Preparation method of molybdenum disulfide piezoelectric material and application thereof

Abstract

The present application relates to piezoelectric material, specifically to a preparation method of molybdenum disulfide piezoelectric material and application thereof. In the present application, 3R-MoS2 is prepared first, and then the 3R-MoS2 is ball milled to obtain molybdenum disulfide piezoelectric material with a large number of sulfur vacancies and active sites. Compared with the 3R-MoS2 without ball milling, the molybdenum disulfide piezoelectric material has better piezoelectric activation ability. And on the basis of common ultrasound, another method of bubbling is provided, which can also trigger the piezoelectric effect of molybdenum disulfide, and has nearly the same catalytic degradation efficiency under the advantages of more economical and environmental protection.

Description

Technical Field

[0001] This invention relates to piezoelectric materials, specifically to a method for preparing molybdenum disulfide piezoelectric materials and their applications. Background Technology

[0002] The piezoelectric effect is a physical phenomenon where deformation of a piezoelectric material under external stress induces spontaneous polarization (carrier separation), creating a built-in electric field and resulting in polarization charges on the material's surface. When a piezoelectric material deforms and generates a built-in electric field (piezoelectric potential), its band structure changes, thereby endowing the material with catalytic activity. In piezoelectric-driven persulfate-based advanced oxidation (PS-AOPs) technology, improving the piezoelectric performance of piezoelectric catalysts is crucial for enhancing the removal of organic pollutants. Molybdenum disulfide (MoS2), a graphite-like layered transition metal dihalogen (TMD), has attracted widespread attention. MoS2 exhibits various crystal structures, among which metastable 3R-MoS2, due to its phase structure breaking the inversion symmetry of arbitrary layer numbers, possesses excellent piezoelectric properties in both multilayer and bulk 3R-MoS2.

[0003] However, controlling the particle size and defect structure of 3R-MoS2, or combining it with other materials to form heterojunctions, are all ways to further improve its piezoelectric catalytic performance, but research in this area has not been reported in the literature. Meanwhile, more economical and environmentally friendly piezoelectric effect triggering methods also need further development and research, which can provide theoretical guidance for the rational design of high-performance piezoelectric catalysts and the enhancement of antibiotic removal. Summary of the Invention

[0004] Based on this, the present invention provides a method for preparing molybdenum disulfide piezoelectric materials and their applications, thereby solving at least one problem in the prior art.

[0005] In a first aspect, the present invention provides a method for preparing a molybdenum disulfide piezoelectric material, comprising the following steps:

[0006] Molybdate, alkali and a first solvent are mixed and the first solvent is evaporated to obtain precursor powder;

[0007] Sulfur is sublimated, and the sublimated sulfur is brought into contact with the precursor powder through a carrier gas to react fully, yielding 3R-MoS2.

[0008] The 3R-MoS2 was ball-milled to obtain the molybdenum disulfide piezoelectric material.

[0009] In this invention, 3R-MoS2 is first prepared, and then the 3R-MoS2 is ball-milled to obtain a molybdenum disulfide piezoelectric material with a large number of sulfur vacancies and active sites. Compared with unmilled 3R-MoS2, the molybdenum disulfide piezoelectric material has better piezoelectric activation ability.

[0010] Secondly, the present invention provides the application of the molybdenum disulfide piezoelectric material in activated persulfate.

[0011] Thirdly, the present invention provides a method for activating persulfate, comprising the following steps:

[0012] The molybdenum disulfide piezoelectric material, persulfate, and a second solvent are mixed and then subjected to ultrasonic or bubbling treatment.

[0013] Fourthly, the present invention provides the application of the molybdenum disulfide piezoelectric material in wastewater treatment.

[0014] Fifthly, the present invention provides a wastewater treatment method, which includes the following steps:

[0015] The molybdenum disulfide piezoelectric material, persulfate, and wastewater are mixed and then subjected to ultrasonic or bubbling treatment.

