Preparation and application method of carbon-doped molybdenum disulfide PVDF microspheres with piezoelectric catalytic degradation properties

Abstract

This invention relates to a method for preparing and applying carbon-doped molybdenum disulfide (PVDF) microspheres with piezoelectric catalytic degradation properties. The preparation of carbon-doped molybdenum disulfide (PVDF) microspheres with piezoelectric catalytic degradation properties includes the following steps: (1) preparation of MoS2 / C composite material, (2) preparation of PVDF microspheres, and (3) application of piezoelectric catalytic materials to degrade organic pollutants in water. The method for preparing PVDF microspheres in this invention is simple to operate, low in cost, environmentally friendly, and easy to scale up for production. The microspheres have good piezoelectric catalytic properties and self-cleaning properties, and can be used for piezoelectric catalysis and wastewater treatment. The degradation of organic pollutants is achieved by utilizing water flow dynamics and low-frequency vibration to excite piezoelectric properties.

Description

[Technical Field]

[0001] This invention belongs to the field of wastewater treatment technology, and relates to a method for preparing and applying carbon-doped molybdenum disulfide PVDF microspheres with piezoelectric catalytic degradation properties. [Background Technology]

[0002] Due to their antibacterial properties, antibiotics have been widely used in disease treatment and aquaculture, with an estimated growth rate of 67% in antibacterial drug consumption between 2010 and 2030. Tetracycline, as an antibiotic, ranks second in both production and use. However, a significant amount of tetracycline cannot be metabolized and broken down in the metabolic processes of humans and animals, with over two-thirds of tetracycline released into the environment, endangering human living environments and ecological security. To reduce the potential accumulation risk caused by tetracycline residues in the environment, tetracycline removal technologies are urgently needed. To date, various technologies have been applied to remove and degrade tetracycline, such as adsorption, photocatalysis, piezoelectric catalysis, biochemical treatment, and membrane separation. Among these, physical methods for tetracycline removal include ion exchange, membrane technology, and adsorption. A common problem with physical methods is that their removal principle essentially transfers pollutants from one system to another without completely removing or destroying them, posing a risk of secondary pollution. Further treatment of the pollutants is still required, so we need to find more efficient and energy-saving removal methods. Chemical methods include complexation, wet oxidation, and advanced oxidation. Biological methods include plant degradation and microbial degradation. This method utilizes the absorption and accumulation of antibiotics by plants and microorganisms, altering their structure and properties to convert them into smaller molecules, thereby reducing antibiotic concentration. This method is more suitable for treating low concentrations of pollutants; high concentrations may cause plants and microorganisms to lose their degradation activity. Although this method is environmentally friendly and pollution-free, its high cost and low degradation efficiency make the search for more efficient, low-energy, and low-cost tetracycline removal technologies particularly important.

[0003] In recent years, piezoelectric catalysis technology has attracted much attention due to its advantages such as industrial applications, low cost, environmental compatibility, and excellent degradation performance for organic matter. During piezoelectric catalytic degradation, electrons and holes can separate, forming a surface potential under mechanical vibration. Then, dissolved oxygen / water reacts with the separated electrons / holes in an oxidation / reduction reaction, generating active substances that lead to the decomposition of pollutants. To improve the piezoelectric catalytic activity of materials in degrading organic pollutants, various piezoelectric catalysts have been synthesized. For example, Jin et al. reported that BaTiO3 nanowires exhibited a high piezoelectric catalytic potential in the decomposition of methyl orange, finding that over 90% of methyl orange could be degraded by barium titanate nanowires within 160 minutes. Lin et al. demonstrated that Pb(Zr) 0.52 Ti 0.48O3 exhibits high piezoelectric catalytic activity towards lime 7. However, most research has focused on the removal of organic dyes and antibiotics. Therefore, there are many aspects that need further improvement in the piezoelectric catalytic degradation of antibiotics, particularly degradation efficiency and mechanisms. [Summary of the Invention]

[0004] [Technical problem to be solved]

[0005] To address the technical problem of lacking effective methods for removing antibiotics from tap water in water purification plants, this invention provides a method for preparing and applying carbon-doped molybdenum disulfide (PVDF) microspheres with excellent piezoelectric catalytic degradation performance. The carbon-doped PVDF microspheres of this invention are simple to prepare, easy to use, environmentally friendly, and easily recyclable. They maintain high activity even after multiple degradation cycles, exhibiting excellent stability and sufficient mechanical strength.

