Method for preparing polymeric nitrogen material with high yield and polymeric nitrogen material

Abstract

The present invention discloses a method for preparing polymeric nitrogen materials with high yield and the polymeric nitrogen materials, belonging to the technical field of energetic materials, and is used to solve one of the following technical problems: (1) In the prior art, the method for synthesizing cg-PN requires relatively high pressure, harsh conditions and is not easy to achieve; (2) The content of cg-PN synthesized in the prior art is relatively low; (3) The cg-PN synthesized in the prior art cannot stably exist under normal pressure. The method for preparing polymeric nitrogen materials with high yield includes: mixing an azide precursor, carbon nanotubes or a carbon nanotube film with a liquid to obtain a mixture, and heating, holding and cooling the mixture in a low-vacuum environment to obtain the polymeric nitrogen materials, wherein the mass of the carbon nanotubes or the carbon nanotube film is 1% to 100% of the azide precursor. The preparation method of the present invention can reduce the synthesis pressure to obtain polymeric nitrogen materials, the method is simple, and the yield of the polymeric nitrogen materials is high.

Description

Technical Field

[0001] The present invention belongs to the technical field of energetic materials, and particularly relates to a method for preparing polymeric nitrogen materials with high yield and the polymeric nitrogen materials. Background Art

[0002] The energy density of traditional energetic materials has gradually approached its theoretical limit and it is difficult to meet the increasing demand for energy density in practical applications. Due to its unique electronic structure, nitrogen has the potential to form high energy density materials. The bond energy of the N≡N triple bond is 954 kJ / mol, and the bond energy of the N-N single bond is 160 kJ / mol. The polymeric nitrogen (hereinafter abbreviated as cg-PN) material formed by N-N single bonds will release huge energy when decomposed into gaseous N≡N triple bond nitrogen, and the cg-PN material is expected to play an important role in practical applications. At present, the synthesis of cg-PN usually needs to be carried out under extreme conditions such as high temperature and high pressure. Eremets et al. reported that cg-PN was successfully synthesized with molecular nitrogen as the precursor under the conditions of a pressure of about 110 GPa and a temperature of 2000 K. Unfortunately, cg-PN cannot exist stably under normal pressure.

[0003] In recent years, cg-PN has been studied in detail theoretically, but there are few experimental reports. The synthesis of cg-PN usually needs to be carried out under extreme conditions such as high temperature and high pressure, which puts forward high requirements for experimental equipment and technology. How to obtain cg-PN with higher yield under normal pressure is still an urgent problem to be solved. Summary of the Invention

[0004] In view of the above analysis, the present invention aims to provide a method for preparing polymeric nitrogen materials with high yield and the polymeric nitrogen materials to solve one of the following technical problems: (1) The method for synthesizing cg-PN in the prior art requires high pressure, harsh conditions and is not easy to implement; (2) The content of cg-PN synthesized in the prior art is low; (3) The cg-PN synthesized in the prior art cannot exist stably under normal pressure.

[0005] The object of the present invention is mainly achieved by the following technical solutions:

[0006] The present invention provides a method for preparing polymeric nitrogen materials with high yield, including: mixing an azide precursor, carbon nanotubes or a carbon nanotube film with a liquid to obtain a mixture, and heating, insulating and cooling the mixture in a low vacuum environment to obtain polymeric nitrogen materials (hereinafter abbreviated as cg-PN materials); the mass of the carbon nanotubes or the carbon nanotube film is 1% - 100% of the azide precursor.

[0007] Further, the carbon nanotubes include one or more of carboxylated single-walled carbon nanotubes, single-walled carbon nanotubes, carboxylated multi-walled carbon nanotubes, amino-functionalized multi-walled carbon nanotubes, graphitized multi-walled carbon nanotubes, and graphitized carboxylated multi-walled carbon nanotubes.

[0008] Further, the preparation method includes: mixing an azide precursor, carbon nanotubes, and a liquid to obtain a mixed solution, and heating, holding, and cooling the mixed solution in a low-vacuum environment to obtain a polymeric nitrogen material.

[0009] Further, the preparation method includes: mixing an azide precursor and a liquid to obtain a mixed solution, laying a carbon nanotube film in a vessel, placing the mixed solution on the carbon nanotube film, and heating, holding, and cooling the vessel and the substances in the vessel in a low-vacuum environment to obtain a polymeric nitrogen material.