[0016] Due to the adoption of the above technical solutions, the embodiments of the present invention have at least the following beneficial effects: the molybdenum disulfide piezoelectric material is pure 3R-MoS2, and the ball milling process generates sulfur vacancies and active sites, which can generate more holes and charge carriers, thereby greatly improving the ability to activate persulfate; the use of molybdenum disulfide piezoelectric material to activate persulfate generates a large number of sulfate radicals and hydroxyl radicals, and the obtained radicals can then be used to achieve various purposes, such as degrading organic pollutants and treating environmental pollution. Attached Figure Description

[0017] Figure 1 The image shows a SEM image of 3R-MoS2 prepared in Example 1 of this invention.

[0018] Figure 2 This is a SEM image of BM-MoS2 prepared in Example 1 of the present invention.

[0019] Figure 3 The removal effect of carbamazepine in Examples 2, 3, and Comparative Examples 1-3 of the present invention is shown.

[0020] Figure 4 The removal effect of phenol in Examples 4, 5, and Comparative Examples 4-6 of the present invention is shown.

[0021] Figure 5 The removal effects of different organic pollutants in Examples 16-19 of the present invention are shown.

[0022] Figure 6 The removal effect of carbamazepine in Examples 20-22 of the present invention is shown. Detailed Implementation

[0023] The following will provide a clear and complete description of the concept and technical effects of the present invention, so as to fully explain the purpose, solution and effects of the present invention.

[0024] Bulk MoS2 can be exfoliated to obtain monolayer or few-layer two-dimensional MoS2 materials. These two-dimensional piezoelectric materials exhibit unique electrical and piezoelectric properties. MoS2 has various crystal structures, among which metastable 3R-MoS2, due to its phase structure breaking the inversion symmetry of arbitrary layer number, exhibits excellent piezoelectric properties in both multilayer and bulk 3R-MoS2. Furthermore, the five-layer two-dimensional 3R-MoS2 structure possesses the largest piezoelectric constant, approximately 13% higher than that of monolayer MoS2. Therefore, 3R-MoS2 shows better application prospects in piezoelectric catalytic activation of persulfate. However, related research is scarce. Additionally, controlling the particle size and defect structure of 3R-MoS2, or combining it with other materials to form heterojunctions, are all ways to further improve its piezoelectric catalytic performance, but research in this area has not been reported in the literature. Therefore, this invention provides a method for preparing molybdenum disulfide piezoelectric materials and their applications.

[0025] In a first aspect, the present invention provides a method for preparing a molybdenum disulfide piezoelectric material, comprising the following steps:

[0026] Molybdate, alkali and a first solvent are mixed and the first solvent is evaporated to obtain precursor powder;

[0027] Sulfur is sublimated, and the sublimated sulfur is brought into contact with the precursor powder through a carrier gas to react fully, yielding 3R-MoS2.

[0028] The 3R-MoS2 was ball-milled to obtain the molybdenum disulfide piezoelectric material.

[0029] In some preferred embodiments, the molybdate is at least one selected from ammonium molybdate, sodium molybdate, and magnesium molybdate. More preferably, the molybdate is ammonium molybdate tetrahydrate.

[0030] In some preferred embodiments, the alkali is at least one selected from potassium hydroxide and sodium hydroxide. More preferably, the alkali is potassium hydroxide.

[0031] In some preferred embodiments, the first solvent is water. More preferably, the first solvent is ultrapure water.

[0032] In some preferred embodiments, the first solvent is rotary evaporated under stirring conditions. More preferably, the stirring rate is 300 rpm, and the rotary evaporation is carried out at 40-60°C.

[0033] In some preferred embodiments, sulfur powder and the precursor powder are placed in a quartz boat and placed in the high-temperature zone of a tube furnace, where the sulfur powder is sublimated at 600-700°C.

[0034] In some preferred embodiments, the carrier gas is an inert gas, such as nitrogen (N2) or argon (Ar).

[0035] In some preferred embodiments, the flow rate of the carrier gas is 60-80 sccm.

[0036] In some preferred embodiments, the mass ratio of sulfur to the precursor powder is 1:(2-5).

