Microdifferential gas explosion modified carbon-coated metal nanomaterial device and preparation method

Abstract

The invention discloses a millisecond gas explosion modified carbon-coated metal nanomaterial device and a preparation method. The device comprises a detonation tube inner cavity and a detonation tube outer cavity which are arranged in a sleeved mode. An inner cavity of the detonation pipe is connected with an inner cavity gas filling pipe, an inner cavity vacuumizing / exhausting pipe, an inner cavity vacuum meter and an inner cavity ignition device; control valves are arranged on the inner cavity gas filling pipe, the inner cavity vacuumizing / exhausting pipe and the inner cavity vacuum meter; the detonation tube outer cavity is connected with an outer cavity vacuum meter, an outer cavity inflation tube, an outer cavity ignition device, an outer cavity vacuumizing tube and an outer cavity exhaust / drainage tube; control valves are arranged on the outer cavity vacuum meter, the outer cavity inflation tube, the outer cavity vacuumizing tube and the outer cavity exhaust / drainage tube; the inner cavity inflating tube and the outer cavity inflating tube are provided with two inflating ports; the inner cavity ignition device and the outer cavity ignition device can be connected with the high-energy igniter and the millisecond high-energy igniter; according to the preparation method, preparation and heat treatment of the nano material are almost synchronously carried out by utilizing the device, and the post-treatment efficiency of the nano material prepared by a gas-phase detonation method is remarkably improved.

Description

Technical Field

[0001] The invention belongs to the technical field of nano material synthesis, and particularly relates to a device for modifying carbon-coated metal nano material by slight difference gas explosion and a preparation method thereof. Background Art

[0002] The gas phase detonation method is a method of preparing nanomaterials by using combustible gas explosion, which is characterized by high efficiency and convenience. However, for carbon-coated metal nanomaterials, such as carbon-coated iron nanoparticles, carbon-coated cobalt nanoparticles, etc., due to the instantaneous nature of the gas explosion reaction, the initial samples prepared by gas phase detonation have low metal core crystallinity, low carbon layer graphitization degree, and unclear core-shell structure. In order to obtain carbon-coated metal nanomaterials with higher physicochemical properties, it is often necessary to carry out heat treatment of the initial samples prepared by gas phase detonation under inert gas protection. This undoubtedly adds difficulty to the originally efficient and convenient gas phase detonation nanomaterial preparation method.

[0003] Gas explosions can release huge amounts of energy instantly, generating high temperatures and pressures, and can be used to study the modification of nanomaterials. Yan Honghao et al. studied the modification characteristics of carbon nanotubes through explosive explosions and found that the graphitized tubular structure of carbon nanotubes would be destroyed under the action of high explosives. Zhao Tiejun et al. tried to modify carbon-coated iron nanoparticles by detonation using secondary gas explosions, and pointed out that secondary explosions can achieve changes in the physical phase and morphology of carbon-coated iron nanoparticles. However, secondary explosions can easily cause oxidation of metal particles.

[0004] In the published patent: Synthesis of Nano-carbon-coated Iron by Gas Phase Detonation Using Pentacarbonyl Iron as Iron Source (2017104986367), the detonation modification of the prepared materials cannot be carried out well, and the modification efficiency such as heat treatment of the materials is very low. Summary of the invention

[0005] In order to overcome the defects in the prior art, the present invention provides a device and a preparation method for a micro-difference gas explosion modified carbon-coated metal nanomaterial, which can realize almost simultaneous preparation and heat treatment of nanomaterials, can significantly improve the efficiency of post-processing of nanomaterials prepared by gas phase detonation method, and is conducive to the application and promotion of gas phase detonation method in the preparation of nanomaterials.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions: a device for modifying carbon-coated metal nanomaterials by slight difference gas explosion, comprising a detonation tube, wherein the detonation tube comprises a detonation tube inner cavity and a detonation tube outer cavity which are mutually nested and isolated;

[0007] The inner cavity of the detonation tube is connected to an inner cavity gas filling tube, an inner cavity vacuum / exhaust tube, an inner cavity vacuum gauge and an inner cavity ignition device, and the inner cavity gas filling tube, the inner cavity vacuum / exhaust tube and the inner cavity vacuum gauge are all provided with control valves;

