Preparation method and application of a doped and regulated defective MoO3@NiCo-LDH@polyaniline core-shell nanocomposite array material

Abstract

Preparation method and application of a doped and regulated defective MoO3@NiCo-LDH@polyaniline core-shell nanocomposite array material, which relates to a preparation method and application of a core-shell nanocomposite array material. The purpose of the present invention is to solve the problems of poor conductivity, cyclic stability, low specific capacity and poor photoelectrocatalytic effect existing in the actual application of existing optoelectronic information materials. Method: First, prepare MoO3; second, prepare an ion-doped defective MoO3@NiCo-LDH core-shell structure material; third, prepare a MoO3@NiCo-LDH@polyaniline core-shell nanocomposite array material by electrodeposition; fourth, perform plasma treatment. A doped and regulated defective MoO3@NiCo-LDH@polyaniline core-shell nanocomposite array material is used as an electrochromic material or a photoelectrocatalytic material, and is used as an electrode material in supercapacitors, lithium-ion batteries or zinc-ion batteries.

Description

Technical Field

[0001] The present invention relates to a preparation method and application of a core-shell nano composite array material. Background Art

[0002] Optoelectronic information functional materials have broad application prospects in the fields of optics and electrical energy storage, such as being applicable to electrochemical capacitors, electrochromic smart windows, lithium-ion batteries, and the field of photocatalysis. However, the performance of a single material is limited in practical applications. It is necessary to improve the material performance through doping or compounding, designing the material structure, and combining the synergistic effects of different component materials. Material selection and structure design are the keys to improving optoelectronic performance. Among many inorganic and organic materials, MoO3 has excellent redox activity and has good rate performance and cycle stability as an electrode material. However, the specific capacitance of MoO3 materials in existing literature and their conductivity as metal oxides are not ideal, and the performance of photocatalytic degradation of dyes also needs to be improved greatly, with a large gap from practical applications. To overcome these drawbacks, NiCo-LDH (nickel-cobalt layered double hydroxide) and polyaniline (PANI) are added as auxiliary materials. NiCo-LDH has good charge conductivity, high capacitance, and electrochemical activity, which helps to improve the conductivity and energy storage capacity of the material. As a conductive polymer, polyaniline not only has excellent conductivity but also has good mechanical flexibility and environmental stability, and can further enhance the conductivity and mechanical properties of the composite material. By combining MoO3, NiCo-LDH, and polyaniline, the present invention can form a core-shell nanostructure. This composite material significantly improves the specific capacitance, conductivity, and photocatalytic performance through the synergistic effects among its components, providing a broader prospect for its practical application. Summary of the Invention

[0003] The object of the present invention is to solve the problems existing in existing optoelectronic information materials in practical applications, such as poor conductivity, cycle stability, low specific capacity, and poor photocatalytic effect, and to provide a preparation method and application of a doped and regulated MoO3@NiCo-LDH@polyaniline core-shell nano composite array material containing defects.

[0004] A preparation method of a doped and regulated MoO3@NiCo-LDH@polyaniline core-shell nano composite array material rich in defects is specifically completed according to the following steps:

[0005] I. Preparation of MoO3 by low-temperature water bath thermal method:

[0006] ①. Add Na2MoO4 powder to deionized water and stir for a period of time to obtain an Na2MoO4 aqueous solution;

[0007] ②. Prepare an acidic solution with a pH value of 1 to 6.5 by mixing concentrated sulfuric acid or concentrated hydrochloric acid with water;

[0008] ③. Drop the acidic solution with a pH value of 1 to 6.5 into the aqueous solution of Na2MoO4, stir for a period of time to obtain a mixed solution; heat the mixed solution at 40°C to 85°C for a period of time, then cool it to room temperature to obtain a reaction product; wash the reaction product and then dry it to obtain MoO3 powder;

[0009] II. Preparation of ion-doped defective MoO3@NiCo-LDH core-shell structure material by freeze-drying method:

[0010] ①. Add MoO3 powder, nickel salt, cobalt salt, alkaline substance and metal salt into deionized water, and ultrasonically mix them evenly to obtain a precursor mixed solution;

[0011] ②. Put the precursor mixed solution into a freeze-dryer and freeze-dry it for a period of time. After the temperature of the reaction product returns to room temperature, wash, dry and perform plasma treatment on the reaction product. Finally, calcine it at 350°C to 850°C for 2h to 30h to obtain an ion-doped defective MoO3@NiCo-LDH core-shell structure material;

[0012] The specific process parameters of the plasma treatment described in step II② are: adopting plasma technology, introducing oxygen gas, with a treatment power of 100W to 1000W and a treatment time of 5min to 30min;

[0013] III. Preparation of MoO3@NiCo-LDH@polyaniline core-shell nano-composite array material by electrodeposition method:

[0014] ①. Add polyaniline and lithium perchlorate into deionized water to obtain a deposition solution;

