Reaction device for liquid-phase pulse discharge shock wave treatment and nano material preparation method

Abstract

The invention provides a reaction device for liquid-phase pulse discharge shock wave treatment and a nano material preparation method, relates to the technical field of chemical reaction equipment, and aims to solve the technical problem of insufficient shock wave pressurization of an existing reaction device. The reaction device comprises a tank body, a cover body and an electric arc generating device, the tank body is provided with a first inner wall with an ellipsoidal surface, and the ellipsoidal surface is formed by rotating an ellipse along a long axis; the arc generating device penetrates through the cover body and extends into the tank body, a discharge point of the arc generating device is located at a first focus of the tank body, and the first focus is located above a second focus of the tank body; the cover body covers the top of the tank body, and the cover body is provided with a second inner wall with the middle protruding towards the interior of the tank body; the second inner wall is a surface formed by rotating one branch of the hyperbolic curve, and the rotating shaft of the branch is the axis where the real axis of the hyperbolic curve is located; the third focus, close to the other branch, of the hyperbolic curve coincides with the first focus. According to the reaction device, the pressurization convergence effect is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of chemical reaction equipment, and in particular to a reaction device for liquid-phase pulsed discharge shock wave treatment and a method for preparing nanomaterials. Background Art

[0002] Liquid-phase discharge is a new discipline developed in the 1950s and occupies an important position in high-voltage technology. Liquid-phase pulsed discharge instantaneously forms a high-intensity electric field between electrodes within the microsecond time scale, and uses the electric field to accelerate electrons to generate high-energy electrons. The high-energy electrons collide with atoms and molecules to form a plasma channel. Since the discharge time is in the microsecond time scale and the discharge current reaches the order of 1-10 2 kA, a large amount of energy is obtained by the plasma channel in an extremely short time, and the temperature is as high as 10 4 -10 5 K, and the pressure can reach 10 0 -10 2 Gpa. Under such conditions, the liquid medium forms a plasma with high density and high pressure. This plasma channel has a strong ultraviolet radiation ability and expands outward at supersonic speed to generate shock waves. Summary of the Invention

[0003] The purpose of the present invention is to provide a reaction device for liquid-phase pulsed discharge shock wave treatment and a method for preparing nanomaterials, so as to solve the technical problem of insufficient shock wave pressure increase in the existing reaction device.

[0004] To achieve the above purpose, the present invention provides the following technical solutions:

[0005] In the first aspect, the present invention provides a reaction device for liquid-phase pulsed discharge shock wave treatment, including a tank body, a cover body and an arc generating device. The tank body has a first inner wall with an ellipsoidal surface, and the ellipsoidal surface is formed by rotating an ellipse along its major axis;

[0006] The arc generating device penetrates through the cover body and extends into the tank body, and the discharge point of the arc generating device is located at the first focus of the tank body, and the first focus is located above the second focus of the tank body;

[0007] The cover body is covered on the top of the tank body, and the cover body has a second inner wall that protrudes toward the inside of the tank body in the middle;

[0008] The second inner wall is a surface formed by rotating a branch of a hyperbola, and the rotation axis of the branch is the axis where the real axis of the hyperbola is located;

[0009] The third focus of the hyperbola close to the other branch coincides with the first focus.

[0010] According to at least one embodiment of the present invention, the hyperbola satisfies: Y = 12.444 + 0.889×(1 + (x / 7.521) 2 ) 1 / 2 .

[0011] According to at least one embodiment of the present invention, the ellipse satisfies: Y = 4×(1 - (x 2 / 14.222 2 )) 1 / 2 , with an eccentricity of 0.458 and a ratio of the major axis to the minor axis of 1.125.

[0012] According to at least one embodiment of the present invention, the distance between the first focus and the second focus is 82.46 cm.

[0013] According to at least one embodiment of the present invention, the reaction device further includes four positioning bolts evenly distributed along the circumferential direction of the tank body;

[0014] The positioning bolts penetrate through the tank body and extend to the inside of the tank body, and are close to the central position of the tank body.

