Vanadium-doped ZIF-8-derived nitrogen-doped heterogeneous ZnTe powder as well as preparation method and application thereof

Abstract

The invention discloses a preparation method of vanadium-doped ZIF-8-derived nitrogen-doped out-phase ZnTe powder, which comprises the following steps: by taking a mixed liquid of water and dimethylformamide as a solvent and taking vanadyl acetylacetonate and zinc nitrate hexahydrate as a vanadium source and a zinc source respectively, carrying out cooperative control on the concentrations, the ratio, the reaction temperature and the reaction time of the vanadium source and the zinc source to obtain the vanadium-doped ZIF-8-derived nitrogen-doped out-phase ZnTe powder. The ZnV-ZIF precursor is prepared by a coprecipitation method; and mixing the precursor with Te powder, and calcining. According to the method, a V element is introduced into ZIF-8 in situ by using a coprecipitation method, the element distribution is uniform, the quantity is controllable, and the doping effect of V and the adjustment of a ZnTe homogeneous and heterogeneous heterostructure can be well ensured.

Description

Technical Field

[0001] The present invention belongs to the technical field of preparation methods of zinc telluride composite powders, and particularly relates to nitrogen-doped heterogeneous ZnTe powders derived from vanadium-doped ZIF-8, and also relates to the preparation method and application of the powders. Background Art

[0002] Zinc telluride (ZnTe) has a typical zinc blende structure, in which zinc atoms and tellurium atoms are connected to each other by covalent bonds to form a face-centered cubic lattice. It is a direct bandgap semiconductor, and the bandgap width at room temperature is about 2.26 eV. This structure endows it with some unique physical properties, such as high symmetry and good optical properties. Currently, it has shown good characteristics in electrical, optical, and thermal properties. (1) It can effectively absorb and emit light of specific wavelengths in optoelectronic device applications; (2) It has a high electron mobility, which is beneficial to the transmission of electrons inside the material, thus showing potential application value in some high-speed electronic devices; (3) It has good absorption and emission capabilities for visible light and near-infrared light. It has a high luminous efficiency and can be used to prepare optoelectronic devices such as light-emitting diodes (LEDs) and laser diodes; (4) In the field of nonlinear optics, it has a large nonlinear optical coefficient and can achieve functions such as frequency conversion of light, such as second harmonic generation; (5) Its thermal conductivity is relatively low and can be used in some micro-nano optoelectronic devices with requirements for thermal isolation. Therefore, ZnTe has shown high application value in light-emitting diodes (LEDs), laser diodes, solar cells, electrochemical secondary batteries, nonlinear optical devices, and detectors, etc.

[0003] Currently, the preparation methods of ZnTe mainly include chemical vapor deposition (CVD), molecular beam epitaxy (MBE), and melt growth methods, etc., and these methods usually require high temperatures. Summary of the Invention

[0004] The purpose of the present invention is to provide a preparation method of nitrogen-doped heterogeneous ZnTe powders derived from vanadium-doped ZIF-8, which solves the problem of high temperature required in the existing ZnTe preparation process.

[0005] Another purpose of the present invention is to provide nitrogen-doped heterogeneous ZnTe powders derived from vanadium-doped ZIF-8.

[0006] The third purpose of the present invention is to provide the application of nitrogen-doped heterogeneous ZnTe powders derived from vanadium-doped ZIF-8 in lithium-sulfur batteries.

[0007] The first technical solution adopted in the present invention is a method for preparing vanadium-doped ZIF-8-derived nitrogen-doped heterogeneous ZnTe powder. Using a mixed liquid of water and dimethylformamide as the solvent, vanadyl acetylacetonate and zinc nitrate hexahydrate are used as the vanadium source and zinc source respectively. By synergistically controlling their concentrations and ratios, reaction temperature, and reaction time, the co-precipitation method is used to prepare the ZnV-ZIF precursor; then the precursor is mixed with Te powder and calcined.