[0015] ②. Use the ion-doped defective MoO3@NiCo-LDH core-shell structure material as the working electrode, Ag / AgCl as the reference electrode, and a Pt sheet as the counter electrode. Immerse the working electrode, reference electrode and counter electrode into the deposition solution, and perform deposition treatment for a period of time by the constant current method. Then take out the working electrode, wash and dry the working electrode. Finally, anneal it at 350°C to 850°C to obtain a MoO3@NiCo-LDH@polyaniline core-shell nano-composite array material;

[0016] IV. Perform plasma treatment on the surface of the MoO3@NiCo-LDH@polyaniline core-shell nano-composite array material to change the surface properties and obtain a doped and regulated defective MoO3@NiCo-LDH@polyaniline core-shell nano-composite array material;

[0017] The specific process parameters of the plasma treatment described in Step 4 are as follows: Using plasma technology, oxygen gas is introduced, the treatment power is 10 W to 1000 W, and the treatment time is 5 min to 30 min.

[0018] A doped and regulated defective MoO3@NiCo-LDH@polyaniline core-shell nanocomposite array material is used as an electrode material in supercapacitors, lithium-ion batteries or zinc-ion batteries.

[0019] The product of the present invention contains excellent-performance MoO3, as well as the prepared NiCo-LDH and polyaniline as electrode materials. By regulating the doping to contain an appropriate amount of defects in the material and combining the synergistic effect between different components of the material, the optoelectronic performance of the material is significantly improved. In addition, through plasma treatment, oxygen defects are generated in the crystal structure of the product, the material lattice expands, and the lattice binding energy is changed; this is conducive to the formation of lattice defects, the generation of oxygen defects, the improvement of conductivity and hydrophilicity, and the increase of active center sites, which stimulates the resonance effect between plasmas; the improvement of conductivity is achieved by regulating the concentration of semiconductor carriers, thereby optimizing the electrochemical performance of the product. Finally, the three-dimensional core-shell structure has a large specific surface area. Coating a layer of polyaniline on the outer layer of the product can effectively increase the contact with the electrolyte, protect the internal electrode material structure to be stable and enhance the conductivity, and can improve the lithium-ion transport rate by virtue of the synergistic cooperation of multiple metals, so as to achieve both anti-corrosion and good conduction performance, direct contact with the electrolyte, reduce the corrosion of the electrolyte, and inhibit the occurrence of side reactions. In addition, the polyaniline conductive polymer has good conductivity. This is of positive significance for improving the overall electrochemical performance of the product. The prepared nanomaterials in the experiment have good electrochemical performance and have potential application value in supercapacitors, lithium-ion batteries, zinc-ion batteries, electrochromics and photocatalysis.

[0020] The present invention improves the excellent optoelectronic performance of the material by doping and regulating MoO3@NiCo-LDH@polyaniline to form defects. The preparation method and application of the material have the following beneficial effects:

[0021] 1. The entire synthesis process of the ion-doped and regulated defective MoO3@NiCo-LDH@polyaniline core-shell structured nanomaterial prepared by the present invention is safe, pollution-free, and the operation process is relatively simple. This core-shell structure has a large specific surface area, increases the contact area with the electrolyte, can effectively shorten the distance of electron separation and transfer, and improve the ion diffusion coefficient of internal movement; at the same time, this core-shell structure also increases the specific surface area and active sites, providing favorable conditions for enhancing the electrochemical performance;

[0022] 2. The ion-doped and defect-regulated MoO3@NiCo-LDH@polyaniline core-shell nanocomposite array material prepared by the present invention has good wettability in an alkaline aqueous solution, is easy to come into full contact with the electrolyte, and exhibits good cycle stability performance;

[0023] 3. In the present invention, the ion doping and plasma treatment technology together result in the prepared material being also rich in oxygen defects, optimizing the conductivity and hydrophilicity of the composite material;

[0024] 4. In the present invention, the three-dimensional core-shell structure and the coating of the polyaniline conductive polymer effectively buffer the volume change of the electrode material during the reaction and avoid the direct contact of the active materials, reducing the occurrence of side reactions;

[0025] 5. The ion-doped and defect-regulated MoO3@NiCo-LDH@polyaniline core-shell nanocomposite array material prepared by the present invention has wide applications and can be applied to supercapacitor electrode materials, lithium-ion batteries, zinc-ion batteries, electrochromics, and photoelectrocatalysis fields;

[0026] 6. The supercapacitors and electrochromic devices assembled using the ion-doped and defect-regulated MoO3@NiCo-LDH@polyaniline core-shell nanocomposite array material prepared by the present invention have excellent cycle stability, specific capacitance, energy density, and power density. Description of the Drawings

[0027] Figure 1 Cyclic voltammograms of the battery composed of the ion-doped and defect-regulated MoO3@NiCo-LDH@polyaniline core-shell nanocomposite array material prepared in Example 1 at different potential windows;

[0028] Figure 2 Specific surface area and pore size distribution diagrams of the ion-doped and defect-regulated MoO3@NiCo-LDH@polyaniline core-shell nanocomposite array material prepared in Example 1;

