Method for preparing layered heterojunction by topotactic transformation, layered heterojunction prepared and use thereof

Abstract

The application relates to a method for preparing a layered heterojunction through topological conversion, the prepared layered heterojunction and application, the method uses water and gaseous substances as reaction mediums, uses hydrogen peroxide as an expanding exfoliation agent, uses layered vanadium pentoxide, molybdenum trioxide and manganese dioxide as precursors, uses boric acid as a dopant, uses a polymer with a charged functional group as a surface charge modifier, and obtains a layered heterojunction through hydrothermal reaction, nitrogenization treatment, sulfurization treatment, phosphorization treatment and controllable oxidation; the topological conversion reaction method first obtains a layered two-dimensional heterojunction precursor by means of hydrogen peroxide as an expanding exfoliation agent, and then inherits the layered structure characteristics of the precursor through gaseous reaction by means of the two-dimensional limited structure of the precursor, so that a heterojunction product with different components is obtained, and when the prepared layered heterojunction is used as a zinc ion battery positive electrode material, the specific capacity is higher than 320 mAh g ‑1 , the rate performance is good, and the cyclic performance is excellent.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of battery materials, and particularly relates to a method for preparing a layered heterojunction through topological conversion, the layered heterojunction prepared and application thereof. BACKGROUND

[0002] Aqueous zinc ion battery has excellent performances such as high safety, environmental friendliness and low cost, and is a potential candidate for large-scale static energy storage and wearable flexible electronic devices. The aqueous zinc ion battery mainly uses a material capable of storing zinc ions as a positive electrode, uses zinc as a negative electrode, and uses a medium capable of effectively conducting zinc ions as an electrolyte. The battery is charged and discharged by reversible insertion and extraction of zinc ions in the positive electrode material. Although the types of zinc ion battery positive electrode materials are increasing with the deepening of research, the demand for developing positive electrode materials with high zinc storage capacity, high power density and excellent cycle stability is still urgent.

[0003] In recent years, manganese-based, vanadium-based and molybdenum-based positive electrodes are widely used in zinc ion batteries. Among them, the vanadium-based positive electrode has the advantages of high capacity, excellent rate performance and good cycle stability; the manganese-based positive electrode has the advantages of high voltage platform and good cycle stability; and the molybdenum-based positive electrode has the advantage of good cycle stability. Since the positive electrode material with a heterojunction structure can achieve a synergistic enhancement effect, it is of great significance to develop a new type of heterojunction zinc storage positive electrode material. At the same time, the layered structure heterojunction has rich active sites and excellent structural stability, which can simultaneously significantly improve the energy and power density of the positive electrode material, thereby helping to significantly improve the comprehensive performance index of the zinc ion battery. SUMMARY

[0004] The technical problem to be solved by the application is to realize controllable preparation of various layered heterojunctions. Water and gaseous substances are directly used as reaction media, hydrogen peroxide is used as an expansion peeling agent, layered vanadium pentoxide, molybdenum trioxide and manganese dioxide are used as precursors, boric acid is used as a dopant, and a polymer with a charged functional group is used as a surface charge modifier. Through a hydrothermal reaction, a layered heterojunction with a two-dimensional structure is first obtained. Through a further topological conversion reaction, a heterojunction material with an expected layered structure is provided, which greatly increases the types of layered heterojunctions that can be prepared. Moreover, the prepared layered heterojunction can be used as a positive electrode material for a zinc ion battery.

[0005] To solve the above technical problems, the application adopts the following technical solutions:

[0006] The application discloses a method for preparing a layered heterojunction by adopting a topological conversion reaction, and the layered heterojunction prepared by the method and application.

[0007] According to a specific and preferred aspect of the application, the method for preparing a layered heterojunction by adopting a topological conversion reaction provided by the application comprises the following steps:

[0008] (A) adding a precursor into water, adding a dopant boric acid, fully stirring and mixing, then adding a hydrogen peroxide aqueous solution, and then placing the mixture into a reaction kettle for hydrothermal reaction after rapid stirring; the precursor is any two of vanadium pentoxide, molybdenum trioxide and manganese dioxide with a layered crystal structure;

[0009] (B) cooling the obtained product to room temperature after the hydrothermal reaction, and then performing freeze-drying on the product to obtain a layered heterojunction with a two-dimensional structure;

[0010] (C) performing further nitridation treatment, sulfidation treatment, phosphorization treatment and controllable oxidation on the layered heterojunction obtained in step (B) to obtain layered heterojunctions with different components.

[0011] Further, the adding amount of the precursor in step (A) is 0.01-0.5 moles per liter; the mass fraction of the hydrogen peroxide aqueous solution used is 5%-30%, the adding amount of the hydrogen peroxide solution is 10%-20% of the volume of the solvent water, the rapid stirring time is 5 minutes, the molar ratio of the boric acid to the precursor in step (1) is (0.0-0.5):1; the hydrothermal reaction temperature is 120-200 DEG C, the hydrothermal reaction time is 1-36 hours, and the total volume of the reactants and the solvent in the hydrothermal reaction accounts for 70%-90% of the volume of the reaction kettle.

[0012] Further, the temperature of the nitridation treatment in step (C) is 500-800°C, the reaction time is 1-12 hours, and the reaction atmosphere is ammonia / argon, wherein the volume ratio of ammonia is 1-10%; the temperature of the sulfidation treatment is 400-900°C, the reaction time is 2-12 hours, and the reaction atmosphere is hydrogen sulfide / argon, wherein the volume ratio of hydrogen sulfide is 1-5%; the temperature of the phosphidation treatment is 600-900°C, the reaction time is 5-12 hours, and the phosphorus source precursor is one of red phosphorus or triphenylphosphine, the red phosphorus or triphenylphosphine is placed at the inlet (upstream) of the carrier gas, and the reactant is placed at the gas outlet (downstream); the temperature of the controllable oxidation treatment is 300-600°C, the reaction time is 1-8 hours, and the gas is argon / oxygen, wherein the volume fraction of oxygen is 0.01-0.2%.

[0013] Further, the layered heterojunction obtained in step (B) is: vanadium pentoxide / molybdenum trioxide layered heterojunction, interstitial boron-doped vanadium pentoxide / molybdenum trioxide layered heterojunction, δ-manganese dioxide / molybdenum trioxide layered heterojunction, interstitial boron-doped δ-manganese dioxide / molybdenum trioxide layered heterojunction, δ-manganese dioxide / vanadium pentoxide layered heterojunction, and interstitial boron-doped δ-manganese dioxide / vanadium pentoxide layered heterojunction.

[0014] Further, the layered heterojunction with different components obtained in step (C) is:

[0015] vanadium nitride / molybdenum nitride layered heterojunction, vanadium disulfide / molybdenum disulfide layered heterojunction, vanadium pentoxide / molybdenum disulfide layered heterojunction, vanadium phosphide / molybdenum phosphide layered heterojunction.

[0016] interstitial boron-doped vanadium nitride / molybdenum nitride layered heterojunction, interstitial boron-doped vanadium disulfide / molybdenum disulfide layered heterojunction, interstitial boron-doped vanadium pentoxide / molybdenum disulfide layered heterojunction, and interstitial boron-doped vanadium phosphide / molybdenum phosphide layered heterojunction.

[0017] manganese nitride / molybdenum nitride layered heterojunction, manganese sulfide / molybdenum disulfide layered heterojunction, δ-manganese dioxide / molybdenum disulfide layered heterojunction, manganese phosphide / molybdenum phosphide layered heterojunction.

[0018] interstitial boron-doped manganese nitride / molybdenum nitride layered heterojunction, interstitial boron-doped manganese sulfide / molybdenum disulfide layered heterojunction, interstitial boron-doped δ-manganese dioxide / molybdenum disulfide layered heterojunction, and interstitial boron-doped manganese phosphide / molybdenum phosphide layered heterojunction.

[0019] manganese nitride / vanadium nitride layered heterojunction, manganese sulfide / vanadium disulfide layered heterojunction, manganese phosphide / vanadium phosphide layered heterojunction,

[0020] Gap boron-doped manganese nitride / vanadium nitride layered heterojunction, gap boron-doped manganese sulfide / vanadium disulfide layered heterojunction, gap boron-doped manganese phosphide / vanadium phosphide layered heterojunction.

[0021] According to a specific and preferred aspect of the present application, the present application provides a method for preparing layered heterojunctions by topological conversion, using water and gaseous substances as reaction medium, hydrogen peroxide as exfoliation agent, vanadium pentoxide, molybdenum trioxide and manganese dioxide with layered crystal structure as precursors, and polymers with charged functional groups as surface charge modifiers, by carrying out hydrothermal reaction, surface charge modification and self-assembly to obtain layered heterojunctions with two-dimensional structure, and then by further nitridation treatment, sulfidation treatment, phosphidation treatment to obtain layered heterojunctions with two-dimensional structure, which specifically comprises the following steps:

[0022] (I) adding vanadium pentoxide, molybdenum trioxide and manganese dioxide with layered crystal structure into water respectively, then adding hydrogen peroxide solution, stirring rapidly and then placing in a reaction kettle for hydrothermal reaction;

[0023] (II) cooling to room temperature after the hydrothermal reaction is completed, and then carrying out freeze-drying on the obtained product to obtain layered vanadium pentoxide nanosheets, layered molybdenum trioxide nanosheets and layered δ-manganese dioxide nanosheets;

[0024] (III) using polymers with charged functional groups as surface charge modifiers to modify the surface charge of vanadium pentoxide and δ-manganese dioxide nanosheets, and then carrying out electrostatic self-assembly of different charged components in solution to obtain layered heterojunctions;

[0025] (IV) using further nitridation treatment, sulfidation treatment, phosphidation treatment on the layered heterojunctions obtained in step (III) to obtain layered heterojunctions with different components.