[0008] The characteristics of the present invention also lie in that It is specifically implemented according to the following steps: Step 1, measure 200 ml to 250 ml of dimethylformamide and slowly add it to 200 ml to 250 ml of deionized water, and magnetically stir for 3 min to 10 min to obtain a uniform mixed solvent S; Step 2, weigh 1.428 g to 2.142 g of zinc nitrate hexahydrate and 0.636 g to 0.954 g of vanadyl acetylacetonate and add them simultaneously to 200 ml to 250 ml of the mixed solvent S, and magnetically stir for 10 min to 40 min to obtain a uniformly dispersed transparent solution A; Step 3, weigh 1.36 g to 2.04 g of 2-methylimidazole and add it to 200 ml to 250 ml of the mixed solvent S, and magnetically stir for 10 min to 40 min to obtain a uniformly dispersed transparent solution B; Step 4, pour solution B into solution A, magnetically stir for 20 min to 40 min to obtain a suspension C, and place the suspension C in a cool place and let it stand for 20 h to 28 h; Step 5, perform low-temperature centrifugation on the standing suspension C, centrifuge at a speed of 7000 r / min to 9000 r / min for 3 min to 10 min, collect the product after washing 2 to 5 times with the mixed solvent S, place the collected product in a vacuum drying oven for drying, vacuum dry at 60 °C to 80 °C for 18 h to 36 h and then collect the product to obtain the powder of VZn-ZIF-8; Step 6, weigh 0.2 g to 0.6 g of the VZn-ZIF-8 powder and 0.4 g to 1.2 g of elemental Te powder and grind for 5 min to 10 min to mix the two substances evenly. Then, put the above mixture into a magnetic boat, put the magnetic boat into a tube furnace, and calcine it in an argon atmosphere to obtain the vanadium-doped ZIF-8-derived nitrogen-doped heterogeneous ZnTe powder.

[0009] In step 2, the molar ratio of zinc nitrate hexahydrate to vanadyl acetylacetonate is 2:1, and the molar ratio value fluctuates up and down by no more than 0.5.

[0010] In Step 5, both the cleaning with the mixed solvent S and the product collection are carried out by centrifugation. Before the product is placed in a vacuum drying oven for drying, it is sealed with plastic wrap, and the plastic wrap is perforated. After vacuum drying, the product needs to be ground in a mortar for 5 min to 10 min before collection.

[0011] In Step 6, the calcination conditions are as follows: the heating rate is 2 °C / s to 5 °C / s, the reaction temperature is 780 °C to 820 °C, and the reaction time is 110 min to 130 min.

[0012] In Step 6, the mass ratio of Te powder to VZn-ZIF-8 powder is 2:1, and the mass ratio value fluctuates up and down by no more than 0.5.

[0013] Another technical solution adopted by the present invention is the vanadium-doped ZIF-8-derived nitrogen-doped heterogeneous ZnTe powder prepared by the preparation method of vanadium-doped ZIF-8-derived nitrogen-doped heterogeneous ZnTe powder. The powder is a structure stacked by uniform polyhedral particles with a diameter of 500 nm.

[0014] The third technical solution adopted by the present invention is the application of vanadium-doped ZIF-8-derived nitrogen-doped heterogeneous ZnTe powder in lithium-sulfur batteries.

[0015] The beneficial effects of the present invention are as follows: 1) In the present invention, the co-precipitation method is used to introduce V element in-situ in ZIF-8. The element distribution is uniform, the amount is controllable, and it can well ensure the doping effect of V and the regulation of the ZnTe homogeneous and heterogeneous structure. 2) Since the present invention uses the co-precipitation method and the calcination reaction to directly synthesize the final structure, the synthesized ZnTe product has high crystallinity, the synthesized nitrogen-doped carbon has a good degree of graphitization, and thus has good conductivity. In addition, there is a good interfacial combination between the nitrogen-doped carbon, ZnTe, and the two-phase ZnTe. Moreover, the synthesis route is simple, the product structure is controllable, and large-scale equipment and harsh reaction conditions are not required. 3) The vanadium source used in the present invention is vanadyl acetylacetonate, the zinc source is zinc nitrate hexahydrate, and the solvent is water and dimethylformamide (DMF). They are cheap, easy to obtain, and have low cost. The whole reaction has a high yield, is easy to control, and is environmentally friendly. The product does not require post-treatment and is suitable for large-scale production. Description of the Drawings