[0029] Figure 3 Specific capacitance diagrams of the ion-doped and defect-regulated MoO3@NiCo-LDH@polyaniline core-shell nanocomposite array material prepared in Example 1 under different current density conditions;

[0030] Figure 4 5000-cycle stability test diagram of the ion-doped and defect-regulated MoO3@NiCo-LDH@polyaniline core-shell nanocomposite array material prepared in Example 1 at a current density of 1 A / g;

[0031] Figure 5Impedance diagrams of the ion-doped and defect-regulated MoO3@NiCo-LDH@polyaniline core-shell nanocomposite array material prepared in Example 1 during the first test at a current density of 1 A / g and after 5000 cycles;

[0032] Figure 6 Charge-discharge comparison diagrams of the ion-doped and defect-regulated MoO3@NiCo-LDH@polyaniline core-shell nanocomposite array material prepared in Example 1 during the first cycle and the last cycle at a current density of 1 A / g. In the figure, (a) is the first cycle and (b) is the last cycle;

[0033] Figure 7 Cyclic voltammetry curve test diagrams of the ion-doped and defect-regulated MoO3@NiCo-LDH@polyaniline core-shell nanocomposite array material prepared in Example 1 when bent at different angles;

[0034] Figure 8 Scanning electron microscope image comparison diagrams of the ion-doped and defect-regulated MoO3@NiCo-LDH@polyaniline core-shell nanocomposite array material prepared using the present invention during the first cycle and the last cycle at a current density of 1 A / g;

[0035] Figure 9 Photocatalytic ultraviolet-visible light spectra of rhodamine B and methylene blue using the ion-doped and defect-regulated MoO3@NiCo-LDH@polyaniline core-shell nanocomposite array material prepared in Example 1. In the figure, (a) is rhodamine B and (b) is methylene blue. Detailed implementation manners

[0036] Detailed implementation manner 1: A preparation method of a doped and regulated MoO3@NiCo-LDH@polyaniline core-shell nanocomposite array material rich in defects in this implementation manner is specifically completed according to the following steps:

[0037] I. Preparation of MoO3 by low-temperature water bath thermal method:

[0038] ①. Add Na2MoO4 powder to deionized water, stir for a period of time to obtain an aqueous Na2MoO4 solution;

[0039] ②. Prepare an acidic solution with a pH value of 1 to 6.5 by mixing concentrated sulfuric acid or concentrated hydrochloric acid with water;

[0040] ③. Drop the acidic solution with a pH value of 1 to 6.5 into the aqueous Na2MoO4 solution, stir for a period of time to obtain a mixed solution; heat the mixed solution at 40°C to 85°C for a period of time, then cool it to room temperature to obtain a reaction product; wash the reaction product and then dry it to obtain MoO3 powder;

[0041] II. Preparation of ion-doped defective MoO3@NiCo-LDH core-shell structure materials by freezing method:

[0042] ① Add MoO3 powder, nickel salt, cobalt salt, alkaline substance and metal salt into deionized water, and ultrasonically mix them evenly to obtain a precursor mixed solution;

[0043] ② Put the precursor mixed solution into a freeze dryer for freeze drying for a period of time. After the temperature of the reaction product returns to room temperature, wash, dry and perform plasma treatment on the reaction product. Finally, calcine it at 350°C to 850°C for 2h to 30h to obtain ion-doped defective MoO3@NiCo-LDH core-shell structure materials;

[0044] The specific process parameters of the plasma treatment described in step II ② are: adopt plasma technology, introduce oxygen gas, the treatment power is 100W to 1000W, and the treatment time is 5min to 30min;

[0045] III. Preparation of MoO3@NiCo-LDH@polyaniline core-shell nanocomposite array materials by electrodeposition method:

[0046] ① Add polyaniline and lithium perchlorate into deionized water to obtain a deposition solution;

[0047] ② Use the ion-doped defective MoO3@NiCo-LDH core-shell structure material as the working electrode, Ag / AgCl as the reference electrode, and a Pt sheet as the counter electrode. Immerse the working electrode, reference electrode and counter electrode into the deposition solution, and perform deposition treatment for a period of time by the constant current method. Then take out the working electrode, wash and dry the working electrode, and finally anneal it at 350°C to 850°C to obtain MoO3@NiCo-LDH@polyaniline core-shell nanocomposite array materials;

[0048] IV. Perform plasma treatment on the surface of the MoO3@NiCo-LDH@polyaniline core-shell nanocomposite array materials to change the surface properties and obtain doped and regulated defective MoO3@NiCo-LDH@polyaniline core-shell nanocomposite array materials;

[0049] The specific process parameters of the plasma treatment described in step IV are: adopt plasma technology, introduce oxygen gas, the treatment power is 10W to 1000W, and the treatment time is 5min to 30min.

