Self-luminous materials based on alpha radionuclides and their preparation methods and applications

Abstract

The present invention relates to a self-luminous material based on an alpha-radioactive nuclide, its preparation method, and its application, belonging to the field of nuclear technology applications. The preparation method of the present invention comprises the following steps: dissolving an alpha-radioactive nuclide compound, a lanthanide compound, and an organic ligand in a solvent, and reacting to obtain the self-luminous material based on the alpha-radioactive nuclide. The self-luminous material based on the alpha-radioactive nuclide of the present invention can address the problems of low energy conversion efficiency of traditional alpha-radioactive nuclide photovoltaic cells and poor alpha-irradiation stability of fluorescent materials, ultimately reducing the amount of radioactivity used in nuclear batteries and increasing their output power and service life.

Description

Technical Field

[0001] The present invention belongs to the field of nuclear technology application, and in particular relates to a self-luminous material based on alpha radioactive nuclides, and a preparation method and application thereof. Background Art

[0002] Radioactive photovoltaic (RPV) nuclear batteries (RPVs) utilize high-energy particles released from the spontaneous decay of radionuclides to bombard fluorescent materials, causing them to emit light. The light energy is then converted into electrical energy through the photovoltaic effect of photovoltaic modules. Most of these batteries physically couple the radioactive source to a scintillator, requiring a radioactive source with a certain degree of penetrating power. Therefore, the vast majority of RPVs currently use beta-radiation sources. Compared to the beta nuclides used in traditional beta RPVs, alpha radionuclides have a higher power per unit activity, typically 2-3 orders of magnitude higher. This allows RPVs to achieve higher efficiency with a smaller radioactivity and a higher degree of integration. Alpha isotope batteries offer unique advantages and could play an important role in applications requiring small, concealed, low-power, long-term stable output power, particularly in low-power microdevices such as microsensors for deep space and deep-sea exploration, embedded human health monitoring chips in the biomedical field, and smart wearable electronic devices for future military applications.

[0003] Currently, there is very little research on α-nuclear photocells. There are three main reasons for this. First, due to the short effective range of α-nuclear photocells, the energy of α-nuclear photocells can only act on the surface of the fluorescent material, resulting in a low radiation conversion rate. Second, the radiation source and the phosphor of traditional α-nuclear photocells are physically stacked, and the radiation source is severely absorbed, resulting in a large amount of energy being wasted, resulting in a low energy conversion rate of the nuclear battery. Some researchers used 300mCi 238 PuO2 is used to power α-nuclear photocells, and the energy density per unit activity is only 70μW·Ci -1 , significantly lower than the theoretical value of 33.1mW·Ci -1 By changing the way the radiation source is loaded or selecting gaseous fluorescent materials to maximize the interaction between the radiation and the fluorescent material, the problem of low energy conversion efficiency can be alleviated to a certain extent. 63 Ni 2+ The solution was spin-coated onto the ZnS:Cu surface, and the energy conversion efficiency was increased by 4.5 times compared with the traditional physical stacking mode. 210 When Po is loaded into a gaseous scintillator (Ar or Xe), the fluidity of the gas maximizes the interaction between the radiation and the scintillator, greatly improving the energy conversion rate from radiation energy to light energy. Thirdly, traditional inorganic fluorescent materials have poor alpha irradiation stability, which greatly reduces the service life of the battery. There is currently no relevant new technology in this area.

[0004] In summary, existing methods for improving energy conversion efficiency essentially rely on physically dispersing the radiation source. However, physical dispersion is uncontrollable and difficult to achieve uniform distribution, and the problem of radiation absorption still exists. Furthermore, physical dispersion still fails to address the weak penetration of α-rays, preventing them from penetrating the interior of the fluorescent material. Furthermore, gaseous scintillators are expensive, have low radioluminescence efficiency, and still fail to address the issue of α-ray irradiation stability. Summary of the Invention

[0005] Therefore, the technical problem to be solved by the present invention is to overcome the problems in the prior art of traditional α-nuclear photoelectric cells where the radiation originates from absorption and the α-irradiation stability of the fluorescent material is poor.

[0006] In order to solve the above technical problems, the present invention provides a self-luminous material based on α-radionuclide and its preparation method and application

[0007] The first object of the present invention is to provide a method for preparing a self-luminous material based on α-radioactive nuclides, comprising the following steps: dissolving a compound of an α-radioactive nuclide, a lanthanide compound, and an organic ligand in a solvent, and reacting to obtain the self-luminous material based on the α-radioactive nuclide.