[0016] Figure 1 It is the X-ray diffraction pattern of the product prepared in Example 1 of the present invention; Figure 2 It is the scanning electron microscope image of the product prepared in Example 1 of the present invention. Detailed Embodiments

[0017] The present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0018] The present invention provides a preparation method of vanadium-doped ZIF-8-derived nitrogen-doped heterogeneous ZnTe powder, which is specifically implemented according to the following steps: Step 1, measure 200 ml to 250 ml of dimethylformamide and slowly add it to 200 ml to 250 ml of deionized water, and magnetically stir for 3 min to 10 min to obtain a uniform mixed solvent S; Step 2, weigh 1.428 g to 2.142 g of zinc nitrate hexahydrate and 0.636 g to 0.954 g of vanadyl acetylacetonate and add them simultaneously to 200 ml to 250 ml of the mixed solvent S, and magnetically stir for 10 min to 40 min to obtain a uniformly dispersed transparent solution A; In Step 2, the molar ratio of zinc nitrate hexahydrate to vanadyl acetylacetonate is 2:1, and the molar ratio value fluctuates up and down by no more than 0.5; an excessive vanadium source will affect the appearance of ZIF-8 dodecahedra, and a too low vanadium source cannot play the role of doping and regulating the homogeneous and heterogeneous structure of ZnTe; Step 3, weigh 1.36 g to 2.04 g of 2-methylimidazole and add it to 200 ml to 250 ml of the mixed solvent S, and magnetically stir for 10 min to 40 min to obtain a uniformly dispersed transparent solution B; Step 4, pour solution B into solution A, magnetically stir for 20 min to 40 min to obtain a suspension C, and place the suspension C in a cool place and let it stand for 20 h to 28 h; Step 5, perform low-temperature centrifugation on the standing suspension C, centrifuge at a speed of 7000 r / min to 9000 r / min for 3 min to 10 min, collect the product after washing 2 to 5 times with the mixed solvent S, place the collected product in a vacuum drying oven for drying, vacuum dry at 60 °C to 80 °C for 18 h to 36 h, and then collect the product to obtain VZn-ZIF-8 powder; In Step 5, both the washing of the mixed solvent S and the collection of the product are carried out by centrifugation. Before the product is placed in the vacuum drying oven for drying, it is sealed with plastic wrap and the plastic wrap is perforated. After vacuum drying, the product needs to be ground in a mortar for 5 min to 10 min before it can be collected; Step 6, weigh 0.2 g to 0.6 g of VZn-ZIF-8 powder and 0.4 g to 1.2 g of elemental Te powder and grind for 5 min - 10 min to mix the two substances evenly. Then, put the above mixture into a magnetic boat, put the magnetic boat into a tube furnace, and calcine in an argon atmosphere to obtain vanadium-doped ZIF-8-derived nitrogen-doped heterogeneous ZnTe powder; The calcination conditions in Step 6 are as follows: the heating rate is 2°C / s to 5°C / s, the reaction temperature is 780°C to 820°C, and the reaction time is 110 min to 130 min; In Step 6, the mass ratio of Te powder to VZn-ZIF-8 powder is 2:1, and the ratio of the mass ratio fluctuates up and down by no more than 0.5; too much Te powder may lead to excessive Teification of the polyhedron, resulting in large-area fragmentation and wasting of Te powder, while too little Te powder will make it difficult to achieve complete Teification of Zn.

[0019] In the powder prepared by the method for preparing vanadium-doped ZIF-8-derived nitrogen-doped heterogeneous ZnTe powder of the present invention, the ZnTe heterogeneous structure is mainly a homogeneous heterogeneous structure composed of two cubic phases with different a, b, and c values. At the same time, the morphology of the synthesized powder is a uniform dodecahedron with a diameter of about 500 nm, and the surface of the dodecahedron is composed of uniform vanadium-doped heterogeneous ZnTe nanoparticles, and the surface is relatively rough.