[0050] Specific Embodiment 2: The difference between this embodiment and Specific Embodiment 1 is as follows: In step 1①, the molar amount of the Na2MoO4 powder to the volume of deionized water is (0.01 mol - 5 mol):(20 mL - 500 mL); the stirring time in step 1① is 0.5 h - 8 h. Other steps are the same as those in Specific Embodiment 1.

[0051] Specific Embodiment 3: The difference between this embodiment and either Specific Embodiment 1 or 2 is as follows: In step 1③, the molar ratio of the acidic solution with a pH value of 1 - 6.5 to the Na2MoO4 aqueous solution is (0.02 mol - 0.5 mol):(0.01 mol - 5 mol); the stirring time in step 1③ is 0.5 h - 6 h. Other steps are the same as those in Specific Embodiment 1 or 2.

[0052] Specific Embodiment 4: The difference between this embodiment and any one of Specific Embodiments 1 to 3 is as follows: In step 1③, the heating time of the mixed solution at 40°C - 85°C is 2 h - 50 h; in step 1③, the reaction product is washed 2 - 4 times with deionized water and anhydrous ethanol respectively; the drying temperature in step 1③ is 40 - 80°C, and the drying time is 3 h - 48 h. Other steps are the same as those in Specific Embodiments 1 to 3.

[0053] Specific Embodiment 5: The difference between this embodiment and any one of Specific Embodiments 1 to 4 is as follows: In step 2①, the nickel salt is nickel chloride, nickel sulfate or nickel nitrate; the cobalt salt in step 2① is one or a mixture of two of cobalt chloride and cobalt nitrate; the basic substance in step 2① is ammonia water with a mass fraction of 25%, sodium hydroxide, potassium hydroxide or lithium hydroxide; the metal salt in step 2① is lanthanum chloride. Other steps are the same as those in Specific Embodiments 1 to 4.

[0054] Specific Embodiment 6: The difference between this embodiment and any one of Specific Embodiments 1 to 5 is as follows: In step 2①, the concentration of MoO3 powder in the precursor mixed solution is 1 g / L - 100 g / L; the concentration of nickel salt in the precursor mixed solution in step 2① is 5 g / L - 100 g / L; the concentration of cobalt salt in the precursor mixed solution in step 2① is 0.1 mol / L - 20 mol / L; the concentration of the basic substance in the precursor mixed solution in step 2① is 1 g / L - 100 g / L; the concentration of lanthanum chloride in the precursor mixed solution in step 2① is 3 g / L - 100 g / L. Other steps are the same as those in Specific Embodiments 1 to 5.

[0055] Embodiment 7: The difference between this embodiment and any one of Embodiments 1 to 6 is as follows: In step 2②, the temperature of freeze-drying is -100°C to -180°C, the pressure is 25 ± 1 Pa, and the time of freeze-drying is 3 h to 30 h; in step 2②, the washing is carried out by washing with deionized water 3 to 7 times; the temperature of the drying is 30°C to 70°C, and the time of drying is 5 h to 42 h. Other steps are the same as those in Embodiments 1 to 6.

[0056] Embodiment 8: The difference between this embodiment and any one of Embodiments 1 to 7 is as follows: In step 3①, the mass ratio of polyaniline to the volume of deionized water is (5 g to 40 g):(20 mL to 1000 mL); in step 3①, the mass ratio of lithium perchlorate to the volume of deionized water is (3 g to 35 g):(20 mL to 1000 mL); in step 3②, the constant current used for deposition treatment is 1 mA to 1000 mA, and the time of deposition treatment is 5 min to 30 min; in step 3②, the working electrode is cleaned 3 to 4 times with water or absolute ethanol; the temperature of the drying is 30°C to 70°C, and the time of drying is 5 h to 40 h; in step 3②, the annealing time at 350°C to 850°C is 1 h to 12 h. Other steps are the same as those in Embodiments 1 to 7.

[0057] Embodiment 9: This embodiment is a doped and regulated MoO3@NiCo-LDH@polyaniline core-shell nanocomposite array material containing defects used as an electrochromic material or a photoelectrocatalytic material.

[0058] Embodiment 10: This embodiment is a doped and regulated MoO3@NiCo-LDH@polyaniline core-shell nanocomposite array material containing defects used as an electrode material in a supercapacitor, a lithium-ion battery or a zinc-ion battery.

[0059] The following examples are used to verify the beneficial effects of the present invention:

[0060] Example 1: A preparation method of an ion-doped and regulated MoO3@NiCo-LDH@polyaniline core-shell nanocomposite array material is specifically completed according to the following steps:

[0061] I. Preparation of MoO3 by low-temperature water bath thermal method:

[0062] ①. Add Na2MoO4 powder into deionized water and stir for 5 h to obtain an Na2MoO4 aqueous solution;

[0063] In step 1①, the molar ratio of Na2MoO4 powder to the volume of deionized water is 0.03 mol:50 mL;

[0064] ②. Prepare an acidic solution with a pH value of 5 by mixing concentrated hydrochloric acid with a mass fraction of 36% and water.