[0008] In one embodiment of the present invention, the α radionuclide in the compound of α radionuclide is selected from one or more of americium, plutonium and curium; and the valence state of the α radionuclide is positive trivalent.

[0009] In one embodiment of the present invention, the americium is selected from 243 Am and / or 243 Am; plutonium is selected from 242 Pu; curium is selected from 244 Cm.

[0010] In one embodiment of the present invention, the lanthanide element in the lanthanide compound is selected from one or more of terbium Tb, europium Eu, neodymium Nd and samarium Sm; and the valence state of the lanthanide element in the lanthanide compound is positive trivalent.

[0011] In one embodiment of the present invention, the organic ligand is selected from one or more of mellitic acid, benzenetetracarboxylic acid and terephthalic acid.

[0012] In one embodiment of the present invention, the solvent is selected from one or more of water, methanol, ethanol and acetonitrile.

[0013] In one embodiment of the present invention, the molar ratio of the α-radioactive nuclide compound to the lanthanide compound is 1:999-1:49.

[0014] In one embodiment of the present invention, the reaction time is 6h-48h.

[0015] The second object of the present invention is to provide a self-luminous material based on α-radionuclide prepared by the method described above.

[0016] The third object of the present invention is to provide an application of the self-luminous material based on α-radioactive nuclides in nuclear batteries.

[0017] The technical solution of the present invention has the following advantages over the prior art:

[0018] (1) The self-luminescent material based on α radioactive nuclides of the present invention is a molecular design concept of chemically bonding α radioactive nuclides to the luminescent center of lanthanide compounds with fluorescent properties. 241 Am, 243 Am, 242 Pu and 244 Cm is doped into the lanthanide organic-inorganic hybrid scintillator. Since the ionic radius of trivalent α radioactive nuclides and trivalent lanthanide elements are similar, and the coordination chemical properties are extremely similar, the α radioactive nuclides will be evenly distributed in the material and located at the site of the lanthanide elements in the material. Since the α radioactive nuclides are evenly distributed in the material, the distance between the nuclides increases and they disperse with each other, which greatly reduces the self-absorption of the radiation source itself. In addition, the radioactive nuclides are located inside the material, and the radiation does not need to enter from the outside, and the distance between them and the lanthanide elements at the luminescence center is shortened to The energy attenuation during α-ray transmission is greatly reduced.

[0019] (2) The application described in the present invention proposes a new nuclear battery energy conversion mode, which can solve the problems of low energy conversion rate of traditional α nuclear photoelectric cells and poor α irradiation stability of fluorescent materials, and ultimately reduce the radioactivity of nuclear batteries and improve the output power and service life of nuclear batteries. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to make the content of the present invention more clearly understood, the present invention is further described in detail below according to specific embodiments of the present invention in conjunction with the accompanying drawings, wherein:

[0021] Figure 1 Based on the test example 1 of the present invention 243 Actual pictures of Am's green self-luminous material; the upper picture is a photo taken during the day, and the lower picture is a photo taken under dark conditions.

[0022] Figure 2 This is the design theory of the self-luminous material of the present invention, wherein the left side is the traditional self-luminous material, and the right side is the self-luminous material based on α-radioactive nuclides of the present invention.

[0023] Figure 3 This is the test example 2 of the present invention based on243 Am's green self-luminous material luminescence intensity change diagram.

[0024] Figure 4 This is the test example 3 of the present invention based on 243 Comparison chart of the luminous intensity of Am's green self-luminous materials.

[0025] Figure 5 Schematic diagram of the radiation-induced photovoltaic effect nuclear battery in Test Example 4 of the present invention.

[0026] Figure 6 This is the IV curve of the radiation-induced photovoltaic effect nuclear battery in Test Example 4 of the present invention.

[0027] Figure 7 This is a comparison chart of key parameters such as the energy conversion rate and unit activity power density of the nuclear photovoltaic cell in Test Example 4 of the present invention. DETAILED DESCRIPTION

[0028] The present invention will be further described below with reference to the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it. However, the embodiments are not intended to limit the present invention.

[0029] In the present invention, unless otherwise specified, the valence state of the α radionuclide in the compound of the α radionuclide is +3.

