A 1H-pyrazole copper co-crystal complex, a synthesis method thereof and applications thereof in supercapacitors

Abstract

The present invention discloses a 1H-pyrazole copper co-crystal complex, a synthesis method thereof and an application thereof in a supercapacitor: The unit cell of the compound contains a five-coordinate copper complex, a six-coordinate copper complex and a free water molecule, and its unit cell structural formula is shown as formula (I); The preparation method is as follows: (1) CuSO4·5H2O and 1H-pyrazole are added into a mixed solvent of acetonitrile and water, and stirred at 25 °C for 10-20 min until completely dissolved to obtain a mixed solution; (2) The mixed solution obtained in step (1) is hydrothermally reacted at 110-130 °C for 140-160 h, filtered and washed to obtain a single crystal grade 1H-pyrazole copper co-crystal complex, and the yield is 75-83%. The present invention has the advantages of simple process, low cost, easy control of chemical reactants, good repeatability, high yield, excellent supercapacitor performance, etc. #imgabs0#

Description

Technical Field

[0001] The present invention belongs to the field of metal complexes and also to the field of chemical energy storage applications, and particularly relates to a 1H-pyrazole copper co-crystal complex, a synthesis method thereof, and an application thereof in a supercapacitor. Background Art

[0002] Supercapacitors can be classified differently according to the energy storage mechanism, electrode materials, and types of electrolytes. According to the different storage mechanisms, they can be divided into electric double layer capacitors and pseudocapacitors. According to the different electrode materials used, they can be further divided into metal oxide supercapacitors, carbon-based supercapacitors, polymer supercapacitors, and hybrid supercapacitors. Electric double layer capacitors mainly use carbon materials with a high specific surface area and a small internal resistance; while pseudocapacitors mainly use transition metal oxides, hydrate materials, doped polymers, and the like.

[0003] According to the classification of electrolytes, they can be divided into aqueous electrolyte capacitors and non-aqueous electrolyte capacitors. Electrode materials are one of the core factors affecting the performance of electrochemical capacitors and are currently a research hotspot in electrochemical capacitors. It is the material basis for the electrode to store charges and generate capacitance, and its own electrochemical performance directly affects the electrochemical performance of supercapacitor devices. Currently, traditional electrochemical capacitor electrode materials are mainly divided into three categories: carbon-based materials, metal oxides, and conductive polymer materials. However, each of these three materials has its own drawbacks.

[0004] To obtain capacitors with excellent performance such as power density, energy density, and service life to the greatest extent, researchers have been dedicated to studying materials with excellent electrical conductivity, a large specific surface area, and improved electrolyte wettability. As a new type of material, metal complexes have a large specific surface area, adjustable pore sizes, and rich redox metal centers, which can meet the above two conditions simultaneously. Therefore, they have become a research hotspot in the development and application of supercapacitor electrode materials in recent years. Summary of the Invention

[0005] Aiming at the deficiencies of the prior art, the purpose of the present invention is to provide a 1H-pyrazole copper co-crystal complex, a synthesis method thereof, and an application thereof in a supercapacitor.

[0006] The technical solution of the present invention is outlined as follows:

[0007] A 1H-pyrazole copper co-crystal complex: The unit cell of this compound contains a five-coordinate copper complex, a six-coordinate copper complex, and a free water molecule, and its unit cell structural formula is shown as formula (I):

[0008]

[0009] A method for synthesizing a 1H-pyrazole copper co-crystal complex, comprising the following steps:

[0010] (1) Add CuSO4·5H2O and 1H-pyrazole to a mixed solvent of acetonitrile and water, stir at 25 °C for 10 - 20 min until completely dissolved to obtain a mixed solution;

[0011] (2) Hydrothermally react the mixed solution obtained in step (1) at 110 - 130 °C for 140 - 160 h, filter and wash to obtain a single-crystal grade 1H-pyrazole copper co-crystal complex with a yield of 75 - 83%;

[0012] The reaction equation in step (2) is:

[0013]

[0014] Furthermore, the dosage ratio of CuSO4·5H2O, 1H-pyrazole, and the mixed solvent of acetonitrile and water is (0.250 - 0.65) g : (0.115 - 0.600) g : (12 - 18) mL.

