CN114664572A - A synthetic method for simultaneously preparing high-performance supercapacitor positive and negative electrode materials using Co-MOF arrays as precursors - Google Patents

Abstract

A synthetic method for simultaneously preparing high-performance super capacitor positive and negative electrode materials by taking a Co-MOF array as a precursor comprises the steps of firstly, mixing Ni (NO) with the molar ratio of 1 (3-9)₃)₂·6H₂Dissolving O and 2-MI in water respectively, and vertically immersing 1 x 1cm of foamed Nickel (NF) or foamed iron nickel (FNF) to obtain Co-MOF @ NF and Co-MOF @ FNF. Co-MOF @ NF was then soaked to 76mg Ni (NO)₃)₂Preparing CN-LDH by using the ethanol solution, and immersing the CN-LDH into the solution containing 1-12 mmol of L^‑1NaVO (NaVO)₃Standing in the aqueous solution to obtain CNV; soaking Co-MOF @ FNF into 1-6 mg mL^‑1Fe(NO₃)₃·9H₂Obtaining CF-LDH by O aqueous solution, and immersing the array in a solution containing 1-12 mmol L^‑1NaVO (NaVO)₃And standing in the aqueous solution to obtain CFV. Immersing CNV or CFV into a solution containing 2.5mg mL^‑1～10mg mL^‑1The reaction was carried out at 160 ℃ for 12 hours to obtain CNVS-x or CFVS (x ═ TAA solution concentration/2.5) as the target product. The preparation strategy for constructing two trimetal sulfide composite materials based on the same Co-MOF precursor provided by the invention improves the electron transfer rate and enhances the energy density of a super capacitor.

Description

A synthetic method for simultaneously preparing high-performance supercapacitor positive and negative electrode materials using Co-MOF arrays as precursors

technical field

The invention belongs to the technical field of functional nanocomposite materials, and in particular relates to a synthesis method for simultaneously preparing two trimetallic sulfide composite materials by using Co-metal organic framework material as a precursor and its electrochemical energy storage application.

Background technique

Supercapacitors are electrochemical energy storage devices widely used in hybrid electric vehicles, smart grids, and flexible electronic devices, and have received increasing attention due to their high power density, long life, environmental friendliness, and good safety. Although supercapacitors have ultra-high power density and can complete a complete charge-discharge cycle in a few seconds, the performance of supercapacitor energy density is really unsatisfactory, generally lower than 30Wh kg ^-1 , which limits its further promotion and large-scale application. . Electrode materials are the core of supercapacitors, so how to design high-performance supercapacitor positive and negative electrodes and prepare hybrid supercapacitor devices is an effective strategy to improve the energy density of supercapacitor devices.

Metal-organic frameworks (MOFs) are porous three-dimensional network materials composed of organic ligands and inorganic ions or clusters through coordination bonds. Due to the advantages of specific surface area, abundant and tunable pore structure, and highly dispersed metal centers, it is considered as an ideal precursor for the preparation of supercapacitor electrode materials. In recent years, the preparation of MOFs-derived electrode materials using the reversibility of coordination bonds based on ion-exchange or liquid etching strategies has attracted the attention of countless researchers. During the MOFs etching process, organic ligands will be replaced by inorganic ions and small molecules to form free coordinating anions, and inorganic anions and released organic ligands will move in and out of the material, which provides more opportunities for ion migration. channels, resulting in excellent supercapacitor performance. Since the MOFs etching process is a thermodynamically spontaneous ion exchange process, it can be completed at a lower reaction temperature, making the ion exchange method more controllable, simpler, and more energy-efficient. A new approach to the performance of positive and negative battery materials.

Transition metal sulfides (TMSs), such as Co ₉ S ₈ , Ni ₃ S ₂ and FeS ₂ , are an ideal class of pseudocapacitors/batteries due to their fast redox activity, high capacity storage, and cycling stability electrode material. It has been reported that TMSs doped with high-valent elements, such as Mo, W, V, etc., can not only generate a large number of defect sites and provide more electroactive centers, but also form heterostructures that provide abundant channels and pore structures, Facilitates rapid diffusion of ions and improved redox kinetics. Therefore, designing and regulating the high-valent element doping of TMSs and optimizing the product structure, morphology, and composition are effective strategies to construct high-performance electrode materials.