[0026] Further, in step (I), vanadium pentoxide, molybdenum trioxide and manganese dioxide with layered crystal structure are added into water in an amount of 0.01-0.5 moles per liter; the mass fraction of the hydrogen peroxide solution used is 5%-30%, the amount of hydrogen peroxide added is 10-20% of the volume of the solvent water, and the rapid stirring time is 5 minutes; the hydrothermal reaction temperature is 120-200°C, the hydrothermal reaction time is 1-36 hours, and the total volume of the reactants and solvent in the hydrothermal reaction accounts for 70%-90% of the volume of the reaction kettle.

[0027] Further, in step (III), the polymers with charged functional groups as surface charge modifiers are polyethyleneimine (weight average molecular weight of 7.5×10 5 ) and poly(diallyldimethylammonium chloride) (weight average molecular weight of 2×10 5one of the following: V2O5, MnO2, MoO3, and the surface modifier has a charge ratio of (0.8-1):1 with the oxide nanosheet; and the molar ratio of the two kinds of oxide nanosheets with opposite charges in the step (III) is (0.5-1):1.

[0028] Further, in the step (IV), the temperature of the nitridation treatment is 500-800℃, the reaction time is 1-12 hours, and the reaction atmosphere is ammonia / argon, wherein the volume ratio of ammonia is 1-10%; the temperature of the sulfidation treatment is 400-900℃, the reaction time is 2-12 hours, and the reaction atmosphere is hydrogen sulfide / argon, wherein the volume ratio of hydrogen sulfide is 1-5%; the temperature of the phosphidation treatment is 600-900℃, the reaction time is 5-12 hours, the phosphorus source precursor is one of red phosphorus or triphenylphosphine, the red phosphorus or triphenylphosphine is placed at the inlet (upstream) of the carrier gas, and the reactant is placed at the gas outlet (downstream); the temperature of the controllable oxidation treatment is 300-600℃, the reaction time is 1-8 hours, and the gas is argon / oxygen, wherein the volume fraction of oxygen is 0.01-0.2%.

[0029] Further, the layered heterojunction obtained in the step (III) is:

[0030] Vanadyl pentoxide / polymer / molybdenum trioxide layered heterojunction, δ-manganese dioxide / polymer / molybdenum trioxide layered heterojunction, δ-manganese dioxide / polymer / vanadyl pentoxide layered heterojunction;

[0031] The layered heterojunction with different components obtained in the step (IV) is:

[0032] Vanadium nitride / nitrogen-doped carbon / molybdenum nitride layered heterojunction, vanadium disulfide / sulfur-doped carbon / molybdenum disulfide layered heterojunction, vanadium phosphide / phosphorus-doped carbon / molybdenum phosphide layered heterojunction;

[0033] Manganese nitride / nitrogen-doped carbon / molybdenum nitride layered heterojunction, manganese sulfide / sulfur-doped carbon / molybdenum disulfide layered heterojunction, manganese phosphide / phosphorus-doped carbon / molybdenum phosphide layered heterojunction;

[0034] Manganese nitride / nitrogen-doped carbon / vanadium nitride layered heterojunction, manganese sulfide / sulfur-doped carbon / vanadium disulfide layered heterojunction, and manganese phosphide / phosphorus-doped carbon / vanadium phosphide layered heterojunction.

[0035] The application also provides the use of the layered heterojunction prepared by the preparation method as a positive electrode material of a zinc ion battery.

[0036] According to a specific aspect, the following steps are taken to prepare a positive electrode sheet of a zinc ion battery:

[0037] (1) Layered heterojunction, acetylene black, polyvinylidene fluoride are mixed uniformly in the proportion of 8:1:1, and then are mixed with N-methyl pyrrolidone to form a paste, and then the paste is uniformly coated on a titanium foil;

[0038] (2) Drying in a vacuum oven at 80 DEG C for 12 hours.

[0039] The method for testing the electrochemical performance of the electrode material is as follows:

[0040] (1) The simulated battery adopts a button type CR2032, wherein the electrolyte is 3M zinc trifluoromethane sulfonate or 2M zinc sulfate aqueous solution, and the negative electrode is a zinc sheet.

[0041] (2) The reversible capacity and cycle performance of the electrode material are tested and analyzed by using constant current charging and discharging.

[0042] The topological transformation reaction method of the application can first use hydrogen peroxide as an expansion exfoliation agent to well expand and exfoliate vanadium pentoxide, molybdenum trioxide and δ-manganese dioxide with two-dimensional layered structure to obtain a precursor with a nanosheet structure, and then can well inherit the layered structure characteristics of the precursor by using the two-dimensional limited structure of the layered two-dimensional heterojunction precursor to obtain a heterojunction product with different components through a gas phase reaction.

[0043] The application also relates to the use of the above-prepared vanadium pentoxide / molybdenum trioxide layered heterojunction, interstitial boron-doped vanadium pentoxide / molybdenum trioxide layered heterojunction, delta-manganese dioxide / molybdenum trioxide layered heterojunction, interstitial boron-doped delta-manganese dioxide / molybdenum trioxide layered heterojunction, delta-manganese dioxide / vanadium pentoxide layered heterojunction, interstitial boron-doped delta-manganese dioxide / vanadium pentoxide layered heterojunction, vanadium pentoxide / polymer / molybdenum trioxide layered heterojunction, delta-manganese dioxide / polymer / molybdenum trioxide layered heterojunction, delta-manganese dioxide / polymer / vanadium pentoxide layered heterojunction, vanadium nitride / molybdenum nitride layered heterojunction, vanadium disulfide / molybdenum disulfide layered heterojunction, vanadium pentoxide / molybdenum disulfide layered heterojunction, vanadium phosphide / molybdenum phosphide layered heterojunction, interstitial boron-doped vanadium nitride / molybdenum nitride layered heterojunction, interstitial boron-doped vanadium disulfide / molybdenum disulfide layered heterojunction, interstitial boron-doped vanadium pentoxide / molybdenum disulfide layered heterojunction, interstitial boron-doped vanadium phosphide / molybdenum phosphide layered heterojunction, manganese nitride / molybdenum nitride layered heterojunction, manganese sulfide / molybdenum disulfide layered heterojunction, delta-manganese dioxide / molybdenum disulfide layered heterojunction, manganese phosphide / molybdenum phosphide layered heterojunction, interstitial boron-doped manganese nitride / molybdenum nitride layered heterojunction, interstitial boron-doped manganese sulfide / molybdenum disulfide layered heterojunction, interstitial boron-doped delta-manganese dioxide / molybdenum disulfide layered heterojunction, interstitial boron-doped manganese phosphide / molybdenum phosphide layered heterojunction, manganese nitride / vanadium nitride layered heterojunction, manganese sulfide / vanadium disulfide layered heterojunction, manganese phosphide / vanadium phosphide layered heterojunction, interstitial boron-doped manganese nitride / vanadium nitride layered heterojunction, interstitial boron-doped manganese sulfide / vanadium disulfide layered heterojunction, interstitial boron-doped manganese phosphide / vanadium phosphide layered heterojunction, vanadium nitride / nitrogen-doped carbon / molybdenum nitride layered heterojunction, vanadium disulfide / sulfur-doped carbon / molybdenum disulfide layered heterojunction, vanadium phosphide / phosphorus-doped carbon / molybdenum phosphide layered heterojunction, manganese nitride / nitrogen-doped carbon / molybdenum nitride layered heterojunction, manganese sulfide / sulfur-doped carbon / molybdenum disulfide layered heterojunction, manganese phosphide / phosphorus-doped carbon / molybdenum phosphide layered heterojunction, manganese nitride / nitrogen-doped carbon / vanadium nitride layered heterojunction, manganese sulfide / sulfur-doped carbon / vanadium disulfide layered heterojunction and manganese phosphide / phosphorus-doped carbon / vanadium phosphide layered heterojunction as a zinc ion battery positive electrode material, wherein the above layered heterojunctions have a specific capacity higher than 320 mAh g -1 , good rate performance and excellent cycle performance when used as a zinc ion battery positive electrode material.

[0044] Compared with the prior art, the application has the following advantages due to the implementation of the above technical solutions:

[0045] (1) the present application adopts easily available layered oxides and hydrogen peroxide as precursor raw materials; (2) controllable preparation of various layered heterojunctions is realized; (3) water and gaseous substances are directly used as reaction media, hydrogen peroxide is used as an expansion exfoliation agent, and a heterojunction material with expected layered structure is provided by means of topological transformation reaction, so that the types of layered heterojunctions that can be prepared are greatly increased, and controllable synthesis of various layered heterojunctions is realized; (4) when the layered heterojunction prepared by the present application is used as a positive electrode material of a zinc ion battery, the specific capacity is higher than 320 mAh g -1 , the rate performance is good, and the cyclic performance is excellent.