[0015] Furthermore, the volume ratio of acetonitrile to water in the mixed solvent is 1:1.

[0016] Application of the 1H-pyrazole copper co-crystal complex prepared by the said synthesis method in a supercapacitor.

[0017] Furthermore, using the 1H-pyrazole copper co-crystal complex as the active material, acetylene black as the conductive agent, and polytetrafluoroethylene emulsion as the binder, after grinding evenly, load it on a nickel foam substrate and vacuum dry at 45 - 75 °C for 8 - 12 h to obtain a supercapacitor electrode material.

[0018] Furthermore, the mass ratio of the 1H-pyrazole copper co-crystal complex, acetylene black, and polytetrafluoroethylene emulsion is 8 : (1 - 5) : 1.

[0019] Furthermore, when the current density is 1 A / g, the specific capacitance of this supercapacitor electrode material reaches 410.6 F / g;

[0020] When the current density increases from 1 A / g to 2 A / g, the specific capacitance retention rate of this supercapacitor electrode material reaches 97.1%;

[0021] Under the conditions of 6 mol / L KOH electrolyte and a current density of 1 A / g, after 2000 charge-discharge cycle tests, the capacitance retention rate of this supercapacitor electrode material is ≥98.5%.

[0022] Advantages of the present invention:

[0023] (1) The present invention first hydrothermally synthesizes a 1H-pyrazole copper co-crystal complex with a novel chemical structure and spatial configuration of penta-coordinated and hexa-coordinated copper complexes by using a mixed solvent of CuSO4·5H2O, 1H-pyrazole, acetonitrile and water. When the complex is applied to electrode materials, in the supercapacitor test, it has the advantages of high capacity, good cycle stability, mild conditions, reusability, economy and environmental protection.

[0024] (2) The synthesis method of the present invention has the advantages of simple process, low cost, easy control of chemical reactants, good repeatability, etc., and the product has a high yield and excellent supercapacitor performance. Brief Description of the Drawings

[0025] Figure 1 is the spatial configuration diagram of the 1H-pyrazole copper co-crystal complex synthesized by the present invention;

[0026] Figure 2 is the XRD diagram of the 1H-pyrazole copper co-crystal complex synthesized in Example 1;

[0027] Figure 3 is the supercapacitor performance diagram of the electrode material prepared from the 1H-pyrazole copper co-crystal complex in Example 4;

[0028] Figure 4 is the cycle stability diagram of the electrode material prepared from the 1H-pyrazole copper co-crystal complex in Example 4;

[0029] Figure 5 is the synthesis method flow chart of the 1H-pyrazole copper co-crystal complex of the present invention. Detailed Description of the Invention

[0030] The following further elaborates on the present invention in conjunction with examples, so that those skilled in the art can implement it with reference to the text of the specification.

[0031] The present invention provides a 1H-pyrazole copper co-crystal complex of an embodiment: the unit cell of the compound contains a penta-coordinated copper complex, a hexa-coordinated copper complex and a free water molecule, and its unit cell structural formula is shown as formula (I):

[0032]

[0033] The synthesis method of the 1H-pyrazole copper co-crystal complex of this embodiment includes the following steps:

[0034] (1) Add CuSO4·5H2O and 1H-pyrazole into a mixed solvent of acetonitrile and water, stir at 25 °C for 10 - 20 min until completely dissolved to obtain a mixed solution;

[0035] (2) Hydrothermally react the mixed solution obtained in step (1) at 110 - 130 °C for 140 - 160 h, filter and wash to obtain single-crystalline 1H-pyrazole copper co-crystal complex with a yield of 75 - 83%;

[0036] The reaction equation in step (2) is:

[0037]

[0038] The dosage ratio of the mixed solvent of CuSO4·5H2O, 1H-pyrazole, acetonitrile and water is (0.250 - 0.65) g : (0.115 - 0.600) g : (12 - 18) mL; the volume ratio of acetonitrile to water in the mixture is 1:1.