[0065] ③. Drop the acidic solution with a pH value of 5 into the aqueous solution of Na2MoO4, stir for 3 h to obtain a mixed solution; heat the mixed solution at 50 °C for 10 h, then cool it to room temperature to obtain a reaction product; wash the reaction product 3 times with deionized water and anhydrous ethanol respectively, and then dry it at 60 °C for 22 h to obtain MoO3 powder.

[0066] In step ③ of step one, the molar ratio of the acidic solution with a pH value of 5 to the aqueous solution of Na2MoO4 is 0.05 mol:0.4 mol.

[0067] II. Preparation of ion-doped defective-rich MoO3@NiCo-LDH core-shell structure material by freezing method:

[0068] ①. Add MoO3 powder, nickel salt, cobalt salt, alkaline substance and metal salt to deionized water, and ultrasonically mix them evenly to obtain a precursor mixed solution.

[0069] The nickel salt mentioned in step ① of step two is nickel nitrate.

[0070] The cobalt salt mentioned in step ① of step two is cobalt chloride.

[0071] The alkaline substance mentioned in step ① of step two is sodium hydroxide.

[0072] The metal salt mentioned in step ① of step two is lanthanum chloride.

[0073] The concentration of MoO3 powder in the precursor mixed solution mentioned in step ① of step two is 72 g / L.

[0074] The concentration of nickel salt in the precursor mixed solution mentioned in step ① of step two is 34 g / L.

[0075] The concentration of cobalt salt in the precursor mixed solution mentioned in step ① of step two is 0.5 mol / L.

[0076] The concentration of alkaline substance in the precursor mixed solution mentioned in step ① of step two is 25 g / L.

[0077] The concentration of metal salt in the precursor mixed solution mentioned in step ① of step two is 30 g / L.

[0078] ②. Put the precursor mixed solution into a freeze dryer for freeze drying for a period of time. After the temperature of the reaction product returns to room temperature, wash, dry and perform plasma treatment on the reaction product, and finally calcine it at 550 °C for 25 h to obtain an ion-doped defective-rich MoO3@NiCo-LDH core-shell structure material.

[0079] In step ②, the temperature of freeze-drying is -120 °C, the pressure is 25 ± 1 Pa, and the time of freeze-drying is 12 h;

[0080] In step ②, the washing is carried out 5 times with deionized water; the temperature of drying is 55 °C, and the time of drying is 15 h;

[0081] In step ②, the specific process parameters of plasma treatment are as follows: microwave plasma is adopted, oxygen gas is introduced, the treatment power is 600 W, and the treatment time is 15 min;

[0082] III. Preparation of MoO3@NiCo-LDH@polyaniline core-shell nanocomposite array materials by electrodeposition method:

[0083] ①. Add polyaniline and lithium perchlorate into deionized water to obtain a deposition solution;

[0084] In step ③①, the mass ratio of polyaniline to the volume of deionized water is 11 g:50 mL;

[0085] In step ③①, the mass ratio of lithium perchlorate to the volume of deionized water is 18 g:60 mL;

[0086] ②. Use the ion-doped defective MoO3@NiCo-LDH core-shell structure material as the working electrode, Ag / AgCl as the reference electrode, and a Pt sheet as the counter electrode. Immerse the working electrode, reference electrode, and counter electrode into the deposition solution, and carry out deposition treatment for a period of time by the constant current method. Then take out the working electrode, wash and dry the working electrode, and finally anneal it at 550 °C for 5 h to obtain the MoO3@NiCo-LDH@polyaniline core-shell nanocomposite array material;

[0087] In step ③②, the constant current used for deposition treatment is 380 mA, and the time of deposition treatment is 6 min;

[0088] In step ③②, the working electrode is washed 3 times with water or absolute ethanol; the temperature of drying is 45 °C, and the time of drying is 15 h;

[0089] IV. Carry out plasma treatment on the MoO3@NiCo-LDH@polyaniline core-shell nanocomposite array material to obtain an ion-doped and regulated defective MoO3@NiCo-LDH@polyaniline core-shell nanocomposite array material;

[0090] In step IV, the specific process parameters of plasma treatment are as follows: plasma technology is adopted, oxygen gas is introduced, the treatment power is 600 W, and the treatment time is 25 min.

[0091] Application Example 1: A battery assembled with the ion-doped and defect-regulated MoO3@NiCo-LDH@polyaniline core-shell nanocomposite array material prepared in Example 1 was specifically completed as follows:

[0092] Asymmetric supercapacitor assembly: The ion-doped and defect-regulated MoO3@NiCo-LDH@polyaniline core-shell nanocomposite array material prepared in Example 1 was used as the positive electrode, carbon nanotubes (CNTs) as the negative electrode, and KOH solution as the electrolyte. A separator was added between the positive and negative electrodes to prepare the MoO3@NiCo-LDH@polyaniline / / CNTs asymmetric device. The geometric surface area of each electrode was 1 cm 2 , with KOH solution as the electrolyte. The electrolyte was prepared by adding 11.2 g of KOH to 150 mL of deionized water and then continuously stirring with a magnetic stirrer for 2 h until the solution became transparent; the positive and negative electrode materials and the separator were immersed in the electrolyte for 10 min, then taken out from the electrolyte and assembled together.