SUMMARY OF THE INVENTION

The present invention proposes a strategy combining two-step etching and one-step vulcanization, successively introducing cations (Ni ²⁺ /Fe ³⁺ ) and anions (VO ₃ ^- ) into the interior of Co-MOF to realize co-doping of anions and cations; Through the precise controllable vulcanization process, the prepared trimetallic heterosulfides not only maintain the parent framework of Co-MOF, but also have high specific surface area and abundant pore structure. The prepared electrode materials can be used as positive and negative electrodes of supercapacitors, respectively, with ultra-high specific capacity and excellent cycle stability.

In order to construct a supercapacitor device with high energy density, the present invention is based on the Co-MOF precursor, through a strategy of combining etching and vulcanization, and simultaneously constructing high-performance supercapacitor positive and negative electrode materials. The synthesis of electrode materials can be achieved through the following technical routes:

1. A synthetic method for simultaneously preparing high-performance supercapacitor positive and negative electrode materials with Co-MOF array as precursor, comprising the following steps:

(1) Preparation of Co-MOF precursor: a certain molar ratio (1:(3-9)) of cobalt nitrate hexahydrate (Ni(NO ₃ ) ₂ ·6H ₂ O) and dimethylimidazole (2-MI ) were dissolved in deionized water respectively, then the above two solutions were mixed, and a piece of 1*1cm foam nickel (NF) or foam iron nickel (FNF) was immersed in the above solution vertically, and allowed to stand for 1-18h at room temperature to obtain Co-MOF@NF grown on Ni foam current collector and Co-MOF@FNF grown on Fe Ni foam current collector.

(2) Preparation of basic cobalt nickel vanadate (CNV): First, the Co-MOF array prepared in (1) was immersed in 25 mL of ethanol solution containing 76 mg Ni(NO ₃ ) ₂ for 1-16 h to prepare Co-coated Co-MOF arrays. /Ni-LDH shell layer Co-MOF(CN-LDH); then the above array was further immersed in NaVO ₃ aqueous solution containing 1-12 mmol L ^-1 , and stirred at room temperature for 1-3 hours to etch the inner Co. -MOF core to give basic cobalt nickel vanadate CNV.

(3) Preparation of basic cobalt iron vanadate (CFV): First, soak the Co-MOF precursor prepared in (1) on the iron-nickel foam to 1-6 mg mL ^-1 Fe(NO ₃ ) ₃ ·9H ₂ O aqueous solution for 1-10 min to obtain Co-MOF (CF-LDH) coated with Co/Fe-LDH shell layer; then the above array was further immersed in NaVO ₃ aqueous solution containing 1-12 mmol L ^-1 , and incubated at room temperature Under stirring for 1 to 3 hours, the inner Co-MOF core is etched to obtain basic cobalt iron vanadate CFV.

(4) Ni/V-doped Co ₃ S ₄ and Co/Ni- doped VS ₂ heterostructures (CNVS) and Fe/V-doped Co ₃ S ₄ and Co/Fe- doped VS ₂ heterostructures Preparation of structure (CFVS): Immerse CNV or CFV in 3 mL of thioacetamide (TAA) solution containing 2.5 mg mL ^-1 to 10 mg mL ^-1 and react at 160 °C for 12 hours to obtain the target product CNVS- x or CFVS (where x is TAA solution concentration/2.5).

The preparation method according to claim 1, characterized in that: the molar ratio of the step (1) cobalt nitrate hexahydrate (Ni(NO ₃ ) ₂ ·6H ₂ O) and dimethylimidazole (2-MI) was 1:8; the standing time at room temperature was 2 hours to synthesize Co-MOFs with uniform morphology and size.

The preparation method according to claim 1, characterized in that: the step (2) is soaked in an ethanol solution of Ni(NO ₃ ) ₂ for 10h to ensure that there is enough Ni source in the CN-LDH for step ( 3); the optimal concentration of the NaVO ₃ aqueous solution is 6 mmol L ^-1 , and the optimal stirring time at room temperature is 2 hours, so as to achieve sufficient etching of the Co-MOF core.

The preparation method according to claim 1, characterized in that: the optimal concentration of the Fe(NO ₃ ) ₃ 9H ₂ O solution in the step (3) is 4 mg ml ^-1 , and the Co/Fe-LDH-coated The optimal time is 5min to reduce the damage of Fe(NO ₃ ) ₃ ·9H ₂ O to the Co-MOF array structure.

The preparation method according to claim 1 is characterized in that: the optimal concentration of TAA in the step (4) is 7.5 mg mL ^-1 to form a Co ₃ S ₄ and VS ₂ heterostructure.