[0037] In some preferred embodiments, the 3R-MoS2 and the abrasive are placed in a grinding jar and ball-milled in a planetary ball mill.

[0038] In some preferred embodiments, the abrasive is an agate ball with a diameter of 4.5-6.5 mm, and the mass ratio of the abrasive to the 3R-MoS2 is 100:1.

[0039] Secondly, the present invention provides the application of the molybdenum disulfide piezoelectric material in activated persulfate.

[0040] Thirdly, the present invention provides a method for activating persulfate, comprising the following steps:

[0041] The molybdenum disulfide piezoelectric material, persulfate, and a second solvent are mixed and then subjected to ultrasonic or bubbling treatment.

[0042] In some preferred embodiments, the persulfate is at least one selected from potassium peroxymonosulfate and sodium persulfate. More preferably, the persulfate is potassium peroxymonosulfate.

[0043] In some preferred embodiments, the second solvent is water or water containing organic matter (such as organically contaminated groundwater, organic industrial wastewater, etc.).

[0044] In some preferred embodiments, the frequency of the ultrasound is 30-80 kHz, and the duration of the ultrasound is 90-120 min. More preferably, the power of the ultrasound is 400 W, the frequency of the ultrasound is 40 kHz, and the duration of the ultrasound is 90 min.

[0045] Fourthly, the present invention provides the application of the molybdenum disulfide piezoelectric material in wastewater treatment.

[0046] Fifthly, the present invention provides a wastewater treatment method, which includes the following steps:

[0047] The molybdenum disulfide piezoelectric material, persulfate, and wastewater are mixed and then subjected to ultrasonic or bubbling treatment.

[0048] In some preferred embodiments, the wastewater contains organic matter. More preferably, the wastewater contains at least one of phenol, carbamazepine, atrazine, metronidazole, and bisphenol A.

[0049] In some preferred embodiments, the concentration of the molybdenum disulfide piezoelectric material is 0.05-0.5 g / L. More preferably, the concentration of the molybdenum disulfide piezoelectric material is 0.3 g / L.

[0050] In some preferred embodiments, the concentration of the persulfate is 0.1-2 mmol / L. More preferably, the concentration of the persulfate is 0.5 mmol / L.

[0051] In some preferred embodiments, the bubbling treatment refers to introducing gas for bubbling (also known as aeration). More preferably, the gas is nitrogen, oxygen, or air, and the gas introduction rate is 80 sccm.

[0052] Compared to the preparation method of 3R-MoS2 powder provided in invention patent application CN115504510A, the preparation process of this invention is simpler, less time-consuming, uses inexpensive and readily available raw materials with low toxicity, and the heating process is simple to operate, which is conducive to the batch preparation of materials. Compared to the method of activating persulfate with 2H phase MoS2 nanoflowers disclosed in invention patent application CN1131355594A, the material of this invention has a significant advantage in the degradation of pollutants in the same piezoelectric catalytic system. On this basis, the performance of the material is further improved after ball milling. Under the conditions that the amount of persulfate is reduced from 3.25 mmol / L to 0.5 mmol / L and the overall reaction time is shortened from 210 min to 120 min, almost the same degradation rate can be achieved. It can be seen that 3R-MoS2 itself not only has better piezoelectric properties, but ball milling further enriches its active sites, increases its specific surface area, and the presence of S vacancies is more conducive to the generation of electrons and holes, thus further improving the degradation efficiency. Therefore, 3R-MoS2 has a better application prospect in piezoelectric catalytic activation of persulfate technology.

[0053] Meanwhile, while ultrasonic vibration is one of the conditions for triggering the piezoelectric effect of MoS2, ultrasonic cleaners suffer from drawbacks such as high energy consumption and noise pollution. Building on this, the bubbling method, which introduces nanobubbles into the pollutant reaction solution via an atomizer, can also achieve nearly the same degradation efficiency. This application method complements the application methods of 3R-MoS2 piezoelectric catalysis for PMS degradation of organic pollutants, providing a more economical and environmentally friendly triggering mechanism.

[0054] The following are some typical examples.