[0030] Example 1

[0031] The α-radioactive nuclide-based self-luminous material and its preparation method of the present invention specifically include the following steps:

[0032] Will 243 The nitrate of Am and terbium nitrate were mixed in a molar ratio of 1:99 and dissolved in water, and then mixed with an equal molar ratio of benzene hexacarboxylic acid ligand solution. The mixed solution was allowed to stand for 12 hours to obtain a ligand based on 243 Am's green self-luminous material.

[0033] Example 2

[0034] The α-radioactive nuclide-based self-luminous material and its preparation method of the present invention specifically include the following steps:

[0035] Will 241 The nitrate of Am and europium nitrate were mixed in a molar ratio of 2:98 and dissolved in water, and then mixed with an equal molar ratio of benzene hexacarboxylic acid ligand solution. The mixed solution was allowed to stand for 12 hours to obtain a ligand based on 241 Am's red self-luminous material.

[0036] Example 3

[0037] The α-radioactive nuclide-based self-luminous material and its preparation method of the present invention specifically include the following steps:

[0038] Will 243 The nitrate of Am, terbium nitrate and europium nitrate were mixed in a molar ratio of 2:49:49 and dissolved in water, and then mixed with an equal molar ratio of benzene hexacarboxylic acid ligand solution. The mixed solution was allowed to stand for 12 hours to obtain a ligand based on 243 Am's yellow self-luminous material.

[0039] Example 4

[0040] The α-radioactive nuclide-based self-luminous material and its preparation method of the present invention specifically include the following steps:

[0041] Will 242 Pu nitrate and terbium nitrate were mixed in a molar ratio of 1:99 and dissolved in water, and then mixed with an equal molar ratio of benzene hexacarboxylic acid ligand solution. The mixed solution was allowed to stand for 12 hours to obtain a ligand based on 242 Pu green self-luminous material.

[0042] Example 5

[0043] The α-radioactive nuclide-based self-luminous material and its preparation method of the present invention specifically include the following steps:

[0044] Will 244 The nitrate of Cm and terbium nitrate were mixed in a molar ratio of 1:99 and dissolved in water, and then mixed with an equal molar ratio of benzene tetracarboxylic acid ligand solution, and the mixed solution was allowed to stand for 48 hours to obtain a ligand based on 244 Yellow self-luminous material of Cm.

[0045] Example 6

[0046] The α-radioactive nuclide-based self-luminous material and its preparation method of the present invention specifically include the following steps:

[0047] Will 241 The nitrate of Am and europium nitrate were mixed in a molar ratio of 1:99 and dissolved in water, and then mixed with a DMF solution of terephthalic acid ligand in an equal molar ratio. The mixed solution was placed in an oven at 120°C for 48 hours to obtain a nitrate-based 241 Am's red self-luminous material.

[0048] Comparative Example 1

[0049] Tritium tubes are currently the most common self-luminous material. This material uses tritium as the radiation source and ZnS as the scintillator. This type of self-luminous material has a low radiation energy conversion rate and a short service life.

[0050] Comparative Example 2

[0051] Will243 After the nitrate of Am is mixed with terbium nitrate, a luminescent material with an external radioactive source is obtained.

[0052] Test Example 1

[0053] Based on the different conditions prepared in Example 1 243 The green self-luminous material of Am was observed, and the results were as follows Figure 1 As shown. Figure 1 It can be seen that the self-luminescence phenomenon induced by α-radioactive nuclides shows that the material has extremely strong luminescence properties, which can be seen by the naked eye under dark conditions. Figure 2 As shown, the present application adopts a molecular design concept based on the self-luminous material of α radioactive nuclides to chemically bond the radioactive nuclides with the luminescent center of the fluorescent material. 243 Am doped into a Tb 3+ In organic-inorganic hybrid lanthanide compounds. Due to the trivalent americium element (Am 3+ ) and trivalent lanthanides (Tb 3+ ) have similar ionic radii and extremely similar coordination chemical properties, so 243 Am will be evenly distributed in the material and in the material Tb 3+ Because 243 Am is evenly distributed in the material, the distance between Am and Am increases, and they disperse with each other, which greatly reduces the self-absorption of the radioactive source itself; in addition, 243 Am is located inside the material, and the rays do not need to enter from the outside, and the distance between it and the luminous center Tb is shortened to The energy attenuation of α-ray transmission is greatly reduced. 243 The alpha particles produced by the decay of Am will excite the surrounding Tb 3+ glowing.

