A target, a target preparation method and a method for preparing phosphorus-embedded fullerenes

Abstract

The application belongs to the field of fullerene intercalation preparation, and particularly relates to a target material, a target material preparation method and a method for preparing phosphorus intercalated fullerene. The target material comprises a solid precursor base and a mixed solid powder. The mixed solid powder comprises a fullerene intercalation powder and a solid powder adhesive. The solid precursor base is provided with a recess. The mixed solid powder is filled into the recess of the solid precursor base through at least one time of stamping and shaping, and the solid precursor base and the mixed solid powder are subjected to at least one time of high-temperature adhesive forming after stamping and shaping. The application can well solve the problem of toxicity harm to the environment and people caused by gaseous precursor synthesis of intercalated fullerene, and is helpful to promote the synthesis of more types of intercalated fullerene and the research and development of related fields of intercalated fullerene.

Description

Technical Field

[0001] The present invention belongs to the field of endohedral fullerene preparation, and in particular relates to a target material, a target material preparation method and a method for preparing phosphorus endohedral fullerene. Background Art

[0002] Currently, traditional and commonly used methods for synthesizing endohedral fullerenes mostly utilize gaseous precursors. While some gaseous precursors are inert or environmentally benign, others are highly toxic and pose significant risks to the environment and laboratory personnel. This use of gaseous precursors to synthesize endohedral fullerenes restricts the synthesis of some endohedral fullerenes, hindering subsequent experimental research and the development of related research technologies. Therefore, it is necessary to seek new technical solutions to improve these endohedral fullerene preparation methods. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a non-toxic and safe method for preparing phosphorus endohedral fullerene based on red phosphorus.

[0004] The present invention provides a solid precursor target material for synthesizing phosphorus endohedral fullerenes, comprising a solid precursor base and mixed solid powder;

[0005] The mixed solid powder includes fullerene embedment powder and solid powder binder;

[0006] The solid precursor base is provided with a depression, and the mixed solid powder is filled in the depression of the solid precursor base through at least one stamping and shaping, and after the stamping and shaping, the solid precursor base and the mixed solid powder are subjected to at least one high-temperature bonding molding.

[0007] Furthermore, the fullerene endoprosthesis powder includes red phosphorus powder with a purity of 99.99%.

[0008] Furthermore, the solid powder adhesive includes a thermoplastic polyurethane elastomer (TPU-80) powder having a melting point of 80° C. or a thermoplastic polyurethane elastomer (TPU-110) powder having a melting point of 110° C.

[0009] In order to improve the adhesion between the mixed solid powder and the solid precursor base, a solid powder adhesive is used. After the two powders are mixed, they are first punched and formed with the solid precursor base by a stamping and shaping device for the first time. Then, the fullerene embedded powder and TPU are melted and fully mixed at high temperature and then bonded with the solid precursor base for the second time.

[0010] Furthermore, the material of the solid precursor base is oxygen-free copper. Copper is generally divided into red copper, brass, bronze, and cupronickel. Oxygen-free copper is a type of red copper (pure copper) with an oxygen content of no more than 0.003%, a total impurity content of no more than 0.05%, and a copper purity greater than 99.95%. The copper base provides good electrical and thermal conductivity and enhances the overall strength of the target material. Compared to other materials such as brass, bronze, and cupronickel, it is purer and will not cause any unnecessary effects.

[0011] Furthermore, the solid precursor base is cylindrical, 5 mm in height, 50.8 mm in outer diameter, 40.8 mm in recessed inner diameter, and 2 mm in recessed depth. In this embodiment, the size of the target loading position in the magnetron sputtering apparatus is fixed at 50.8 mm, which corresponds to the outer diameter of the solid precursor base. Since the target is loaded vertically (standing upright) on a vertical plane perpendicular to the horizontal line, and a target pressure assembly with a central circular hole is provided to lock and secure the target in rotation (this central hole allows the gas source to bombard the target). The diameter of the central circular hole is less than 40.8 mm. If the inner diameter of the base recess is less than 40.8 mm, then after the target is filled with phosphorus-containing powder, if the filler falls off from the base, it may fall out of the circular hole as a whole. However, if the inner diameter of the recess is 40.8 mm, even if the filler falls off from the base, it cannot fall out of the circular hole as a whole and will be stuck between the target pressure assembly and the base. The solid precursor base height of 5mm is within the appropriate range. During the reaction, the bombardment of the gas source consumes the phosphorus-containing powder on the surface, causing the height to decrease. Prolonged bombardment completely exposes the base. Therefore, from the perspective of the entire reaction process, 5mm is sufficient to support the consumption during the reaction. If it is too low, the consumption of the entire reaction cannot be completed. If it is too high, the target assembly will be difficult to rotate and buckle.