[0046] In summary, the method for preparing layered heterojunctions by topological transformation reaction of the present application can realize controllable preparation of various layered heterojunctions, provide a heterojunction material with expected layered structure, greatly increase the types of layered heterojunctions that can be prepared, and the obtained layered heterojunctions are very ideal positive electrode materials of zinc ion batteries; in addition, the preparation method starts from easily available layered oxides and hydrogen peroxide, and is prepared by a process with high repeatability, simple process and short time consumption, and is very suitable for industrial production. BRIEF DESCRIPTION OF DRAWINGS

[0047] Figure 1 It is a preparation flowchart of Example 1;

[0048] Figure 2 It is a scanning electron microscope image of the V2O5 / MoS2 layered heterojunction prepared in Example 1, and it can be seen that the product has a two-dimensional sheet structure;

[0049] Figure 3 It is a preparation flowchart of Example 2;

[0050] Figure 4 It is a scanning electron microscope image of the interstitial boron-doped V2O5 / MoS2 layered heterojunction prepared in Example 2, and it can be seen that the product has a two-dimensional sheet structure;

[0051] Figure 5 It is a preparation flowchart of Example 3;

[0052] Figure 6 It is a scanning electron microscope image of the δ-MnO2 / MoS2 layered heterojunction prepared in Example 3, and it can be seen that the product has a two-dimensional sheet structure;

[0053] Figure 7 It is a preparation flowchart of Example 4;

[0054] Figure 8 It is a scanning electron microscope image of the interstitial boron-doped δ-MnO2 / MoS2 layered heterojunction prepared in Example 4, and it can be seen that the product has a two-dimensional sheet structure;

[0055] Figure 9 Preparation flow chart of Example 5;

[0056] Figure 10 The scanning electron microscope image of the manganese sulfide / vanadium disulfide layered heterojunction prepared in Example 5 shows that the product has a two-dimensional sheet structure;

[0057] Figure 11 Preparation flow chart of Example 6;

[0058] Figure 12 Preparation flow chart of Example 7;

[0059] Figure 13 Preparation flow chart of Example 8;

[0060] Figure 14 Preparation flow chart of Example 9. DETAILED DESCRIPTION

[0061] The application will be further described below in conjunction with specific examples. It should be understood that the following examples are only used to illustrate the application and not used to limit the scope of the application, and those skilled in the art can make some non-essential improvements and adjustments to the application according to the above content.

[0062] Example 1

[0063] This example uses the method of topological conversion reaction to prepare a layered heterojunction, and the steps are as follows:

[0064] (1) Vanadium pentoxide (0.01 moles per liter) and molybdenum trioxide (0.01 moles per liter) with a layered crystal structure are added to 30 milliliters of water, and are thoroughly stirred and mixed, and then 3 milliliters of a 30% mass fraction hydrogen peroxide aqueous solution is added, and is quickly stirred for 5 minutes, and is placed in a reaction kettle for hydrothermal reaction, and the hydrothermal reaction temperature is 180°C, and the hydrothermal reaction time is 12 hours, and the total volume of the reactants and the solvent in the hydrothermal reaction accounts for 70% of the volume of the reaction kettle;

[0065] (2) After cooling to room temperature, the product is freeze-dried, and after drying, a vanadium pentoxide / molybdenum trioxide layered heterojunction nanosheet with a two-dimensional structure is obtained;

[0066] (3) The vanadium pentoxide / molybdenum trioxide layered heterojunction nanosheet obtained in step (2) is further subjected to nitrogenization treatment, sulfidation treatment, phosphidation treatment and controllable oxidation to obtain layered heterojunctions with different components, as follows:

[0067] a. The vanadium pentoxide / molybdenum trioxide layered heterojunction nanosheet obtained in step (2) is subjected to further nitridation treatment to obtain a vanadium nitride / molybdenum nitride layered heterojunction; the temperature of the nitridation treatment is 800°C, the reaction time is 2 hours, and the reaction atmosphere is ammonia gas / argon, wherein the volume ratio of ammonia gas is 5%;

[0068] b. The vanadium pentoxide / molybdenum trioxide layered heterojunction nanosheet obtained in step (2) is subjected to further sulfidation treatment to obtain a vanadium disulfide / molybdenum disulfide layered heterojunction; the temperature of the sulfidation treatment is 700°C, the reaction time is 6 hours, and the reaction atmosphere is hydrogen sulfide / argon, wherein the volume ratio of hydrogen sulfide is 2%; the obtained vanadium disulfide / molybdenum disulfide layered heterojunction is subjected to controllable oxidation treatment to obtain a vanadium pentoxide / molybdenum disulfide layered heterojunction; the temperature of the controllable oxidation treatment is 500°C, the reaction time is 2 hours, and the gas is argon / oxygen, wherein the volume fraction of oxygen is 0.01%;

[0069] c. The vanadium pentoxide / molybdenum trioxide layered heterojunction nanosheet obtained in step (2) is subjected to further phosphidation treatment to obtain a vanadium phosphide / molybdenum phosphide layered heterojunction; the temperature of the phosphidation treatment is 700°C, the reaction time is 5 hours, and the phosphorus source precursor is red phosphorus; the red phosphorus is at the inlet (upstream) of the carrier gas, and the reactant is at the gas outlet (downstream).

[0070] Figure 1 is a specific preparation process. The morphology of the obtained vanadium pentoxide / molybdenum disulfide layered heterojunction is characterized Figure 2 ), and it can be seen that the product is a two-dimensional sheet structure.

[0071] The obtained layered heterojunction (vanadium pentoxide / molybdenum trioxide layered heterojunction, vanadium nitride / molybdenum nitride layered heterojunction, vanadium disulfide / molybdenum disulfide layered heterojunction, vanadium pentoxide / molybdenum disulfide layered heterojunction, and vanadium phosphide / molybdenum phosphide layered heterojunction) is made into a working electrode according to the method provided by the present application and corresponding performance tests are carried out; the electrolyte is 3M zinc trifluoromethanesulfonate, and the charge / discharge current is 100mAg -1 The specific capacity is higher than 320mAh g -1 when charging / discharging; the capacity retention rate is greater than 78% after 2000 cycles when the charge / discharge current is 1000mAg -1 .

[0072] Example 2

[0073] In this example, the layered heterojunction is prepared by topological conversion reaction, and the steps are as follows:

[0074] (1) Vanadium pentoxide (0.05 mol / L) and molybdenum trioxide (0.05 mol / L) with layered crystal structure were added into 30 mL of water, a dopant boric acid was added, the molar ratio of boric acid to vanadium and manganese oxides was 0.3:1, and the mixture was stirred thoroughly, then 6 mL of 10% hydrogen peroxide aqueous solution was added, the mixture was stirred rapidly for 5 minutes, and the mixture was placed in a reaction kettle for hydrothermal reaction, the hydrothermal reaction temperature was 190°C, and the hydrothermal reaction time was 5 hours, and the total volume of the reactants and the solvent accounted for 85% of the volume of the reaction kettle during the hydrothermal reaction;

[0075] (2) The mixture was cooled to room temperature, and then the product was freeze-dried to obtain boron-doped interstitial vanadium pentoxide / molybdenum trioxide layered heterojunction with a two-dimensional structure;

[0076] (3) The boron-doped interstitial vanadium pentoxide / molybdenum trioxide layered heterojunction nanosheet obtained in step (2) was subjected to further nitrogenization treatment, sulfidation treatment, phosphidation treatment, and controllable oxidation to obtain layered heterojunctions with different components, as follows:

[0077] a. The boron-doped interstitial vanadium pentoxide / molybdenum trioxide layered heterojunction nanosheet obtained in step (2) was subjected to further nitrogenization treatment to obtain boron-doped interstitial vanadium nitride / molybdenum nitride layered heterojunction; the nitrogenization treatment temperature was 750°C, the reaction time was 2 hours, and the reaction atmosphere was ammonia / argon, wherein the volume fraction of ammonia was 5%;

[0078] b. The boron-doped interstitial vanadium pentoxide / molybdenum trioxide layered heterojunction nanosheet obtained in step (2) was subjected to further sulfidation treatment to obtain boron-doped interstitial vanadium disulfide / molybdenum disulfide layered heterojunction; the sulfidation treatment temperature was 400°C, the reaction time was 12 hours, and the reaction atmosphere was hydrogen sulfide / argon, wherein the volume fraction of hydrogen sulfide was 1%; the boron-doped interstitial vanadium disulfide / molybdenum disulfide layered heterojunction obtained was subjected to controllable oxidation treatment to obtain boron-doped interstitial vanadium pentoxide / molybdenum disulfide layered heterojunction; the controllable oxidation treatment temperature was 600°C, the reaction time was 1 hour, and the gas was argon / oxygen, wherein the volume fraction of oxygen was 0.2%;

[0079] c. The boron-doped interstitial vanadium pentoxide / molybdenum trioxide layered heterojunction nanosheet obtained in step (2) was subjected to further phosphidation treatment to obtain boron-doped interstitial vanadium phosphide / molybdenum phosphide layered heterojunction; the phosphidation treatment temperature was 600°C, the reaction time was 5 hours, and the phosphorus source precursor was triphenylphosphine, which was placed at the carrier gas inlet (upstream), and the reactant was placed at the gas outlet (downstream), and the carrier gas was argon.

