Preparation of cobalt metal alkene-doped tungsten disulfide piezoelectric material and application of cobalt metal alkene-doped tungsten disulfide piezoelectric material in synergistic degradation of antibiotics and hexavalent chromium

Abstract

The invention relates to the technical field of sewage treatment, in particular to preparation of a cobalt metal alkene-doped tungsten disulfide piezoelectric material and application of the cobalt metal alkene-doped tungsten disulfide piezoelectric material in synergistic degradation of antibiotics and hexavalent chromium. The material is prepared by combining a hydrothermal synthesis method with a chemical vapor deposition technology, and cobalt metal alkene is uniformly doped in a tungsten disulfide nanosheet layer to form a composite catalyst with excellent piezoelectric property. The material realizes efficient synergistic degradation of antibiotics and hexavalent chromium under the ultrasonic action, and has good cycle stability. The preparation method provided by the invention is simple and low in cost, and the obtained material has wide application prospects in the fields of sewage treatment, environmental remediation and the like, and is particularly suitable for efficient synergistic treatment of combined pollution.

Description

Technical Field

[0001] The present invention relates to the preparation of a transition metal sulfide piezoelectric composite material and its application in the synergistic degradation of antibiotics and hexavalent chromium, belonging to the technical field of sewage treatment.

Background Art

[0002] Due to the rapid development of industrialization, the emissions of harmful pollutants such as antibiotics and hexavalent chromium have been increasing continuously, which has become a major global environmental problem. Antibiotics are commonly used in the medical and agricultural fields and are often released into the environment through medical wastewater and agricultural runoff, resulting in the continuous pollution of aquatic ecosystems and the emergence of antibiotic-resistant bacteria. At the same time, due to the high solubility and bioaccumulation ability of hexavalent chromium, it is a highly dangerous and mobile pollutant found in industrial wastewater, posing a serious threat to human health and the environment. When antibiotics and hexavalent chromium coexist in water, their interaction makes their removal complicated, thus significantly increasing the challenges related to pollution treatment. Traditional treatment methods, including chemical, physical, and biological processes, usually have limited effectiveness in treating such complex co-pollution. Therefore, the development of new and efficient treatment technologies capable of simultaneously removing antibiotics and hexavalent chromium has become the focus of environmental science research.

[0003] Piezoelectrocatalysis is an emerging water treatment technology that has attracted much attention in recent years due to its unique ability to convert external mechanical vibration into chemical energy, thus enabling efficient degradation of pollutants. Under the drive of the piezoelectric effect, mechanical actions such as stirring, ultrasonic waves, friction, and extrusion can cause polarization inside the piezoelectric material, allowing the reaction to occur with low energy input. The redox reaction between the aqueous medium and the piezoelectric-induced charge carriers (electrons / holes) can form highly reactive oxygen-containing free radicals, including superoxide anion (·O2-) and hydroxyl radical (·OH). These active substances have a significant impact on the oxidative degradation of pollutants.

[0004] Tungsten disulfide is an emerging piezoelectrocatalytic material with a unique non-centrosymmetric structure, which is a typical characteristic of two-dimensional materials. Its unique properties enable it to efficiently convert mechanical energy into electrical energy and are very effective in the degradation of organic pollutants and hydrogen production applications, making it a promising material in the field of piezoelectrocatalysis. However, due to the semiconductor properties of tungsten disulfide and its relatively wide bandgap, its piezoelectrocatalytic performance is usually low. Therefore, it is of great significance to study and optimize the piezoelectrocatalytic performance of tungsten disulfide to achieve the efficient degradation of antibiotics and hexavalent chromium in water.

[0005] Cobalt metallene is a metal nanosheet with a thickness usually only of atomic layers (single layer or multiple layers), having a remarkable specific surface area, abundant defect sites, and excellent electrical conductivity. These properties make it a promising candidate material for regulating the energy band structure and catalytic performance of piezoelectric materials. By compounding cobalt metallene with tungsten disulfide material, a composite material with excellent piezoelectric properties is obtained. With the help of the band gap difference and piezoelectric effect of the two materials, the separation of electrons / holes is promoted, and the piezoelectric catalytic performance of the material can be strengthened.