[0006] [Technical Solution]

[0007] An application of carbon-doped molybdenum disulfide PVDF microspheres with excellent piezoelectric catalytic degradation performance in degrading organic pollutants includes the following steps:

[0008] (1) Preparation of MoS2 / C composite material:

[0009] Weigh anhydrous sodium molybdate, thiourea, and glucose in a ratio of 1:1:2 to 1:2:4 and place them in a beaker. Measure 600-800 ml of deionized water using a graduated cylinder and pour it into the beaker. Seal the beaker with plastic wrap and stir thoroughly for 5-8 hours. Pour the mixture into a hydrothermal reactor and heat it in an oven at 180-250℃ for 24-36 hours. After heating, wash with deionized water and ethanol until the filtrate is clear and colorless. Dry the resulting material in an oven. Grind the dried material using an agate mortar and pestle, then place it in a sealed bag and store it in a dry place.

[0010] (2) Preparation of MoS2 / C / PVDF microspheres:

[0011] Transfer DMF into a small beaker, weigh MoS2 / C powder and PVDF into the small beaker, stir at 40-60℃ for 20-80 min; place in an ultrasonic cleaner and sonicate to disperse evenly; add phase transfer agent to the beaker, and use a peristaltic pump to drop the phase transfer agent to obtain MoS2 / C material microspheres; wash the obtained microspheres with deionized water and soak them in water for later use;

[0012] (3) Application of piezoelectric catalytic materials in the degradation of organic pollutants in water:

[0013] At room temperature, the prepared microspheres are placed in a pollutant solution and poured into a degradation device. The air pump is turned on to make the microspheres roll evenly in the floating bubbles. The solution is taken every ten minutes, filtered through a filter membrane, and the absorbance of the solution is measured using a UV-Vis spectrophotometer.

[0014] In step (2), the mass fraction of MoS2 / C material added is 1-10%.

[0015] The phase transfer agent in step (2) is prepared by mixing water and isopropanol in a ratio of 1:1 to 1:2, adding 0.5% to 2% sodium dodecyl sulfate, and stirring to dissolve.

[0016] The contaminants in step (3) include antibiotics such as tetracycline, oxytetracycline, ofloxacin, and chlortetracycline, as well as organic dyes such as rhodamine B and methylene blue.

[0017] In step (3), the degradation device consists of a glass tube, an air pump, and a gas distributor. The solution is placed in the glass tube, and the air pump pumps air into the glass tube through the gas distributor to disturb the solution in the glass tube.

[0018] [Beneficial Effects]

[0019] This invention obtains a composite material with excellent properties by doping MoS2 with carbon materials to control its morphology, and explores the degradation performance of the composite material. The composite material was synthesized using a hydrothermal method, and its degradation efficiency for tetracycline was investigated. During piezoelectric catalytic degradation, electrons and holes can be separated, and a surface potential can be formed during mechanical vibration. Then, dissolved oxygen / water reacts with the separated electrons / holes in an oxidation / reduction reaction, generating active free radicals with a significant piezoelectric effect. The carbon-doped molybdenum disulfide PVDF microspheres prepared in this invention can piezoelectrically catalytically degrade organic pollutants at room temperature, showing significant performance in tetracycline degradation with lower energy consumption. [Attached Image Description]

[0020] Figure 1 XRD diffraction patterns of MoS2, MoS2 / C and MoS2 / C / PVDF-1 microspheres

[0021] Figure 2 SEM images of MoS2 (a), MoS2 / C (b), and MoS2 / C / PVDF microspheres (c).

[0022] Figure 3 TEM images of MoS2(a) and MoS2 / C(b)

[0023] Figure 4 Degradation effect under different material loading

Detailed Implementation Methods

[0024] To further illustrate the technical means and effects adopted by the present invention in order to achieve the intended purpose, the following detailed description is provided in conjunction with the accompanying drawings and embodiments.