[0080] Figure 2 is a specific preparation process. The morphology of the boron-doped interstitial vanadium pentoxide / molybdenum disulfide layered heterojunction obtained was characterized Figure 4), it can be seen that the product is a two-dimensional sheet structure.

[0081] The obtained layered heterojunction (interstitial boron-doped vanadium pentoxide / molybdenum trioxide, interstitial boron-doped vanadium nitride / molybdenum nitride layered heterojunction, interstitial boron-doped vanadium disulfide / molybdenum disulfide layered heterojunction, interstitial boron-doped vanadium pentoxide / molybdenum disulfide layered heterojunction, interstitial boron-doped vanadium phosphide / molybdenum phosphide layered heterojunction) is made into a working electrode according to the method provided by the present application and corresponding performance tests are carried out. The electrolyte is 3M zinc trifluoromethanesulfonate, and the charge and discharge current density is 100mAg-1. -1 The specific capacity is higher than 330mAh g-1 when charging and discharging. -1 The capacity retention rate is greater than 79% after 2000 cycles when charging and discharging at 1000mAg-1.

[0082] Example 3

[0083] In this embodiment, the layered heterojunction is prepared by topological conversion reaction, and the steps are as follows:

[0084] (1) δ-manganese dioxide (0.5 moles per liter) and molybdenum trioxide (0.5 moles per liter) with layered crystal structure are added to 30ml of water, and are fully stirred and mixed, and then 4.5ml of 5% mass fraction hydrogen peroxide aqueous solution is added, and is quickly stirred for 5 minutes, and is placed in a reaction kettle for hydrothermal reaction. The hydrothermal reaction temperature is 200℃, the hydrothermal reaction time is 1 hour, and the total volume of the reactants and the solvent in the hydrothermal reaction accounts for 70% of the volume of the reaction kettle.

[0085] (2) After cooling to room temperature, the product is freeze-dried, and δ-manganese dioxide / molybdenum trioxide layered heterojunction with two-dimensional structure is obtained after drying;

[0086] (3) The δ-manganese dioxide / molybdenum trioxide layered heterojunction obtained in step (2) is further treated by nitrogenization, sulfurization, phosphorization and controllable oxidation to obtain layered heterojunctions with different components, as follows:

[0087] a. The δ-manganese dioxide / molybdenum trioxide layered heterojunction obtained in step (2) is further treated by nitrogenization to obtain manganese nitride / molybdenum nitride layered heterojunction. The nitrogenization treatment temperature is 500℃, the reaction time is 12 hours, and the reaction atmosphere is ammonia gas / argon gas, wherein the volume ratio of ammonia gas is 10%;

[0088] b. The δ-manganese dioxide / molybdenum trioxide layered heterojunction nanosheet obtained in step (2) is subjected to further sulfidation treatment to obtain a manganese sulfide / molybdenum disulfide layered heterojunction; the temperature of the sulfidation treatment is 900°C, the reaction time is 2 hours, and the reaction atmosphere is hydrogen sulfide / argon, wherein the volume ratio of hydrogen sulfide is 1%; the obtained manganese sulfide / molybdenum disulfide layered heterojunction is subjected to controllable oxidation treatment to obtain a δ-manganese dioxide / molybdenum disulfide layered heterojunction; the temperature of the controllable oxidation treatment is 450°C, the reaction time is 3 hours, and the gas is argon / oxygen, wherein the volume fraction of oxygen is 0.01%;

[0089] c. The δ-manganese dioxide / molybdenum trioxide layered heterojunction nanosheet obtained in step (2) is subjected to further phosphidation treatment to obtain a manganese phosphide / molybdenum phosphide layered heterojunction; the temperature of the phosphidation treatment is 850°C, the reaction time is 12 hours, and the phosphorus source precursor is red phosphorus; the red phosphorus is placed at the inlet of the carrier gas (upstream), and the reactant is placed at the gas outlet (downstream); the carrier gas is argon.

[0090] Figure 5 is a specific preparation process. The morphology of the obtained δ-manganese dioxide / molybdenum disulfide layered heterojunction is characterized Figure 6 ), and it can be seen that the product is a two-dimensional sheet structure.

[0091] The obtained layered heterojunction (δ-manganese dioxide / molybdenum trioxide layered heterojunction, manganese nitride / molybdenum nitride layered heterojunction, manganese sulfide / molybdenum disulfide layered heterojunction, δ-manganese dioxide / molybdenum disulfide layered heterojunction, manganese phosphide / molybdenum phosphide layered heterojunction) is made into a working electrode according to the method provided by the present application and corresponding performance tests are carried out; the electrolyte is 3M zinc trifluoromethanesulfonate, and the specific capacity is measured at 100mAg -1 , 500mAg -1 , and 1000mAg -1 .

[0092] Example 4

[0093] In this example, the layered heterojunction is prepared by topological conversion reaction, and the steps are as follows:

[0094] (1) δ-manganese dioxide with layered crystal structure (0.2 mol / L) and molybdenum trioxide (0.3 mol / L) were added into 30 mL water, and a doping agent boric acid was added, the molar ratio of boric acid to manganese oxide was 0.1:1, and the molar ratio of boric acid to molybdenum oxide was 0.3:1, and the mixture was stirred well, and then 5.4 mL of 30% hydrogen peroxide aqueous solution was added, and stirred rapidly for 5 minutes, and then placed in a reaction kettle for hydrothermal reaction, the temperature of the hydrothermal reaction was 120°C, and the hydrothermal reaction time was 36 hours, and the total volume of the reactants and the solvent in the hydrothermal reaction accounted for 90% of the volume of the reaction kettle;

[0095] (2) cooled to room temperature, and then the product was freeze-dried, and the dried product was interstitial boron-doped δ-manganese dioxide / molybdenum trioxide layered heterojunction with two-dimensional structure;

[0096] (3) The interstitial boron-doped δ-manganese dioxide / molybdenum trioxide layered heterojunction obtained in step (2) was subjected to further nitrogenization treatment, sulfidation treatment, phosphorization treatment and controllable oxidation to obtain layered heterojunctions with different components, as follows:

[0097] a. The interstitial boron-doped δ-manganese dioxide / molybdenum trioxide layered heterojunction obtained in step (2) was subjected to further nitrogenization treatment to obtain an interstitial boron-doped manganese nitride / molybdenum nitride layered heterojunction; the nitrogenization treatment temperature was 550°C, the reaction time was 3 hours, and the reaction atmosphere was ammonia / argon, wherein the volume fraction of ammonia was 5%;

[0098] b. The interstitial boron-doped δ-manganese dioxide / molybdenum trioxide layered heterojunction obtained in step (2) was subjected to further sulfidation treatment to obtain an interstitial boron-doped manganese sulfide / molybdenum disulfide layered heterojunction; the sulfidation treatment temperature was 650°C, the reaction time was 5 hours, and the reaction atmosphere was hydrogen sulfide / argon, wherein the volume fraction of hydrogen sulfide was 5%; the obtained interstitial boron-doped manganese sulfide / molybdenum disulfide layered heterojunction was subjected to controllable oxidation treatment to obtain an interstitial boron-doped δ-manganese dioxide / molybdenum disulfide layered heterojunction; the controllable oxidation treatment temperature was 580°C, the reaction time was 4 hours, and the gas was argon / oxygen, wherein the volume fraction of oxygen was 0.02%;

[0099] c. The interstitial boron-doped δ-manganese dioxide / molybdenum trioxide layered heterojunction obtained in step (2) was subjected to further phosphorization treatment to obtain an interstitial boron-doped manganese phosphide / molybdenum phosphide layered heterojunction; the phosphorization treatment temperature was 650°C, the reaction time was 6 hours, and the phosphorus source precursor was triphenylphosphine, which was placed at the inlet (upstream) of the carrier gas, and the reactant was placed at the gas outlet (downstream), and the carrier gas was argon.

[0100] Figure 7is a specific preparation process. The morphology of the obtained interstitial boron-doped δ-manganese dioxide / molybdenum disulfide layered heterojunction is characterized Figure 8 , and it can be seen that the product is a two-dimensional sheet structure.

[0101] The obtained layered heterojunction (interstitial boron-doped δ-manganese dioxide / molybdenum trioxide layered heterojunction, interstitial boron-doped manganese nitride / molybdenum nitride layered heterojunction, interstitial boron-doped manganese sulfide / molybdenum disulfide layered heterojunction, interstitial boron-doped δ-manganese dioxide / molybdenum disulfide layered heterojunction, interstitial boron-doped manganese phosphide / molybdenum phosphide layered heterojunction) is made into a working electrode according to the method provided by the present application and corresponding performance tests are carried out. The electrolyte is 3M zinc trifluoromethanesulfonate, and the specific capacity is 325mAh g -1 or more at 100mAg -1 or more at 1000mAg -1 and the capacity retention rate is greater than 81% after 2000 cycles.

