like zinc oxide microspheres is 1:1:2.

[0030] The finally prepared nitrogen and phosphorus doped porous flower-like zinc oxide microspheres have a flower-like structure, which is self-assembled by a large number of porous nanosheets, with a particle size of about 14 μm and a specific surface area of 416 m 3 ·g −1 . The contents of Zn, O, N, and P are 56.5 wt%, 14.9 wt%, 8.9 wt%, and 19.7 wt% respectively.

[0031] Example 4 Preparation method of sulfur and phosphorus doped porous flower-like zinc oxide microsphere infrared smoke screen material, the specific steps are as follows: (1)Preparation of porous flower-like zinc oxide microspheres: 4 mol of zinc acetate and 4 mol of cetyltrimethylammonium bromide were added to a beaker containing 5.5 L of ethylene glycol and 6.5 L of deionized water, and mechanically stirred for 3 h to form a homogeneous transparent solution at a rotation speed of 400 revolutions per minute. Subsequently, the above solution was transferred to a stainless-steel autoclave containing 5 mol of urea, and mechanically stirred for 3 h at a rotation speed of 600 revolutions per minute. Then, the autoclave was maintained at 130 °C for 18 h. After the reaction, the zinc oxide precursor was taken out, washed alternately with deionized water and ethanol five times each, and then vacuum dried at 80 °C for 12 h. Finally, the sample was annealed in air at 600 °C for 1 h to obtain porous flower-like zinc oxide microspheres (Porous flower-like ZnO microspheres, ZnO).

[0032] (2) Preparation of sulfur and phosphorus doped porous flower-like zinc oxide microspheres (S,P-ZnO): S,P-ZnO was prepared by chemical vapor deposition in an argon atmosphere at 300 °C for 1 h. Sublimed sulfur / sodium hypophosphite and ZnO obtained in step (1) were placed on two separate porcelain boats in a tube furnace, with the former upstream and the latter downstream. Sublimed sulfur and sodium hypophosphite are the sources of S and P elements respectively, and the mass ratio of sublimed sulfur, sodium hypophosphite and porous flower-like zinc oxide microspheres is 1:1:2.

[0033] The finally prepared sulfur and phosphorus doped porous flower-like zinc oxide microspheres have a flower-like structure, which is self-assembled by a large number of porous nanosheets, with a particle size of about 14 μm and a specific surface area of 359 m 3 ·g −1 . Zn, O, S, and P are 56.9 wt%, 15.3 wt%, 14.8 wt%, and 13.0 wt% respectively.

[0034] Example 5 Preparation method of nitrogen-doped porous flower-like zinc oxide microsphere infrared smoke screen material, the specific steps are as follows:[[]]END]] (1) Preparation of porous flower-like zinc oxide microspheres:[[]]END]] 4 mol of zinc acetate and 5 mol of cetyltrimethylammonium bromide were added to a beaker containing 6.0 L of ethylene glycol and 6.0 L of deionized water, and mechanically stirred for 2 h to form a homogeneous transparent solution at a rotation speed of 800 revolutions per minute. Subsequently, the above solution was transferred to a stainless-steel autoclave containing 5 mol of urea, and mechanically stirred for 2 h at a rotation speed of 900 revolutions per minute. Then, the autoclave was maintained at 110 °C for 20 h. After the reaction, the zinc oxide precursor was taken out, washed alternately with deionized water and ethanol five times each, and then vacuum dried at 80 °C for 12 h. Finally, the sample was annealed in air at 300 °C for 2 h to obtain porous flower-like zinc oxide microspheres (Porous flower-like ZnO microspheres, ZnO).

[0035] (2) Preparation of nitrogen-doped porous flower-like zinc oxide microspheres (N-ZnO): N-ZnO was prepared by chemical vapor deposition in an argon atmosphere at 500 °C for 1 h. Urea and ZnO obtained in step (1) were respectively placed on two separate porcelain boats in a tubular furnace, with the former upstream and the latter downstream. Urea is the source of N element, and the mass ratio of urea to porous flower-like zinc oxide microspheres is 1:1.

[0036] The finally prepared nitrogen-doped porous flower-like zinc oxide microspheres have a flower-like structure, which is self-assembled by a large number of porous nanosheets, with a particle size of about 14 μm and a specific surface area of 379 m 3 ·g −1 . Zn, O, and N are 59.4 wt%, 15.2 wt%, and 25.4 wt% respectively.