The preparation method according to claim 1, wherein the CNVS prepared in the step (4) can be used as a positive electrode material of a supercapacitor, and the prepared CFVS can be used as a negative electrode material of a supercapacitor.

As a further feature of the present invention: two kinds of trimetallic sulfide electrode materials (CNVS/CFVS) based on the same Co-MOF precursor obtained through step (4) are used as positive and negative electrode materials for hybrid supercapacitors, respectively, Has excellent electrochemical properties. When tested under the three-electrode system, the specific capacity of CNVS-x was as high as 4096-6556 mF cm ^-2 under the voltage range of 0-0.5V and the current density of 2mA cm ^-2 . The capacity retention rate was 85% after the second cycle; the specific capacity of CFVS was as high as 6195mFcm ^{-2 under the voltage range of -1.1-(-0.1V) and the current density of 5mA cm -2 .}

The present invention is used as a further feature of the present invention: the two trimetallic sulfide electrode materials (CNVS/CFVS) constructed based on the same Co-MOF precursor obtained through step (4) are used as the positive and negative electrodes of the hybrid supercapacitor, respectively. The two-electrode hybrid supercapacitor was assembled with polar materials, and the energy density was as high as 0.73mWh·cm ^-2 under the power density of 0.4mW cm ^-2 .

Due to adopting the above technical solutions, the present invention has the following beneficial effects:

The prepared leaf-like trimetallic sulfides are constructed based on the same Co-MOF precursor, and the principle is based on the reversibility of coordination bonds to realize the in-situ substitution reaction of ions. For the Co/M-LDH coating process (M=Ni ²⁺ /Fe ³⁺ ), the hydrolysis of Ni ²⁺ (Fe ³⁺ ) ions produces Ni(Fe)-LDH crystallites and H ⁺ ions, H ⁺ ions The Co-MOF was further corroded to release Co ^{2+ ions} , which further co-precipitated with M-LDH (M=Ni or Fe) crystallites on the surface of the triangular flaky Co-MOF to form a core-shell structure Co-MOF@ M-LDH. Since Fe ³⁺ ions have stronger hydrolysis ability than Ni ²⁺ ions, and the etching reaction of Co-MOF is driven by H ⁺ ions, the time of Co/Fe-LDH coating is longer than that of Co/Ni-LDH coating Covering time is short. For the NaVO etching process, a large amount of ^OH- anions were generated through the hydrolysis process of NaVO ^, and the anion-exchange reaction of ^OH- and ₂ - _MeIM- further etched the Co-MOF in Co-MOF@Ni(Fe)-LDH nucleus, thereby introducing V element to form CNV. Finally, the three-metal co-doped hollow Co/M/V-LDH nanosheet arrays were transferred to hierarchical Co/M/VS arrays (M=Ni or Fe), Ni/V- or Fe/V-doped Co ₃ S ₂ nanoparticles are randomly distributed on Co/Ni- or Co/Fe- doped VS ₂ nanoplates, forming a heterogeneous interface, which rapidly enhances the interaction of electrons and electrolytes in the reaction kinetics transfer rate, providing more electroactive sites for deep redox reactions, enhancing the specific capacity and energy density of supercapacitors. Therefore, the two leaf-shaped trimetallic sulfides prepared by the method of the present invention based on the same Co-MOF precursor have excellent electrochemical properties. Specifically, the specific capacity of CNVS-x at a current density of 2 mA cm ^-2 reached 4096-6556 F g ^-1 , of which the optimal sample CNVS-3 maintained 85% of the initial capacity after 3000 cycles: CFVS at -1.1-( -0.1V) voltage range and a current density of 5mA cm ^-2 , the specific capacity is as high as 6195mF cm ^-2 .

Detailed ways

The technical features of the present invention are described below with reference to the specific experimental scheme and the accompanying drawings, but the present invention is not limited thereto. The test methods described in the following examples are conventional methods unless otherwise specified; the instruments and materials can be obtained from commercial sources unless otherwise specified.