[0102] Example 5

[0103] In this embodiment, the layered heterojunction is prepared by topological conversion reaction, and the steps are as follows:

[0104] (1) δ-manganese dioxide (0.25 moles per liter) and vanadium pentoxide (0.35 moles per liter) with layered crystal structure are added to 30 milliliters of water, and are thoroughly stirred and mixed, and then 6 milliliters of 20% mass fraction hydrogen peroxide aqueous solution is added, and is quickly stirred for 5 minutes, and is placed in a reaction kettle for hydrothermal reaction, and the hydrothermal reaction temperature is 150℃, and the hydrothermal reaction time is 24 hours, and the total volume of the reactants and the solvent in the hydrothermal reaction accounts for 75% of the volume of the reaction kettle;

[0105] (2) After cooling to room temperature, the product is freeze-dried, and after drying, δ-manganese dioxide / vanadium pentoxide layered heterojunction with two-dimensional structure is obtained;

[0106] (3) The δ-manganese dioxide / vanadium pentoxide layered heterojunction obtained in step (2) is further treated by nitridation, sulfidation and phosphidation to obtain layered heterojunctions with different components, as follows:

[0107] a. The δ-manganese dioxide / vanadium pentoxide layered heterojunction obtained in step (2) is further treated by nitridation to obtain manganese nitride / vanadium nitride layered heterojunction; the nitridation temperature is 750℃, the reaction time is 8 hours, and the reaction atmosphere is ammonia / argon, wherein the volume fraction of ammonia is 8%;

[0108] b. The δ-manganese dioxide / vanadium pentoxide layered heterostructure nanosheets obtained in step (2) are further subjected to sulfidation treatment to obtain manganese sulfide / vanadium disulfide layered heterostructures; the sulfidation treatment temperature is 680℃, the reaction time is 7 hours, the reaction atmosphere is hydrogen sulfide / argon, and the volume percentage of hydrogen sulfide is 5%.

[0109] c. Further phosphating treatment is applied to the δ-manganese dioxide / vanadium pentoxide layered heterostructure nanosheets obtained in step (2) to obtain manganese phosphide / vanadium phosphide layered heterostructures; the phosphating treatment temperature is 620℃, the reaction time is 3 hours, the phosphorus source precursor is triphenylphosphine, the triphenylphosphine is placed in the carrier gas inlet (upstream), the reactant is placed in the gas outlet (downstream), and the carrier gas is argon.

[0110] Figure 9 This describes the specific preparation process. The morphology of the obtained manganese sulfide / vanadium disulfide layered heterostructure was characterized. Figure 10 As can be seen, the product has a two-dimensional sheet-like structure.

[0111] The obtained layered heterojunctions (δ-manganese dioxide / vanadium pentoxide layered heterojunction, manganese nitride / vanadium nitride layered heterojunction, manganese sulfide / vanadium disulfide layered heterojunction, manganese phosphide / vanadium phosphide layered heterojunction) were fabricated into working electrodes according to the method provided in this invention and their performance was tested accordingly. The electrolyte was 3M zinc trifluoromethanesulfonate, at 100 mAg. -1 During charging and discharging, the specific capacity is higher than 327mAh g. -1 At 1000mAg -1 After 2000 charge-discharge cycles, the capacity retention rate is greater than 82%.

[0112] Example 6

[0113] This embodiment employs a topological transformation reaction to prepare layered heterostructures, and the steps are as follows:

[0114] (1) Add δ-manganese dioxide (0.1 mol per liter) and vanadium pentoxide (0.1 mol per liter) with layered crystal structure to 30 ml of water, add boric acid as a dopant, the molar ratio of boric acid to vanadium and manganese oxide is 0.2:1, stir and mix thoroughly, then add 6 ml of 15% hydrogen peroxide aqueous solution, stir rapidly for 5 minutes, place in a reaction vessel for hydrothermal reaction, the temperature of hydrothermal reaction is 140℃, the hydrothermal reaction time is 8 hours, and the total volume of reactants and solvent in hydrothermal reaction accounts for 80% of the volume of reaction vessel;

[0115] (2) Cool to room temperature and then freeze-dry the product to obtain a two-dimensional interstitial boron-doped δ-manganese dioxide / vanadium pentoxide layered heterojunction.

[0116] (3) The interstitial boron-doped δ-manganese dioxide / vanadium pentoxide layered heterojunction obtained in step (2) is subjected to further nitridation treatment, sulfidation treatment, phosphorization treatment to obtain layered heterojunctions with different components, as follows:

[0117] a. The interstitial boron-doped δ-manganese dioxide / vanadium pentoxide layered heterojunction obtained in step (2) is subjected to further nitridation treatment to obtain an interstitial boron-doped manganese nitride / vanadium nitride layered heterojunction; the temperature of the nitridation treatment is 680°C, the reaction time is 3 hours, and the reaction atmosphere is ammonia / argon, wherein the volume ratio of ammonia is 2%;

[0118] b. The interstitial boron-doped δ-manganese dioxide / vanadium pentoxide layered heterojunction nanosheet obtained in step (2) is subjected to further sulfidation treatment to obtain an interstitial boron-doped manganese sulfide / vanadium disulfide layered heterojunction; the temperature of the sulfidation treatment is 750°C, the reaction time is 5 hours, and the reaction atmosphere is hydrogen sulfide / argon, wherein the volume ratio of hydrogen sulfide is 2%;

[0119] c. The interstitial boron-doped δ-manganese dioxide / vanadium pentoxide layered heterojunction nanosheet obtained in step (2) is subjected to further phosphorization treatment to obtain an interstitial boron-doped manganese phosphide / vanadium phosphide layered heterojunction; the temperature of the phosphorization treatment is 700°C, the reaction time is 5 hours, and the phosphorus source precursor is triphenylphosphine; triphenylphosphine is placed at the inlet (upstream) of the carrier gas, and the reactant is placed at the gas outlet (downstream); the carrier gas is argon.

[0120] Figure 11 is a specific preparation process. The obtained layered heterojunctions (interstitial boron-doped δ-manganese dioxide / vanadium pentoxide layered heterojunction, interstitial boron-doped manganese nitride / vanadium nitride layered heterojunction, interstitial boron-doped manganese sulfide / vanadium disulfide layered heterojunction, and interstitial boron-doped manganese phosphide / vanadium phosphide layered heterojunction) are made into working electrodes according to the method provided in the present application and subjected to corresponding performance tests; the electrolyte is a 2M zinc sulfate aqueous solution, and the specific capacitance is measured at 100 mAg -1 The specific capacitance is higher than 324 mAh g -1 at 1000 mAg -1 The capacity retention rate is greater than 79% after 2000 cycles of charge and discharge.

[0121] Example 7

[0122] In this example, the layered heterojunction is prepared by topological conversion reaction, and the steps are as follows:

[0123] (1) Vanadium pentoxide (0.1 mole per liter) and molybdenum trioxide (0.2 mole per liter) with layered crystal structure were added into 30 ml of water respectively, and mixed well by stirring, and then 3 ml of 30% mass fraction hydrogen peroxide solution was added respectively, and stirred rapidly for 5 minutes, and then placed in a reaction kettle for hydrothermal reaction, the temperature of the hydrothermal reaction was 180℃, and the hydrothermal reaction time was 10 hours, and the total volume of the reactants and solvent in the hydrothermal reaction accounted for 75% of the volume of the reaction kettle;

[0124] (2) cooled to room temperature, and then the product was freeze-dried, and the dried product was vanadium pentoxide nanosheet and molybdenum trioxide nanosheet with two-dimensional structure;

[0125] (3) the surface charge of the vanadium pentoxide nanosheet was modified by using a polymer surface charge modifier with a charged functional group, the polymer surface charge modifier with a charged functional group was polyethyleneimine (weight average molecular weight 7.5 x 10 5 ), and the ratio of the charge carried by the added surface charge modifier (based on the number of moles of polymer repeating units) to the charge possessed by the vanadium pentoxide nanosheet (based on the number of moles of vanadium element) was 0.8:1, 5 mg / ml of polyethyleneimine solution was first prepared, and then 1 mg / ml of vanadium pentoxide nanosheet dispersion was added to the polyethyleneimine solution at a rate of 200 μl per second while stirring, and the mixture was uniformly stirred at room temperature for 12 hours, and then centrifuged and dried at 60℃ to obtain polyethyleneimine modified vanadium pentoxide, and then the polyethyleneimine modified vanadium pentoxide was prepared into a 1 mg / ml suspension, and 1 mg / ml of molybdenum trioxide suspension was added to the obtained modified vanadium pentoxide suspension at a rate of 500 μl per second while stirring, so as to perform electrostatic self-assembly of two different charged components, the molar ratio of the vanadium pentoxide and molybdenum trioxide nanosheets with opposite charges in the electrostatic self-assembly was 1:1, and the mixture was uniformly stirred at room temperature for 8 hours to obtain a vanadium pentoxide / polymer / molybdenum trioxide layered heterojunction;