[0037] Example 6 Preparation method of sulfur-doped porous flower-like zinc oxide microsphere infrared smoke screen material, the specific steps are as follows: (1) Preparation of porous flower-like zinc oxide microspheres: 4 mol of zinc acetate and 4 mol of cetyltrimethylammonium bromide were added to a beaker containing 4.5 L of ethylene glycol and 7.5 L of deionized water, and mechanically stirred for 3 h to form a homogeneous transparent solution at a rotation speed of 800 revolutions per minute. Subsequently, the above solution was transferred to a stainless-steel autoclave containing 4 mol of urea, and mechanically stirred for 1 h at a rotation speed of 600 revolutions per minute. Then, the autoclave was maintained at 120 °C for 17 h. After the reaction, the zinc oxide precursor was taken out, washed alternately with deionized water and ethanol five times each, and then vacuum dried at 80 °C for 12 h. Finally, the sample was annealed in air at 500 °C for 2 h to obtain porous flower-like zinc oxide microspheres (Porous flower-like ZnO microspheres, ZnO).

[0038] (2) Preparation of sulfur-doped porous flower-like zinc oxide microspheres (S-ZnO): S-ZnO was prepared by chemical vapor deposition in an argon atmosphere at 400 °C for 3 h. Sublimed sulfur and the ZnO obtained in step (1) were respectively placed on two separate porcelain boats in a tube furnace, with the former upstream and the latter downstream. Sublimed sulfur is the source of S element, and the mass ratio of sublimed sulfur to porous flower-like zinc oxide microspheres is 1:1.

[0039] The finally prepared sulfur-doped porous flower-like zinc oxide microspheres have a flower-like structure, which is self-assembled by a large number of porous nanosheets, with a particle size of about 14 μm and a specific surface area of 416 m 3 ·g −1 . Zn, O, and S are 58.5 wt%, 16.4 wt%, and 25.1 wt% respectively.

[0040] Example 7 Preparation method of phosphorus-doped porous flower-like zinc oxide microsphere infrared smoke screen material, the specific steps are as follows: (1) Preparation of porous flower-like zinc oxide microspheres: 5 mol of zinc acetate and 5 mol of cetyltrimethylammonium bromide were added to a beaker containing 4.0 L of ethylene glycol and 8.0 L of deionized water, and mechanically stirred for 4 h to form a uniform transparent solution with a rotation speed of 700 revolutions per minute. Subsequently, the above solution was transferred to a stainless steel autoclave containing 5 mol of urea, and mechanically stirred for 1 h with a rotation speed of 900 revolutions per minute. Then the autoclave was maintained at 110 °C for 18 h. After the reaction, the zinc oxide precursor was taken out, washed alternately with deionized water and ethanol five times each, and then vacuum dried at 80 °C for 12 h. Finally, the sample was annealed in air at 300 °C for 2 h to obtain porous flower-like zinc oxide microspheres (Porous flower-like ZnO microspheres, ZnO).

[0041] (2) Preparation of phosphorus-doped porous flower-like zinc oxide microspheres (P-ZnO): P-ZnO was prepared by chemical vapor deposition in an argon atmosphere at 300 °C for 3 h. Sodium hypophosphite and the ZnO obtained in step (1) were respectively placed on two separate porcelain boats in a tube furnace, with the former upstream and the latter downstream. Sodium hypophosphite is the source of P element, and the mass ratio of sodium hypophosphite to porous flower-like zinc oxide microspheres is 1:1.

[0042] The finally prepared phosphorus-doped porous flower-like zinc oxide microspheres have a flower-like structure, which is self-assembled by a large number of porous nanosheets, with a particle size of about 14 μm and a specific surface area of 395 m 3 ·g −1 . Zn, O, and P are 57.9 wt%, 15.8 wt%, and 26.3 wt% respectively.

[0043] Experimental Example According to the "Indoor Test Method for the Obscuring / Interfering Performance of Smoke Screen on Infrared Thermal Imager" (GJB 5323-2004), when the product of the optical path and the mass concentration is not greater than 12 g / m 2 , the infrared attenuation performance of the heteroatom-doped porous flower-like zinc oxide microspheres prepared in Examples 1-7, the undoped porous flower-like zinc oxide microspheres, the existing silver-plated glass microspheres and graphene nanosheets was tested in a smoke chamber. The effective volume of the smoke chamber was not less than 20 m³, and the test frequency band was 8 μm to 14 μm. The test results are shown in Table 1; Table 1 Infrared attenuation test data of the doped porous flower-like zinc oxide microspheres, undoped porous flower-like zinc oxide microspheres, existing silver-plated glass microspheres and graphene nanosheets prepared in Examples 1-7 It can be seen that when the mass of the dispersed smoke screen material is 48 g, the attenuation rates of N,S,P-ZnO, N,S-ZnO, N,P-ZnO, S,P-ZnO, N-ZnO, S-ZnO and P-ZnO prepared in Examples 1-7 for infrared rays in the range of 8 μm to 14 μm are 83.9%, 75.1%, 74.2%, 75.8%, 60.2%, 59.2% and 61.1% respectively, showing strong infrared attenuation performance. With the increase in the types of doped atoms, the polarization loss ability is further enhanced.