[0020] Example 1 The method for preparing vanadium-doped ZIF-8-derived nitrogen-doped heterogeneous ZnTe powder is specifically implemented according to the following steps: Step 1, measure 250 ml of dimethylformamide (DMF) and slowly add it to 250 ml of deionized water, and magnetically stir for 3 min to obtain a uniform mixed solvent S; Step 2, weigh 1.785 g of zinc nitrate hexahydrate and 0.795 g of vanadyl acetylacetonate and add them to 250 ml of mixed solvent S at the same time, and magnetically stir for 20 min to obtain a uniformly dispersed transparent solution A; Step 3, weigh 1.97 g of 2-methylimidazole and add it to 250 ml of mixed solvent S, and magnetically stir for 20 min to obtain a uniformly dispersed transparent solution B; Step 4, pour solution B into solution A, magnetically stir for 30 min to obtain a suspension C, and place the suspension C in a cool place and let it stand for 24 h; Step 5, perform low-temperature centrifugation on the standing suspension C, centrifuge at a speed of 8000 r / min for 5 min, collect the product after washing 3 times with mixed solvent S, place the collected product in a vacuum drying oven for drying, vacuum dry at 70°C for 24 h, and then collect the product to obtain VZn-ZIF-8 powder; Step 6, weigh 0.4 g of VZn-ZIF-8 powder and 0.8 g of elemental Te powder and grind for 10 min to mix the two substances evenly, then put the above mixture into a magnetic boat, put the magnetic boat into a tube furnace, and calcine at a temperature of 800°C for 120 min in an argon atmosphere to obtain vanadium-doped ZIF-8-derived nitrogen-doped heterogeneous ZnTe powder.

[0021] AsFigure 1 As shown, all the diffraction peaks are very thin and strong (indicating high crystallinity) and are composed of two sub-diffraction peaks. The left sub-diffraction peak can be matched with the PDF# 15-0746 or PDF# 89-3054 card, and the right sub-diffraction peak can be matched with the PDF# 75-2085 card. The three cards correspond to the cubic phase (43m(216)) crystal phase. The main difference lies in the values of a, b, and c. For the PDF# 15-0746 card, a = b = c = 6.1026 Å; for the PDF# 89-3054 card, a = b = c = 6.098 Å; for the PDF# 75-2085 card, a = b = c = 6.07 Å. Therefore, the ZnTe heterogeneous structure is mainly a polymorphic heterostructure composed of two cubic phases with different a, b, and c values.

[0022] As Figure 2 shown, the morphology of the synthesized powder is uniform dodecahedra with a diameter of about 500 nm. The surface of the dodecahedra is composed of uniformly vanadium-doped heterogeneous ZnTe nanoparticles, and the surface is relatively rough.

[0023] Example 2 A preparation method of vanadium-doped ZIF-8-derived nitrogen-doped heterogeneous ZnTe powder is specifically implemented according to the following steps: Step 1, measure 200 ml of dimethylformamide (DMF) and slowly add it to 200 ml of deionized water, and stir magnetically for 10 min to obtain a uniform mixed solvent S; Step 2, weigh 1.785 g of zinc nitrate hexahydrate and 0.795 g of vanadyl acetylacetonate and add them to 250 ml of the mixed solvent S at the same time, and stir magnetically for 10 min to obtain a uniformly dispersed transparent solution A; Step 3, weigh 1.36 g of 2-methylimidazole and add it to 250 ml of the mixed solvent S, and stir magnetically for 10 min to obtain a uniformly dispersed transparent solution B; Step 4, pour solution B into solution A, stir magnetically for 30 min to obtain a suspension C, and place the suspension C in a cool place and let it stand for 24 h; Step 5, perform low-temperature centrifugation on the standing suspension C, centrifuge at a speed of 7000 r / min for 3 min, collect the product after washing twice with the mixed solvent S, place the collected product in a vacuum drying oven for drying, and collect the product after vacuum drying at 70 °C for 18 h to obtain the powder of VZn-ZIF-8; Step 6, Weigh 0.4 g of VZn-ZIF-8 powder and 0.8 g of elemental Te powder, grind them for 5 min to mix the two substances evenly, then put the above mixture into a magnetic boat, place the magnetic boat into a tubular furnace, and calcine it at a temperature of 780 °C for 110 min in an argon atmosphere to obtain nitrogen-doped heterogeneous ZnTe powder derived from vanadium-doped ZIF-8.