[0010] Further, the heating rate is 2-10 °C / min.

[0011] Further, the cooling rate is 50-200 °C / min.

[0012] Further, the azide precursor includes one or more of NH4N3, NaN3, LiN3, and KN3.

[0013] Further, the liquid includes water, alcohol, an acid solution, or a base solution.

[0014] Further, the mass of the liquid is more than 40% of the azide precursor.

[0015] Further, the acid solution is one or more of hydrochloric acid solution and acetic acid solution.

[0016] The present invention also provides a polymeric nitrogen material, which is prepared by the above-mentioned preparation method.

[0017] Compared with the prior art, the present invention can at least achieve one of the following technical effects:

[0018] 1) The high-yield preparation method of the polymeric nitrogen material of the present invention promotes the decomposition of the azide precursor and participates in the reaction by adding a liquid and carbon nanotubes or a carbon nanotube film to synthesize the polymeric nitrogen material, breaking through the condition of high pressure required by the traditional method for synthesizing cg-PN materials, greatly reducing the synthesis difficulty, and becoming a new method for synthesizing cg-PN materials.

[0019] 2) The high-yield preparation method of the polymeric nitrogen material of the present invention is very simple and easy to implement, greatly reducing the experimental difficulty.

[0020] 3) The method for preparing polymeric nitrogen materials with high yield according to the present invention obtains polymeric nitrogen materials with higher yield, and the polymeric nitrogen materials prepared by this method can maintain their stability at normal temperature and pressure, breaking through the limitation that the polymeric cg-PN materials in the traditional technology can only exist under high pressure. This characteristic makes the material expected to open up new application prospects in the fields of energy storage, high-energy density energetic materials, etc.

[0021] Other features and advantages of the present invention will be described in the following specification, and some of them will be obvious from the specification or understood by implementing the present invention. The objectives and other advantages of the present invention can be achieved and obtained by the structure specifically pointed out in the written specification and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The drawings are only for the purpose of showing specific embodiments and are not considered as a limitation of the present invention. Throughout the drawings, the same reference numerals represent the same components.

[0023] Figure 1 It is the Raman spectrum of the cg-PN material of Example 1 of the present invention;

[0024] Figure 2 It is the Raman spectrum of the cg-PN material of Example 2 of the present invention;

[0025] Figure 3 It is the Raman spectrum of the cg-PN material of Example 3 of the present invention;

[0026] Figure 4 It is the Raman spectrum of the cg-PN material of Example 4 of the present invention;

[0027] Figure 5 It is the Raman spectrum of Comparative Example 1 of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0028] The following further describes in detail a method for preparing polymeric nitrogen materials with high yield and polymeric nitrogen materials in combination with specific embodiments. These embodiments are only for the purpose of comparison and explanation, and the present invention is not limited to these embodiments.

[0029] The present invention provides a method for preparing polymeric nitrogen materials with high yield, including: mixing an azide precursor, carbon nanotubes or a carbon nanotube film with a liquid to obtain a mixture, and heating the mixture to a holding temperature, holding, and cooling in a low-vacuum environment to obtain a cg-PN material.

[0030] Specifically, the above azide precursor includes one or more of NH4N3, NaN3, LiN3, and KN3.

[0031] Specifically, the above carbon nanotubes include one or more of carboxylated single-walled carbon nanotubes, single-walled carbon nanotubes, carboxylated multi-walled carbon nanotubes, aminated multi-walled carbon nanotubes, graphitized multi-walled carbon nanotubes, and graphitized carboxylated multi-walled carbon nanotubes.

[0032] Specifically, considering that too much mass of carbon nanotubes will result in a low relative content of cg-PN in the product, which is not conducive to fully exerting its energy performance; too little will lead to a decrease in the conversion rate of cg-PN, which is not conducive to increasing the yield of cg-PN. Therefore, the mass of the above carbon nanotubes or carbon nanotube film is controlled to be 1% - 100% of the azide precursor. For example, the mass of the carbon nanotube film is 5%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90% of the azide precursor.

[0033] Specifically, the above liquid includes water, alcohol, acid solution, or alkali solution, etc.