[0015] According to at least one embodiment of the present invention, the tank body has at least one first viewing window and at least one second viewing window, the first viewing window faces the first focus, and the second viewing window faces the second focus.

[0016] According to at least one embodiment of the present invention, the tank body has two first viewing windows and two second viewing windows, the two first viewing windows are opposite to each other, and the two second viewing windows are opposite to each other;

[0017] The connection line of the two first viewing windows is perpendicular to the connection line of the two second viewing windows.

[0018] According to at least one embodiment of the present invention, the arc generating device includes two electrode rods and two electrode heads, and the two electrode rods penetrate through the cover body and extend into the tank body;

[0019] The two electrode heads are respectively arranged at the ends of the two electrode rods located inside the tank body, and each electrode head is perpendicular to the corresponding electrode rod;

[0020] The end of the electrode head facing away from the electrode rod has a 45° chamfer.

[0021] According to at least one embodiment of the present invention, the cover body includes a first insulating block and a second insulating block. The first insulating block is fixedly arranged on the tank body, a groove is formed in the central part of the top surface of the first insulating block, and the second insulating block is embedded in the groove;

[0022] The two electrode rods penetrate through the first insulating block and the second insulating block and extend into the tank body.

[0023] Second, the present invention also provides a method for preparing a nanomaterial, which is prepared by using the reaction device described in the first aspect. The method includes:

[0024] Assemble the tank body and suspend the sample near the second focus;

[0025] Inject a conductive solution into the opening of the tank body, and cover the opening with the cover body. Among them, the conductive solution includes one of distilled water, ammonia water, organic solution and inorganic salt solution;

[0026] The arc generating device instantaneously discharges to generate plasma in the conductive solution, so that the sample forms a nanomaterial.

[0027] Among one or more technical solutions provided in the exemplary embodiments of the present invention, at least one of the following beneficial effects can be achieved.

[0028] In the reaction device for liquid-phase pulsed discharge shock wave treatment according to the exemplary embodiment of the present invention, the first inner wall of the tank body is set as a curved surface of an ellipsoid. The ellipsoid is formed by rotating an ellipse along the major axis, that is, the tank body is generally a long ellipsoid. The first focus of the ellipse is on the upper side and the second focus is on the lower side. The cover body is covered on the top of the tank body, and the shape of the second inner wall of the cover body is a surface formed by rotating a branch of a hyperbola. Specifically, the rotation axis of the branch is the axis where the real axis of the hyperbola is located. Among them, the third focus of the hyperbola close to the other branch coincides with the first focus. The discharge point of the arc generating device is located on the first focus of the tank body. Thus, the first inner wall and the second inner wall together form the entire inner wall surface of the cavity of the reaction device. Based on this, when a pulsed discharge shock wave is generated at the discharge point, large cavities will be generated at the discharge point. When the shock wave is reflected by the second inner wall of the cover body, it will not penetrate the large cavity, but avoid the large cavity and converge to the second focus, without hindering the reflection and convergence of the shock wave, thus avoiding the impedance mismatch interface generated by the large cavity; the part of the shock wave reflected by the second inner wall converges to the second focus after being reflected by the first inner wall twice. Therefore, the overall energy utilization efficiency can be improved and the pressure boosting effect is better.

[0029] When the sample is placed near the second focus in the tank body, the material preparation area can be far away from the discharge area (the first focus), avoiding the influence of the "magnetic pinch" effect of the plasma on the product, realizing the decoupling of the shock wave effect and the electromagnetic effect, reducing the complexity of the material synthesis process, and efficiently preparing nanomaterials with smaller and more uniform particle sizes. Description of the Drawings

[0030] The accompanying drawings illustrate exemplary embodiments of the present invention and, together with the description thereof, are used to explain the principles of the present invention. These drawings are included to provide a further understanding of the present invention and are included in this specification and form a part of this specification;