[0126] (4) the vanadium pentoxide / polymer / molybdenum trioxide layered heterojunction obtained in step (3) was subjected to further nitridation treatment, sulfidation treatment, and phosphorization treatment to obtain layered heterojunctions with different components, as follows:

[0127] a. the vanadium pentoxide / polymer / molybdenum trioxide layered heterojunction obtained in step (3) was subjected to further nitridation treatment to obtain a vanadium nitride / nitrogen-doped carbon / molybdenum nitride layered heterojunction, the temperature of the nitridation treatment was 650℃, the reaction time was 10 hours, and the reaction atmosphere was ammonia / argon, wherein the volume fraction of ammonia was 10%;

[0128] b. The vanadium pentoxide / polymer / molybdenum trioxide layered heterojunction obtained in step (3) is subjected to further sulfurization treatment to obtain a vanadium disulfide / sulfur-doped carbon / molybdenum disulfide layered heterojunction; the temperature of the sulfurization treatment is 690°C, the reaction time is 6 hours, and the reaction atmosphere is hydrogen sulfide / argon, wherein the volume ratio of hydrogen sulfide is 5%;

[0129] c. The vanadium pentoxide / polymer / molybdenum trioxide layered heterojunction obtained in step (2) is subjected to further phosphorization treatment to obtain a vanadium phosphide / phosphorus-doped carbon / molybdenum phosphide layered heterojunction; the temperature of the phosphorization treatment is 650°C, the reaction time is 2 hours, the phosphorus source precursor is triphenylphosphine, the triphenylphosphine is placed at the carrier gas inlet (upstream), the reactant is placed at the gas outlet (downstream), and the carrier gas is argon.

[0130] Figure 12 is a specific preparation process. The obtained layered heterojunction (vanadium pentoxide / polymer / molybdenum trioxide layered heterojunction, vanadium nitride / nitrogen-doped carbon / molybdenum nitride layered heterojunction, vanadium disulfide / sulfur-doped carbon / molybdenum disulfide layered heterojunction, vanadium phosphide / phosphorus-doped carbon / molybdenum phosphide layered heterojunction) is made into a working electrode according to the method provided in the present application and corresponding performance tests are carried out, the electrolyte is a 2M zinc sulfate aqueous solution, and the specific capacity is measured at 100 mAg -1 The specific capacity is higher than 331 mAh g -1 when charging and discharging; the capacity retention rate is greater than 85% after 2000 cycles at 1000 mAg -1 .

[0131] Example 8

[0132] In this example, the layered heterojunction is prepared by a topological conversion reaction, and the steps are as follows:

[0133] (1) δ-manganese dioxide (0.2 moles per liter) and molybdenum trioxide (0.3 moles per liter) with a layered crystal structure are respectively added to 30 milliliters of water, thoroughly stirred and mixed, and then 6 milliliters of a 10% mass fraction hydrogen peroxide aqueous solution is added, rapidly stirred for 5 minutes, and then placed in a reaction kettle for hydrothermal reaction, wherein the hydrothermal reaction temperature is 180°C, the hydrothermal reaction time is 24 hours, and the total volume of the reactants and the solvent in the hydrothermal reaction accounts for 85% of the volume of the reaction kettle;

[0134] (2) After cooling to room temperature, the product is freeze-dried, and after drying, δ-manganese dioxide and molybdenum trioxide nanosheets with a two-dimensional structure are obtained;

[0135] (3) Then, the δ-manganese dioxide nanosheet surface is modified by using a polymer surface charge modifier with a charged functional group, and the polymer surface charge modifier with a charged functional group is poly(diallyldimethylammonium chloride) (weight average molecular weight is 2 x 105 ), and the ratio of the charge carried by the added surface charge modifier (based on the number of moles of polymer repeating units) to the charge possessed by the δ-manganese dioxide nanosheet (based on the number of moles of manganese element) is 0.8:1, 8 milligrams per milliliter of poly(diallyldimethylammonium chloride) solution is first configured, and then 0.5 milligrams per milliliter of δ-manganese dioxide nanosheet dispersion is added to the poly(diallyldimethylammonium chloride) solution at a rate of 200 microliters per second while stirring, and uniform stirring is performed at room temperature for 12 hours, and δ-manganese dioxide nanosheet modified with poly(diallyldimethylammonium chloride) is obtained after centrifugation and drying at 60°C, and then the δ-manganese dioxide modified with poly(diallyldimethylammonium chloride) is configured into a 0.5 milligrams per milliliter suspension, and then 0.5 milligrams per milliliter of molybdenum trioxide suspension is added to the obtained modified δ-manganese dioxide suspension at a rate of 500 microliters per second while stirring, and electrostatic self-assembly of δ-manganese dioxide and molybdenum trioxide nanosheets with opposite charges is performed at a molar ratio of 0.5:1, and then uniform stirring is performed at room temperature for 6 hours to obtain a δ-manganese dioxide / polymer / molybdenum trioxide layered heterojunction;

[0136] (4) The δ-manganese dioxide / polymer / molybdenum trioxide layered heterojunction obtained in step (3) is subjected to further nitridation treatment, sulfidation treatment, and phosphorization treatment to obtain layered heterojunctions with different components, as follows:

[0137] a. The δ-manganese dioxide / polymer / molybdenum trioxide layered heterojunction obtained in step (3) is subjected to further nitridation treatment to obtain a manganese nitride / nitrogen-doped carbon / molybdenum nitride layered heterojunction; the temperature of the nitridation treatment is 650°C, the reaction time is 10 hours, and the reaction atmosphere is ammonia / argon, with the volume fraction of ammonia being 6%;

[0138] b. The δ-manganese dioxide / polymer / molybdenum trioxide layered heterojunction obtained in step (3) is subjected to further sulfidation treatment to obtain a manganese nitride / sulfur-doped carbon / molybdenum disulfide layered heterojunction; the temperature of the sulfidation treatment is 700°C, the reaction time is 5 hours, and the reaction atmosphere is hydrogen sulfide / argon, with the volume fraction of hydrogen sulfide being 5%;

[0139] c. The δ-manganese dioxide / polymer / molybdenum trioxide layered heterojunction obtained in step (2) is subjected to further phosphorization treatment to obtain a manganese phosphide / phosphorus-doped carbon / molybdenum phosphide layered heterojunction; the temperature of the phosphorization treatment is 650°C, the reaction time is 3 hours, and the phosphorus source precursor is triphenylphosphine, which is placed at the inlet (upstream) of the carrier gas, and the reactant is placed at the gas outlet (downstream), and the carrier gas is argon.

[0140] Figure 13is a specific preparation process. The obtained layered heterojunction (δ-manganese dioxide / polymer / molybdenum trioxide layered heterojunction, manganese nitride / nitrogen-doped carbon / molybdenum nitride layered heterojunction, manganese sulfide / sulfur-doped carbon / molybdenum disulfide layered heterojunction, manganese phosphide / phosphorus-doped carbon / molybdenum phosphide layered heterojunction) is made into a working electrode according to the method provided by the present application and corresponding performance tests are carried out. The electrolyte is a 2M zinc sulfate aqueous solution, and the specific capacity is 335mAh g -1 at 100mAg -1 at 1000mAg -1 The capacity retention rate is greater than 82% after 2000 cycles of charging and discharging.

[0141] Example 9

[0142] In this embodiment, the layered heterojunction is prepared by a topological conversion reaction, and the steps are as follows:

[0143] (1) δ-manganese dioxide (0.15 moles per liter) and vanadium pentoxide (0.25 moles per liter) with a layered crystal structure are respectively added to 30 milliliters of water, and are fully stirred and mixed, then 3 milliliters of 10% mass fraction hydrogen peroxide solution is respectively added and stirred quickly for 5 minutes, and is respectively placed in a reaction kettle for hydrothermal reaction. The hydrothermal reaction temperature is 190°C, the hydrothermal reaction time is 10 hours, and the total volume of the reactants and the solvent in the hydrothermal reaction accounts for 75% of the volume of the reaction kettle.