[0034] Specifically, the above acid solution can be one or more of hydrochloric acid solution and acetic acid solution.

[0035] Specifically, the concentration of the above acid solution can be 0.01 - 0.1 mol / L.

[0036] Specifically, the above alkali solution can be one or more of calcium hydroxide solution and sodium hydroxide solution.

[0037] Specifically, the concentration of the above alkali solution can be 0.1 - 5 mol / L.

[0038] Considering that it is more difficult to evacuate to a low vacuum when the mass of the liquid is too much; when the mass of the liquid is too little, the azide precursor cannot be completely dissolved. Therefore, the mass of the above liquid is controlled to be more than 40% of the azide precursor. Preferably, the mass ratio of the liquid to the azide precursor is 4 - 5:1 - 2.

[0039] Specifically, the vacuum degree of the above low-vacuum environment is 0 - 200 Pa, such as 10 Pa, 20 Pa, 30 Pa, 40 Pa, 50 Pa, 60 Pa, 70 Pa, 80 Pa, 90 Pa, 120 Pa, 140 Pa, 160 Pa, 180 Pa, 200 Pa.

[0040] Specifically, the mixture is heated to 70 - 350 °C, kept warm for 3 - 24 h, and then cooled to obtain the cg-PN material.

[0041] Specifically, when the azide precursor is NH4N3, the heat preservation temperature is 70 - 90 °C. For example, 75 °C, 80 °C, 85 °C.

[0042] Specifically, when the azide precursor is LiN3, the heat preservation temperature is 90 - 105 °C, such as 95 °C, 100 °C, 105 °C.

[0043] Specifically, when the azide precursor is NaN3, the heat preservation temperature is 200 - 280 °C, such as 210 °C, 220 °C, 230 °C, 240 °C, 250 °C, 260 °C, 270 °C.

[0044] Specifically, when the azide precursor is KN3, the heat preservation temperature is 250 - 350 °C, such as 260 °C, 270 °C, 280 °C, 290 °C, 300 °C, 310 °C, 320 °C.

[0045] Considering that too high a heating rate will cause uneven heating of the raw materials, and too low a heating rate will result in insufficient sintering and prolonged sintering time. Therefore, the heating rate is controlled at 2 - 10 °C / min, such as 3 °C / min, 4 °C / min, 5 °C / min, 6 °C / min, 7 °C / min, 8 °C / min, 9 °C / min.

[0046] Specifically, the above preparation method includes: mixing the azide precursor, carbon nanotubes and liquid to obtain a mixed solution, and under a low vacuum environment, heating, heat-preserving and cooling the mixed solution to obtain the cg-PN material.

[0047] Specifically, the above preparation method includes: mixing the azide precursor and liquid to obtain a mixed solution, laying the carbon nanotube film in a container, placing the mixed solution on the carbon nanotube film, and under a low vacuum environment, heating, heat-preserving and cooling the container and the substances in the container to obtain the cg-PN material.

[0048] Specifically, the above preparation method includes the following steps:

[0049] S1. Weigh the azide precursor, carbon nanotubes and liquid;

[0050] S2. Put the weighed raw materials in a container, and then perform ultrasonic treatment in an ultrasonic cleaner to prepare a suspension;

[0051] S3. Place the above suspension in a container (such as on a glass slide, in a quartz boat or crucible), and then place it in a tube furnace and evacuate the tube furnace;

[0052] S4. Perform operations such as vacuum or flowing gas protection, heating to the heat preservation temperature and heat preservation on the sample in the above tube furnace;

[0053] S5. Cool down the above tube furnace, that is, synthesize the cg-PN material.

[0054] Specifically, in the above S2, the container is a glass beaker or a glass weighing bottle, etc.

[0055] Specifically, in the above S2, if the ultrasonic time is too long, the substance will be damaged or the solution properties will change. If it is too short, the raw materials cannot be fully and evenly mixed. Therefore, the ultrasonic time is controlled to be 8 - 15 min, such as 9 min, 10 min, 11 min, 12 min, 13 min, 14 min.