[0008] The outer cavity of the detonation tube is connected to an outer cavity vacuum gauge, an outer cavity gas-filling pipe, an outer cavity ignition device, an outer cavity vacuum-pumping pipe and an outer cavity exhaust / drain pipe, and the outer cavity vacuum gauge, the outer cavity gas-filling pipe, the outer cavity vacuum-pumping pipe and the outer cavity exhaust / drain pipe are all provided with control valves;

[0009] The inner cavity gas filling tube and the outer cavity gas filling tube each have two gas filling ports for respectively filling two reaction gases;

[0010] The inner cavity ignition device and the outer cavity ignition device are ignition devices that can be connected to a high energy igniter and a micro-difference high energy igniter.

[0011] Furthermore, the ends of the detonation tube inner cavity and the detonation tube outer cavity are connected by a sealing flange.

[0012] Furthermore, the sealing flange includes an inner cavity sealing flange and an outer cavity sealing flange, the inner cavity sealing flange is arranged at the end of the inner cavity of the detonation tube, and the outer cavity sealing flange is arranged at the end of the outer cavity of the detonation tube, and the inner cavity sealing flange and the outer cavity sealing flange are fastened and connected by bolts.

[0013] Furthermore, the inner cavity inflation tube, the inner cavity vacuum / exhaust tube, the inner cavity vacuum gauge and the inner cavity ignition device are all arranged on the inner cavity sealing flange.

[0014] Preferably, the inner cavity of the detonation tube is a seamless stainless steel tube or a titanium alloy tube.

[0015] Preferably, the outer cavity of the detonation tube is a seamless stainless steel tube or a titanium alloy tube.

[0016] The present invention further proposes a method for preparing a carbon-coated metal nanomaterial, which is carried out using the micro-difference gas explosion modified carbon-coated metal nanomaterial device, and comprises the following steps:

[0017] Step 1, placing the reaction raw materials in the clean and dry inner cavity of the detonation tube;

[0018] Step 2, opening the inner cavity vacuum gauge, and connecting the vacuum pump to the inner cavity of the detonation tube through the inner cavity vacuum / exhaust pipe to vacuumize the inner cavity of the detonation tube, and when the inner cavity vacuum indication number reaches the set value, closing the control valve of the inner cavity vacuum / exhaust pipe;

[0019] Step 3, two reaction gases in a certain ratio are charged into the inner cavity of the detonation tube through the inner cavity charging pipe until the inner cavity vacuum indication number is 0;

[0020] Step 4: Open the vacuum gauge of the outer cavity, and connect the vacuum pump to the vacuum pump through the vacuum pump pipe of the outer cavity to evacuate the outer cavity of the detonation tube. When the vacuum gauge of the outer cavity reaches the set value, close the control valve of the vacuum pump pipe of the outer cavity;

[0021] Step 5, two reaction gases in a certain ratio are charged into the outer cavity of the detonation tube through the outer cavity charging pipe until the vacuum indication number of the outer cavity is 0;

[0022] Step 6, connecting the inner cavity ignition device and the outer cavity ignition device to the differential high energy igniter, setting the differential time and starting the differential high energy igniter to sequentially detonate the mixed gas in the inner cavity of the detonation tube and the outer cavity of the detonation tube;

[0023] Step 7: After the reaction is completed, the nano powders deposited in the inner cavity of the detonation tube are collected through the inner cavity vacuum / exhaust pipe.

[0024] The technical principle of the present invention is: for the general gas phase detonation method, there is only one detonation, while the micro-difference detonation means that there is a time difference in the detonation, which can produce two explosions. Because the micro-difference is only a few milliseconds, and the two explosions can be completed in a few milliseconds, that is, the preparation and post-treatment of the nanomaterials are completed almost at the same time, so a lot of time can be saved for the modification of the nanomaterials. Specifically in the present invention, there is a micro-difference detonation between the inner cavity of the detonation tube and the outer cavity of the detonation tube, the gas explosion in the inner cavity of the detonation tube can prepare carbon-coated metal nanomaterials, and the high temperature generated by the gas explosion in the outer cavity of the detonation tube can be heat-treated and modified for the carbon-coated metal nanomaterials prepared in the inner cavity of the detonation tube, so that the preparation and heat treatment of the nanomaterials are almost carried out simultaneously.