[0006] Patent CN109264784A discloses a preparation method of a three-dimensional self-assembled flower-like tungsten disulfide nanomaterial. In this method, WO3·0.33H2O precursor is first prepared from sodium tungstate dihydrate by hydrothermal reaction, and then the precursor is mixed with thioacetamide and calcined at high temperature to obtain the flower-like tungsten disulfide material. This preparation method has a relatively complex process. In addition to the hydrothermal reaction, secondary high-temperature calcination is also required.

[0007] In summary, the present invention aims to provide an application of a tungsten disulfide piezoelectric composite material. Compared with other technologies, the main difference of the present invention lies in designing a tungsten disulfide piezoelectric composite material. Cobalt metallene is coupled with tungsten disulfide to form a modified composite piezoelectric material with high piezoelectric catalytic activity, and the efficient synergistic degradation of antibiotics and hexavalent chromium in water is realized through the driving force-induced piezoelectric effect. Compared with other technologies, this method has the following advantages: the material synthesis process is simple, green and non-toxic, and the cost is low; the prepared modified piezoelectric composite material has good stability and high mechanical strength, and is easier to realize industrial application. In summary, the invention provides a promising material and method for the sewage treatment field to realize the efficient synergistic degradation of antibiotics and hexavalent chromium, and has great application potential.

Summary of the Invention

[0008] [Technical Problems to be Solved]

[0009] The present invention aims to solve the problems such as low catalytic activity of existing piezoelectric catalytic materials for water treatment and easy secondary pollution. For this purpose, a method for synergistically degrading antibiotics and hexavalent chromium is proposed. This method couples tungsten disulfide, which is simple to prepare, green and non-toxic, with cobalt metallene having excellent properties to significantly enhance the piezoelectric catalytic performance of the material, and has good stability and high mechanical strength.

[0010] [Technical Solution]

[0011] The preparation of a cobalt metallene-doped tungsten disulfide piezoelectric material and its application in synergistically degrading antibiotics and hexavalent chromium include the following steps:

[0012] (1) Weigh 200 mg of cobalt acetylacetonate in a beaker, add N-N dimethylformamide, n-butylamine and deionized water, and stir for 15 min to mix evenly.

[0013] (2) Transfer the solution obtained in step (1) to a polytetrafluoroethylene hydrothermal reactor, seal it, and place it in a forced ventilation drying oven. Conduct hydrothermal synthesis at 220 °C for 48 h, naturally cool to room temperature, and add cyclohexane and ethanol to wash several times to obtain the cobalt metalene material.

[0014] (3) Weigh Na2WO4·2H2O, add deionized water to dissolve it, adjust the pH value to 2.5 - 4 with hydrochloric acid, add ascorbic acid, stir to dissolve, and dilute to 250 ml; weigh 80 ml of the above liquid, add thioacetamide, and stir to dissolve.

[0015] (4) Weigh the cobalt metalene material obtained in step (2), after ultrasonic dispersion, transfer the obtained solution to a polytetrafluoroethylene hydrothermal reactor, seal it, and place it in an air drying oven. Conduct hydrothermal synthesis at 180 - 220 °C for 24 - 48 hours.

[0016] (5) Wash the material prepared in step (4) several times with ethanol and deionized water, and dry it in vacuum at 60 °C for 10 hours, then grind it into powder to obtain the cobalt metalene doped tungsten disulfide piezoelectric composite material.

[0017] (6) Prepare a co - existing solution of 50 mg / L antibiotic and hexavalent chromium (store in the dark), dilute it to 10 mg / L for standby. Take 50 mL of the solution, add a certain amount of the piezoelectric composite material, and conduct piezoelectric catalytic degradation test under ultrasonic condition. Take samples every 5 min, after filtering through a 0.22 μm filter membrane, use an ultraviolet spectrophotometer to measure the absorbance to analyze the concentration change.

[0018] 2. In the step (1), the volume ratio of N - N dimethylformamide, n - butylamine to deionized water is 20 mL:1 mL:4 mL, and the stirring speed is 300 - 500 rpm.

[0019] 3. In the step (3), the mass ratio of Na2WO4·2H2O, ascorbic acid, and thioacetamide is 4:3:1, the volume of added deionized water is 50 - 100 Ml, and the hydrochloric acid concentration is 1 - 3 mol / L

[0020] 4. In the step (6), the antibiotics include ciprofloxacin hydrochloride, oxytetracycline, levofloxacin, chlortetracycline, tetracycline, etc.