[0056] Specifically, in the above S3, the number of vacuum pumping times is 1 - 4 times. The vacuum degree after vacuum pumping treatment is 0 - 200 Pa, such as 10 Pa, 20 Pa, 30 Pa, 40 Pa, 50 Pa, 60 Pa, 70 Pa, 80 Pa, 90 Pa, 120 Pa, 140 Pa, 160 Pa, 180 Pa, 200 Pa.

[0057] Specifically, in the above S4, the vacuum degree of the vacuum is 1 - 5 Pa, such as 2 Pa, 3 Pa, 4 Pa, 5 Pa.

[0058] Specifically, in the above S4, the gas includes oxygen, hydrogen, nitrogen, argon, helium, etc., and one or more gases can be introduced.

[0059] Considering that in S4, if the gas flow rate is too large, the pressure in the tubular furnace will be too high, which is not conducive to the synthesis of cg - PN materials. Therefore, the gas flow rate is controlled to be 1 - 50 standard cubic centimeters per minute. For example, 10 standard cubic centimeters per minute, 20 standard cubic centimeters per minute, 30 standard cubic centimeters per minute, 40 standard cubic centimeters per minute.

[0060] Specifically, in the above S4, the heating rate of the tubular furnace is set to 2 - 10 °C / min, such as 3 °C / min, 4 °C / min, 5 °C / min, 6 °C / min, 7 °C / min, 8 °C / min, 9 °C / min; the holding time is 3 - 24 h, such as 4 h, 5 h, 7 h, 10 h, 12 h, 15 h, 18 h, 20 h, 22 h.

[0061] Specifically, in the above S4, generally, a rapid cooling method is adopted, and the cooling rate is 50 - 200 °C / min, such as 50 °C / min, 100 °C / min, 150 °C / min, 200 °C / min.

[0062] Or, the above preparation method includes the following steps:

[0063] S1. Weigh the azide precursor and the liquid; cut the carbon nanotube film;

[0064] S2. Place the weighed azide precursor and the liquid in a container for dissolution to obtain a mixed solution;

[0065] S3. Lay the cut carbon nanotube film flat in a container (such as a glass slide, quartz boat or crucible), drop the mixed solution on the carbon nanotube film, and then place the container in a tube furnace and evacuate the tube furnace.

[0066] S4. Perform operations such as vacuum or flowing gas protection, heating to the holding temperature and holding for the sample in the above tube furnace.

[0067] S5. Cool down the above tube furnace to obtain the cg-PN material.

[0068] Specifically, in the above S2, the container is a glass beaker or a glass weighing bottle, etc.

[0069] Specifically, in the above S3, the number of evacuation times is 1 to 4 times. The vacuum degree after the evacuation treatment is 0 to 200 Pa, such as 10 Pa, 20 Pa, 30 Pa, 40 Pa, 50 Pa, 60 Pa, 70 Pa, 80 Pa, 90 Pa, 120 Pa, 140 Pa, 160 Pa, 180 Pa, 200 Pa.

[0070] Specifically, in the above S4, the vacuum degree of the vacuum is 1 to 5 Pa, such as 2 Pa, 3 Pa, 4 Pa, 5 Pa.

[0071] Specifically, in the above S4, the gas includes oxygen, hydrogen, nitrogen, argon or helium, etc., and one or more gases can be introduced.

[0072] Considering that in S4, too large gas flow rate will cause too high pressure in the tube furnace, which is not conducive to the synthesis of the cg-PN material. Therefore, control the gas flow rate to be 1 to 50 standard cubic centimeters per minute. For example, 10 standard cubic centimeters per minute, 20 standard cubic centimeters per minute, 30 standard cubic centimeters per minute, 40 standard cubic centimeters per minute.

[0073] Specifically, in the above S4, the heating rate of the tube furnace is set to 2 to 10 °C / min, and the holding time is 3 to 24 h. For example, 4 h, 5 h, 7 h, 10 h, 12 h, 15 h, 18 h, 20 h, 22 h.

[0074] Specifically, in the above S4, generally use a rapid cooling method, and the cooling rate is 50 to 200 °C / min. For example, 50 °C / min, 100 °C / min, 150 °C / min, 200 °C / min.

[0075] The present invention also provides a kind of polymerized nitrogen material prepared by the above preparation method.