[0025] Therefore, the beneficial effects produced by the present invention are:

[0026] 1) The initial samples of carbon materials such as carbon-coated metal nanoparticles can be prepared by using the inner cavity of the device for modifying carbon-coated metal nanomaterials by slight difference gas explosion alone.

[0027] 2) The inner cavity and outer cavity of the invented device can be used simultaneously to achieve modification and optimization of the physical phase, morphology and other properties of carbon-coated metal nanomaterials.

[0028] 3) The invented device can realize almost simultaneous preparation and heat treatment of nanomaterials, which can significantly improve the efficiency of post-processing of nanomaterials prepared by gas phase detonation method, and contribute to the application and promotion of gas phase detonation method in the preparation of nanomaterials. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0030] Figure 1 Schematic diagram of the device for modifying carbon-coated metal nanomaterials by slight difference gas explosion of the present invention;

[0031] Figure 2 This is a transmission electron microscope (TEM) image of a carbon-coated iron nanoparticle sample prepared by non-differential gas phase detonation;

[0032] Figure 3 This is a TEM picture of carbon-coated iron nanoparticles prepared by the micro-difference gas explosion modification device of the present invention;

[0033] Figure 4 These are the Raman spectra of carbon-coated cobalt nanoparticles prepared by non-differential and differential gas explosion modification devices.

[0034] In the figure: 1. Inner cavity inflation tube; 2-1. Inner cavity sealing flange; 2-2. Outer cavity sealing flange; 3. Outer cavity vacuum gauge; 4. Outer cavity inflation tube; 5. Detonation tube outer cavity; 6. Outer cavity ignition device; 7. Inner cavity vacuum / exhaust tube; 8. Inner cavity ignition device; 9. Outer cavity vacuum tube; 10. Outer cavity exhaust / drainage tube; 11. Detonation tube inner cavity; 12. Inner cavity vacuum gauge; 13. Control valve. DETAILED DESCRIPTION

[0035] The preferred embodiments of the present invention are described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0036] Example 1

[0037] The structure of the micro-difference gas explosion modified carbon-coated metal nanomaterial device proposed by the present invention is as follows: Figure 1 As shown, it includes a detonation tube, and the detonation tube includes a detonation tube inner cavity 11 and a detonation tube outer cavity 5, and the detonation tube outer cavity 5 is arranged around the detonation tube inner cavity 11, and the two are isolated from each other. The two ends of the detonation tube inner cavity 11 and the detonation tube outer cavity 5 are respectively connected by sealing flanges to achieve isolation of the two chambers. The sealing flange is divided into an inner cavity sealing flange 2-1 and an outer cavity sealing flange 2-2, the inner cavity sealing flange 2-1 is located at both ends of the detonation tube inner cavity 11, and the outer cavity sealing flange 2-2 is located at both ends of the detonation tube outer cavity 5, and the outer cavity sealing flange 2-2 is provided with a center hole for the detonation tube inner cavity 11 to pass through, and the inner cavity sealing flange 2-1 and the outer cavity sealing flange 2-2 are fastened and connected by bolts.

[0038] The detonation tube inner cavity 11 is a seamless stainless steel tube or a titanium alloy tube, and is a reaction chamber for preparing carbon-coated metal nanomaterials by gas phase detonation. The detonation tube inner cavity 11 is connected with an inner cavity gas filling tube 1, an inner cavity vacuum / exhaust tube 7, an inner cavity vacuum gauge 12 and an inner cavity ignition device 8. The two opposite ends of the detonation tube inner cavity 11 are respectively a first end and a second end. The inner cavity gas filling tube 1 is arranged at the first end of the detonation tube inner cavity 11, and is used to inflate the detonation tube inner cavity 11. The inner cavity vacuum / exhaust tube 7 is arranged at the second end of the detonation tube inner cavity 11, and the inner cavity vacuum / exhaust tube 7 is used to connect the exhaust device to vacuum the detonation tube inner cavity 11 and to connect the collection device to collect the nano powder after the reaction in the detonation tube inner cavity 11. The inner cavity vacuum gauge 12 is connected to the detonation tube inner cavity 11 to detect the pressure value in the cavity. The ignition end of the inner cavity ignition device 8 is located in the inner cavity 11 of the detonation tube, and the inner cavity ignition device 8 is a spark plug that can connect a high-energy igniter and a micro-difference high-energy igniter. The inner cavity gas filling pipe 1, the inner cavity vacuum / exhaust pipe 7, and the inner cavity vacuum gauge 12 are all provided with a control valve 13 to control the opening and closing of the corresponding pipelines.