[0025] Example 1: Preparation and application of MoS2 / C / PVDF-0.5 microspheres. The specific preparation and application methods are as follows.

[0026] (1) Preparation of MoS2 / C composite material:

[0027] Weigh anhydrous sodium molybdate, thiourea, and glucose in a 1:1:2 ratio and place them in a beaker. Measure 600 ml of deionized water using a graduated cylinder and pour it into the beaker. Seal the beaker with plastic wrap and stir thoroughly for 5 hours. Pour the mixture into a hydrothermal reactor and heat it in an oven at 200°C for 24 hours. After heating, wash with deionized water and ethanol until the filtrate is clear and colorless. Place the obtained material in an oven to dry. Grind the dried material using an agate mortar and pestle, then place it in a sealed bag and store it in a dry place.

[0028] (2) Preparation of MoS2 / C / PVDF microspheres:

[0029] DMF was transferred into a small beaker, and 0.5% MoS2 / C powder and PVDF were weighed and poured into the small beaker. The mixture was stirred at 40-60℃ for 20 minutes. The mixture was then placed in an ultrasonic cleaner and ultrasonically dispersed to ensure uniform dispersion. A phase transfer agent was added to the beaker, and the phase transfer agent was dripped into the beaker using a peristaltic pump to obtain MoS2 / C material microspheres. The obtained microspheres were washed with deionized water and then soaked in water for later use.

[0030] (3) Application of piezoelectric catalytic materials in the degradation of organic pollutants in water:

[0031] At room temperature, the prepared microspheres were placed in a pollutant solution and poured into a degradation device. The air pump was turned on, allowing the microspheres to tumble evenly amidst floating bubbles. The solution was sampled every ten minutes, filtered through a filter membrane, and the absorbance was measured using a UV-Vis spectrophotometer. The tetracycline removal rate of PVDF microspheres with a MoS2 / C loading of 1% reached 89.98%.

[0032] Example 2: Preparation and application of MoS2 / C / PVDF-1 microspheres. The specific preparation and application methods are as follows.

[0033] (1) Preparation of MoS2 / C composite material:

[0034] Weigh anhydrous sodium molybdate, thiourea, and glucose in a 1:1:2 ratio and place them in a beaker. Measure 600 ml of deionized water using a graduated cylinder and pour it into the beaker. Seal the beaker with plastic wrap and stir thoroughly for 5 hours. Pour the mixture into a hydrothermal reactor and heat it in an oven at 200°C for 24 hours. After heating, wash with deionized water and ethanol until the filtrate is clear and colorless. Place the obtained material in an oven to dry. Grind the dried material using an agate mortar and pestle, then place it in a sealed bag and store it in a dry place.

[0035] (2) Preparation of MoS2 / C / PVDF microspheres:

[0036] DMF was transferred into a small beaker, and 5% MoS2 / C powder and PVDF were weighed and poured into the small beaker. The mixture was stirred at 40-60℃ for 20 minutes. The mixture was then placed in an ultrasonic cleaner and ultrasonically dispersed to ensure uniform dispersion. A phase transfer agent was added to the beaker, and the phase transfer agent was dripped into the beaker using a peristaltic pump to obtain MoS2 / C material microspheres. The obtained microspheres were washed with deionized water and soaked in water for later use.

[0037] (3) Application of piezoelectric catalytic materials in the degradation of organic pollutants in water:

[0038] At room temperature, the prepared microspheres were placed in a pollutant solution and poured into a degradation device. The air pump was turned on, allowing the microspheres to tumble evenly amidst floating bubbles. The solution was sampled every ten minutes, filtered through a filter membrane, and the absorbance was measured using a UV-Vis spectrophotometer. The tetracycline removal rate of PVDF microspheres with a MoS2 / C loading of 1% reached 91.88%.

[0039] Example 3: Preparation and application of MoS2 / C / PVDF-1.5 microspheres. The specific preparation and application methods are as follows.