[0093] Figure 1 Figure shows the cyclic voltammograms of the battery composed of the ion-doped and defect-regulated MoO3@NiCo-LDH@polyaniline core-shell nanocomposite array material prepared in Example 1 at different potential windows;

[0094] Figure 1 Figure shows the cyclic voltammograms of the MoO3@NiCo-LDH@polyaniline / / CNTs asymmetric device at different voltage windows at a scanning rate of 10 mV / s. It can be clearly seen from the figure that the working voltage window can reach up to 1.6 V, which indicates that the device can store and release more energy within a larger voltage range, thus improving the energy storage capacity and efficiency.

[0095] Figure 2 Figure shows the specific surface area and pore size distribution diagram of the ion-doped and defect-regulated MoO3@NiCo-LDH@polyaniline core-shell nanocomposite array material prepared in Example 1;

[0096] From Figure 2 it can be seen that: the specific surface area of the MoO3@NiCo-LDH@polyaniline core-shell nanocomposite array material is as high as 156.7 m 2 / g. This relatively large specific surface area provides a large contact area for the electrolyte, enabling sufficient contact between the electrolyte and the electrode material during the electrochemical reaction. In Figure 2In (b), we were able to observe the pore size distribution map of the material. It is obvious that the pore sizes are mainly concentrated around 15 nm. This intertwined pore structure of such a size not only provides a channel for the rapid diffusion of the electrolyte, but also increases the specific surface area of the material, further promoting the contact between the electrolyte ions and the electrode material, thus effectively enhancing the electrochemical activity and performance of the material.

[0097] Figure 3 It is the specific capacitance diagram of the ion-doped and regulated defective MoO3@NiCo-LDH@polyaniline core-shell nano-composite array material prepared in Example 1 under different current density conditions;

[0098] From Figure 3 it can be seen that when the current densities are 1, 2, 3, 5, and 8 A / g, the corresponding specific capacitances of the MoO3@NiCo-LDH@polyaniline material. The discharge time and specific capacitance of the material decrease with the increase of the current density. This is because at high current densities, a small part of the material cannot participate in the reaction fully. However, the degree of decrease is still within a reasonable range, indicating that the material maintains good electrochemical performance at high current densities, showing excellent electrical conductivity and structural stability.

[0099] Figure 4 It is the 5000-cycle stability test diagram of the ion-doped and regulated defective MoO3@NiCo-LDH@polyaniline core-shell nano-composite array material prepared in Example 1 at a current density of 1 A / g;

[0100] From Figure 4 it can be seen that: after 5000 cycles, the specific capacitance decreases from 1210 F / g to 1142 F / g, and the specific capacitance retention rate is 94.3%. This indicates that the MoO3@NiCo-LDH@polyaniline material has excellent cycle stability.

[0101] Figure 5 It is the impedance diagram of the ion-doped and regulated defective MoO3@NiCo-LDH@polyaniline core-shell nano-composite array material prepared in Example 1 at a current density of 1 A / g for the first test and after 5000 cycles;

[0102] From Figure 5 it can be seen that: after 5000 cycles, only the slope of the curve changes slightly. This shows that the diffusion ability of the electrode becomes weaker but the change is not significant, indicating that the MoO3@NiCo-LDH@polyaniline core-shell nano-composite array material has long-term electrochemical stability.

[0103] Figure 6Figure showing the charge-discharge comparison of the ion-doped and defect-regulated MoO3@NiCo-LDH@polyaniline core-shell nanocomposite array material prepared in Example 1 at a current density of 1 A / g for the first and last cycles. In the figure, (a) is for the first cycle and (b) is for the last cycle;

[0104] From Figure 6 it can be seen that there is no obvious change in the charge-discharge comparison figure between the first and last cycles, indicating that the composite array material can still maintain good electrochemical performance after multiple charge-discharge cycles, without significant capacity decay or performance degradation.

[0105] Figure 7 Figure showing the cyclic voltammetry curves of the ion-doped and defect-regulated MoO3@NiCo-LDH@polyaniline core-shell nanocomposite array material prepared in Example 1 bent at different angles;

[0106] From Figure 7 it can be seen that after the MoO3@NiCo-LDH@polyaniline is bent at different angles, the shape and characteristic peak positions of the CV curves remain unchanged after bending, indicating that the electrochemically active sites of the material do not significantly decrease or become inactivated due to bending. This shows that the material has excellent mechanical stability and structural toughness and can maintain the stability of its electrochemical performance under different deformation states.