[0144] (2) After cooling to room temperature, the product is freeze-dried, and after drying, δ-manganese dioxide and vanadium pentoxide nanosheets with a two-dimensional structure are obtained;

[0145] (3) Then, a polymer is used to modify the surface charge of the δ-manganese dioxide nanosheets. The polymer surface charge modifier with a charged functional group is polyethyleneimine (weight average molecular weight of 7.5×10 5) and the ratio of the charge carried by the added surface modifier (based on the number of moles of polymer repeating units) to the charge possessed by the oxide nanosheet (based on the number of moles of manganese element) is 0.9:1, 10 milligrams per milliliter of polyethyleneimine solution is first configured, and then 0.5 milligrams per milliliter of manganese dioxide nanosheet dispersion solution is added to the polyethyleneimine solution at a rate of 200 microliters per second while stirring, and the solution is uniformly stirred at room temperature for 12 hours, and after centrifugation and drying at 60°C, polyethyleneimine modified manganese dioxide nanosheets are obtained, and then the manganese dioxide with polyethyleneimine modification is configured into a 2 milligrams per milliliter suspension, and then 2 milligrams per milliliter of vanadium pentoxide suspension is added to the obtained modified manganese dioxide suspension while stirring at a rate of 500 microliters per second, and the molar ratio of the electrostatically self-assembled manganese dioxide and vanadium pentoxide nanosheets with opposite charges is 0.8:1, so that the electrostatic self-assembly of the two charged components in the solution is carried out, and then the solution is uniformly stirred at room temperature for 10 hours to obtain a manganese dioxide / polymer / vanadium pentoxide layered heterojunction;

[0146] (4) Further nitrogenization treatment, sulfurization treatment, and phosphorization treatment can be performed on the manganese dioxide / polymer / vanadium pentoxide layered heterojunction obtained in step (3) to obtain layered heterojunctions with different components, as follows:

[0147] a. Further nitrogenization treatment is performed on the manganese dioxide / polymer / vanadium pentoxide layered heterojunction obtained in step (3) to obtain a manganese nitride / nitrogen-doped carbon / vanadium nitride layered heterojunction; the nitrogenization treatment temperature is 720°C, the reaction time is 12 hours, and the reaction atmosphere is ammonia / argon, with the volume ratio of ammonia being 8%;

[0148] b. Further sulfurization treatment is performed on the manganese dioxide / polymer / vanadium pentoxide layered heterojunction obtained in step (3) to obtain a manganese nitride / sulfur-doped carbon / vanadium disulfide layered heterojunction; the sulfurization treatment temperature is 690°C, the reaction time is 9 hours, and the reaction atmosphere is hydrogen sulfide / argon, with the volume ratio of hydrogen sulfide being 5%;

[0149] c. Further phosphorization treatment is performed on the manganese dioxide / polymer / vanadium pentoxide layered heterojunction obtained in step (2) to obtain a manganese phosphide / phosphorus-doped carbon / vanadium phosphide layered heterojunction; the phosphorization treatment temperature is 660°C, the reaction time is 3 hours, the phosphorus source precursor is triphenylphosphine, triphenylphosphine is placed at the carrier gas inlet (upstream), the reactant is placed at the gas outlet (downstream), and the carrier gas is argon.

[0150] Figure 14is a specific preparation process. The obtained layered heterojunctions (δ-manganese dioxide / polymer / vanadium pentoxide layered heterojunction, manganese nitride / nitrogen-doped carbon / vanadium nitride layered heterojunction, manganese sulfide / sulfur-doped carbon / vanadium disulfide layered heterojunction, and manganese phosphide / phosphorus-doped carbon / vanadium phosphide layered heterojunction) are made into working electrodes according to the method provided in the present application and corresponding performance tests are carried out. The electrolyte is a 2M zinc sulfate aqueous solution, and the specific capacity is 336mAh g -1 The specific capacity is higher than 336mAh g -1 when charging and discharging. -1 The capacity retention rate is greater than 84% after 2000 cycles when charging and discharging.

[0151] Example 10

[0152] In this embodiment, the layered heterojunction is prepared by a topological transformation reaction, and the steps are as follows:

[0153] (1) δ-manganese dioxide (0.15 moles per liter) and vanadium pentoxide (0.15 moles per liter) with a layered crystal structure are respectively added to 30 milliliters of water, fully stirred and mixed, then 4.5 milliliters of 30% mass fraction hydrogen peroxide aqueous solution is added, and stirred quickly for 5 minutes. Then, they are respectively placed in a reaction kettle for hydrothermal reaction, and the hydrothermal reaction temperature is 160℃, the hydrothermal reaction time is 24 hours, and the total volume of the reactants and the solvent in the hydrothermal reaction accounts for 85% of the volume of the reaction kettle.

[0154] (2) After cooling to room temperature, the product is freeze-dried, and after drying, δ-manganese dioxide and vanadium pentoxide nanosheets with a two-dimensional structure are obtained;

[0155] (3) The surface charge of the δ-manganese dioxide nanosheet is modified by using a polymer surface charge modifier with a charged functional group. The polymer surface charge modifier with a charged functional group is poly(diallyldimethylammonium chloride) (weight average molecular weight of 2×10 5) and the ratio of the charge of the added surface modifier (based on the number of moles of polymer repeating units) to the charge of the oxide nanosheet (based on the number of moles of manganese element) is 1:1, 6 milligrams per milliliter of poly(diallyldimethylammonium chloride) solution is first configured, and then 0.2 milligrams per milliliter of manganese dioxide nanosheet dispersion solution is added to the poly(diallyldimethylammonium chloride) solution at a rate of 200 microliters per second while stirring, and the solution is uniformly stirred at room temperature for 12 hours, and after drying at 60°C by centrifugation, poly(diallyldimethylammonium chloride)-modified manganese dioxide nanosheets are obtained, and then the manganese dioxide with poly(diallyldimethylammonium chloride) modification is configured into a 1 milligram per milliliter suspension, and then 1 milligram per milliliter of vanadium pentoxide suspension is added to the obtained modified manganese dioxide suspension while stirring at a rate of 200 microliters per second, so that the solution is subjected to electrostatic self-assembly of different charged components, and the molar ratio of the oppositely charged manganese dioxide and vanadium pentoxide nanosheets in the electrostatic self-assembly is 1:1, and then the solution is uniformly stirred at room temperature for 12 hours to obtain a manganese dioxide / polymer / vanadium pentoxide layered heterojunction;

[0156] (4) The manganese dioxide / polymer / vanadium pentoxide layered heterojunction obtained in step (3) is subjected to further nitridation treatment, sulfidation treatment, and phosphorization treatment to obtain layered heterojunctions with different components, as follows:

[0157] a. The manganese dioxide / polymer / vanadium pentoxide layered heterojunction obtained in step (3) is subjected to further nitridation treatment to obtain a manganese nitride / nitrogen-doped carbon / vanadium nitride layered heterojunction; the temperature of the nitridation treatment is 750°C, the reaction time is 12 hours, and the reaction atmosphere is ammonia / argon, with the volume ratio of ammonia being 8%;

[0158] b. The manganese dioxide / polymer / vanadium pentoxide layered heterojunction obtained in step (3) is subjected to further sulfidation treatment to obtain a manganese nitride / sulfur-doped carbon / vanadium disulfide layered heterojunction; the temperature of the sulfidation treatment is 700°C, the reaction time is 9 hours, and the reaction atmosphere is hydrogen sulfide / argon, with the volume ratio of hydrogen sulfide being 5%;

[0159] c. The manganese dioxide / polymer / vanadium pentoxide layered heterojunction obtained in step (2) is subjected to further phosphorization treatment to obtain a manganese phosphide / phosphorus-doped carbon / vanadium phosphide layered heterojunction; the temperature of the phosphorization treatment is 600°C, the reaction time is 5 hours, and the phosphorus source precursor is triphenylphosphine, which is placed at the inlet (upstream) of the carrier gas, and the reactant is placed at the gas outlet (downstream), and the carrier gas is argon.

[0160] The obtained layered heterojunctions (delta-manganese dioxide / polymer / vanadium pentoxide layered heterojunction, manganese nitride / nitrogen-doped carbon / vanadium nitride layered heterojunction, manganese sulfide / sulfur-doped carbon / vanadium disulfide layered heterojunction and manganese phosphide / phosphorus-doped carbon / vanadium phosphide layered heterojunction) are made into working electrodes according to the method provided in the application and corresponding performance tests are carried out, the electrolyte is 2M zinc sulfate aqueous solution, and the specific capacity is 335mAh g -1 The specific capacity is higher than 335mAh g -1 when charging and discharging; the capacity retention rate is greater than 85% after 2000 cycles at 1000mAg -1 when charging and discharging.

[0161] The application can realize controllable preparation of various layered heterojunctions, directly uses water and gaseous substances as reaction medium, uses hydrogen peroxide as expansion exfoliation agent, realizes controllable synthesis of various layered heterojunctions by means of topological transformation reaction, and provides a heterojunction material with expected layered structure, greatly increases the types of layered heterojunctions that can be prepared, and further realizes controllable synthesis of various layered heterojunctions. The obtained layered heterojunctions can be used for zinc ion battery positive electrode materials. This has very important significance for promoting synthesis of new functional layered heterojunctions and development of high-performance zinc ion batteries.

[0162] The above is only the preferred embodiment of the application and is not used to limit the application. The application can have various changes and variations for those skilled in the art. Any modification, equivalent replacement, improvement, etc. within the spirit and principle of the application should be included in the protection scope of the application.