[0039] In order to prevent the pipe on the detonation tube inner cavity 11 from passing through the detonation tube outer cavity 5, the inner cavity inflation pipe 1, the inner cavity vacuum / exhaust pipe 7, the inner cavity vacuum gauge 12 and the inner cavity ignition device 8 are all arranged at both ends of the detonation tube inner cavity 11 and pass through the inner cavity sealing flange 2-1.

[0040] The detonation tube outer cavity 5 is a seamless stainless steel tube or a titanium alloy tube, which is a reaction chamber for micro-difference gas explosion modified carbon-coated metal nanomaterials. The side of the detonation tube outer cavity 5 is connected with an outer cavity vacuum gauge 3, an outer cavity gas filling tube 4, an outer cavity ignition device 6, an outer cavity vacuum tube 9 and an outer cavity exhaust / drain pipe 10. The outer cavity vacuum gauge 3 is used to detect the pressure value in the detonation tube outer cavity 5. The outer cavity gas filling tube 4 is used to inflate the detonation tube outer cavity 5. The ignition end of the outer cavity ignition device 6 is located in the detonation tube outer cavity 5, and the outer cavity ignition device 6 is a spark plug that can connect a high-energy igniter with a micro-difference high-energy igniter. The outer cavity vacuum tube 9 is used to connect the exhaust device to exhaust the detonation tube outer cavity 5. The outer cavity exhaust / drain pipe 10 is used for exhausting and draining the detonation tube outer cavity 5 after the reaction. The outer cavity vacuum gauge 3, the outer cavity inflation tube 4, the outer cavity vacuum tube 9 and the outer cavity exhaust / drainage tube 10 are all provided with control valves.

[0041] Furthermore, the outer cavity vacuum pipe 9 and the outer cavity exhaust / drain pipe 10 are integrated on a pipe with a three-way pipe, and the pipe is connected to the detonation tube outer cavity 5.

[0042] Specifically, the inner cavity vacuum / exhaust pipe 7, the outer cavity vacuum pipe 9 and the outer cavity exhaust / drainage pipe 10 are seamless stainless steel pipes, which can simultaneously meet the requirements of vacuuming, exhaust gas and water discharge.

[0043] The inner cavity gas filling tube 1 and the outer cavity gas filling tube 4 are three-way seamless stainless steel tubes and are equipped with three control valves 13 so that two reaction gases can be filled at the same time.

[0044] When the device is used to prepare carbon-coated metal nanomaterials, the gas used is common combustible gas such as hydrogen, methane, liquefied gas, etc., and the gas explosion in the outer cavity 5 of the detonation tube must meet zero oxygen or oxygen-rich balance.

[0045] Gas explosion produces a high temperature of about 3000K and a pressure of several MPa. The carbon-coated metal nanomaterials prepared in the detonation tube are heat-treated and modified using the differential initiation principle. Therefore, the experimental device should meet certain requirements of high temperature resistance, high pressure resistance, high physical and chemical stability and thermal conductivity.

[0046] Test Example 1

[0047] Use the attached Figure 1 The device in the experiment of preparing carbon-coated iron nanoparticles by non-differential gas phase detonation was used. First, the inner cavity 11 of the detonation tube was cleaned and kept dry, and then 2.0g of ferrocene was evenly placed in the inner cavity 11 of the detonation tube. Then, the inner cavity sealing flange 2-1 at the end of the inner cavity 11 of the detonation tube was installed, the control valve 13 of the inner cavity vacuum gauge 12 was opened, and the vacuum pump was connected to the inner cavity vacuum pumping / exhaust pipe 7 to vacuum the inner cavity 11 of the detonation tube. When the reading of the inner cavity vacuum gauge 12 was less than -0.095MPa, the control valve 13 on the inner cavity vacuum pumping / exhaust pipe 7 was closed. Hydrogen and oxygen were sequentially filled in a molar ratio of 2:1 through the inner cavity filling pipe 1 until the reading of the inner cavity vacuum gauge 12 was zero. After 10 minutes, the inner cavity ignition device 8 was connected to the high-energy igniter to detonate the inner cavity mixed gas. After 5 minutes, the inner cavity vacuum pumping / exhaust pipe 7 connected to the collection device was opened to collect the nanopowders precipitated in the inner cavity 11 of the detonation tube. Finally, the powder was characterized and analyzed.