[0031] Figure 1 is a schematic cross-sectional structure diagram of a reaction device according to an embodiment of the present invention;

[0032] Figure 2 is a schematic diagram of the pressure boosting principle of a reaction device according to an embodiment of the present invention;

[0033] Figure 3 is a schematic circuit structure diagram of a reaction device according to an embodiment of the present invention;

[0034] Figure 4 is a simplified grid schematic diagram of a reaction device model according to an embodiment of the present invention;

[0035] Figure 5A is the simulation effect of the first stage when a shock wave propagates according to an embodiment of the present invention;

[0036] Figure 5B is the simulation effect of the second stage when a shock wave propagates according to an embodiment of the present invention;

[0037] Figure 5C is the simulation effect of the first stage when a shock wave pursues according to an embodiment of the present invention;

[0038] Figure 5D is the simulation effect of the second stage when a shock wave pursues according to an embodiment of the present invention;

[0039] Figure 5E is the simulation effect of the first stage when a shock wave focuses according to an embodiment of the present invention;

[0040] Figure 5F is the simulation effect of the second stage when a shock wave focuses according to an embodiment of the present invention.

[0041] Reference numerals:

[0042] 10, tank body; 11, first inner wall; 12, second inner wall;

[0043] 20, cover body; 21, first insulating block; 22, second insulating block;

[0044] 31, electrode rod; 32, electrode head;

[0045] 40, second viewing window; 41, positioning bolt;

[0046] 51, power supply; 52, capacitor;

[0047] G1, the first focus; G2, the second focus; G3, the third focus. Detailed implementation manners

[0048] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clear and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0049] The liquid-phase pulsed discharge shock wave focusing method provides a closed tank with a specific shape. The high-pressure and high-temperature arc rapidly compresses the water near it to form a high-intensity shock wave. Pulsed discharge will generate large cavities at the discharge point, which hinders the reflection and convergence of part of the shock wave, resulting in part of the energy being difficult to be effectively utilized and being unfavorable for the convergence and pressurization effect.

[0050] In the related technologies, in the research on the preparation of carbon nanomaterials by liquid-phase pulsed discharge, a discharge method with low power and long pulse width is mostly used. During the formation process of carbon nanomaterials, the precursor is affected by the thermo-mechanical-electromagnetic coupling effect, resulting in complex product components, large differences in microstructural morphology, and complex product formation mechanisms. The research on the preparation of silicon quantum dots by liquid-phase pulsed discharge shows that due to the "magnetic pinch" effect of the plasma, the diffusion of discharge products will be inhibited, forming a high-density area of products, resulting in a relatively high particle size of the products and a low synthesis efficiency of silicon quantum dots.

[0051] In view of the above problems, the reaction device for liquid-phase pulsed discharge shock wave treatment provided by the exemplary embodiment of the present invention sets the inner wall surface of the tank body as a reflecting surface formed by the rotation of a hyperbola and an ellipse, so that the foci of the hyperbola and the ellipse coincide, thereby enhancing the convergence and pressurization effect.

[0052] Figure 1 is a schematic cross-sectional structure diagram of the reaction device according to the embodiment of the present invention. As Figure 1 shown, the reaction device for liquid-phase pulsed discharge shock wave treatment provided by the exemplary embodiment of the present invention includes a tank body 10, a cover body 20 and an arc generating device. The tank body 10 has a first inner wall 11 with an ellipsoidal surface, and the ellipsoidal surface is formed by the rotation of an ellipse along the long axis; the arc generating device penetrates through the cover body 20 and extends into the tank body 10, and the discharge point of the arc generating device is located at the first focus G1 of the tank body 10, and the first focus G1 is located above the second focus G2 of the tank body 10; the cover body 20 is covered on the top of the tank body 10, and the cover body 20 has a second inner wall 12 that protrudes inwardly toward the inside of the tank body 10; the second inner wall 12 is a surface formed by the rotation of a branch of a hyperbola, and the rotation axis of the branch is the axis where the real axis of the hyperbola is located; the third focus G3 of the hyperbola close to the other branch coincides with the first focus G1