[0021] 5. The piezoelectric composite material used in the step (6) can be 20 mg, 30 mg, or 40 mg.

[0022] 6. The ultrasonic frequency in the step (6) can be 80 kHz, 90 kHz, or 100 kHz.

[0023] [Beneficial effects]

[0024] Compared with the prior art, the present invention mainly has the following beneficial effects:

[0025] (1) The preparation method of the tungsten disulfide piezoelectric composite material provided by the present invention is simple, green, non-toxic, and low-cost. The composite material has good stability and high mechanical strength.

[0026] (2) The tungsten disulfide piezoelectric composite material provided by the present invention has excellent piezoelectric properties and universality, and can efficiently synergistically degrade various antibiotics and hexavalent chromium in water; there is no secondary pollution during the degradation process, and the reusability is high, making it easier to achieve industrial application.

Description of the Drawings

[0027] Figure 1 SEM image of the Co-ene / WS2 piezoelectric composite material prepared by the present invention

[0028] Figure 2 Effect curve diagram of piezoelectric catalytic synergistic degradation of organic pollutants and hexavalent chromium by the Co-ene / WS2 piezoelectric composite material prepared by the present invention

[0029] Figure 3 Cyclic performance diagram of piezoelectric catalytic synergistic degradation of the Co-ene / WS2 piezoelectric composite material prepared by the present invention

Detailed Embodiments

[0030] To further elaborate on the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the following further details the present invention through specific embodiments. It should be noted that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0031] Example 1:

[0032] The preparation of a tungsten disulfide piezoelectric composite material and its application in water purification and antibacterial are as follows.

[0033] (1) Weigh 200 mg of cobalt acetylacetonate in a beaker, add 20 ml of N-N dimethylformamide, 1 ml of n-butylamine, and 4 ml of deionized water, and stir for 15 minutes to mix evenly.

[0034] (2) Transfer the solution obtained in step (1) to a polytetrafluoroethylene hydrothermal reaction kettle, seal it, and place it in a forced ventilation drying oven. Perform hydrothermal synthesis at 220 °C for 48 hours, naturally cool to room temperature, and wash several times with cyclohexane and ethanol to obtain the cobalt metal ene material.

[0035] (3) Weigh 8.00 g of Na2WO4·2H2O, dissolve it in 100 ml of deionized water, adjust the pH value to 3 - 3.5 with 3 mol / L hydrochloric acid, add 6.3 g of ascorbic acid, stir to dissolve, and dilute to 250 ml; weigh 80 ml of the above liquid, add 1.5 g of thioacetamide, stir to dissolve,

[0036] (4) Weigh the cobalt metalene material obtained in step (2), after ultrasonic dispersion, transfer the resulting solution to a polytetrafluoroethylene hydrothermal reactor, seal it and place it in an air drying oven, and perform hydrothermal synthesis at 180 °C for 48 hours.

[0037] (5) Wash the material prepared in step (4) several times with ethanol and deionized water, and dry it in vacuum at 60 °C for 10 hours, then grind it into powder to obtain the cobalt metalene-doped tungsten disulfide piezoelectric composite material.

[0038] (6) Prepare a coexisting solution of 50 mg / L antibiotic and hexavalent chromium (store in the dark), dilute it to 10 mg / L for standby. Take 50 mL of the solution and add 30 mg of the piezoelectric composite material, and perform piezoelectric catalytic degradation test under ultrasonic wave at 100 kHz. Take samples every 5 min, after filtering through a 0.22 μm filter membrane, use an ultraviolet spectrophotometer to measure the absorbance to analyze the concentration change.

[0039] Example 2:

[0040] The preparation of a tungsten disulfide piezoelectric composite material and its application in water purification and antibacterial, the specific preparation and application methods are as follows.

[0041] (1) Weigh 200 mg of cobalt acetylacetonate in a beaker, add 20 ml of N-N dimethylformamide, 1 ml of n-butylamine and 4 ml of deionized water, stir for 15 min to mix evenly.

[0042] (2) Transfer the solution obtained in step (1) to a polytetrafluoroethylene hydrothermal reaction kettle, seal it and place it in a forced ventilation drying oven. Perform hydrothermal synthesis at 220 °C for 48 h, naturally cool to room temperature, and wash it several times with cyclohexane and ethanol to obtain the cobalt metalene material.