[0076] The polymeric nitrogen material of the present invention is formed by N-N single bonds and releases a huge amount of energy when decomposed into N≡N triple bonds. Its energy release capacity far exceeds that of traditional energetic materials. At the same time, due to its high energy density and the advantage that the decomposition product is nitrogen, it is expected to play an important role in practical applications.

[0077] Due to the hybridization of carbon nanotubes and cg-PN during the solubilization process, charge transfer is achieved in the polymeric nitrogen material of the present invention, enabling the polymeric nitrogen material to stably exist at normal temperature and pressure.

[0078] In the preparation method of the present invention, by adding a liquid and carbon nanotubes or a carbon nanotube film, the decomposition of the azide precursor is promoted and it participates in the reaction to synthesize the polymeric nitrogen material, improving the yield of the polymeric nitrogen material and reducing the pressure required for synthesizing the polymeric nitrogen material. Compared with the reaction for synthesizing polymeric nitrogen material under high temperature and high pressure, the synthesis pressure is greatly reduced, significantly reducing the synthesis difficulty and becoming a new method for synthesizing polymeric nitrogen material.

[0079] The polymeric nitrogen material of the present invention is formed by N-N single bonds and releases a huge amount of energy when decomposed into N≡N triple bond nitrogen. Its energy release capacity far exceeds that of traditional energetic materials. At the same time, due to its high energy density and the advantage that the decomposition product is nitrogen, it is expected to play an important role in practical applications.

[0080] The cg-PN material obtained by the high-yield preparation method of the polymeric nitrogen material of the present invention has a higher yield. For example, in the Raman spectrum, the intensity of the Raman peak corresponding to the A mode of the cg-PN material is above 16000, such as 16001 - 194377, which is more than 1 times that of the raw material characteristic peak, such as 1.36 times - 8 times. And the cg-PN material of the present invention can maintain its stability at normal temperature and pressure, breaking through the limitation that the polymeric cg-PN material in traditional technology can only exist under high pressure. This characteristic makes the material expected to open up new application prospects in the fields of energy storage, high-energy density energetic materials, etc.

[0081] In the examples and comparative examples of the present invention, a Renishaw Raman spectrometer was used for Raman spectroscopy measurement. The laser wavelength was 532 nm, the grating was 2400 l / mm, the power output was 0.5% - 5% (for example: 0.5%, 1% or 5%), the integration time was 10 - 120 s (for example: 10 s, 30 s, 60 or 120 s), the integration times were 1 - 4 times (for example: 1 time, 2 times, 3 times or 4 times), and the Raman spectroscopy test range was 100 - 1500 cm -1 。

[0082] Example 1

[0083] This example provides a high-yield preparation method of a polymeric nitrogen material and the polymeric nitrogen material. The high-yield preparation method includes:

[0084] S1. Weigh the azide precursor, carbon nanotubes and liquid;

[0085] S2. Place the weighed raw materials in a container, and then perform ultrasonic treatment in an ultrasonic cleaner to obtain a suspension;

[0086] S3. Drop the above suspension on a glass slide, then place it in a tube furnace and evacuate the tube furnace;

[0087] S4. Perform operations such as flowing gas protection, heating and heat preservation on the sample in the above tube furnace;

[0088] S5. Cool down the above tube furnace, that is, synthesize cg-PN.

[0089] Specifically, in the above S1, the azide precursor is selected as KN3, and the mass of KN3 is 100 mg.

[0090] Specifically, in the above S1, the carbon nanotubes are selected as carboxylated multi-walled carbon nanotubes, and the mass is 7 mg.

[0091] Specifically, in the above S1, the liquid is selected as water, and the mass of water is 500 mg.

[0092] Specifically, in the above S2, the container is a glass weighing bottle.

[0093] Specifically, in the above S2, the ultrasonic time is 10 min.

[0094] Specifically, in the above S3, the number of evacuations is 3 times. The vacuum degree after the evacuation treatment is 20 Pa.

[0095] Specifically, in the above S4, nitrogen and argon are introduced simultaneously as gases, and the gas flow rates are 15 standard cubic centimeters per minute respectively.

[0096] Specifically, in the above S4, the heat preservation temperature is 300 °C.

[0097] Specifically, in the above S4, the heating rate of the tube furnace is set at 4 °C / min, and the heat preservation time of the tube furnace for the sample is 3 h.