[0053] In practical applications, the sample to be reacted is placed at the second focus G2 of the tank body 10, and a conductive solution is poured into and filled at the top of the tank body 10 as a discharge medium. Then, the cover body 20 together with the arc generating device is covered on the top opening of the tank body 10 and fixed. The arc generating device generates an arc to form large cavitation bubbles and high-energy shock waves in the discharge medium, and the shock waves propagate through the conductive solution, such as water, ammonia water, organic solutions, and inorganic salt solutions. A high-density current passes through the discharge electrodes, passes through the medium between the electrodes in a very short time, and injects a large amount of energy into the medium in the form of Joule heating, resulting in a rapid rise in the medium temperature, rapid phase change, and sharp volume expansion. The shock waves are reflected multiple times by the first inner wall 11 and the second inner wall 12 and then converge to the sample at the second focus G2. Using the transient high-density current and strong electromagnetic field, the chemical bonds of the medium molecules are broken to form free atoms, so that corresponding products can be formed at the second focus G2.

[0054] Exemplarily, the liquid medium can also be organic solutions such as ethanol and ferrocene, inorganic metal solutions such as iron nitrate and iron chloride, distilled water, ammonia water, etc.

[0055] Exemplarily, when the reaction device discharges, it can break the chemical bonds of the liquid medium in the tank body 10 to form free radicals, form a low-density large-range plasma in the organic liquid medium, decompose organic molecules to form free carbon atoms, and then nucleate and grow to form carbon nanomaterials. For example, various nanomaterials such as graphene, carbon nanotubes, black phosphorene, silicon quantum dots, and carbon quantum dots can be prepared.

[0056] Optionally, organic solutions such as ethanol and methanol are used as the reaction precursors of carbon quantum dots, ammonia water, etc. are used as the nitrogen-doped original solution, inorganic metal solutions such as iron nitrate and iron chloride or organic solutions such as ferrocene are used to provide metal single-atom loading, and a nitrogen-doped carbon quantum dot-based metal single-atom catalyst can be prepared by using the reaction device.

[0057] Figure 2 It is the pressure boosting schematic diagram of the reaction device according to the embodiment of the present invention. As Figure 2 shown, the reflection path of the shock wave in the second inner wall 12 formed by a hyperbola and the first inner wall 11 formed by an ellipse. When pulsed discharge is carried out at the first focus G1, which is also the third focus G3 of the hyperbola, a large cavitation bubble is generated at this position. Since the shock wave speed is much higher than the material movement speed, before the large cavitation bubble expands, a part of the shock wave hitting the second inner wall 12 is reflected by the second inner wall 12 and then converges to the second focus G2 after being reflected twice by the first inner wall 11, thus bypassing the large cavitation bubble. Thereby, the impedance mismatch interface is avoided, the overall energy utilization efficiency can be improved, the pressure boosting effect is better, and the pressure at the second focus G2 can be increased by dozens of times.

[0058] Furthermore, since the material preparation area (the second focus G2) is far away from the magnetic pinch effect area, the influence of the plasma magnetic pinch effect on the product is avoided, the decoupling of the shock wave effect and the electromagnetic effect is achieved, the complexity of the material synthesis process is reduced, and nanomaterials with smaller and more uniform particle size can be efficiently prepared.

[0059] In some embodiments, the hyperbola satisfies: Y=12.444+0.889×(1+(x / 7.521) 2 ) 1 / 2 .

[0060] In some embodiments, the ellipse satisfies: Y = 4×(1-(x 2 / 14.222 2 )) 1 / 2 , the eccentricity is 0.458, and the ratio of the major axis to the minor axis is 1.125.

[0061] Exemplarily, the distance between the first focus G1 and the second focus G2 is 82.46 cm.