[0043] (3) Weigh 8.00 g of Na2WO4·2H2O, dissolve it in 100 ml of deionized water, adjust the pH value to 3.5 - 4 with 3 mol / L hydrochloric acid, add 6.3 g of ascorbic acid, stir to dissolve, and dilute to 250 ml; weigh 80 ml of the above liquid, add 1.5 g of thioacetamide, stir to dissolve,

[0044] (4) Weigh the cobalt metalene material obtained in step (2), after ultrasonic dispersion, transfer the resulting solution to a polytetrafluoroethylene hydrothermal reactor, seal it and place it in an air drying oven, and perform hydrothermal synthesis at 220 °C for 24 hours.

[0045] (5) Wash the material prepared in step (4) several times with ethanol and deionized water, and dry it in vacuum at 60 °C for 10 hours, then grind it into powder to obtain the cobalt metallene-doped tungsten disulfide piezoelectric composite material.

[0046] (6) Prepare a coexisting solution of 50 mg / L antibiotic and hexavalent chromium (store in the dark), and dilute it to 10 mg / L for standby. Take 50 mL of the solution and add 20 mg of the piezoelectric composite material, and conduct piezoelectric catalytic degradation tests under ultrasonic waves at 90 kHz. Take samples every 5 minutes, filter them through a 0.22 μm filter membrane, and measure the absorbance with a UV spectrophotometer to analyze the concentration change.

Claims

1. Preparation of a cobalt metallene-doped tungsten disulfide piezoelectric material and its application in synergistically degrading antibiotics and hexavalent chromium, characterized in that, The specific steps are as follows: (1) Weigh 200 mg of cobalt acetylacetonate into a beaker, add N-N dimethylformamide, n-butylamine and deionized water, stir for 15 min, and mix evenly. (2) Transfer the solution obtained in step (1) to a polytetrafluoroethylene hydrothermal reaction kettle, seal it and place it in a forced ventilation drying oven. Carry out hydrothermal synthesis at 220 °C for 48 h, naturally cool to room temperature, and wash several times with cyclohexane and ethanol to obtain the cobalt metalene material. (3) Weigh Na2WO4·2H2O, add deionized water to dissolve it, adjust the pH value to 2.5 - 4 with hydrochloric acid, add ascorbic acid, stir to dissolve, and dilute to 250 ml; weigh 80 ml of the above liquid, add thioacetamide, and stir to dissolve. (4) Weigh the cobalt metalene material obtained in step (2), after ultrasonic dispersion, transfer the obtained solution to a polytetrafluoroethylene hydrothermal reactor, seal it and place it in an air drying oven, and carry out hydrothermal synthesis at 180 - 220 °C for 24 - 48 hours. (5) Wash the material prepared in step (4) several times with ethanol and deionized water, and dry it in vacuum at 60 °C for 10 hours, and grind it into powder to obtain the cobalt metalene doped tungsten disulfide piezoelectric composite material. (6) Prepare a coexisting solution of 50 mg / L antibiotic and hexavalent chromium (stored in the dark), dilute it to 10 mg / L for standby. Take 50 mL of the solution and add a certain amount of the piezoelectric composite material, and carry out piezoelectric catalytic degradation test under ultrasonic. Take a sample every 5 min, after filtering through a 0.22 μm filter membrane, use an ultraviolet spectrophotometer to measure the absorbance to analyze the concentration change.

2. The preparation method according to claim 1, characterized in that: The volume ratio of N-N dimethylformamide, n-butylamine to deionized water is 20 mL:1 mL:4 mL, and the stirring speed is 300 - 500 rpm.

3. The preparation method according to claim 1, characterized in that: The mass ratio of Na2WO4·2H2O, ascorbic acid, thioacetamide is 4:3:1, the volume of deionized water added is 50 - 100 mL, and the hydrochloric acid concentration is 1 - 3 mol / L.

4. According to claim 1, it is characterized in that: The antibiotics include ciprofloxacin hydrochloride, oxytetracycline, levofloxacin, chlortetracycline, tetracycline, etc.

5. According to claim 1, it is characterized in that: The piezoelectric composite material used can be 20 mg, 30 mg, 40 mg.

6. According to claim 1, characterized in that: The ultrasonic frequency can be 80 kHz, 90 kHz, 100 kHz.

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