[0098] Specifically, in the above S5, the cooling rate is 50 °C / min.

[0099] The Raman spectrum of the cg-PN material synthesized in this example is as Figure 1 shown. In the Raman spectrum, there are 4 obvious strong peaks at 142 cm -1 , 634 cm -1 , 1268 cm -1 and 1340 cm -1 There is N3- The vibrational lattice mode, bending v2 mode, and symmetric stretching v1 mode correspond to strong peaks at 142 cm -1 , 1268 cm -1 and 1340 cm -1 wavelengths, respectively, while 634 cm -1 corresponds to the Raman peak of the A mode of the cg-PN material. The intensity of the peak is 170740, which is about 6.235 times that of the raw material characteristic peak, indicating that the cg-PN material was synthesized by this method.

[0100] Example 2

[0101] This example provides a method for preparing a polymer nitrogen material with a high yield and the polymer nitrogen material. The steps of this example are substantially the same as those of Example 1, except that:

[0102] In S1, the mass of the carboxylated multi-walled carbon nanotubes is 30 mg.

[0103] The Raman spectrum of the cg-PN material synthesized in this example is as Figure 2 shown. 634 cm -1 corresponds to the Raman peak of the A mode of the cg-PN material. The intensity of the peak is 194377, which is about 5.701 times that of the raw material characteristic peak, indicating that the cg-PN material was synthesized by this method.

[0104] Example 3

[0105] This example provides a method for preparing a polymer nitrogen material with a high yield and the polymer nitrogen material. The steps of this example are substantially the same as those of Example 1, except that:

[0106] S1. Use a highly conductive carbon nanotube film;

[0107] S2. Dissolve the weighed azide precursor and liquid in a container to obtain a mixed solution;

[0108] S3. Lay the cut highly conductive carbon nanotube film flat in a quartz boat, drop the above mixed solution on the highly conductive carbon nanotube film, and then place the quartz boat in a tube furnace and evacuate the tube furnace.

[0109] Specifically, in the above S1, the size of the highly conductive carbon nanotube film is 3 cm × 1 cm.

[0110] Specifically, in the above S2, there is no need to prepare a suspension by ultrasonic treatment.

[0111] The Raman spectrum of the cg-PN material synthesized in this example is as Figure 3 shown. 634 cm -1For the Raman peak corresponding to the A mode of cg-PN, the intensity of the peak is 139822, which is about 5.501 times that of the raw material characteristic peak, indicating that the polymeric cg-PN material is synthesized by this method.

[0112] Example 4

[0113] This example provides a method for preparing a polymeric nitrogen material with a high yield and a polymeric nitrogen material. The preparation method includes:

[0114] S1. Weigh the azide precursor, carbon nanotubes and liquid;

[0115] S2. Place the weighed raw materials in a container, and then perform ultrasonic treatment in an ultrasonic cleaner to obtain a suspension;

[0116] S3. Drop the above suspension on a quartz boat, and then place it in a tube furnace and evacuate the tube furnace;

[0117] S4. Perform operations such as protecting the sample in the tube furnace with flowing gas, heating and heat preservation;

[0118] S5. Cool down the tube furnace, and then the cg-PN material is synthesized.

[0119] Specifically, in the above S1, the azide precursor is selected as NaN3, and the mass of NaN3 is 100 mg.

[0120] Specifically, in the above S1, the carbon nanotubes are selected as carboxylated multi-walled carbon nanotubes, and the mass is 7 mg.

[0121] Specifically, in the above S1, the liquid is selected as water, and the mass of water is 500 mg.

[0122] Specifically, in the above S2, the container is a glass weighing bottle.

[0123] Specifically, in the above S2, the ultrasonic time is 10 min.

[0124] Specifically, in the above S3, the number of evacuation times is 3 times. The vacuum degree after evacuation treatment is 20 Pa.

[0125] Specifically, in the above S4, nitrogen and argon are introduced simultaneously as gases, and the gas flow rates are 15 standard cubic centimeters per minute respectively.

[0126] Specifically, in the above S4, the heat preservation temperature is 250 °C.

