Application of GO (at) TUB75 as capacitor dielectric material

Abstract

The invention discloses an application of GO (at) TUB75 as a capacitor dielectric material, the GO (at) TUB75 is formed by compounding TUB75 and graphene oxide, the graphene oxide is in a folded sheet layer shape, the TUB75 is in a nanocrystalline flower shape, and the graphene oxide grows on the surface of the TUB75. The GO (at) TUB75 has a relatively stable capacitance value from 9.4 pF to 6.7 pF in a large range from 1 MHz to 110 MHz, and the lowest loss angle is 0.06.

Description

[0001] Technical field

[0002] The present invention belongs to the field of preparation of dielectric materials, and particularly relates to the use of GO (graphene oxide) @ TUB75 as a dielectric material for capacitors. Background art

[0003] A capacitor is one of the three basic electronic components. Its principle is to induce dielectric polarization through a rapid electric field to store electrical energy. A capacitor usually consists of a conductive plate and a dielectric insulating layer. The dielectric layer separates the two conductive plates. After applying a voltage across the capacitor, the electrical energy generated by the entire system is stored in the surface charges separated on the dielectric layer and the conductive plates.

[0004] Metal-Organic Framework (MOF) is a coordination polymer formed by the self-assembly of metal central ions and organic ligands. Since its emergence in the 1990s, it has been a popular research direction in today's new lightweight materials. Metal-Organic Framework has various advantages such as high porosity, large specific surface area, highly ordered pore structure, and structural designability. These advantages make it an excellent research platform for lightweight materials and also enable it to have broad application prospects in the fields of proton, ion conduction, gas adsorption, gas separation, catalysis, etc.

[0005] As an important branch of metal-organic complexes, metal-organic phosphonate complexes have also been studied by many scientists in recent years. The phosphonic acid group in metal-organic phosphonate complexes has three oxygen atoms that can bond to metals, which makes the organic phosphonate complexes have rich coordination modes and is more conducive to designing the required composite structures. At the same time, the C-P bond energy in the organic phosphonic acid group is high, which has an inductive effect on the formation of metal-organic phosphonate complexes, strengthening the interaction between the metal central ion and the oxygen atom and making the metal-organic phosphonate complexes have better chemical and thermal stability. Metal-organic phosphonate complexes have thus become a major research hotspot.

[0006] In summary, it is feasible to use phosphonate organic complexes as regulators for capacitor dielectrics. TUB75 has the advantages of low density, strong chemical stability, and rich interfaces. Summary of the invention

[0007] The present invention provides an application of a dielectric material GO@TUB75 with TUB75 as an additive in a capacitor.

[0008] The technical solution for implementing the present invention is: the use of GO@TUB75 as a dielectric material for capacitors. The GO@TUB75 is composed of TUB75 and graphene oxide. The graphene oxide is in a wrinkled sheet shape, and the TUB75 is in a nanocrystalline flower shape. The graphene oxide grows on the surface of TUB75.

[0009] Preferably, the mass ratio of GO to TUB75 in GO@TUB75 is 3-5:1, and preferably 3:1.

[0010] Preferably, the GO@TUB75 has a relatively stable capacitance value of 9.4 pF to 6.7 pF in a large range from 1 MHz to 110 MHz, and the minimum loss angle is 0.06.

[0011] Preferably, GO@TUB75 is prepared by the following steps:

[0012] Within 5 minutes, the methanol solutions of 1,4-naphthalenediphosphonic acid and 4,4'-bipyridine are respectively and uniformly dropped into the methanol mixed dispersion of copper sulfate and graphene oxide. During the dropping process, continuous stirring is carried out. After the dropping is completed, stirring is continued for 20 minutes. After the reaction is completed, filtration, washing, and drying are carried out to obtain GO@TUB75.

[0013] Specifically, the mass ratio of 1,4-naphthalenediphosphonic acid, copper sulfate, and graphene oxide is 2:3:3.