[0044] The above embodiments are the preferred embodiments of the present invention, mainly showing and describing the main features and basic principles of the present invention. However, the implementation embodiments of the present invention are not limited by the above embodiments. Without departing from the spirit and scope of the present invention, any modifications, alterations, substitutions, combinations, and simplifications made by those skilled in the relevant fields and technologies shall be regarded as within the scope of the present invention.

Claims

1. A heteroatom-doped porous flower-shaped zinc oxide microsphere infrared smoke interference material, characterized in that: It has a flower-like structure, which is self-assembled from a large number of porous nanosheets, with a particle size of 2-15 μm and a specific surface area of ​​350-420 m 3 ·g −1 , of which zinc oxide accounts for 70-75wt% and heteroatoms account for 25-30wt%.

2. The method for preparing the heteroatom-doped porous flower-shaped zinc oxide microsphere infrared smoke interference material according to claim 1, characterized in that: The specific steps are as follows: (1) Preparation of porous flower-like zinc oxide microspheres: Add zinc oxyacid salt and hexadecyltrimethylammonium bromide into a beaker containing ethylene glycol and deionized water, and stir mechanically for 2-4 h to form a uniform transparent solution; then transfer the solution into a stainless steel autoclave containing urea and stir mechanically for 1-3 h; Then the autoclave was kept at 100-140°C for 16-24 h. After the reaction was completed, the zinc oxide precursor was taken out and naturally cooled to room temperature. After being washed alternately with deionized water and ethanol five times each, the sample was vacuum dried at 80°C for 12 h. Finally, the sample was heated to 300-700°C in a sintering furnace at a temperature of 10°C / min. After being kept for 1-4 h, it was naturally cooled to room temperature. A large number of holes were generated in the composed zinc oxide microsphere nanosheets, and porous flower-like zinc oxide microspheres were obtained. (2) Preparation of heteroatom-doped porous flower-like zinc oxide microspheres: The heteroatom doping source and the porous flower-like zinc oxide microspheres obtained in step (1) are placed on two separate porcelain boats in a tubular furnace, the former being upstream and the latter being downstream, and the heteroatom doped porous flower-like zinc oxide microspheres are prepared at 300-500° C. for 1-3 h under a protective atmosphere.

3. The method for preparing the heteroatom-doped porous flower-shaped zinc oxide microsphere infrared smoke interference material according to claim 2, characterized in that: In step (1), the zinc oxyacid salt is selected from zinc acetate, zinc nitrate or zinc sulfate; the molar ratio of the zinc oxyacid salt, hexadecyltrimethylammonium bromide and urea is 0.6-1:1:0.6-1.

67.

4. The method for preparing the heteroatom-doped porous flower-shaped zinc oxide microsphere infrared smoke interference material according to claim 2, characterized in that: In step (1), the volume ratio of the molar amount of any one of zinc oxyacid salt, hexadecyltrimethylammonium bromide or urea to the mixture of ethylene glycol and deionized water is 3-5 mol:12L; wherein the volume ratio of ethylene glycol to deionized water is 0.5-1:

1.

5. The method for preparing the heteroatom-doped porous flower-shaped zinc oxide microsphere infrared smoke interference material according to claim 2 or 4, characterized in that: The rotation speed of the mechanical stirring in step (1) is 400-1000 rpm; the volume ratio of ethylene glycol to deionized water is 0.7-0.75:

1.

6. The method for preparing the heteroatom-doped porous flower-shaped zinc oxide microsphere infrared smoke interference material according to claim 2, characterized in that: The heteroatom doped in step (2) is any one or more of the three elements N, S and P, and the mass ratio of the heteroatom doping source to the porous flower-shaped zinc oxide microspheres is 1-3:

1.

7. The method for preparing the heteroatom-doped porous flower-shaped zinc oxide microsphere infrared smoke interference material according to claim 2 or 6, characterized in that: The sources of N, S and P elements are urea, sublimated sulfur and sodium hypophosphite respectively; the mass ratio of the heteroatom doping source to the porous flower-shaped zinc oxide microspheres is 1:1; and the protective atmosphere is selected from one or more of nitrogen or argon.

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