[0040] (1) Preparation of MoS2 / C composite material:

[0041] Weigh anhydrous sodium molybdate, thiourea, and glucose in a 1:1:2 ratio and place them in a beaker. Measure 600 ml of deionized water using a graduated cylinder and pour it into the beaker. Seal the beaker with plastic wrap and stir thoroughly for 5 hours. Pour the mixture into a hydrothermal reactor and heat it in an oven at 200°C for 24 hours. After heating, wash with deionized water and ethanol until the filtrate is clear and colorless. Place the obtained material in an oven to dry. Grind the dried material using an agate mortar and pestle, then place it in a sealed bag and store it in a dry place.

[0042] (2) Preparation of MoS2 / C / PVDF microspheres:

[0043] DMF was transferred into a small beaker, and 1.5% of MoS2 / C powder and PVDF were weighed and poured into the small beaker. The mixture was stirred at 40-60℃ for 20 minutes. The mixture was then placed in an ultrasonic cleaner and ultrasonically dispersed to ensure uniform dispersion. A phase transfer agent was added to the beaker, and the phase transfer agent was dripped into the beaker using a peristaltic pump to obtain MoS2 / C material microspheres. The obtained microspheres were washed with deionized water and then soaked in water for later use.

[0044] (3) Application of piezoelectric catalytic materials in the degradation of organic pollutants in water:

[0045] At room temperature, the prepared microspheres were placed in a pollutant solution and poured into a degradation device. The air pump was turned on, allowing the microspheres to tumble evenly amidst floating bubbles. The solution was sampled every ten minutes, filtered through a filter membrane, and the absorbance was measured using a UV-Vis spectrophotometer. The tetracycline removal rate of PVDF microspheres with a MoS2 / C loading of 1% reached 90.83%.

Claims

1. An application of carbon-doped molybdenum disulfide PVDF microspheres with excellent piezoelectric catalytic degradation performance in degrading organic pollutants, characterized in that, Includes the following steps: (1) Preparation of MoS2 / C composite material: Weigh anhydrous sodium molybdate, thiourea, and glucose in a ratio of 1:1:2 to 1:2:4 and place them in a beaker. Measure 600-800 ml of deionized water using a graduated cylinder and pour it into the beaker. Seal the beaker with plastic wrap and stir thoroughly for 5-8 hours. Pour the mixture into a hydrothermal reactor and heat it in an oven at 180-250 ℃ for 24-36 hours. After heating, wash with deionized water and ethanol until the filtrate is clear and colorless. Dry the resulting material in an oven. Grind the dried material using an agate mortar and pestle, then place it in a sealed bag and store it in a dry place. (2) Preparation of MoS2 / C / PVDF microspheres: DMF was transferred to a small beaker, and MoS2 / C powder and PVDF were weighed and poured into the small beaker. The mixture was stirred at 40-60℃ for 20-80 minutes. The mixture was then placed in an ultrasonic cleaner and ultrasonically dispersed to ensure uniform dispersion. A phase transfer agent was added to the beaker, and the phase transfer agent was dripped into the beaker using a peristaltic pump to obtain MoS2 / C / PVDF material microspheres. The obtained microspheres were washed with deionized water and soaked in water for later use. The phase transfer agent was prepared by mixing water and isopropanol in a ratio of 1:1 to 1:2, adding 0.5%-2% sodium dodecyl sulfate, and stirring to dissolve. (3) Application of piezoelectric catalytic materials in the degradation of organic pollutants in water: At room temperature, the prepared microspheres are placed in a pollutant solution and poured into a degradation device. The air pump is turned on to make the microspheres roll evenly in the floating bubbles. The solution is taken every ten minutes, filtered through a filter membrane, and the absorbance of the solution is measured using a UV-Vis spectrophotometer.

2. The application according to claim 1, characterized in that: The contaminants in step (3) include tetracycline, oxytetracycline, ofloxacin, chlortetracycline, rhodamine B, or methylene blue.

3. The application according to claim 1, characterized in that: In step (3), the degradation device consists of a glass tube, an air pump, and a gas distributor. The solution is placed in the glass tube, and the air pump pumps air into the glass tube through the gas distributor to disturb the solution in the glass tube.

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