[0039] The 1H-pyrazole copper co-crystal complex of this example is applied to supercapacitors: using 1H-pyrazole copper co-crystal complex as the active material, acetylene black as the conductive agent, and polytetrafluoroethylene emulsion as the binder, and the mass ratio of 1H-pyrazole copper co-crystal complex, acetylene black, and polytetrafluoroethylene emulsion is 8 : (1 - 5) : 1. After grinding evenly, it is loaded on a nickel foam substrate and vacuum dried at 45 - 75 °C for 8 - 12 h to obtain a supercapacitor electrode material.

[0040] Example 1

[0041] A synthesis method of 1H-pyrazole copper co-crystal complex, comprising the following steps:

[0042] (1) Add 0.250 g of analytical pure CuSO4·5H2O and 0.115 g of analytical pure 1H-pyrazole to a mixed solution of 12 mL of acetonitrile and water with an equal volume ratio, stir at room temperature of 25 °C for 12 min until the reactants are completely dissolved to obtain a clear and transparent mixed solution;

[0043] (2) Transfer the mixed solution prepared in step (1) to a reaction kettle with a polytetrafluoroethylene liner, hydrothermally react at 110 °C for 140 h, cool to room temperature of 25 °C, open the kettle, filter, and wash with anhydrous acetonitrile to obtain single-crystalline 1H-pyrazole copper co-crystal complex with a yield of 75%.

[0044] Characterize the 1H-pyrazole copper co-crystal complex synthesized in Example 1 by X-ray single crystal diffraction, infrared spectroscopy, mass spectrometry, and nuclear magnetic resonance hydrogen spectrum / carbon spectrum, and confirm that its structural formula is as shown in formula (I):

[0045]

[0046] Example 2

[0047] A synthesis method of 1H-pyrazole copper co-crystal complex, comprising the following steps:

[0048] (1) Add 0.420 g of analytical pure CuSO4·5H2O and 0.365 g of analytical pure 1H-pyrazole into a 18 mL mixed solution of acetonitrile and water with equal volume ratio. Stir at room temperature of 25 °C for 18 min until the reactants are completely dissolved to obtain a clear and transparent mixed solution;

[0049] (2) Transfer the mixed solution prepared in step (1) to a reaction kettle lined with polytetrafluoroethylene. Carry out hydrothermal reaction at 120 °C for 150 h. After cooling to room temperature of 25 °C, open the kettle, filter, and wash with anhydrous acetonitrile to obtain a single crystal grade 1H-pyrazole copper co-crystal complex with a yield of 80%.

[0050] Example 3

[0051] A synthesis method of 1H-pyrazole copper co-crystal complex, comprising the following steps:

[0052] (1) Add 0.650 g of analytical pure CuSO4·5H2O and 0.600 g of analytical pure 1H-pyrazole into a 20 mL mixed solution of acetonitrile and water with equal volume ratio. Stir at room temperature of 25 °C for 20 min until the reactants are completely dissolved to obtain a clear and transparent mixed solution;

[0053] (2) Transfer the mixed solution prepared in step (1) to a reaction kettle lined with polytetrafluoroethylene. Carry out hydrothermal reaction at 130 °C for 160 h. After cooling to room temperature of 25 °C, open the kettle, filter, and wash with anhydrous acetonitrile to obtain a single crystal grade 1H-pyrazole copper co-crystal complex with a yield of 83%.

[0054] Example 4

[0055] Prepare a supercapacitor electrode material using the 1H-pyrazole copper co-crystal complex prepared in Example 1: Grind the 1H-pyrazole copper co-crystal complex prepared in Example 1, acetylene black, and polytetrafluoroethylene emulsion evenly according to a mass ratio of 8:1:1, and load it on a nickel foam substrate. Dry in vacuum at 60 °C for 12 h to obtain a supercapacitor electrode material.