[0055] Example 1

[0056] Molybdenum disulfide piezoelectric material (BM-MoS2) was prepared according to the following steps:

[0057] (1) Dissolve ammonium molybdate tetrahydrate and sodium hydroxide in ultrapure water and evaporate by rotary evaporation at 60°C to obtain precursor powder (white powder).

[0058] (2) The precursor powder and sublimed sulfur powder were respectively loaded into a quartz boat, placed in the high-temperature zone of a tube furnace, and nitrogen gas was introduced (to make the tube furnace oxygen-free). The temperature was increased to 650℃ for annealing at a temperature gradient of 10℃ / min for 30min to generate black 3R-MoS2 powder. The powder was washed with ultrapure water and ethanol and filtered. The filter residue was dried in an oven to obtain 3R-MoS2 powder.

[0059] (3) Place 3R-MoS2 powder and 6.5mm diameter agate ball milling material in an agate ball milling jar at a mass ratio of 1:100, put them in a planetary ball mill, mill for 5 hours, collect and wash them to obtain BM-MoS2.

[0060] Scanning electron microscopy (SEM) was performed on 3R-MoS2 and BM-MoS2 from this embodiment. The results are as follows: Figure 1 and Figure 2 As shown. Among them, Figure 1 SEM images of 3R-MoS2 Figure 2 SEM images of BM-MoS2.

[0061] Example 2

[0062] Follow these steps to activate persulfate with BM-MoS2 and treat organic pollutant wastewater containing carbamazepine:

[0063] (1) Carbamazepine was added to ultrapure water to obtain organic pollutant wastewater with an initial carbamazepine concentration of 20 mg / L;

[0064] (2) Add BM-MoS2 to the organic pollutant wastewater to be treated and stir for 30 minutes to reach adsorption equilibrium;

[0065] (3) Add potassium persulfate to the wastewater containing organic pollutants to be treated;

[0066] (4) Stir at 30℃ for 90 min;

[0067] The concentration of potassium persulfate was 0.5 mmol / L, and the dosage of BM-MoS2 was 0.3 g / L.

[0068] This embodiment is labeled MoS2 / PMS.

[0069] Example 3

[0070] Follow these steps to activate persulfate with BM-MoS2 and treat organic pollutant wastewater containing carbamazepine:

[0071] (1) Carbamazepine was added to ultrapure water to obtain organic pollutant wastewater with an initial carbamazepine concentration of 20 mg / L;

[0072] (2) Add BM-MoS2 to the organic pollutant wastewater to be treated and stir for 30 minutes to reach adsorption equilibrium;

[0073] (3) Add potassium persulfate to the wastewater containing organic pollutants to be treated;

[0074] (4) Sonicate at 30℃ for 90 min;

[0075] The concentration of potassium persulfate was 0.5 mmol / L, and the dosage of BM-MoS2 was 0.3 g / L.

[0076] This embodiment is labeled MoS2 / PMS / US.

[0077] Comparative Example 1

[0078] Treat wastewater containing carbamazepine-containing organic pollutants with BM-MoS2 using the following steps:

[0079] (1) Carbamazepine was added to ultrapure water to obtain organic pollutant wastewater with an initial carbamazepine concentration of 20 mg / L;

[0080] (2) Add BM-MoS2 to the organic pollutant wastewater to be treated and stir for 120 min at 30°C;

[0081] The dosage of BM-MoS2 was 0.3 g / L.

[0082] This comparative example is labeled MoS2only.

[0083] Comparative Example 2

[0084] Treat wastewater containing organic pollutants such as carbamazepine with potassium persulfate using the following steps:

[0085] (1) Carbamazepine was added to ultrapure water to obtain organic pollutant wastewater with an initial carbamazepine concentration of 20 mg / L;

[0086] (2) Add potassium persulfate to the wastewater containing organic pollutants to be treated;

[0087] (3) Sonicate at 30℃ for 90 min;

[0088] The concentration of potassium persulfate was 0.5 mmol / L.

[0089] This comparative example is labeled PMS / US.