[0054] Test Example 2

[0055] Based on Example 1 243 The stability test of Am's green self-luminous material was carried out by using a liquid scintillation counter to test the photon count changes of the same sample over a period of one year. The results are as follows Figure 3 As shown. Figure 3 It can be seen that within a year, the photon count received by the liquid scintillation counter has basically not changed, indicating that the luminous intensity of the self-luminous material has basically not changed within a year, proving the luminous stability of the self-luminous material.

[0056] Test Example 3

[0057] In order to verify that the molecular design concept of chemical bonding between radioactive nuclides and the luminescent center of fluorescent materials can significantly improve the radiation utilization rate, the molecular design concept of chemical bonding between radioactive nuclides and the luminescent center of fluorescent materials can significantly improve the radiation utilization rate.243 The luminous intensity of the green self-luminous material of Am was compared with the luminous intensity of the luminous material with an external radiation source in Comparative Example 2, and the photon count was characterized by a liquid scintillation counter. The results are as follows: Figure 4 As shown. Figure 4 It can be seen that the built-in nuclide method increases the luminous intensity by 8,000 times compared with the external case, proving that the molecular design concept of chemically bonding radioactive nuclides to the luminescent centers of fluorescent materials can significantly improve radiation utilization.

[0058] Test Example 4

[0059] Based on Example 1 243 The green self-luminous material of Am is encapsulated in a quartz tank and simply physically coupled with a perovskite (CsPbI3) solar cell to assemble a new type of radiation-induced photovoltaic effect nuclear battery, such as Figure 5 shown.

[0060] The electrical properties of the assembled radiation-induced photovoltaic effect nuclear battery were tested, and its current-voltage curve was tested. Based on the results, its short-circuit current, open-circuit voltage, maximum output power, energy conversion rate and unit activity power density were calculated. The results are as follows: Figure 6 As shown. Figure 6 It can be seen that when using only 9μCi 243 In the case of Am, the open circuit voltage of the nuclear battery is 0.46V and the short circuit current density is 13.4nA / cm 2 , the maximum output power is 1.7nW / cm 2 , energy conversion rate 0.3%, unit activity power density can reach 184μW·cm -2 ·Ci -1 , which is also the highest value reported so far for nuclear photovoltaic cells ( Figure 7 ).

[0061] Obviously, the above embodiments are merely examples for clarity of explanation and are not intended to limit the implementation methods. Those skilled in the art will appreciate that other variations or modifications can be made based on the above description. It is not necessary and impossible to enumerate all implementation methods here. Obvious variations or modifications arising therefrom remain within the scope of protection of the present invention.

Claims

1. A method for preparing a self-luminous material based on α-radionuclide, characterized in that: The method comprises the following steps: dissolving a compound of an α-radioactive nuclide, a lanthanide compound and an organic ligand in a solvent, and reacting to obtain the self-luminous material based on the α-radioactive nuclide; The alpha radioactive nuclide in the compound of the alpha radioactive nuclide is selected from one or more of americium, plutonium and curium; the lanthanide element in the lanthanide compound is selected from one or more of terbium, europium, neodymium and samarium; the organic ligand is selected from one or more of benzenehexacarboxylic acid, benzenetetracarboxylic acid and terephthalic acid; and the solvent is selected from one or more of water, methanol, ethanol and acetonitrile.

2. The method for preparing a self-luminous material based on α-radionuclide according to claim 1, characterized in that: The valence state of alpha radionuclides is positive trivalent.

3. The method for preparing a self-luminous material based on α-radionuclide according to claim 2, characterized in that: The americium is selected from 243 Am and / or 243 Am; plutonium is selected from 242 Pu; curium is selected from 244 Cm.

4. The method for preparing a self-luminous material based on α-radionuclide according to claim 1, characterized in that: The valence state of the lanthanide element in the lanthanide compound is positive trivalence.

5. The method for preparing a self-luminous material based on α-radionuclide according to claim 1, characterized in that: The molar ratio of the alpha radioactive nuclide compound to the lanthanide compound is 1:999-1:

49.

6. The method for preparing a self-luminous material based on α-radionuclide according to claim 1, characterized in that: The reaction time is 6h-48h.

7. A self-luminescent material based on alpha radioactive nuclides prepared by the method according to any one of claims 1 to 6.

8. Use of the self-luminous material based on α-radionuclide according to claim 7 in a nuclear battery.

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