[0062] like Figure 1 As shown, the tank body 10 is composed of two substantially identical upper and lower parts connected together by a flange. At the lower part of the flange of the lower part of the tank body 10, four positioning bolts 41 penetrating the tank body 10 are evenly arranged along the circumference of the tank body 10, that is, the four positioning bolts 41 are close to the center of the tank body 10, and the four positioning bolts 41 are opposite to each other. Steel wires can be wound around the parts of the two opposite positioning bolts 41 inside the tank body 10, and steel wires can also be wound around the other two opposite positioning bolts 41. The two steel wires are arranged in a cross, and the sample bag can be hung more stably at the intersection of the two, so that the sample is placed near the second focus G2.

[0063] In practical applications, by adjusting the length of the positioning bolt 41 extending into the tank body 10 and the angle of the steel wire wrapped around the positioning bolt 41, the point position of the sample can be conveniently adjusted, thereby obtaining different phase change effects and thus different products.

[0064] In some embodiments, Figure 1 As shown, the tank body 10 has at least one first viewing window (not shown in the figure) and at least one second viewing window 40, the first viewing window faces the first focus G1, and the second viewing window 40 faces the second focus G2.

[0065] For example, the tank body 10 has two oppositely disposed second viewing windows 40 and two oppositely disposed first viewing windows, wherein a connecting line of the two first viewing windows and a connecting line of the two second viewing windows 40 are perpendicular to each other.

[0066] The two second viewing windows 40 and the two first viewing windows that are symmetrically arranged can avoid the instability of the shock wave focusing conditions caused by the asymmetry of the inner wall of the tank body 10. At the same time, the two connecting lines are perpendicular to each other, which can ensure the wall thickness of the tank cover and the tank body 10, and further ensure that the reaction device can withstand the load of the shock wave.

[0067] The structures of the first viewing window and the second viewing window 40 are the same, and both are welded to the tank body 10. They have flange covers for fixing optical glass, and high-speed cameras are installed outside each first viewing window and second viewing window 40 to record the shock wave.

[0068] Exemplarily, through the first viewing window, the formation and diffusion process of the shock wave can be observed. According to the change of the gray value in the high-speed photography results, data such as the shock wave propagation speed, plasma diffusion speed, change of the density of the compressed liquid medium, and cavitation pulsation frequency generated by pulsed discharge can be obtained.

[0069] Through the second viewing window 40, the convergence of the shock wave and the subsequent cavitation phenomenon in the shock wave convergence area can be observed. According to the change of the gray value in the high-speed photography results, results such as the shock wave speed in the convergence area and the change of the density of the liquid phase medium can be obtained, and parameters such as the converging shock wave pressure and adiabatic temperature rise can be calculated by combining empirical formulas.

[0070] In some embodiments, the tank body 10 is also provided with an interface for setting a pressure sensor along the vertical direction, and the pressure change at each point on the axis can also be measured through the pressure sensor.

[0071] As Figure 1 shown, the arc generating device includes two electrode rods 31 and two electrode heads 32. The two electrode rods 31 penetrate through the cover body 20 and extend into the tank body 10; the two electrode heads 32 are respectively located at the ends of the two electric shock rods in the tank body 10, and each electrode head 32 is perpendicular to the corresponding electrode rod 31; the end of the electrode head 32 facing away from the electrode rod 31 has a 45° chamfer.

[0072] The cover body 20 includes a first insulating block 21 and a second insulating block 22. The first insulating block 21 is fixedly arranged on the tank body 10. A groove is opened at the central part of the top surface of the first insulating block 21, and the second insulating block 22 is embedded in the groove; the two electrode rods 31 penetrate through the first insulating block 21 and the second insulating block 22 and extend into the tank body 10.

[0073] The first insulating block 21 and the second insulating block 22 can be insulating high-temperature nylon materials that can withstand a temperature of 800°C. The surface of the first insulating block 21 facing the center of the tank body 10 is the second inner wall 12 of the hyperbola.