[0090] Comparative Example 3

[0091] Treat wastewater containing carbamazepine-containing organic pollutants with BM-MoS2 using the following steps:

[0092] (1) Carbamazepine was added to ultrapure water to obtain organic pollutant wastewater with an initial carbamazepine concentration of 20 mg / L;

[0093] (2) Add BM-MoS2 to the organic pollutant wastewater to be treated and stir for 30 minutes to reach adsorption equilibrium;

[0094] (3) Sonicate at 30℃ for 90 min;

[0095] The dosage of BM-MoS2 was 0.3 g / L.

[0096] This comparative example is labeled MoS2 / US.

[0097] For Examples 2, 3, and Comparative Examples 1-3, 0.5 mL of solution was taken every 10 minutes starting from 0 min, filtered through a 0.22 μm filter membrane, and 0.5 mL of ethanol was added as a free radical quencher to terminate the reaction. The solutions were stored in 1.5 mL liquid chromatography vials for determining carbamazepine concentration. Results are as follows: Figure 3 As shown, BM-MoS2 itself has a strong adsorption capacity for carbamazepine (MoS2only); in the system with only potassium persulfate and ultrasound, carbamazepine hardly degrades (PMS / US); in the system with only BM-MoS2, the adsorption rate of carbamazepine is about 50% (MoS2only), and with ultrasound, the degradation rate of carbamazepine in this system is about 54% (MoS2 / US); under the condition of no ultrasound and BM-MoS2 activating PMS, the degradation rate of carbamazepine is 92% (MoS2 / PMS); in the system with both potassium persulfate and BM-MoS2 and ultrasound, the removal capacity of carbamazepine is the strongest, reaching a degradation rate of 99.6% in 90 minutes (MoS2 / PMS / US), indicating that ultrasound plays an important synergistic role in the process of MoS2 activating PMS.

[0098] Comprehensive comparison shows that BM-MoS2 deforms under ultrasonic disturbance, activates potassium persulfate through piezoelectric effect, significantly improves the activation efficiency of potassium persulfate, generates free radicals, and promotes the degradation of carbamazepine.

[0099] Example 4

[0100] This embodiment is basically the same as embodiment 2, except that: (1) Phenol is added to ultrapure water to obtain organic pollutant wastewater with an initial phenol concentration of 10 mg / L.

[0101] Example 5

[0102] This embodiment is basically the same as embodiment 3, except that: (1) Phenol is added to ultrapure water to obtain organic pollutant wastewater with an initial phenol concentration of 10 mg / L.

[0103] Comparative Example 4

[0104] This comparative example is basically the same as comparative example 1, except that: (1) Phenol was added to ultrapure water to obtain organic pollutant wastewater with an initial phenol concentration of 10 mg / L.

[0105] Comparative Example 5

[0106] This comparative example is basically the same as comparative example 2, except that: (1) Phenol was added to ultrapure water to obtain organic pollutant wastewater with an initial phenol concentration of 10 mg / L.

[0107] Comparative Example 6

[0108] This comparative example is basically the same as comparative example 3, except that: (1) Phenol was added to ultrapure water to obtain organic pollutant wastewater with an initial phenol concentration of 10 mg / L.

[0109] For Examples 4, 5, and Comparative Examples 4-6, starting from 0 min, 0.5 mL of solution was taken every 10 min and filtered through a 0.22 μm filter membrane. 0.5 mL of ethanol was added as a free radical quencher to terminate the reaction, and the solution was stored in a 1.5 mL liquid chromatography vial for determining the phenol concentration. The results are as follows: Figure 4 As shown, BM-MoS2 itself has a certain adsorption capacity for phenol (MoS2only); in the system with only potassium persulfate and ultrasound, phenol is almost not degraded (PMS / US); in the system with only BM-MoS2, the adsorption rate of phenol is about 20% (MoS2only), and with ultrasound, the degradation rate of phenol in this system is about 25% (MoS2 / US); under the condition of no ultrasound and BM-MoS2 activating PMS, the degradation rate of phenol is greater than 60% (MoS2 / PMS); in the system with both potassium persulfate and BM-MoS2 and ultrasound, the phenol removal capacity is the strongest, reaching a degradation rate of 98.35% in 90 min (MoS2 / PMS / US), indicating that ultrasound plays an important synergistic role in the process of MoS2 activating PMS.