[0024] Example 3 Preparation method of nitrogen-doped heterogeneous ZnTe powder derived from vanadium-doped ZIF-8, which is specifically implemented according to the following steps: Step 1, Measure 210 ml of dimethylformamide (DMF) and slowly add it to 210 ml of deionized water, and stir magnetically for 5 min to obtain a uniform mixed solvent S; Step 2, Weigh 1.785 g of zinc nitrate hexahydrate and 0.795 g of vanadyl acetylacetonate, and add them to 250 ml of mixed solvent S at the same time, and stir magnetically for 30 min to obtain a uniformly dispersed transparent solution A; Step 3, Weigh 1.97 g of 2-methylimidazole and add it to 250 ml of mixed solvent S, and stir magnetically for 10 min to obtain a uniformly dispersed transparent solution B; Step 4, Pour solution B into solution A, stir magnetically for 25 min to obtain a suspension C, and place suspension C in a cool place and let it stand for 25 h; Step 5, Centrifuge the standing suspension C at a low temperature, centrifuge at a speed of 7500 r / min for 3 min, collect the product after washing it 3 times with mixed solvent S, place the collected product in a vacuum drying oven for drying, and collect the product after vacuum drying at 70 °C for 24 h to obtain the powder of VZn-ZIF-8; Step 6, Weigh 0.4 g of VZn-ZIF-8 powder and 0.8 g of elemental Te powder, grind them for 10 min to mix the two substances evenly, then put the above mixture into a magnetic boat, place the magnetic boat into a tubular furnace, and calcine it at a temperature of 800 °C for 120 min in an argon atmosphere to obtain nitrogen-doped heterogeneous ZnTe powder derived from vanadium-doped ZIF-8.

[0025] Example 4 Preparation method of nitrogen-doped heterogeneous ZnTe powder derived from vanadium-doped ZIF-8, which is specifically implemented according to the following steps: Step 1, Measure 220 ml of dimethylformamide (DMF) and slowly add it to 220 ml of deionized water, and stir magnetically for 10 min to obtain a uniform mixed solvent S; Step 2, Weigh 1.785 g of zinc nitrate hexahydrate and 0.795 g of vanadyl acetylacetonate, and add them to 230 ml of mixed solvent S at the same time, and stir magnetically for 40 min to obtain a uniformly dispersed transparent solution A; Step 3: Weigh 1.75 g of 2-methylimidazole and add it to 250 ml of mixed solvent S. Stir magnetically for 40 min to obtain a uniformly dispersed transparent solution B. Step 4: Pour solution B into solution A, stir magnetically for 40 min to obtain a suspension C, and leave suspension C to stand in a cool place for 28 h. Step 5: Centrifuge the standing suspension C at a low temperature, centrifuge at a speed of 9000 r / min for 10 min, collect the product after washing 3 times with mixed solvent S, place the collected product in a vacuum drying oven for drying, and collect the product after vacuum drying at 80 °C for 36 h to obtain the powder of VZn-ZIF-8. Step 6: Weigh 0.4 g of VZn-ZIF-8 powder and 0.8 g of elemental Te powder, grind for 10 min to mix the two substances evenly, then put the above mixture into a magnetic boat, put the magnetic boat into a tube furnace, and calcine at a temperature of 820 °C for 130 min in an argon atmosphere to obtain the nitrogen-doped heterogeneous ZnTe powder derived from vanadium-doped ZIF-8.