[0127] Specifically, in the above S4, the heating rate of the tube furnace is set to 4 °C / min, and the heat preservation time of the tube furnace for the sample is 3 h.

[0128] Specifically, in the above S5, the cooling rate is 50 °C / min.

[0129] The Raman spectrum of the cg-PN material synthesized in this example is as Figure 4 shown. In the Raman spectrum, there are 4 obvious strong peaks at 142 cm -1 , 634 cm -1 , 1268 cm -1 and 1340 cm -1 . The vibrational lattice mode, bending v2 mode, and symmetric stretching v1 mode of N3 - correspond to the strong peaks at 142 cm -1 , 1268 cm -1 and 1340 cm -1 wavelengths respectively, while 634 cm -1 corresponds to the Raman peak of the A mode of cg-PN, and the intensity of the peak is 16001, which is about 1.695 times that of the raw material characteristic peak, indicating that the polymeric cg-PN material is synthesized by this method.

[0130] Example 5

[0131] This example provides a method for preparing a polymeric nitrogen material with high yield and the polymeric nitrogen material. The preparation method includes:

[0132] S1. Weigh the azide precursor, carbon nanotubes, and liquid;

[0133] S2. Place the weighed raw materials in a container, and then perform ultrasonic treatment in an ultrasonic cleaner to obtain a suspension;

[0134] S3. Drop the above suspension onto a quartz boat, and then place it in a tube furnace and evacuate the tube furnace;

[0135] S4. Perform operations such as flowing gas protection, heating, and heat preservation on the sample in the above tube furnace;

[0136] S5. Cool the above tube furnace to synthesize cg-PN.

[0137] Specifically, in the above S1, the azide precursor is selected as LiN3, and the mass of LiN3 is 100 mg.

[0138] Specifically, in the above S1, the carbon nanotubes are selected as amino-functionalized multi-walled carbon nanotubes, and the mass is 10 mg.

[0139] Specifically, in the above S1, the liquid is selected as water, and the mass of water is 500 mg.

[0140] Specifically, in the above S2, the container is a glass weighing bottle.

[0141] Specifically, in the above S2, the ultrasonic time is 10 min.

[0142] Specifically, in the above S3, the number of vacuum pumping times is 3 times. The vacuum degree after the vacuum pumping treatment is 20 Pa.

[0143] Specifically, in the above S4, nitrogen and argon are introduced simultaneously as gases, and the gas flow rates are 15 standard cubic centimeters per minute respectively.

[0144] Specifically, in the above S4, the heat preservation temperature is 100 °C.

[0145] Specifically, in the above S4, the heating rate of the tube furnace is set to 4 °C / min, and the heat preservation time is 3 h.

[0146] Specifically, in the above S5, the cooling rate is 50 °C / min.

[0147] In this embodiment, the same Raman spectrum test as in Embodiment 1 was also carried out, and the results show that the cg-PN material was synthesized by this method. Due to limited space, they will not be listed one by one.

[0148] Embodiment 6

[0149] This embodiment provides a method for preparing a polymer nitrogen material with a high yield and a polymer nitrogen material. The preparation method includes:

[0150] S1. Weigh the azide precursor, carbon nanotubes and liquid;

[0151] S2. Put the weighed raw materials in a container, and then perform ultrasonic treatment in an ultrasonic cleaner to obtain a suspension;

[0152] S3. Drop the above suspension on a quartz boat, and then place it in a tube furnace and perform vacuum pumping treatment on the tube furnace;

[0153] S4. Perform operations such as flowing gas protection, heating and heat preservation on the sample in the above tube furnace;

[0154] S5. Cool the above tube furnace, that is, synthesize the cg-PN material.

[0155] Specifically, in the above S1, the azide precursor is selected as NH4N3, and the mass of NH4N3 is 100 mg.

[0156] Specifically, in the above S1, the carbon nanotubes are selected as amino-functionalized multi-walled carbon nanotubes, and the mass is 10 mg.

[0157] Specifically, in the above S1, the liquid is selected as water, and the mass of water is 500 mg.

[0158] Specifically, in the above S2, the container is a glass weighing bottle.

[0159] Specifically, in the above S2, the ultrasonic time is 10 min.

[0160] Specifically, in the above S3, the number of vacuum pumping times is 3 times. The vacuum degree after the vacuum pumping treatment is 19 Pa.