[0110] Comprehensive comparison shows that, under ultrasonic conditions, using BM-MoS2 to deform under ultrasonic disturbance and activate potassium persulfate through piezoelectric effect can significantly improve the activation efficiency of potassium persulfate, generate free radicals, and promote the degradation of p-phenol.

[0111] Example 6

[0112] Follow these steps to activate persulfate with BM-MoS2 and treat wastewater containing organic pollutants such as carbamazepine:

[0113] (1) Carbamazepine was added to ultrapure water to obtain organic pollutant wastewater with an initial carbamazepine concentration of 20 mg / L;

[0114] (2) Add BM-MoS2 to the organic pollutant wastewater to be treated and stir for 30 minutes to reach adsorption equilibrium;

[0115] (3) Add potassium persulfate to the wastewater containing organic pollutants to be treated;

[0116] (4) Sonicate at 30℃ for 90 min;

[0117] The concentration of potassium persulfate was 1 mmol / L, and the dosage of BM-MoS2 was 0.05 g / L.

[0118] Example 7

[0119] This embodiment is basically the same as embodiment 6, except that the dosage of BM-MoS2 is 0.1 g / L.

[0120] Example 8

[0121] This embodiment is basically the same as embodiment 6, except that the dosage of BM-MoS2 is 0.2 g / L.

[0122] Example 9

[0123] This embodiment is basically the same as embodiment 6, except that the dosage of BM-MoS2 is 0.3 g / L.

[0124] Example 10

[0125] This embodiment is basically the same as embodiment 6, except that the dosage of BM-MoS2 is 0.5 g / L.

[0126] For Examples 6-10, starting from 0 min, 0.5 mL of solution was taken every 10 min and filtered through a 0.22 μm filter membrane. 0.5 mL of ethanol was added as a free radical quencher to terminate the reaction. The solution was stored in a 1.5 mL liquid chromatography vial for determining the carbamazepine concentration. The degradation efficiency of carbamazepine in the system with different BM-MoS2 dosages was calculated at 90 min.

[0127] The removal efficiency of carbamazepine in systems with different catalyst dosages is shown in Table 1. Table 1 shows that when the BM-MoS2 concentration is greater than 0.3 g / L, the reaction rate increase is not significant. This may be due to the interaction of the built-in electric field at the catalyst edge, which enhances collisions between separated charge carriers, causing the forces to cancel each other out and inhibiting the efficiency of BM-MoS2 in activating persulfate, thus leading to a slower increase in the reaction rate. Considering cost, a dosage concentration of 0.3 g / L is more preferred for the same degradation efficiency.

[0128] Table 1. Removal effect of carbamazepine at different BM-MoS2 dosages.

[0129]

[0130] Example 11

[0131] Follow these steps to activate persulfate with BM-MoS2 and treat wastewater containing organic pollutants such as carbamazepine:

[0132] (1) Carbamazepine was added to ultrapure water to obtain organic pollutant wastewater with an initial carbamazepine concentration of 20 mg / L;

[0133] (2) Add BM-MoS2 to the organic pollutant wastewater to be treated and stir for 30 minutes to reach adsorption equilibrium;

[0134] (3) Add potassium persulfate to the wastewater containing organic pollutants to be treated;

[0135] (4) Stir at 30℃ for 90 min;

[0136] The concentration of potassium persulfate was 0.1 mmol / L, and the dosage of BM-MoS2 was 0.3 g / L.

[0137] Example 12

[0138] This embodiment is basically the same as that of Example 11, except that the concentration of potassium persulfate is 0.5 mmol / L.

[0139] Example 13

[0140] This embodiment is basically the same as that of Embodiment 11, except that the concentration of potassium persulfate is 1 mmol / L.