[0012] The present invention also provides a method for preparing a solid precursor target material for synthesizing phosphorus endohedral fullerenes, comprising filling a mixed solid powder containing fullerene endohedral powder and a solid powder binder into a recess of a solid precursor base, and pressing and shaping the mixed solid powder using a stamping and shaping device;

[0013] The pressed mixed solid powder and the solid precursor base are transferred to a high-temperature environment, so that the mixed solid powder is bonded and formed in the high-temperature environment, and the solid precursor target is formed after cooling.

[0014] Furthermore, the stamping and shaping device is a cold heading die, which is used to withstand the compressive stress of the target material during the early stamping and shaping.

[0015] The present invention also provides a method for preparing phosphorus-embedded fullerenes based on red phosphorus, using a magnetron sputtering device, a substrate, a fullerene raw material, and a solid precursor target, comprising the following steps:

[0016] Preparation of phosphorus-embedded fullerenes: A solid precursor target, fullerene raw material, and substrate are placed in corresponding positions of a magnetron sputtering device. The plasma converted from an inert gas source bombards the solid precursor target, and the phosphorus-containing beam obtained by the bombardment is given momentum by the accelerating field voltage to obtain a high-energy phosphorus-containing beam. The high-temperature sublimated fullerene raw material cools and deposits on the surface of the substrate to form a fullerene film. The fullerene film is bombarded by the high-energy phosphorus-containing beam to form phosphorus-embedded fullerenes.

[0017] Furthermore, the method also includes preparing a crude product of phosphorus endohedral fullerene: after the magnetron sputtering is completed, the vacuum chamber is opened at room temperature, and the substrate on which the phosphorus endohedral fullerene is deposited is placed in a solution, and the crude product of phosphorus endohedral fullerene is obtained through ultrasonication, filtration, and rotary evaporation.

[0018] Furthermore, the preparation of phosphorus endohedral fullerene specifically includes:

[0019] S21. Place a solid precursor target, a fullerene raw material, and a substrate at corresponding positions in a magnetron sputtering device. The fullerene raw material is 700 mg of fullerene powder and is placed in a crucible. The substrate is a 3.5 μm copper foil substrate.

[0020] S22, open the cooling device, use the pump device to pump the vacuum chamber to 10 -3 Pa, 30sccm of argon with a purity of ≥99.99% was introduced, and the temperature control was turned on to increase to 400℃ over three hours. Then, PID feedback control was used to set the sublimated fullerene deposition rate to Temperature ranges from 550°C to 650°C;

[0021] In order to ensure that the embedded fullerene is derived from a solid precursor, an inert gas is used in the synthesis process in this step, thereby ensuring the purity of the entire reaction process of the embedded fullerene required for the synthesis.

[0022] S23, the copper foil substrate is wound in a vacuum chamber, and the high-temperature sublimated fullerene cools and deposits on the surface of the copper foil substrate to form a fullerene film. The fullerene film is bombarded by a high-energy phosphorus-containing beam to form phosphorus-endohedral fullerenes. The entire reaction process lasts for 5 hours.

[0023] The preparation of crude phosphorus endohedral fullerene product comprises:

[0024] S24. After the magnetron sputtering is completed, stop heating and wait until the temperature drops to room temperature. After closing the gas pipeline, stop the pump device, open the valve to connect the vacuum chamber to the atmosphere, open the chamber door to take out the copper foil substrate, place the copper foil substrate in toluene solution, and obtain the crude product of phosphorus-embedded fullerene after ultrasonic collection, filtration, and rotary evaporation.

[0025] The beneficial effects of the present invention are:

[0026] 1. In contrast to the common and traditional technical route of using gaseous PH3 to obtain phosphorus atoms by ionizing and then injecting it into fullerene cages, the method of the present invention realizes the effective transformation of red phosphorus in the solid precursor into phosphorus atoms, reducing the toxicity of phosphorus from the source to the embedded atom from highly toxic to low toxicity, providing a safer alternative technical route.

[0027] 2. For some endohedral fullerene synthesis methods that require toxic gases as gaseous precursors, the method of the present invention uses solid precursors instead of gaseous precursors to avoid the dangerous situation of toxic gases that may occur during the synthesis process and harm the environment and people.

[0028] 3. For some embedded fullerenes whose embedded sources cannot or are extremely difficult to obtain from gases, the method of the present invention provides a way to obtain embedded sources from solid precursors, broadening the access to embedded materials.