[0161] Specifically, in the above S4, nitrogen and argon are introduced simultaneously as gases, and the gas flow rates are 15 standard cubic centimeters per minute respectively.

[0162] Specifically, in the above S4, the heat preservation temperature is 80 °C.

[0163] Specifically, in the above S4, the heating rate of the tube furnace is set to 4 °C / min, and the heat preservation time is 3 h.

[0164] Specifically, in the above S5, the cooling rate is 50 °C / min.

[0165] In this embodiment, the polymer cg-PN material is synthesized by using this method.

[0166] In this embodiment, the same Raman spectrum test as in Embodiment 1 is also carried out. The results show that the cg-PN material is synthesized by using this method. Due to limited space, they are not listed one by one.

[0167] The inventors have carried out a large number of studies during the research process. Now, some solutions with poor effects are taken as comparative examples and listed as follows.

[0168] Comparative Example 1

[0169] This comparative example provides a cg-PN material and a preparation method thereof. The steps of this comparative example are substantially the same as those of Embodiment 1, except that:

[0170] S1. Carbon nanotubes are not added;

[0171] S2. The above-mentioned weighed raw materials are placed in a container for dissolution;

[0172] S3. The above liquid is dropped on a glass slide, and then it is placed in a tube furnace and the tube furnace is subjected to vacuum pumping treatment;

[0173] Specifically, in the above S2, it is not necessary to prepare a suspension by ultrasonic treatment.

[0174] The Raman spectrum of the cg-PN material synthesized in this comparative example is as Figure 5 shown, 634 cm -1 corresponds to the Raman peak of the A mode of cg-PN. The cg-PN material is synthesized by using this method, but 634 cm -1The relative intensity of the A-mode Raman peak corresponding to cg-PN is significantly weaker than that at 634 cm in Example 1, Example 2, Example 3, and Example 4 -1 The relative intensity of the A-mode Raman peak corresponding to cg-PN indicates that the addition of carbon nanotubes or carbon nanotube films improves the yield of cg-PN synthesis.

[0175] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. A method for preparing a polymeric nitrogen material with a high yield, characterized in that, Comprising: Mixing an azide precursor, carbon nanotubes or a carbon nanotube film with a liquid to obtain a mixture, and heating, holding, and cooling the mixture to 70-350 °C in a low-vacuum environment to obtain a polymeric nitrogen material; the mass of the carbon nanotubes or the carbon nanotube film is 1%-100% of the azide precursor; The azide precursor includes one or more of NH4N3, NaN3, LiN3, and KN3; The vacuum degree of the low-vacuum environment is 0-200 Pa.

2. The preparation method according to claim 1, wherein The carbon nanotubes include one or more of single-walled carbon nanotubes, carboxylated multi-walled carbon nanotubes, amino-functionalized multi-walled carbon nanotubes, and graphitized multi-walled carbon nanotubes.

3. The preparation method according to claim 2, wherein The single-walled carbon nanotubes are carboxylated single-walled carbon nanotubes; the graphitized multi-walled carbon nanotubes are graphitized carboxylated multi-walled carbon nanotubes.

4. The preparation method according to claim 1, characterized in that, The preparation method includes: mixing an azide precursor and carbon nanotubes with a liquid to obtain a mixed solution, and heating, holding, and cooling the mixed solution in a low-vacuum environment to obtain a polymeric nitrogen material.

5. The preparation method according to claim 1, characterized in that, The preparation method includes: mixing an azide precursor with a liquid to obtain a mixed solution, laying a carbon nanotube film in a vessel, placing the mixed solution on the carbon nanotube film, and heating, holding, and cooling the vessel and the substances in the vessel in a low-vacuum environment to obtain a polymeric nitrogen material.

6. The preparation method according to claim 4 or 5, characterized in that, The heating rate is 2-10 °C / min.

7. The preparation method according to claim 4 or 5, characterized in that The cooling rate is 50-200 °C / min.

8. The preparation method according to claim 1, characterized in that, The liquid includes one or more of water, alcohol, an acid solution, or a base solution.

9. The preparation method according to claim 8, wherein, The acid solution is one or more of a hydrochloric acid solution and an acetic acid solution.

Images