[0107] Figure 8 Figure showing the comparison of scanning electron microscope images of the ion-doped and defect-regulated MoO3@NiCo-LDH@polyaniline core-shell nanocomposite array material prepared using the present invention at a current density of 1 A / g for the first and last cycles;

[0108] From Figure 8 it can be seen that the surface morphology of the material has not changed significantly, indicating that the material has good electrochemical stability at a current density of 1 A / g.

[0109] Application Example 2: Using the ion-doped and defect-regulated MoO3@NiCo-LDH@polyaniline core-shell nanocomposite array material prepared in Example 1 to degrade rhodamine B and methylene blue, which is specifically completed according to the following steps:

[0110] Under the condition of simulated sunlight irradiation, 0.2 g of the ion-doped and defect-regulated MoO3@NiCo-LDH@polyaniline core-shell nanocomposite array material prepared in Example 1 was taken as a catalyst and added to 100 mL of a rhodamine B solution with a concentration of 50 mg / L, and stirred evenly under dark conditions to make it fully mixed to reach the adsorption-desorption equilibrium. Under simulated sunlight conditions, 5 mL of the solution was taken from the solution every 5 minutes, the catalyst was separated and removed from the suspension using a centrifugal separator, and then the absorbance value was measured using a UV-visible spectrophotometer;

[0111] Under the condition of simulated sunlight irradiation, 0.2 g of the ion-doped and defect-regulated MoO3@NiCo-LDH@polyaniline core-shell nanocomposite array material prepared in Example 1 was taken as a catalyst and added to 100 mL of a methylene blue solution with a concentration of 50 mg / L. It was stirred evenly under dark conditions to make it fully mixed to reach the adsorption-desorption equilibrium. Under simulated sunlight conditions, 5 mL of the solution was taken from the solution every 5 minutes, and the catalyst was separated and removed from the suspension using a centrifugal separator, and then the absorbance value was measured using a UV-visible spectrophotometer.

[0112] Figure 9 Figure for the photocatalytic UV-visible light spectra of rhodamine B and methylene blue using the ion-doped and defect-regulated MoO3@NiCo-LDH@polyaniline core-shell nanocomposite array material prepared in Example 1. In the figure, (a) is rhodamine B and (b) is methylene blue;

[0113] From Figure 9 It can be seen that the wavelengths with the strongest absorbance of rhodamine B and methylene blue are at 543 nm and 672 nm respectively. It can be seen that the photocatalytic effect of the nanomaterial MoO3@NiCo-LDH@polyaniline is still very significant and the speed is very fast. From the figure, it can be seen that as the degradation time increases, the absorbance values of rhodamine B and methylene blue gradually decrease, indicating that the dyes are also gradually degraded. After a certain degradation time, the degradation rates of MoO3@NiCo-LDH@polyaniline are 93.2% and 96.8% respectively.

Claims

1. A preparation method of a doped and regulated defective MoO3@NiCo-LDH@polyaniline core-shell nanocomposite array material, characterized in that The preparation method is specifically completed according to the following steps: I. Preparation of MoO3 by low-temperature water bath heating method: ①. Add Na2MoO4 powder into deionized water, stir for a period of time to obtain an aqueous Na2MoO4 solution; ②. Prepare an acidic solution with a pH value of 1 - 6.5 by mixing concentrated sulfuric acid or concentrated hydrochloric acid with water; ③. Drop the acidic solution with a pH value of 1 - 6.5 into the aqueous Na2MoO4 solution, stir for a period of time to obtain a mixed solution; heat the mixed solution at 40°C - 85°C for a period of time, then cool it to room temperature to obtain a reaction product; wash the reaction product and then dry it to obtain MoO3 powder; II. Preparation of ion-doped defect-rich MoO3@NiCo-LDH core-shell structure material by freezing method: ①. Add MoO3 powder, nickel salt, cobalt salt, alkaline substance and metal salt into deionized water, and ultrasonically mix evenly to obtain a precursor mixed solution; ②. Put the precursor mixed solution into a freeze dryer for freeze-drying for a period of time. After the temperature of the reaction product returns to room temperature, wash, dry and perform plasma treatment on the reaction product. Finally, calcine it at 350°C - 850°C for 2h - 30h to obtain an ion-doped defect-rich MoO3@NiCo-LDH core-shell structure material; The specific process parameters of the plasma treatment described in step II② are: adopt plasma technology, introduce oxygen gas, the treatment power is 100W - 1000W, and the treatment time is 5min - 30min; III. Preparation of MoO3@NiCo-LDH@polyaniline core-shell nanocomposite array material by electrodeposition method: ①. Add polyaniline and lithium perchlorate into deionized water to obtain a deposition solution; ②. Use the ion-doped defect-rich MoO3@NiCo-LDH core-shell structure material as the working electrode, Ag / AgCl as the reference electrode, and a Pt sheet as the counter electrode. Immerse the working electrode, reference electrode and counter electrode into the deposition solution, and perform deposition treatment for a period of time by the constant current method. Then take out the working electrode, wash and dry the working electrode, and finally anneal it at 350°C - 850°C to obtain the MoO3@NiCo-LDH@polyaniline core-shell nanocomposite array material; IV. Perform plasma treatment on the surface of the MoO3@NiCo-LDH@polyaniline core-shell nanocomposite array material to change the surface properties and obtain a doped and regulated defect-rich MoO3@NiCo-LDH@polyaniline core-shell nanocomposite array material; The specific process parameters of the plasma treatment described in step IV are: adopt plasma technology, introduce oxygen gas, the treatment power is 10W - 1000W, and the treatment time is 5min - 30min.