[0029] 4. Conventional preparation methods use PH3 (phosphine), which is highly toxic and cannot / is difficult to use in ordinary school laboratories, posing an extremely high risk. This method does not involve the use of PH3. Instead, it uses red phosphorus, which is less toxic and can be used by teachers and students in school laboratories, making it more conducive to conducting research within the school.

[0030] 5. Conventional preparation methods use gaseous PH3, while this method uses solid red phosphorus. This changes the state of the phosphorus source (from gaseous to solid), broadening the source state options. While other conventional preparation methods for endohedral fullerenes are limited to gaseous sources, the success of this method can provide new ideas. This broadens the sources of other endohedral fullerenes.

[0031] That is, the present invention can effectively solve the problem of toxic hazards to the environment and humans caused by synthesizing endohedral fullerenes with gaseous precursors, and help promote the synthesis of more types of endohedral fullerenes and the research and development of related fields of endohedral fullerenes. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 Schematic diagram of a process for preparing a solid precursor target material for synthesizing phosphorus endohedral fullerenes according to the present invention;

[0033] Figure 2 This is a schematic structural diagram of a solid precursor base of the present invention;

[0034] Figure 3 The present invention is a flow chart of a method for preparing phosphorus endohedral fullerenes based on red phosphorus. DETAILED DESCRIPTION

[0035] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0036] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the various components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0037] In addition, the terms "first," "second," and so on, used in this disclosure are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referenced. Thus, a feature specified as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of this disclosure, "plurality" means at least two, such as two or three, unless otherwise specifically defined.

[0038] In the present invention, unless otherwise specified or limited, the terms "connection" and "fixation" should be understood in a broad sense. For example, "fixation" can mean fixed connection, detachable connection, or integration; it can mean mechanical connection, electrical connection, physical connection, or wireless communication connection; it can mean direct connection or indirect connection through an intermediate medium; it can mean internal communication between two elements or interaction between two elements, unless otherwise specified. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0039] In addition, the technical solutions between the various embodiments of the present invention can be combined with each other, but it must be based on the fact that ordinary technicians in this field can implement it. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0040] As attached Figure 1-3 As shown, the present invention also provides the following specific embodiments:

[0041] Example 1

[0042] refer to Figure 1 This embodiment provides a method for preparing a solid precursor target for synthesizing phosphorus endohedral fullerenes, wherein the solid precursor base is as follows Figure 2As shown, the material is selected as oxygen-free copper, and the shape is a cylinder with a recess. The cylinder has a height of 5 mm, an outer diameter of 50.8 mm, an inner diameter of the recess of 40.8 mm, and a recess depth of 2 mm. The method comprises the following steps:

[0043] S11, red phosphorus powder with a mass of 3.2 g and a purity of 99.99% is premixed with a solid powder binder with a mass of 0.8 g in a ceramic mortar, wherein the solid powder binder is a thermoplastic polyurethane elastomer (TPU-80) powder with a melting point of 80°C, that is, the proportion of the solid powder binder added to the total weight is 20%, and the total mass of the mixed solid powder is 4 g.

[0044] S12, pour the mixed solid powder into the recess of the solid precursor base, and use a medicine spoon to flatten the mixed solid powder on the solid precursor base.

[0045] S13, place the solid precursor base filled with the mixed solid powder in a stamping forming device, set the pressure to 10 MPa, and the pressing time to 1 min.

[0046] S14, take out the solid precursor base filled with the mixed solid powder after the first pressing and forming, and place it in a vacuum drying box, set the temperature to 120°C, and keep the high temperature for 30 min, and then naturally cool to room temperature together with the vacuum drying box.

[0047] The preparation method provided in the embodiment can obtain a non-toxic solid precursor target for synthesizing phosphorus-embedded fullerenes, which is stably bonded with the mixed solid powder and the solid precursor base, and the solid precursor target can stably synthesize phosphorus-embedded fullerenes.

[0048] Example 2

[0049] The preparation method provided in the embodiment is for a solid precursor target for synthesizing phosphorus-embedded fullerenes. Compared with Example 1, the solid powder binder used in S11 of the embodiment is a thermoplastic polyurethane elastomer (TPU-110) powder with a melting point of 110°C, and the proportion of the solid powder binder added to the total mass is 10%, and other parameters and processes are the same as those in Example 1.

[0050] Example 3

[0051] The preparation method provided in the embodiment is for a solid precursor target for synthesizing phosphorus-embedded fullerenes. Compared with Example 2, the proportion of the solid powder binder added to the total mass in the embodiment is 5%, and other parameters and processes are the same as those in Example 2.