[0014] Compared with the prior art, the advantages of the present invention are:

[0015] GO@TUB75 is applied to the dielectric material of capacitors for the first time. It is composed of graphene oxide and TUB75. The TUB75 crystal is in a nanoflower shape, and the graphene oxide is in a wrinkled sheet shape and grows on the surface of TUB75.

[0016] When the mass ratio of GO to TUB75 in GO@TUB75 is 3:1, the obtained sample has a relatively stable capacitance value in a large range from 1 MHz to 110 MHz, which is 9.4 pF to 6.7 pF, and the minimum loss angle is 0.06. Description of the Drawings

[0017] Figure 1 Among them, (a) is the scanning electron microscope image of GO@TUB75, and (b) is the scanning electron microscope image of TUB75.

[0018] Figure 2 is the X-ray diffraction pattern of GO@TUB75.

[0019] Figure 3 is the graph of the capacitance value varying with frequency for Example 1, Example 2, and Example 3.

[0020] Figure 4Graph of the loss angle varying with frequency for Example 1, Example 2, and Example 3.

[0021] Figure 5 Graph of the AC conductivity of the equivalent circuit varying with frequency for Example 1, Example 2, and Example 3.

[0022] Figure 6 Graph of the capacitance value varying with frequency for Example 4.

[0023] Figure 7 Graph of the loss angle varying with frequency for Example 4.

[0024] Figure 8 Graph of the AC conductivity of the equivalent circuit varying with frequency for Example 4. Detailed implementation manners

[0025] Phosphonate MOF, as a promising conductive MOF, has broad application prospects due to its excellent chemical and thermal stability. TUB75, as a new type of phosphonate MOF, has applications in proton conduction, gas adsorption, chemical catalysis, etc. The inventor originally intended to apply this material to the field of electromagnetic wave absorption. However, after actual testing, it was found that the electromagnetic wave absorption ability of the material was not ideal. But this material has relatively rich interfaces and contains functional groups such as hydroxyl and carboxyl groups, and may have good polarization phenomena under an external electric field. Therefore, in this invention, TUB75 is compounded with graphene oxide to be used as the dielectric material of a thin-film capacitor.

[0026] Now, in combination with the implementation examples and the attached drawings, the present invention will be further described.

[0027] Example 1:

[0028] Dissolve 0.1 g of 1,4-naphthalenediphosphonic acid in 20 ml of methanol and stir for 5 minutes to dissolve it completely. The concentration of 1,4-naphthalenediphosphonic acid in the resulting solution is 5 mg / ml. The resulting solution is called Solution A. Take another 20 ml of methanol and dissolve 0.01 g of 4,4'-bipyridine in it. The concentration of this solution is 0.5 mg / ml and it is called Solution B. Take another 20 ml of methanol, add 0.15 g of copper sulfate pentahydrate to it. Its concentration is 7.5 mg / ml. Stir to dissolve it completely. Then add 0.15 mg of graphene oxide to the resulting clear solution and ultrasonicate it in an ultrasonic bath for 30 minutes to disperse the graphene oxide fully in the solution. The resulting suspension is called Solution C. Add a magnetic stir bar to the solution and stir it rapidly. Add Solution A and Solution B to Solution C simultaneously and slowly at a uniform speed. The total dropping time is 5 minutes. After the dropping is completed, stir the resulting suspension for another 20 minutes, then filter and wash it with methanol and deionized water respectively. The obtained powder is dried at 50 °C for 4 hours to obtain GO@TUB75. Weigh it and calculate the content of GO and TUB75. The result is 3:1. Its scanning electron microscopy image is as shown in Figure 1 that in (a). The scanning electron microscopy image of TUB75 is as shown in Figure 1 that in (b). The X-ray diffraction pattern of GO@TUB75 is as shown in Figure 2 shown.