[0141] Example 14

[0142] This embodiment is basically the same as that of Embodiment 11, except that the concentration of potassium persulfate is 2 mmol / L.

[0143] Example 15

[0144] This embodiment is basically the same as that of Embodiment 11, except that the concentration of potassium persulfate is 4 mmol / L.

[0145] For Examples 11-15, starting from 0 min, 0.5 mL of solution was taken every 10 min and filtered through a 0.22 μm filter membrane. 0.5 mL of ethanol was added as a free radical quencher to terminate the reaction. The solution was stored in a 1.5 mL liquid chromatography vial for determining the carbamazepine concentration. The degradation efficiency of carbamazepine in the system with different potassium persulfate concentrations was calculated at 90 min.

[0146] The removal efficiency of carbamazepine in systems with different potassium persulfate concentrations is shown in Table 2. Table 2 shows that the reaction rate is inhibited when the potassium persulfate concentration is greater than 2 mmol / L. Considering cost, a dosage concentration of 0.5 mmol / L is more optimal for achieving the same degradation efficiency.

[0147] Table 2. Removal effect of carbamazepine at different potassium persulfate concentrations.

[0148]

[0149] Example 16

[0150] Activate persulfate with BM-MoS2 and treat organic pollutant wastewater according to the following steps:

[0151] (1) Carbamazepine was added to ultrapure water to obtain organic pollutant wastewater with an initial carbamazepine concentration of 20 mg / L;

[0152] (2) Add BM-MoS2 to the organic pollutant wastewater to be treated and stir for 30 minutes to reach adsorption equilibrium;

[0153] (3) Add potassium persulfate to the wastewater containing organic pollutants to be treated;

[0154] (4) Sonicate at 30℃ for 90 min;

[0155] The concentration of potassium persulfate was 0.5 mmol / L, and the dosage of BM-MoS2 was 0.3 g / L.

[0156] Example 17

[0157] This embodiment is basically the same as embodiment 16, except that: (1) Phenol is added to ultrapure water to obtain organic pollutant wastewater with an initial phenol concentration of 10 mg / L.

[0158] Example 18

[0159] This embodiment is basically the same as embodiment 16, except that: (1) Bisphenol A is added to ultrapure water to obtain organic pollutant wastewater with an initial concentration of 10 mg / L of bisphenol A.

[0160] Example 19

[0161] This embodiment is basically the same as embodiment 16, except that: (1) acetaminophen is added to ultrapure water to obtain organic pollutant wastewater with an initial acetaminophen concentration of 10 mg / L.

[0162] For Examples 16-19, 0.5 mL of solution was taken every 10 min and filtered through a 0.22 μm filter membrane. 0.5 mL of ethanol was added as a free radical quencher to terminate the reaction, and the solution was stored in a 1.5 mL liquid chromatography vial for determining the concentrations of the four pollutants. The degradation efficiencies of phenol, bisphenol A, acetaminophen, and carbamazepine were calculated after a 90 min reaction time. The results are as follows: Figure 5 As shown, the ultrasonic system of BM-MoS2 and persulfate has a degradation efficiency of more than 99% for phenol, bisphenol A, acetaminophen, and carbamazepine. This indicates that BM-MoS2 can effectively activate persulfate, thereby effectively treating organic matter in water and has a certain degree of universality in wastewater treatment.

[0163] Example 20

[0164] Activate persulfate with BM-MoS2 and treat organic pollutant wastewater according to the following steps:

[0165] (1) Carbamazepine was added to ultrapure water to obtain organic pollutant wastewater with an initial carbamazepine concentration of 20 mg / L;

[0166] (2) Add BM-MoS2 to the organic pollutant wastewater to be treated and stir for 30 minutes to reach adsorption equilibrium;

[0167] (3) Add potassium persulfate to the wastewater containing organic pollutants to be treated;

[0168] (4) At 30℃, high-purity nitrogen gas was introduced through the atomizer for 120 min at a gas flow rate of 80 sccm;

[0169] The concentration of potassium persulfate was 0.5 mmol / L, and the dosage of BM-MoS2 was 0.3 g / L.