[0048] Analysis results: Figure 2 As shown, the nano powder collected in the detonation tube cavity 11 is carbon-coated iron nanoparticles, the dark part is the iron / iron carbide metal core, the metal core has an irregular shape, and the metal lattice stripes are unclear. The outer layer of the metal core is coated with amorphous carbon, the graphitized structure of the carbon layer is discontinuous, and the degree of graphitization is low.

[0049] Test Example 2

[0050] In this example, the experiment of preparing carbon-coated iron nanoparticles by micro-difference gas phase detonation was carried out according to the device of Example 1. According to the experimental method of Test Example 1, ferrocene was placed in the inner cavity 11 of the detonation tube and the hydrogen and oxygen filling steps were completed. Then, the outer cavity vacuum gauge 3 was opened and the vacuum pump was connected to the outer cavity vacuum pumping tube 9 for vacuuming. When the vacuum indication reading was less than -0.095MPa, the control valve 13 on the outer cavity vacuum pumping tube 9 was closed. Then, hydrogen and oxygen were sequentially filled in a molar ratio of 2:1 through the outer cavity filling tube 4 until the outer cavity vacuum gauge 3 showed zero. After 10 minutes, the outer cavity ignition device 6 and the inner cavity ignition device 8 were connected to the micro-difference high-energy igniter. After setting the micro-difference time, the micro-difference high-energy igniter was started to detonate the mixed gas of the inner cavity and the outer cavity in turn. After 5 minutes, the collection device was connected through the inner cavity vacuum pumping / exhaust pipe 7 to collect the nano powders precipitated in the inner cavity 11 of the detonation tube. Finally, the powder was characterized and analyzed.

[0051] Analysis results: as attached Figure 3 As shown, the core-shell structure of the carbon-coated iron nanoparticles modified by the differential gas explosion collected in the detonation tube cavity 11 is clearly discernible, and the graphitization stripes of the carbon layer outside the metal core are complete. The graphitization degree and crystallinity degree of the carbon-coated iron nanoparticles are significantly improved.

[0052] Test Example 3

[0053] According to the experimental method of Experimental Example 2, ferrocene was replaced with cobalt acetylacetonate, and the remaining steps were the same as those of Experimental Example 2, and carbon-coated cobalt nanoparticles were subjected to differential gas explosion modification. Carbon-coated cobalt nanoparticles were prepared by non-differential gas phase detonation using the method of Experimental Example 1.

[0054] like Figure 4 As shown, the Raman spectrum peak intensity of the carbon-coated cobalt nanoparticles samples prepared and collected by the two methods is significantly improved compared with the peak intensity of the samples obtained by non-differential gas phase detonation, indicating that the differential gas explosion method can effectively improve the degree of graphitization of carbon-coated cobalt nanoparticles.

[0055] In summary, the present invention can realize the preparation of carbon-coated metal nanoparticles through this micro-difference gas explosion modified carbon-coated metal nanomaterial device, and at the same time has the modification of its physical phase and morphology. This provides an experimental device for efficiently and conveniently preparing carbon-coated metal nanoparticles with high crystallinity and good morphology by gas phase detonation, which is conducive to the promotion and application of gas phase detonation method in the preparation of nanomaterials.

[0056] It should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention is described in detail with reference to the above embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the above embodiments or to replace some of the technical features therein by equivalents. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention. The terms used in the description of this application are only for describing specific implementations and are not intended to limit the exemplary implementations according to the present application. For ease of description, the sizes of the various parts shown in the drawings are not drawn according to the actual proportional relationship. The techniques, methods and devices known to ordinary technicians in the relevant fields may not be discussed in detail, but where appropriate, the techniques, methods and devices should be regarded as part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as merely exemplary and not as a limitation. Therefore, other examples of the exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further discussed in subsequent drawings.