2. The preparation method of a doped and regulated defective MoO3@NiCo-LDH@polyaniline core-shell nanocomposite array material according to claim 1, characterized in that The molar ratio of the Na2MoO4 powder to the volume of deionized water described in step I① is (0.01mol - 5mol):(20mL - 500mL); the stirring time described in step I① is 0.5h - 8h.

3. The preparation method of a doped and regulated defective MoO3@NiCo-LDH@polyaniline core-shell nanocomposite array material according to claim 1, characterized in that The molar ratio of the acidic solution with a pH value of 1 to 6.5 and the aqueous Na2MoO4 solution described in Step 1③ is (0.02 mol to 0.5 mol):(0.01 mol to 5 mol); the stirring time described in Step 1③ is 0.5 h to 6 h.

4. The preparation method of a doped and regulated defective MoO3@NiCo-LDH@polyaniline core-shell nanocomposite array material according to claim 1, characterized in that In Step 1③, the heating time of the mixed solution at 40°C to 85°C is 2 h to 50 h; in Step 1③, the reaction product is washed 2 to 4 times with deionized water and anhydrous ethanol in sequence; the drying temperature described in Step 1③ is 40 to 80°C, and the drying time is 3 h to 48 h.

5. The preparation method of a doped and regulated defective MoO3@NiCo-LDH@polyaniline core-shell nanocomposite array material according to claim 1, characterized in that The nickel salt described in Step 2① is nickel chloride, nickel sulfate or nickel nitrate; the cobalt salt described in Step 2① is one or a mixture of two of cobalt chloride and cobalt nitrate; the alkaline substance described in Step 2① is ammonia water with a mass fraction of 25%, sodium hydroxide, potassium hydroxide or lithium hydroxide; the metal salt described in Step 2① is lanthanum chloride.

6. The preparation method of a doped and regulated defective MoO3@NiCo-LDH@polyaniline core-shell nanocomposite array material according to claim 1, wherein The concentration of MoO3 powder in the precursor mixed solution described in Step 2① is 1 g / L to 100 g / L; the concentration of nickel salt in the precursor mixed solution described in Step 2① is 5 g / L to 100 g / L; the concentration of cobalt salt in the precursor mixed solution described in Step 2① is 0.1 mol / L to 20 mol / L; the concentration of alkaline substance in the precursor mixed solution described in Step 2① is 1 g / L to 100 g / L; the concentration of lanthanum chloride in the precursor mixed solution described in Step 2① is 3 g / L to 100 g / L.

7. The preparation method of a doped and regulated defective MoO3@NiCo-LDH@polyaniline core-shell nanocomposite array material according to claim 1, wherein The temperature of freeze-drying described in Step 2② is -100°C to -180°C, the pressure is 25 ± 1 Pa, and the freeze-drying time is 3 h to 30 h; the washing described in Step 2② is washing 3 to 7 times with deionized water; the drying temperature is 30°C to 70°C, and the drying time is 5 h to 42 h.

8. The preparation method of a doped and regulated defective MoO3@NiCo-LDH@polyaniline core-shell nanocomposite array material according to claim 1, characterized in that The mass ratio of polyaniline to the volume of deionized water described in Step 3① is (5 g to 40 g):(20 mL to 1000 mL); the mass ratio of lithium perchlorate to the volume of deionized water described in Step 3① is (3 g to 35 g):(20 mL to 1000 mL); the constant current used for deposition treatment in Step 3② is 1 mA to 1000 mA, and the deposition treatment time is 5 min to 30 min; the working electrode is washed 3 to 4 times with water or anhydrous ethanol; the drying temperature is 30°C to 70°C, and the drying time is 5 h to 40 h; the annealing time at 350°C to 850°C in Step 3② is 1 h to 12 h.

9. Application of a doped and regulated defective MoO3@NiCo-LDH@polyaniline core-shell nanocomposite array material prepared by the preparation method according to claim 1, characterized in that A doped and regulated defective MoO3@NiCo-LDH@polyaniline core-shell nanocomposite array material is used as an electrochromic material or a photoelectrocatalytic material.

10. Application of a doped and regulated defective MoO₃@NiCo-LDH@polyaniline core-shell nanocomposite array material prepared by the preparation method according to claim 1, characterized in that A doped and regulated defective MoO3@NiCo-LDH@polyaniline core-shell nanocomposite array material is used as an electrode material in supercapacitors, lithium-ion batteries or zinc-ion batteries.

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