[0056] Perform electrochemical performance measurement on the supercapacitor electrode material prepared from the 1H-pyrazole copper co-crystal complex in Example 4

[0057] (1) Supercapacitance performance test: Figure 3 The constant current discharge curve diagram of the electrode material prepared in Example 4 at different current densities in a 6 mol / L KOH electrolyte on an electrochemical workstation with a potential window range of 0 - 0.60 V. As Figure 3 can be seen, when the current density is 1 A / g, the specific capacitance of this electrode material reaches 410.6 F / g, indicating that this electrode material has the potential to be used as a supercapacitor. From Figure 3As can be seen, when the current densities are 1 A / g, 2 A / g, 3 A / g, 4 A / g, 5 A / g, 7 A / g, 10 A / g, 15 A / g, and 20 A / g respectively, the specific capacitances are 410.6 F / g, 398.7 F / g, 354.1 F / g, 296.5 F / g, 268 F / g, 250.2 F / g, 214 F / g, 201 F / g, and 186 F / g respectively. When the current density increases from 1 A / g to 2 A / g, the specific capacitance retention rate of the supercapacitor electrode material prepared in Example 4 is as high as 97.1%.

[0058] (2) Cyclic stability test: On the electrochemical workstation, the electrode material prepared in Example 4 was placed in a 6 mol / L KOH electrolyte solution, and a charge-discharge cycle test was carried out 2000 times under the condition of a current density of 1 A / g.

[0059] Figure 4 The cyclic stability diagram of the supercapacitor electrode material prepared in Example 4: As Figure 4 can be seen, after 2000 charge-discharge cycle tests, the capacitance retention rate of the supercapacitor electrode material prepared in Example 4 is ≥98.5%.

[0060] In summary, combined with Figure 3-4 it can be seen that the 1H-pyrazole copper eutectic complex synthesized in Examples 1-3 has high-capacity and cyclic-stable electrochemical characteristics, and has extremely high research and application prospects in supercapacitor electrode materials.

[0061] Although the embodiments of the present invention have been disclosed as above, they are not limited to only the applications listed in the specification and embodiments. It can be fully applied to various fields suitable for the present invention. For those familiar with the field, additional modifications can be easily made. Therefore, without departing from the general concept defined by the claims and the equivalent scope, the present invention is not limited to specific details.

Claims

1. A method for synthesizing a 1H-pyrazole copper co-crystal complex, characterized in that: It includes the following steps: (1) Add CuSO4·5H2O and 1H-pyrazole into a mixed solvent of acetonitrile and water, stir at 25 °C for 10 - 20 min until completely dissolved to obtain a mixed solution; (2) Hydrothermally react the mixed solution obtained in step (1) at 110 - 130 °C for 140 - 160 h, filter and wash to obtain a single crystal grade 1H-pyrazole copper co-crystal complex with a yield of 75 - 83%; The dosage ratio of the CuSO4·5H2O, 1H-pyrazole, and the mixed solvent of acetonitrile and water is (0.250 - 0.65) g : (0.115 - 0.600) g : (12 - 18) mL; The volume ratio of acetonitrile to water in the mixed solvent is 1:

1.

2. Application of a 1H-pyrazole copper co-crystal complex prepared by the synthesis method according to claim 1 in a supercapacitor.

3. The application according to claim 2, characterized in that: Using the 1H-pyrazole copper co-crystal complex as the active material, acetylene black as the conductive agent, and polytetrafluoroethylene emulsion as the binder, after grinding evenly, load it on a nickel foam substrate and vacuum dry at 45 - 75 °C for 8 - 12 h to obtain a supercapacitor electrode material.

4. The application according to claim 3, characterized in that: The mass ratio of the 1H-pyrazole copper co-crystal complex, acetylene black, and polytetrafluoroethylene emulsion is 8 : (1 - 5) :

1.

5. The application according to claim 4, characterized in that: When the current density is 1 A / g, the specific capacitance of this supercapacitor electrode material reaches 410.6 F / g; When the current density increases from 1 A / g to 2 A / g, the specific capacitance retention rate of this supercapacitor electrode material reaches 97.1%; Under the conditions of 6 mol / L KOH electrolyte and a current density of 1 A / g, after 2000 charge-discharge cycle tests, the capacitance retention rate of this supercapacitor electrode material is ≥98.5%.

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