Claims

1. A device for modifying carbon-coated metal nanomaterials by slight difference gas explosion, comprising a detonation tube, characterized in that: The detonation tube comprises a detonation tube inner cavity and a detonation tube outer cavity which are mutually nested and isolated; The inner cavity of the detonation tube is connected to an inner cavity gas filling tube, an inner cavity vacuum / exhaust tube, an inner cavity vacuum gauge and an inner cavity ignition device, and the inner cavity gas filling tube, the inner cavity vacuum / exhaust tube and the inner cavity vacuum gauge are all provided with control valves; The outer cavity of the detonation tube is connected to an outer cavity vacuum gauge, an outer cavity gas-filling pipe, an outer cavity ignition device, an outer cavity vacuum-pumping pipe and an outer cavity exhaust / drain pipe, and the outer cavity vacuum gauge, the outer cavity gas-filling pipe, the outer cavity vacuum-pumping pipe and the outer cavity exhaust / drain pipe are all provided with control valves; The inner cavity gas filling tube and the outer cavity gas filling tube each have two gas filling ports for respectively filling two reaction gases; The inner cavity ignition device and the outer cavity ignition device are ignition devices that can be connected to a high energy igniter and a micro-difference high energy igniter.

2. The device for modifying carbon-coated metal nanomaterials by slight difference gas explosion according to claim 1, characterized in that: The ends of the detonation tube inner cavity and the detonation tube outer cavity are connected through a sealing flange.

3. The device for modifying carbon-coated metal nanomaterials by slight difference gas explosion according to claim 2, characterized in that: The sealing flange comprises an inner cavity sealing flange and an outer cavity sealing flange, wherein the inner cavity sealing flange is arranged at the end of the inner cavity of the detonation tube, and the outer cavity sealing flange is arranged at the end of the outer cavity of the detonation tube, and the inner cavity sealing flange and the outer cavity sealing flange are fastened and connected by bolts.

4. The device for modifying carbon-coated metal nanomaterials by slight difference gas explosion according to claim 3 is characterized in that: The inner cavity inflation tube, the inner cavity vacuum / exhaust tube, the inner cavity vacuum gauge and the inner cavity ignition device are all arranged on the inner cavity sealing flange.

5. The device for modifying carbon-coated metal nanomaterials by slight difference gas explosion according to claim 1, characterized in that: The inner cavity of the detonation tube is a seamless stainless steel tube or a titanium alloy tube.

6. The device for modifying carbon-coated metal nanomaterials by slight difference gas explosion according to claim 1, characterized in that: The outer cavity of the detonation tube is a seamless stainless steel tube or a titanium alloy tube.

7. A method for preparing carbon-coated metal nanomaterials, characterized in that: The method is carried out using the micro-difference gas explosion modified carbon-coated metal nanomaterial device according to any one of claims 1 to 6, and comprises the following steps: Step 1, placing the reaction raw materials in the clean and dry inner cavity of the detonation tube; Step 2, opening the inner cavity vacuum gauge, and connecting the vacuum pump to the inner cavity of the detonation tube through the inner cavity vacuum / exhaust pipe to vacuumize the inner cavity of the detonation tube, and when the inner cavity vacuum indication number reaches the set value, closing the control valve of the inner cavity vacuum / exhaust pipe; Step 3, two reaction gases in a certain ratio are charged into the inner cavity of the detonation tube through the inner cavity charging pipe until the inner cavity vacuum indication number is 0; Step 4: Open the vacuum gauge of the outer cavity, and connect the vacuum pump to the vacuum pump through the vacuum pump pipe of the outer cavity to evacuate the outer cavity of the detonation tube. When the vacuum gauge of the outer cavity reaches the set value, close the control valve of the vacuum pump pipe of the outer cavity; Step 5, two reaction gases in a certain ratio are charged into the outer cavity of the detonation tube through the outer cavity charging pipe until the vacuum indication number of the outer cavity is 0; Step 6, connecting the inner cavity ignition device and the outer cavity ignition device to the differential high energy igniter, setting the differential time and starting the differential high energy igniter to sequentially detonate the mixed gas in the inner cavity of the detonation tube and the outer cavity of the detonation tube; Step 7: After the reaction is completed, the nano powders deposited in the inner cavity of the detonation tube are collected through the inner cavity vacuum / exhaust pipe.

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