[0026] Example 5 A preparation method of nitrogen-doped heterogeneous ZnTe powder derived from vanadium-doped ZIF-8 is specifically implemented according to the following steps: Step 1: Measure 240 ml of dimethylformamide (DMF) and slowly add it to 250 ml of deionized water, stir magnetically for 9 min to obtain a uniform mixed solvent S. Step 2: Weigh 1.785 g of zinc nitrate hexahydrate and 0.795 g of vanadyl acetylacetonate and add them simultaneously to 250 ml of mixed solvent S, stir magnetically for 15 min to obtain a uniformly dispersed transparent solution A. Step 3: Weigh 1.97 g of 2-methylimidazole and add it to 240 ml of mixed solvent S, stir magnetically for 40 min to obtain a uniformly dispersed transparent solution B. Step 4: Pour solution B into solution A, stir magnetically for 40 min to obtain a suspension C, and leave suspension C to stand in a cool place for 20 h. Step 5: Centrifuge the standing suspension C at a low temperature, centrifuge at a speed of 8000 r / min for 9 min, collect the product after washing 5 times with mixed solvent S, place the collected product in a vacuum drying oven for drying, and collect the product after vacuum drying at 80 °C for 36 h to obtain the powder of VZn-ZIF-8. Step 6, weigh 0.4 g of VZn-ZIF-8 powder and 0.8 g of elemental Te powder, grind them for 10 min to mix the two substances evenly, then put the above mixture into a magnetic boat, place the magnetic boat in a tube furnace, and calcine it at 820 °C for 120 min in an argon atmosphere to obtain nitrogen-doped heterogeneous ZnTe powder derived from vanadium-doped ZIF-8.

[0027] Example 6 Preparation method of nitrogen-doped heterogeneous ZnTe powder derived from vanadium-doped ZIF-8, which is specifically implemented according to the following steps: Step 1, measure 250 ml of dimethylformamide (DMF) and slowly add it to 200 ml of deionized water, stir magnetically for 6 min to obtain a uniform mixed solvent S; Step 2, weigh 1.785 g of zinc nitrate hexahydrate and 0.795 g of vanadyl acetylacetonate and add them to 200 ml of mixed solvent S at the same time, stir magnetically for 20 min to obtain a uniformly dispersed transparent solution A; Step 3, weigh 1.97 g of 2-methylimidazole and add it to 250 ml of mixed solvent S, stir magnetically for 20 min to obtain a uniformly dispersed transparent solution B; Step 4, pour solution B into solution A, stir magnetically for 30 min to obtain a suspension C, and place suspension C in a cool place and let it stand for 24 h; Step 5, perform low-temperature centrifugation on the standing suspension C, centrifuge at 8000 r / min for 5 min, collect the product after washing 3 times with mixed solvent S, place the collected product in a vacuum drying oven for drying, vacuum dry it at 70 °C for 24 h, and then collect the product to obtain VZn-ZIF-8 powder; Step 6, weigh 0.4 g of VZn-ZIF-8 powder and 0.8 g of elemental Te powder, grind them for 10 min to mix the two substances evenly, then put the above mixture into a magnetic boat, place the magnetic boat in a tube furnace, and calcine it at 810 °C for 130 min in an argon atmosphere to obtain nitrogen-doped heterogeneous ZnTe powder derived from vanadium-doped ZIF-8.

[0028] The preparation method of the nitrogen-doped heterogeneous ZnTe powder derived from vanadium-doped ZIF-8 of the present invention utilizes the regulation effect of V doping on the ZnTe lattice, and under the condition of exceeding the volatilization temperature of zinc, realizes the controllable construction of the two-phase ZnTe homogeneous and heterogeneous structure. The reaction process is simple, requires a short time, is easy to control, and does not require large equipment and harsh reaction conditions, and the obtained product has a high crystallinity. When the above product is applied as a cathode host material for lithium-sulfur batteries, it can exhibit excellent electrochemical performance and catalytic performance.