Example 1

A synthesis method for simultaneously preparing high-performance supercapacitor positive and negative electrode materials using a Co-MOF array as a precursor, comprising the following steps:

(1) Cobalt nitrate hexahydrate (Ni(NO ₃ ) ₂ ·6H ₂ O) and dimethylimidazole (2-MI) with a molar ratio of 1:8 were dissolved in deionized water, respectively, and then the two solutions were dissolved in deionized water. Mix and vertically immerse a piece of 1*1cm nickel foam (NF) or foam iron nickel (FNF) into the above solution, and let stand for 2 h at room temperature to obtain Co-MOF@NF grown on the foam nickel current collector and grown on Co-MOF@FNF on foamed iron-nickel current collectors. The morphology of Co-MOF@NF is shown in its SEM image (Fig. 1); the crystallinity of Co-MOF@NF is shown in its powder X-ray diffraction pattern (Fig. 2); the morphology of Co-MOF@FNF is shown in its The SEM image (Fig. 3); the crystallinity of Co-MOF@FNF is shown in its powder X-ray diffraction pattern (Fig. 4).

(2) The Co-MOF@NF array prepared in the previous step was soaked in 25 mL ethanol solution containing 76 mg Ni(NO ₃ ) ₂ for 10 h to prepare Co-MOF (CN-LDH) coated with Co/Ni-LDH shell. ), the morphology of CN-LDH is shown by its scanning electron microscope (Fig. 5); the above array was further immersed in NaVO aqueous solution containing ₆ mmol L ^-1 , and stirred at room temperature for 2 h to prepare the target product basic cobalt nickel vanadate cnv. The morphologies of the CNVs are shown by their scanning electron microscopes (Fig. 6).

(3) Immerse the Co-MOF@FNF precursor in step (1) into 4 mg mL ^-1 Fe(NO ₃ ) ₃ ·9H ₂ O aqueous solution for 5 min to obtain Co-MOF coated with Co/Fe-LDH shell layer (CF-LDH), the morphology of CF-LDH is shown by its scanning electron microscope (Fig. 7); the above array was further immersed in NaVO aqueous solution containing ₆ mmol L ^-1 , and stirred at room temperature for 2 h to etch the inner Co -MOF core, the target product basic cobalt iron vanadate CFV was obtained, and the morphology of the CFV was shown by its scanning electron microscope (Fig. 8).

(4) The CNV or CFV prepared in the previous step was immersed in 3 mL of thioacetamide (TAA) solution containing 7.5 mg mL ^-1 , and reacted at 160 °C for 12 hours to obtain the target product CNVS-3 or CFVS. The crystallinity of CNVS-3 is shown in its powder X-ray diffraction pattern (Fig. 9); the morphology of CNVS-3 is shown in its SEM image (Fig. 10), the material maintains the triangular platelet-like morphology of the precursor, and The surface is composed of many ultra-small nanoparticles; the microscopic morphology of CNVS-3 is shown in its TEM image (Fig. 11), and the material is composed of nanoparticles wrapped by nanosheets; the electron energy spectrum of CNVS-3 is shown in its XPS image ( Figure 12), the material contains Co, Ni, V, S, O and other elements, indicating that Ni, V, S are successfully introduced into the derivative material. The constant current charge and discharge of CNVS-3 at different scan rates are shown in Figure 13. The specific capacity of CNVS-3 at a current density of 2 mA cm ^-2 was calculated to reach 6556 mF cm ^-2 , and the initial cycle was maintained for 3000 cycles. 85% of the capacity (Fig. 14); the morphology of CFVS is as shown in its SEM image (Fig. 15), the material maintains the triangular sheet-like morphology of the precursor, and has a small amount of pore structure on the surface, the microscopic morphology of CFVS-3 As shown in its TEM image (Fig. 16); the electron energy spectrum of CFVS is shown in its XPS image (Fig. 17), the material contains elements such as Co, Fe, V, S, O, etc., indicating that Fe, V, S are successfully introduced into derivatives material inside. The constant current charge-discharge of CFVS at different scan rates is shown in Figure 18. The specific capacity of CFVS at a current density of 5 mA cm ^-2 is calculated to reach 6195 mF cm ^-2 , and 82.9% of the initial capacity is maintained for 1000 cycles. (Fig. 19).

Example 2

A synthetic method for simultaneously preparing high-performance supercapacitor positive and negative electrode materials using Co-MOF arrays as precursors

Include the following steps:

(1) The preparation of Co-MOF@NF and Co-MOF@FNF precursors is the same as that in Example 1.

(2) The preparation of CN-LDH is the same as that in Example 1, and this process does not need to perform NaVO ₃ etching treatment on CN-LDH.

(3) The preparation of CFV is the same as that in Example 1.