Claims

1. A method of topotactic conversion to prepare a layered heterojunction, characterized by: The application relates to a method for preparing a layered heterojunction with a two-dimensional structure, which comprises the following steps: (A) adding a precursor into water, adding a dopant boric acid, fully stirring and mixing, then adding a hydrogen peroxide solution, quickly stirring, and then placing into a reaction kettle for hydrothermal reaction; the precursor is any two of vanadium pentoxide, molybdenum trioxide and manganese dioxide with a layered crystal structure; (B) cooling to room temperature after the hydrothermal reaction, and then performing freeze drying on the obtained product to obtain a layered heterojunction with a two-dimensional structure; (C) performing further nitrogenization treatment, phosphorization treatment or sulfurization treatment on the layered heterojunction obtained in step (B), and then performing controllable oxidation treatment to obtain a layered heterojunction with different components. The adding amount of the precursor in step (A) is 0.01-0.5 moles per liter; the mass fraction of the hydrogen peroxide solution used is 5%-30%, the adding amount of the hydrogen peroxide solution is 10%-20% of the volume of the solvent water, the molar ratio of the boric acid to the precursor in step (A) is (0.0-0.5):1; the hydrothermal reaction temperature is 120 DEG C-200 DEG C, the hydrothermal reaction time is 1-36 hours, and the total volume of the reactants and the solvent accounts for 70%-90% of the volume of the reaction kettle. The nitrogenization treatment temperature in step (C) is 500 DEG C-800 DEG C, the reaction time is 1-12 hours, and the reaction atmosphere is ammonia / argon, wherein the volume ratio of ammonia is 1%-10%; the sulfurization treatment temperature is 400 DEG C-900 DEG C, the reaction time is 2-12 hours, and the reaction atmosphere is hydrogen sulfide / argon, wherein the volume ratio of hydrogen sulfide is 1%-5%; the phosphorization treatment temperature is 600 DEG C-900 DEG C, the reaction time is 5-12 hours, the phosphor source precursor is one of red phosphorus or triphenylphosphine, the red phosphorus or triphenylphosphine is placed at the inlet of the carrier gas, the reactants are placed at the gas outlet, and the carrier gas is argon; the controllable oxidation treatment temperature is 300 DEG C-600 DEG C, the reaction time is 1-8 hours, and the gas is argon / oxygen, wherein the volume fraction of oxygen is 0.01%-0.2%. The application also relates to a method for preparing a layered heterojunction with a two-dimensional structure, which comprises the following steps: (A) adding a precursor into water, adding a dopant boric acid, fully stirring and mixing, then adding a hydrogen peroxide solution, quickly stirring, and then placing into a reaction kettle for hydrothermal reaction; the precursor is any two of vanadium pentoxide, molybdenum trioxide and manganese dioxide with a layered crystal structure; (B) cooling to room temperature after the hydrothermal reaction, and then performing freeze drying on the obtained product to obtain a layered heterojunction with a two-dimensional structure; (C) performing further nitrogenization treatment, phosphorization treatment or sulfurization treatment on the layered heterojunction obtained in step (B), and then performing controllable oxidation treatment to obtain a layered heterojunction with different components. ​ ​ 2. A method of topotactic conversion to prepare a layered heterojunction, characterized by: ​ (I) adding vanadium pentoxide, molybdenum trioxide and manganese dioxide with layered crystal structure into water respectively, then adding hydrogen peroxide solution, stirring rapidly and placing in a reaction kettle for hydrothermal reaction; (II) cooling to room temperature after the hydrothermal reaction, and freezing drying the obtained product to obtain layered vanadium pentoxide nanosheet, layered molybdenum trioxide nanosheet and layered δ-manganese dioxide nanosheet; (III) using a polymer surface charge modifier with charged functional groups to modify the surface charge of vanadium pentoxide or δ-manganese dioxide nanosheet, and then electrostatic self-assembling two kinds of oxide nanosheets with opposite charges in solution to obtain a layered heterojunction, the two kinds of oxide nanosheets with opposite charges are: vanadium pentoxide nanosheet modified by surface charge and molybdenum trioxide nanosheet without surface charge modification, δ-manganese dioxide nanosheet modified by surface charge and molybdenum trioxide nanosheet without surface charge modification, or δ-manganese dioxide nanosheet modified by surface charge and vanadium pentoxide nanosheet without surface charge modification; (IV) using further nitrogenization treatment, sulfidation treatment and phosphorization treatment on the layered heterojunction obtained in step (III) to obtain layered heterojunctions with different components; in step (I), vanadium pentoxide, molybdenum trioxide and manganese dioxide with layered crystal structure are added into water in a dosage of 0.01-0.5 mol / L; the mass fraction of hydrogen peroxide solution used is 5%-30%, and the dosage of hydrogen peroxide is 10-20% of the volume of solvent water; the temperature of hydrothermal reaction is 120-200 ℃, the hydrothermal reaction time is 1-36 hours, and the total volume of reactants and solvent accounts for 70%-90% of the volume of the reaction kettle; in step (III), the polymer surface charge modifier with charged functional groups is one of polyethyleneimine and poly(diallyldimethylammonium chloride); in step (IV), the temperature of nitrogenization treatment is 500-800 ℃, the reaction time is 1-12 hours, and the reaction atmosphere is ammonia / argon, wherein the volume ratio of ammonia is 1%-10%; the temperature of sulfidation treatment is 400-900 ℃, the reaction time is 2-12 hours, and the reaction atmosphere is hydrogen sulfide / argon, wherein the volume ratio of hydrogen sulfide is 1%-5%; the temperature of phosphorization treatment is 600-900 ℃, the reaction time is 5-12 hours, and the phosphorus source precursor is one of red phosphorus or triphenylphosphine, the red phosphorus or triphenylphosphine is placed at the inlet of carrier gas, the reactant is placed at the outlet of gas, and the carrier gas is argon.

3. The method of claim 2, wherein the topotactic transformation is performed to prepare a layered heterojunction. in step (III), the charge ratio of the charge carried by the surface charge modifier to the charge possessed by the oxide nanosheet is (0.8-1):1; in step (III), the molar ratio of the two kinds of oxide nanosheets with opposite charges in electrostatic self-assembly is (0.5-1):

1.

4. The method of claim 1, wherein the topotactic transformation produces a layered heterojunction. The layered heterojunction obtained in step (B) is: vanadium pentoxide / molybdenum trioxide layered heterojunction, interstitial boron-doped vanadium pentoxide / molybdenum trioxide layered heterojunction, δ-manganese dioxide / molybdenum trioxide layered heterojunction, interstitial boron-doped δ-manganese dioxide / molybdenum trioxide layered heterojunction, δ-manganese dioxide / vanadium pentoxide layered heterojunction, interstitial boron-doped δ-manganese dioxide / vanadium pentoxide layered heterojunction; The layered heterojunction with different components obtained in step (C) is: Vanadium nitride / molybdenum nitride layered heterojunction, vanadium disulfide / molybdenum disulfide layered heterojunction, vanadium pentoxide / molybdenum disulfide layered heterojunction, vanadium phosphide / molybdenum phosphide layered heterojunction; Interstitial boron-doped vanadium nitride / molybdenum nitride layered heterojunction, interstitial boron-doped vanadium disulfide / molybdenum disulfide layered heterojunction, interstitial boron-doped vanadium pentoxide / molybdenum disulfide layered heterojunction, interstitial boron-doped vanadium phosphide / molybdenum phosphide layered heterojunction; Manganese nitride / molybdenum nitride layered heterojunction, manganese sulfide / molybdenum disulfide layered heterojunction, δ-manganese dioxide / molybdenum disulfide layered heterojunction, manganese phosphide / molybdenum phosphide layered heterojunction; Interstitial boron-doped manganese nitride / molybdenum nitride layered heterojunction, interstitial boron-doped manganese sulfide / molybdenum disulfide layered heterojunction, interstitial boron-doped δ-manganese dioxide / molybdenum disulfide layered heterojunction, interstitial boron-doped manganese phosphide / molybdenum phosphide layered heterojunction; Manganese nitride / vanadium nitride layered heterojunction, manganese sulfide / vanadium disulfide layered heterojunction, manganese phosphide / vanadium phosphide layered heterojunction, Interstitial boron-doped manganese nitride / vanadium nitride layered heterojunction, interstitial boron-doped manganese sulfide / vanadium disulfide layered heterojunction, interstitial boron-doped manganese phosphide / vanadium phosphide layered heterojunction.

5. The method of claim 2 or 3, wherein the topological conversion is performed by: The layered heterojunction obtained in step (III) is: Vanadium pentoxide / polymer / molybdenum trioxide layered heterojunction, δ-manganese dioxide / polymer / molybdenum trioxide layered heterojunction, δ-manganese dioxide / polymer / vanadium pentoxide layered heterojunction; The layered heterojunction with different components obtained in step (IV) is: Vanadium nitride / nitrogen-doped carbon / molybdenum nitride layered heterojunction, vanadium disulfide / sulfur-doped carbon / molybdenum disulfide layered heterojunction, vanadium phosphide / phosphorus-doped carbon / molybdenum phosphide layered heterojunction; Manganese nitride / nitrogen-doped carbon / molybdenum nitride layered heterojunction, manganese sulfide / sulfur-doped carbon / molybdenum disulfide layered heterojunction, manganese phosphide / phosphorus-doped carbon / molybdenum phosphide layered heterojunction; Manganese nitride / nitrogen-doped carbon / vanadium nitride layered heterojunction, manganese sulfide / sulfur-doped carbon / vanadium disulfide layered heterojunction, and manganese phosphide / phosphorus-doped carbon / vanadium phosphide layered heterojunction.

6. Use of the layered heterojunction prepared according to the method of claim 1 or 2 as a positive electrode material for zinc-ion batteries, characterized by: The layered heterojunction has a specific capacity higher than 320 mAh g as a positive electrode material of a zinc ion battery -1 , good rate performance, and excellent cycle performance.

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