[0074] The circumferential edge part of the first insulating block 21 is fastened to the top surface of the tank body 10 by bolts, and the circumferential edge part of the second insulating block 22 is fastened to the bottom of the groove of the first insulating block 21 by bolts. Both the first insulating block 21 and the second insulating block 22 have through holes for two electrode rods 31 to pass through. Thus, the two electrode rods 31 are fixed in the tank body 10 through the first insulating block 21 and the second insulating block 22. On the one hand, after removing the second insulating block 22, the insertion length of the electrode rod 31 can be adjusted, and thus the discharge position of the electrode head 32 can be changed; on the other hand, it can play an insulating and protective role, prevent the liquid of the shock wave from splashing out, and stabilize the position of the electrode head 32 to ensure the stability of discharge.

[0075] When the two electrode heads 32 are electrode heads 32 with a 45° chamfer, it can improve the current density distribution at the electrode tip, reduce electro-erosion, and increase the service life of the electrode head 32.

[0076] Exemplarily, since the shock wave requires a closed space, insulating rubber pads are provided at the connection interfaces of all components.

[0077] Figure 3 It is a schematic diagram of the circuit structure of the reaction device according to an embodiment of the present invention. As Figure 3 shown, the energy supply part of the reaction device mainly consists of a power supply 51 with adjustable voltage and a super-large capacitor 52. The voltage is continuously adjustable, and different explosion energies can be obtained. Thus, it can be preset by a computer or adjusted manually to change the liquid-phase pulsed discharge focusing path, control the focusing gain, and the changes of current and voltage during the reaction process can be traced by an oscilloscope. After discharge, the pressure history curve is recorded by the pressure sensors at each measuring point.

[0078] A specific embodiment is given below to verify the converging and pressurizing effect of the reaction device.

[0079] Through the theory of underwater explosive explosion shock waves, the behavior of liquid-phase discharge shock waves is studied and predicted. For the closed tank configuration of the present invention, the discharge shock wave is equivalently treated as a spherical TNT charge according to the energy equivalence theory, and a TNT sphere with a radius of 6 cm is set to explode.

[0080] Using the LS-DYNA numerical simulation software, a three-dimensional model of the inner wall of the tank body 10 is established.

[0081] The entire model is a water area formed by an ellipsoid formed by rotating an ellipse and a hyperbola, with the major axis / minor axis = 1.125, the number of meshes is 297752, the calculation time is 2 ms, the major axis of the ellipse is 90 cm, the minor axis is 80 cm, and there is a layer of rigid surface meshes outside the water body. Except for the symmetry axis y-axis using symmetric boundaries, other boundaries use non-reflective boundaries.

[0082] The contact between the reflector, water, and air adopts a co - node method, and a multi - material ALE algorithm is used among the three substances. A quarter - model is established, as Figure 4 shown, where Figure 4 is a schematic diagram of the simplified mesh of the reaction device model according to an embodiment of the present invention.

[0083] Figure 5A is the simulation effect of the first stage when the shock wave propagates according to an embodiment of the present invention. As Figure 5A shown, in the first stage when the shock wave propagates on the spherical surface, the explosion shock wave propagates outward in a spherical shape.

[0084] Figure 5B is the simulation effect of the second stage when the shock wave propagates according to an embodiment of the present invention; as Figure 5B shown, in the second stage when the shock wave propagates on the spherical surface, a part of the wave propagates upward towards the second inner wall 12 of the hyperboloid, and the direct wave propagates towards the second focus G2 direction.

[0085] Figure 5C is the simulation effect of the first stage when the shock wave pursues according to an embodiment of the present invention; Figure 5D is the simulation effect of the second stage when the shock wave pursues according to an embodiment of the present invention. As Figure 5C and Figure 5D shown, when the shock wave reflects and pursues, the wave reflected by the second inner wall 12 and the first inner wall 11 pursues the direct wave that has not been reflected for the first time.