Claims

1. A method for preparing nitrogen-doped heterogeneous ZnTe powder derived from vanadium-doped ZIF-8, characterized in that: A mixed liquid of water and dimethylformamide is used as the solvent, acetylacetonato vanadium source and hexahydrate zinc nitrate are used as the vanadium source and zinc source respectively, and their concentrations and ratios, reaction temperature and reaction time are synergistically controlled to prepare the ZnV-ZIF precursor by co-precipitation method; then the precursor is mixed with Te powder and calcined.

2. The method for preparing nitrogen-doped heterogeneous ZnTe powder derived from vanadium-doped ZIF-8 according to claim 1, characterized in that: Please follow the steps below to implement: Step 1, measure 200ml~250ml of dimethylformamide and slowly add it into 200ml~250ml of deionized water, and stir magnetically for 3min~10min to obtain a uniform mixed solvent S; Step 2, weighing 1.428 g to 2.142 g of zinc nitrate hexahydrate and 0.636 g to 0.954 g of vanadyl acetylacetonate and adding them simultaneously to 200 ml to 250 ml of a mixed solvent S, and magnetically stirring for 10 min to 40 min to obtain a uniformly dispersed transparent solution A; Step 3, weigh 1.36 g to 2.04 g of 2-methylimidazole and add it to 200 ml to 250 ml of mixed solvent S, and stir magnetically for 10 min to 40 min to obtain a uniformly dispersed transparent solution B; Step 4, pour solution B into solution A, stir magnetically for 20 min to 40 min to obtain suspension C, and place suspension C in a cool place for 20 h to 28 h; Step 5, centrifuging the suspension C after standing at low temperature, centrifuging at a speed of 7000r / min~9000r / min for 3min~10min, collecting the product after washing with the mixed solvent S 2~5 times, placing the collected product in a vacuum drying oven for drying, vacuum drying at 60°C~80°C for 18h~36h, and collecting the product to obtain VZn-ZIF-8 powder; Step 6, weigh 0.2g~0.6g of VZn-ZIF-8 powder and 0.4g~1.2g of elemental Te powder and grind them for 5min-10min to mix the two substances evenly, then put the above mixture into a magnetic boat, put the magnetic boat into a tubular furnace, and calcine under argon environment to obtain vanadium-doped ZIF-8-derived nitrogen-doped heterogeneous ZnTe powder.

3. The method for preparing nitrogen-doped heterogeneous ZnTe powder derived from vanadium-doped ZIF-8 according to claim 2, characterized in that: In step 2, the molar ratio of zinc nitrate hexahydrate to vanadyl acetylacetonate is 2:1, and the molar ratio fluctuates within 0.

5.

4. The method for preparing nitrogen-doped heterogeneous ZnTe powder derived from vanadium-doped ZIF-8 according to claim 2, characterized in that: In step 5, the mixed solvent S is cleaned and the product is collected by centrifugation. Before the product is placed in a vacuum drying oven for drying, it is sealed with plastic wrap and the plastic wrap is pierced. After vacuum drying, the product needs to be ground in a mortar for 5 minutes to 10 minutes before it can be collected.

5. The method for preparing nitrogen-doped heterogeneous ZnTe powder derived from vanadium-doped ZIF-8 according to claim 2, characterized in that: The calcination conditions in step 6 are: heating rate 2°C / s to 5°C / s, reaction temperature 780°C to 820°C, and reaction time 110min to 130min.

6. The method for preparing nitrogen-doped heterogeneous ZnTe powder derived from vanadium-doped ZIF-8 according to claim 2, characterized in that: In step 6, the mass ratio of Te powder to VZn-ZIF-8 powder is 2:1, and the mass ratio fluctuates within 0.

5.

7. The vanadium-doped ZIF-8-derived nitrogen-doped heterogeneous ZnTe powder prepared by the method for preparing the vanadium-doped ZIF-8-derived nitrogen-doped heterogeneous ZnTe powder according to any one of claims 1 to 6, characterized in that: The powder is a structure formed by stacking uniform polyhedral particles with a diameter of 500 nm.

8. Use of the nitrogen-doped heterogeneous ZnTe powder derived from vanadium-doped ZIF-8 according to claim 7 in lithium-sulfur batteries.

Images