[0052] Example 4

[0053] This embodiment uses the solid precursor target prepared in Example 1 to provide a method for preparing phosphorus-endohedral fullerenes based on red phosphorus, using a magnetron sputtering device, a substrate, a fullerene raw material, and a solid precursor target;

[0054] The magnetron sputtering equipment includes a vacuum chamber module, a magnetron sputtering device module, a cooling device module and a pump module. The vacuum chamber module is connected to the pump module to achieve a vacuum state. The vacuum chamber module has a temperature control system that can use PID feedback to control the temperature and the deposition rate of the object. Since the magnetron sputtering equipment belongs to the existing technology, it will not be described in detail here.

[0055] The process flow chart of the method for preparing phosphorus-embedded fullerene based on red phosphorus is as follows: Figure 3 As shown, the preparation method comprises:

[0056] S21. Place the solid precursor target, fullerene raw material and substrate at corresponding positions in the vacuum chamber of the magnetron sputtering equipment. The magnetron sputtering target is the solid precursor target prepared in Example 1, the substrate is a 3.5 μm copper foil substrate, and the fullerene raw material is 700 mg of fullerene powder, which is placed in a crucible.

[0057] S22, open the cooling device, use the pump device to pump the vacuum chamber to 10 -3 Pa, 30sccm of argon with a purity of ≥99.99% was introduced, and the temperature control was turned on to increase to 400℃ over three hours. Then, PID feedback control was used to set the sublimated fullerene deposition rate to The temperature is in the range of 550°C to 650°C.

[0058] S23: The copper foil substrate is wound in a vacuum chamber. The sublimated fullerene cools and deposits on the surface of the copper foil substrate, forming a fullerene film. The fullerene film is then bombarded with a high-energy phosphorus-containing beam, forming phosphorus-endohedral fullerenes. The entire reaction process lasts 5 hours.

[0059] S24. After the magnetron sputtering is completed, stop heating and wait for the temperature to drop to room temperature. After closing the gas pipeline, stop the pump device, open the valve to connect the vacuum chamber to the atmosphere, open the chamber door to take out the copper foil substrate, place the copper foil substrate in a toluene solution, and obtain a crude phosphorus-embedded fullerene product after ultrasonic collection, filtration, and rotary evaporation. Specifically, ultrasonic collection: completely immerse the copper foil substrate with the product in toluene, use an ultrasonic cleaning machine to promote the full dissolution of the product in toluene, and collect (dissolve) the product in toluene to the maximum extent. Filtration: a type of reduced pressure filtration. During ultrasonic collection, a small amount of insoluble matter will be mixed in the toluene, and these insoluble matter needs to be removed by filtration. Rotary evaporation: a type of reduced pressure distillation, using a rotary evaporator to distill out the toluene, that is, reducing the solvent and increasing the concentration of the product (solute).

[0060] The preparation method provided in this embodiment can collect about 20 mg of fullerene, which is 2.8% of the yield compared to the raw material, and the content of phosphorus endohedral fullerene is 10 ppm.

[0061] Example 5

[0062] This embodiment provides a method for preparing phosphorus endohedral fullerene using a solid precursor. Compared with Example 4, the solid precursor used in this embodiment is prepared using Example 2, and the other processes are the same as Example 4.

[0063] The preparation method provided in this embodiment can collect about 25 mg of fullerene, which is 3.6% of the feed yield, and the content of phosphorus endohedral fullerene is about 15 ppm.

[0064] Example 6

[0065] This embodiment provides a method for preparing phosphorus endohedral fullerene using a solid precursor. Compared with Example 4, the solid precursor used in this embodiment is prepared using Example 3, and the other processes are the same as Example 4.

[0066] The preparation method provided in this embodiment can collect about 17 mg of fullerenes, which is 2.4% of the feed yield. The content of phosphorus-embedded fullerenes is about 50 ppm. In this embodiment, the content of phosphorus-embedded fullerenes obtained increases sharply. The main reason is that based on the same plasma energy, when the solid powder binder is reduced, the overall strength of the target material is relatively weak, and the plasma is more likely to bombard the phosphorus atoms in the target material. That is, the amount of phosphorus atoms knocked out is greater, and thus the number of fullerenes successfully embedded in the phosphorus atoms is greater, resulting in a higher content of phosphorus-embedded fullerenes.

[0067] The contents not described in detail in this specification belong to the prior art known to professional and technical personnel in this field.