[0086] Figure 5E is the simulation effect of the first stage when the shock wave focuses according to an embodiment of the present invention; Figure 5F is the simulation effect of the second stage when the shock wave focuses according to an embodiment of the present invention. As Figure 5E and Figure 5F shown, when the shock wave focuses, the direct wave reflected by the first inner wall 11 converges and coincides with the first - reflection - convergence wave, and the coincidence focus is about 2 cm below the second focus G2 of the ellipsoid.

[0087] The exemplary embodiment of the present invention also provides a method for preparing a nanomaterial, which is prepared by using the reaction device of the above - mentioned embodiment. The preparation method includes:

[0088] Assemble the tank body 10 and suspend the sample near the second focus G2;

[0089] Inject a conductive solution into the opening of the tank body 10 and cover the opening with a cover body 20, where the conductive solution includes one of distilled water, ammonia water, organic solution, and inorganic salt solution;

[0090] The arc generating device instantaneously discharges to generate plasma in the conductive solution, so as to form nanomaterials from the sample.

[0091] By changing the output current, voltage, and power, this reaction device can conveniently generate nanomaterials with different structures and properties according to different requirements. At the same time, it has a simple operation and a very high quenching rate, which is conducive to the formation of high-pressure phase and metastable phase products. The prepared nitrogen-doped carbon quantum dots have uniform particle size, rich surface functional groups, and a high yield.

[0092] The other technical advantages of the above preparation method compared with the prior art are the same as those of the reaction device in the above embodiment, and will not be elaborated here.

[0093] Those skilled in the art should understand that the above embodiments are only for clearly illustrating the present invention, rather than limiting the scope of the present invention. For those skilled in the art, other changes or variations can be made based on the above disclosure, and these changes or variations are still within the scope of the present invention.

Claims

1. A reaction device for liquid phase pulse discharge shock wave treatment, characterized in that: It comprises a tank body, a cover body and an arc generating device, wherein the tank body has a first inner wall with an ellipsoidal surface, and the ellipsoidal surface is formed by rotating an ellipse along a major axis; The arc generating device extends through the cover body into the tank body, and the discharge point of the arc generating device is located at a first focus of the tank body, and the first focus is located above a second focus of the tank body; The cover body is arranged on the top of the tank body, and the cover body has a second inner wall protruding toward the inside of the tank body in the middle; The second inner wall is a surface formed by rotating a branch of a hyperbola.

2. The reaction device according to claim 1, characterized in that: The hyperbola satisfies: Y=12.444+0.889×(1+(x / 7.521) 2 ) 1 / 2 .

3. The reaction device according to claim 1, characterized in that: The ellipse has an eccentricity of 0.458 and a major axis to minor axis ratio of 1.

125.

4. The reaction device according to claim 3, characterized in that: The distance between the first focus and the second focus is 82.46 cm.

5. The reaction device according to any one of claims 1 to 4, characterized in that: The reaction device also includes four positioning bolts evenly distributed along the circumference of the tank body.

6. The reaction device according to claim 5, characterized in that: The tank body has at least one first viewing window and at least one second viewing window, wherein the first viewing window faces the first focal point and the second viewing window faces the second focal point.

7. The reaction device according to claim 6, characterized in that: The tank body has two first viewing windows and two second viewing windows.

8. The reaction device according to claim 5, characterized in that: The arc generating device comprises two electrode rods and two electrode heads, and the two electrode rods penetrate the cover body and extend into the tank body; The two electrode heads are respectively arranged at the ends of the two electrode rods located inside the tank, and each electrode head is perpendicular to the corresponding electrode rod; The end of the electrode head facing away from the electrode rod has a 45° chamfer.

9. The reaction device according to claim 8, characterized in that: The cover body comprises a first insulating block and a second insulating block, the first insulating block is fixed on the tank body, a groove is provided at the center of the top surface of the first insulating block, and the second insulating block is embedded in the groove; The two electrode rods penetrate the first insulating block and the second insulating block and extend into the tank body.

10. A method for preparing a nanomaterial, characterized in that: The method is prepared by using the reaction device described in any one of claims 1 to 9.

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