[0029] After thoroughly grinding the obtained GO@TUB75 in a mortar, weigh 100 mg of the sample and add it to a circular mold (inner diameter 10 mm). Keep it under a pressure of 4 MPa for 30 seconds, then press it into a thin circular disc with a diameter of 10 mm and a thickness of 0.91 mm. Then take out the thin circular disc and spray gold on both sides 3 times, with each spraying time being 30 seconds to fully coat both sides with gold to make Sample 1. The variation of its capacitance value with frequency is as shown in Figure 3 shown. Sample 1 has a relatively stable capacitance value at relatively large frequencies from 1 MHz to 110 MHz. The capacitance value decreases as the frequency increases, from 9.7 pF to 6.7 pF. At the same time, the loss angle of this sample increases as the frequency increases, from 0.06 to 0.53. The variation of its loss angle with frequency is as shown in Figure 4 shown. At the same time, as a dielectric material, GO@TUB75 also has good alternating current conductivity. Its conductivity increases as the frequency increases, with a maximum of 3.39 S / m. The variation of its equivalent circuit alternating current conductivity with frequency is as shown in Figure 5 shown.

[0030] Example 2:

[0031] Only adjust the mass of GO in Example 1 to 0.2 g, that is, the mass ratio of GO to TUB75 is 4:1. Other processes are the same as in Example 1. The variation of its capacitance value with frequency is as shown in Figure 3 shown. The variation of the loss angle with frequency is as shown in Figure 4As shown, its equivalent circuit conductivity changes with frequency as Figure 5 shown.

[0032] Example 3:

[0033] Only adjust the mass of GO in Example 1 to 0.25 g, that is, the mass ratio of GO to TUB75 is 5:1. Other processes are the same as in Example 1. Its capacitance value changes with frequency as Figure 3 shown, and the loss angle changes with frequency as Figure 4 shown. Its equivalent circuit conductivity changes with frequency as Figure 5 shown.

[0034] Example 4:

[0035] Only adjust the mass of GO in Example 1 to 0, that is, graphene oxide is not added. Other processes are the same as in Example 1. Its capacitance value changes with frequency as Figure 6 shown, and the loss angle changes with frequency as Figure 7 shown. Its equivalent circuit conductivity changes with frequency as Figure 8 shown.

[0036] Comparing the test results of Examples 1-4, the composite material GO@TUB75 with GO added and the mass ratio of the addition amount to TUB75 being 3:1 has the best performance. In particular, compared with TUB75, its dielectric storage capacity has been greatly improved.

Claims

1. Use of GO@TUB75 as a dielectric material for capacitors, characterized in that, The GO@TUB75 is composed of TUB75 and graphene oxide. The graphene oxide is in the form of wrinkled sheets, and the TUB75 is in the form of nanocrystalline flowers. The graphene oxide grows on the surface of TUB75.

2. The use according to claim 1, characterized in that, The mass ratio of GO to TUB75 in GO@TUB75 is 3 - 5:

1.

3. The use according to claim 1, characterized in that, The mass ratio of GO to TUB75 in GO@TUB75 is 3:

1.

4. The use according to claim 1, characterized in that, The GO@TUB75 has relatively stable capacitance values ranging from 9.4 pF to 6.7 pF in a large range from 1 MHz to 110 MHz, and the minimum loss angle is 0.

06.

5. The use according to claim 1, characterized in that, The GO@TUB75 is prepared through the following steps: Within 5 minutes, the methanol solutions of 1,4-naphthalenediphosphonic acid and 4,4'-bipyridine are respectively and uniformly dropped into the methanol mixed dispersion of copper sulfate and graphene oxide while continuously stirring during the dropping process. After the dropping is completed, continue stirring for 20 minutes. After the reaction is completed, filter, wash, and dry to obtain GO@TUB75.

6. The use according to claim 5, characterized in that The mass ratio of 1,4-naphthalenediphosphonic acid, copper sulfate to graphene oxide is 2:3:3.

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