[0170] Example 21

[0171] This embodiment is basically the same as embodiment 20, except that pure oxygen is introduced through the nebulizer for 120 minutes.

[0172] Example 22

[0173] Activate persulfate with BM-MoS2 and treat organic pollutant wastewater according to the following steps:

[0174] (1) Carbamazepine was added to ultrapure water to obtain organic pollutant wastewater with an initial carbamazepine concentration of 20 mg / L;

[0175] (2) Add potassium persulfate and BM-MoS2 to the organic pollutant wastewater to be treated, and reach adsorption equilibrium after 30 minutes;

[0176] (3) Sonicate at 30℃ for 120 min;

[0177] The concentration of potassium persulfate was 0.5 mmol / L, and the dosage of BM-MoS2 was 0.3 g / L.

[0178] For Examples 20-22, starting from 0 min, 0.5 mL of solution was taken every 10 min and filtered through a 0.22 μm filter membrane. 0.5 mL of ethanol was added as a free radical quencher to terminate the reaction, and the solution was stored in a 1.5 mL liquid chromatography vial for determining carbamazepine concentration. The results are as follows: Figure 6 As shown, bubbling treatment has the same degradation capacity for pollutants as ultrasonic treatment. The degradation occurs because the atomized bubbles generated after gas introduction burst, creating stress around the catalyst and causing a piezoelectric effect. This activates persulfate to generate free radicals that degrade organic pollutants. The type of gas has almost no effect; dissolved oxygen generated after the introduction of oxygen does not accelerate the degradation rate. Compared to the higher energy consumption and noise of ultrasound, bubbling overcomes these drawbacks while achieving the same activation effect, making it a more energy-efficient and environmentally friendly new piezoelectric activation method.

[0179] The formulas for calculating the degradation efficiency in the above embodiments and comparative examples are as follows:

[0180] ,

[0181] in, C0 This represents the initial concentration of organic pollutants. Ct Organic pollutants t Concentration at any given moment.

[0182] The above description is merely a preferred embodiment of the present invention. The present invention is not limited to the above-described embodiments. Any embodiment that achieves the technical effects of the present invention by the same or equivalent means should fall within the protection scope of the present invention. Within the protection scope of the present invention, various modifications and variations can be made to the technical solutions and / or implementation methods.

Claims

1. A method for preparing a molybdenum disulfide piezoelectric material, characterized in that, Includes the following steps: Molybdate, alkali and a first solvent are mixed and the first solvent is evaporated to obtain precursor powder; Sulfur is sublimated and then contacted with the precursor powder by a carrier gas to obtain 3R-MoS2. The 3R-MoS2 and abrasive were placed in a ball mill jar and ball milled in a planetary ball mill to obtain the molybdenum disulfide piezoelectric material. The abrasive is an agate ball with a diameter of 4.5-6.5 mm, and the mass ratio of the abrasive to the 3R-MoS2 is 100:

1.

2. The method according to claim 1, characterized in that, The molybdate is at least one of ammonium molybdate, sodium molybdate, and magnesium molybdate, the alkali is at least one of potassium hydroxide and sodium hydroxide, and the first solvent is water.

3. The molybdenum disulfide piezoelectric material obtained by the method according to claim 1.

4. The application of the molybdenum disulfide piezoelectric material according to claim 3 in the activation of persulfate.

5. A method for activating persulfate, characterized in that, Includes the following steps: The molybdenum disulfide piezoelectric material of claim 3, persulfate, and a second solvent are mixed and then subjected to ultrasonic treatment or bubbling treatment.

6. The method according to claim 5, characterized in that, The persulfate is at least one of potassium persulfate and sodium persulfate.

7. The application of the molybdenum disulfide piezoelectric material according to claim 3 in wastewater treatment.

8. A wastewater treatment method, characterized in that, Includes the following steps: The molybdenum disulfide piezoelectric material of claim 3, persulfate, and wastewater are mixed and then subjected to ultrasonic or bubbling treatment.

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