Claims

1. A method for preparing phosphorus endohedral fullerene based on red phosphorus, characterized in that: Using magnetron sputtering equipment, a substrate, a fullerene raw material, and a solid precursor target, the process includes the following steps: Preparation of phosphorus-endohedral fullerenes: A solid precursor target, fullerene raw material, and substrate are placed in corresponding positions of a magnetron sputtering device. Plasma converted from an inert gas source bombards the solid precursor target, and the resulting phosphorus-containing beam is given momentum by the accelerating field voltage to obtain a high-energy phosphorus-containing beam. The high-temperature sublimated fullerene raw material cools and deposits on the surface of the substrate to form a fullerene film. The fullerene film is bombarded by the high-energy phosphorus-containing beam to form phosphorus-endohedral fullerenes. The preparation of phosphorus endohedral fullerene specifically comprises: S21. Placing a solid precursor target, a fullerene raw material, and a substrate at corresponding positions in a magnetron sputtering device, wherein the fullerene raw material is 700 mg of fullerene powder and is placed in a crucible, and the substrate is a 3.5 μm copper foil substrate; S22, open the cooling device, use the pump device to pump the vacuum chamber to 10 -3 Pa, 30 sccm of argon with a purity of ≥99.99% was introduced, and the temperature control was turned on to increase the temperature to 400°C over three hours. Subsequently, PID feedback control was used to set the sublimated fullerene deposition rate to 1.2 Å / s through the temperature range of 550°C to 650°C; S23, the copper foil substrate is wound in a vacuum chamber, and the high-temperature sublimated fullerene cools and deposits on the surface of the copper foil substrate to form a fullerene film. The fullerene film is bombarded by a high-energy phosphorus-containing beam to form phosphorus-endohedral fullerenes. The entire reaction process lasts for 5 hours. The preparation of crude phosphorus endohedral fullerene product comprises: S24. After the magnetron sputtering is completed, the heating is stopped and the temperature is allowed to drop to room temperature. The gas pipeline is closed and the pump device is stopped. The valve is opened to connect the vacuum chamber to the atmosphere. The chamber door is opened to remove the copper foil substrate. The copper foil substrate is placed in a toluene solution. After ultrasonic collection, filtration, and rotary evaporation, a crude phosphorus endohedral fullerene product is obtained. The solid precursor target material includes a solid precursor base and mixed solid powder; The mixed solid powder includes fullerene embedment powder and solid powder binder; The solid precursor base is provided with a depression, and the mixed solid powder is filled in the depression of the solid precursor base through at least one stamping and shaping, and after the stamping and shaping, the solid precursor base and the mixed solid powder are subjected to at least one high-temperature bonding molding.

2. The method for preparing phosphorus endohedral fullerene based on red phosphorus according to claim 1, characterized in that: The fullerene intercalation powder includes red phosphorus powder with a purity of 99.99%.

3. The method for preparing phosphorus endohedral fullerene based on red phosphorus according to claim 1, characterized in that: The solid powder adhesive includes thermoplastic polyurethane elastomer powder with a melting point of 80°C or thermoplastic polyurethane elastomer powder with a melting point of 110°C.

4. The method for preparing phosphorus endohedral fullerene based on red phosphorus according to claim 1, wherein: The material of the solid precursor base is oxygen-free copper.

5. The method for preparing phosphorus endohedral fullerene based on red phosphorus according to claim 4, characterized in that: The solid precursor base is a cylinder with a height of 5 mm, an outer diameter of 50.8 mm, a recessed inner diameter of 40.8 mm, and a recessed depth of 2 mm.

6. The method for preparing phosphorus endohedral fullerene based on red phosphorus according to claim 1, wherein: Filling a mixed solid powder containing fullerene embedment powder and a solid powder binder into the recess of the solid precursor base, and pressing the mixed solid powder into shape using a stamping and shaping device; The pressed mixed solid powder and the solid precursor base are transferred to a high-temperature environment, so that the mixed solid powder is bonded and formed in the high-temperature environment, and the solid precursor target is formed after cooling.

7. The method for preparing phosphorus endohedral fullerene based on red phosphorus according to claim 6, characterized in that: The stamping and shaping device is a cold heading die.

8. The method for preparing phosphorus endohedral fullerene based on red phosphorus according to claim 7, characterized in that: The invention also includes preparing a crude product of phosphorus endohedral fullerene: after the magnetron sputtering is completed, the vacuum chamber is opened at room temperature, and the substrate on which the phosphorus endohedral fullerene is deposited is placed in a solution, and the crude product of phosphorus endohedral fullerene is obtained through ultrasonication, filtration, and rotary evaporation.

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