(4) The obtained CN-LDH was directly immersed vertically in 3 mL of thioacetamide (TAA) solution containing 7.5 mg mL ^-1 , and reacted at 160 °C for 12 hours to prepare CNS materials. The constant current charge and discharge of CNS at different scan rates are shown in Figure 20. The specific capacity of CNS at a current density of 2 mA cm ^-2 is calculated to reach 3252 mF cm ^-2 from the figure. The preparation of CFVS is the same as that of Example 1.

Example 3

A synthesis method for simultaneously preparing high-performance supercapacitor positive and negative electrode materials using a Co-MOF array as a precursor, comprising the following steps:

(1) The preparation of Co-MOF precursor is the same as that of Example 1.

(2) The preparation of CNV is the same as in Example 1.

(3) The preparation of CFV is the same as that in Example 1.

(4) The obtained CNV was immersed vertically in 3 mL of thioacetamide (TAA) solution containing 2.5 mg mL ^-1 , and reacted at 160 °C for 12 hours. CNVS-1 material was obtained. The constant current charge-discharge of CNVS-1 at different scan rates is shown in Figure 21. The specific capacity of CNVS-1 at a current density of 2 mA cm ^-2 is calculated to reach 4096 mF cm ^-2 from the figure. The preparation of CFVS is the same as in Example 1.

Example 4

A synthesis method for simultaneously preparing high-performance supercapacitor positive and negative electrode materials using a Co-MOF array as a precursor, comprising the following steps:

(1) The preparation of Co-MOF precursor is the same as that of Example 1.

(2) The preparation of CNV is the same as in Example 1.

(3) The preparation of CFV is the same as that in Example 1.

(4) The obtained CNVs were vertically immersed in 3 mL of thioacetamide (TAA) solution containing 5 mg mL ^-1 , and reacted at 160 °C for 12 hours. CNVS-2 material was obtained. The constant current charge-discharge of CNVS-2 at different scan rates is shown in Figure 22. The specific capacity of CNVS-2 at a current density of 2 mA cm ^-2 is calculated to reach 4920 mF cm ^-2 . The preparation of CFVS is the same as in Example 1.

Example 5

A synthesis method for simultaneously preparing high-performance supercapacitor positive and negative electrode materials using a Co-MOF array as a precursor, comprising the following steps:

(1) The preparation of Co-MOF precursor is the same as that of Example 1.

(2) The preparation of CNV is the same as in Example 1.

(3) The preparation of CFV is the same as that in Example 1.

(4) The obtained CNV was vertically immersed in 3 mL of thioacetamide (TAA) solution containing 10 mg mL ^-1 , and reacted at 160 °C for 12 hours. CNVS-4 material was obtained. The constant current charge and discharge of CNVS-4 at different scan rates are shown in Fig. 23. The specific capacity of CNVS-4 at a current density of 2 mA cm ^-2 is calculated to reach 5076 mF cm ^-2 from the figure. The preparation of CFVS is the same as in Example 1.

The description of the embodiments disclosed in the present invention is not intended to limit the scope of the present invention, but to describe the present invention. Accordingly, the scope of the present invention is not limited by the above embodiments, but is defined by the claims or their equivalents.

Description of drawings:

Fig. 1: Scanning electron microscope image of Co-MOF@NF obtained in Example 1;

Figure 2: X-ray diffraction pattern of Co-MOF@NF obtained in Example 1;

Figure 3: Scanning electron microscope image of Co-MOF@FNF obtained in Example 1;

Figure 4: X-ray diffraction pattern of Co-MOF@FNF obtained in Example 1;

Fig. 5: the scanning electron microscope image of CN-LDH obtained in embodiment 1;

Fig. 6: the scanning electron microscope image of the CNV obtained in embodiment 1;

Fig. 7: the scanning electron microscope image of the CF-LDH obtained in embodiment 1;

Figure 8: Scanning electron microscope image of the CFV obtained in Example 1;

Fig. 9: the X-ray diffraction pattern of CNVS-3 obtained in embodiment 1;

Figure 10: Scanning electron microscope image of CNVS-3 obtained in Example 1;

Figure 11: TEM image of CNVS-3 obtained in Example 1;

Figure 12: the X-ray photoelectron spectrogram of CNVS-3 obtained in Example 1;

Figure 13: The constant current charge-discharge diagram of CNVS-3 obtained in Example 1 under different current densities;

Figure 14: The cycle stability test curve of CNVS-3 obtained in Example 1 in a three-electrode system;

Figure 15: Scanning electron microscope image of the CFVS obtained in Example 1;

Figure 16: TEM image of the CFVS obtained in Example 1;

Figure 17: The X-ray photoelectron spectrogram of the CFVS obtained in Example 1;

Figure 18: The constant current charge-discharge diagram of the CFVS obtained in Example 1 under different current densities;

Figure 19: The cycle stability test curve of the CFVS obtained in Example 1 in the three-electrode system;

Figure 20: The constant current charge-discharge diagram of the CNS obtained in Example 2 under different current densities;

Figure 21: The constant current charge-discharge diagram of CNVS-1 obtained in Example 3 under different current densities;

Figure 22: The constant current charge-discharge diagram of CNVS-2 obtained in Example 4 under different current densities;

Figure 23: The constant current charge-discharge diagram of CNVS-4 obtained in Example 5 at different current densities.

Claims (6)

1. A synthetic method for simultaneously preparing high-performance supercapacitor positive and negative electrode materials by taking a Co-MOF array as a precursor comprises the following steps:

(1) preparation of Co-MOF precursor: cobalt nitrate hexahydrate (Ni (NO) with a certain molar ratio (1 (3-9)) is added₃)₂·6H₂O) and dimethyl imidazole (2-MI) are respectively dissolved in deionized water, then the two solutions are mixed, a piece of 1 x 1cm of foam Nickel (NF) or foam iron (FNF) is vertically immersed in the solution, and the solution is kept stand for 1 to 18 hours at room temperature to obtain the foam nickel afflux flow growing on the foam nickel afflux flowCo-MOF @ NF on the bulk and Co-MOF @ FNF grown on a foamed iron-nickel current collector.

(2) Preparation of basic Cobalt Nickel Vanadate (CNV): firstly, soaking the Co-MOF array prepared in the step (1) into Ni (NO)₃)₂Preparing Co-MOF (CN-LDH) coated with a Co/Ni-LDH shell layer in the ethanol solution for 1-16 h; further immersing the array in a solution containing 1 to 12mmol of L^-1NaVO (NaVO)₃And (3) stirring the aqueous solution at room temperature for 1-3 hours, and etching the internal Co-MOF nuclei to obtain the basic cobalt nickel vanadate CNV.

(3) Preparation of basic cobalt iron vanadate (CFV): firstly, soaking the Co-MOF precursor growing on the foam iron-nickel prepared in the step (1) into 1-6 mg mL^-1Fe(NO₃)₃·9H₂Obtaining Co-MOF (CF-LDH) coated with a Co/Fe-LDH shell layer in an O aqueous solution for 1-10 min; further immersing the array in a solution containing 1 to 12mmol of L^-1NaVO (NaVO)₃And (3) stirring the aqueous solution at room temperature for 1-3 hours, and etching the internal Co-MOF nuclei to obtain basic cobalt ferric vanadate CFV.

(4) Ni/V-doped Co₃S₄And Co/Ni-doped VS₂Heterostructure (CNVS) and Fe/V-doped Co₃S₄And Co/Fe-doped VS₂Preparation of heterostructure (CFVS): immersing CNV or CFV into a solution containing 2.5mg mL^-1～10mg mL^-1In 3mL Thioacetamide (TAA) solution at 160 deg.C for 12 hr to obtain the target product CNVS or CFVS.

2. The method of claim 1, wherein: the step (1) cobalt nitrate hexahydrate (Ni (NO)₃)₂·6H₂O) and dimethylimidazole (2-MI) in a molar ratio of 1: 8; standing for 2 hours at room temperature to synthesize Co-MOF with uniform appearance and size.

3. The method of claim 1, wherein: the step (2) is carried out on Ni (NO)₃)₂Soaking in an ethanol solution for 10h, and using enough Ni source in CN-LDH for the step (3); NaVO₃The optimum concentration of the aqueous solution is 6mmol L^-1And stirring for 2 hours at room temperature to realize the sufficient etching of the Co-MOF core.

4. The method of claim 1, wherein: said step (3) Fe (NO)₃)₃·9H₂The optimum concentration of O solution is 4mg ml^-1The optimal time for Co/Fe-LDH coating is 5min to reduce Fe (NO)₃)₃·9H₂Disruption of Co-MOF array structure by O.

5. The method of claim 1, wherein: the optimal concentration of the TAA in the step (4) is 7.5mg mL^-1To form Co₃S₄And VS₂A heterostructure.

6. The method of claim 1, wherein: the CNVS prepared in the step (4) can be used as a super capacitor anode material, and the CFVS prepared can be used as a super capacitor cathode material.

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