A water purification material and its preparation method

Abstract

This application claims protection for a water purification material and its preparation method, characterized in that: S1: Potassium permanganate and manganese sulfate are added to deionized water / glycerol and stirred to obtain a mixed solution; polyvinylpyrrolidone is added to the mixed solution; after mixing evenly, it is placed in a microwave reactor and reacted at 165 - 180 °C for 0.5 - 2 h to obtain a precipitate, and the obtained precipitate is washed alternately with deionized water and ethanol 3 times; S2: The precipitate obtained in step S1 is added to tert-butanol solvent, cerium nitrate is further added to the solvent, after mixing evenly, it is placed in a microwave reactor and reacted at 160 °C - 180 °C for 0.5 - 2 h to obtain a precipitate, and the obtained precipitate is continuously washed alternately with deionized water and ethanol 3 times; to obtain the MnO2-CeO2 photocatalytic material.

Description

Technical Field

[0001] The present invention belongs to the technical field of sewage purification, and particularly relates to a water purification composite material, a preparation method thereof, and an application in water purification. Background Art

[0002] With the acceleration of the global industrialization process, there are more and more organic substances in water, leading to the deterioration of water environment quality, endangering the survival of aquatic organisms, and threatening the health of humans and livestock due to water pollution. In industry, methods for removing organic substances include adsorption method, biochemical method, coagulation sedimentation method, and photocatalytic degradation method. The photocatalytic degradation method originated in 1972 and is a new sewage treatment method developed in the past 30 years. Since the end of the 1970s, a large number of studies on the photocatalytic degradation treatment of various pollutant wastewaters have been reported. For example, CN115350702A discloses a high-efficiency photocatalyst mullite-type bismuth manganate, a preparation method thereof, and an application. The preparation method includes: adding a manganese source and a bismuth source to ethylene glycol and stirring to obtain a mixed solution, adding polyvinylpyrrolidone and urea and mixing evenly, then adding deionized water and mixing evenly, placing it in a high-pressure autoclave, sealing it, and reacting at 175-200 °C for 10-15 h, collecting the precipitate, washing, and drying to obtain it. The present invention provides a process for preparing mullite-type bismuth manganate by a one-step hydrothermal method, with a simple process and no toxic emissions; the prepared Bi2Mn4O 10 has a spherical-like morphology, high purity, and the particle size is between 50-85 nm; adding the prepared Bi2Mn4O 10 to the sewage to be treated containing organic pollutants, the degradation rate reaches up to 88% after 3 h of light degradation, and the degradation rate after 4 cycles of its reuse decreases by less than 10%, which is suitable for industrial application; CN114345391A discloses a carbon nitride / graphene / manganese dioxide bifunctional catalyst, a preparation method thereof, and an application. The preparation includes: Step 1, obtaining protonated carbon nitride by calcining and acidifying a carbon nitride precursor; Step 2, preparing manganese dioxide and then reacting with a silane coupling agent to obtain amino-functionalized manganese dioxide; Step 3, filtering the graphene dispersion and the amino-functionalized manganese dioxide dispersion by suction and then performing a hydrothermal reaction to obtain a graphene / manganese dioxide material; then filtering the protonated carbon nitride dispersion into the graphene layer and reacting to obtain a carbon nitride / graphene / manganese dioxide bifunctional catalyst. CN112264107A discloses a visible-light photocatalytic material, a preparation method thereof, and an application. The preparation method includes the following steps: (1) dissolving isopropyl titanate in ethyl acetoacetate to obtain solution A, and dissolving nickel stearate in another ethyl acetoacetate solution to obtain solution B, mixing solution A and solution B to obtain a mixed solution, and heating and stirring; (2) dissolving β-cyclodextrin in a mixed solvent composed of water and isopropanol to obtain a β-cyclodextrin solution; (3) adding the mixed solution in step (1) to the β-cyclodextrin solution and performing a hydrothermal reaction; (4) washing the reactant and drying it under vacuum to obtain NiO-doped TiO induced by cyclodextrin2-x Visible light photocatalytic materials. Photocatalytic degradation can degrade a variety of organic substances and mineralize all of them into carbon dioxide, water or less toxic organic substances, which can completely destroy organic substances and meet the requirements of harmless treatment. Currently, it has gradually become an important method for treating organic pollution. How to prepare photocatalytic materials with stable structure, simple process and strong degradation ability is the core and focus of current photocatalytic technology research. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a composite photocatalyst with stable structure, simple preparation process and strong degradation ability for organic pollutants.

[0004] A preparation method of a water purification material includes the following steps:

[0005] S1: Add potassium permanganate and manganese sulfate to deionized water / glycerol and stir to obtain a mixed solution; add polyvinylpyrrolidone to the mixed solution; after mixing evenly, place it in a microwave reactor and react at 165 - 180 °C for 0.5 - 2 h to obtain a precipitate, and wash the obtained precipitate alternately with deionized water and ethanol 3 times;

[0006] S2: Add the precipitate obtained in step S1 to tert-butanol solvent, continue to add cerium nitrate in the solvent, after mixing evenly, place it in a microwave reactor and react at 160 °C - 180 °C for 0.5 - 2 h to obtain a precipitate, and continue to wash the obtained precipitate alternately with deionized water and ethanol 3 times; obtain the MnO2-CeO2 composite material.

[0007] During the experiment, by controlling the proportion of the solvent in the microwave reaction and adding polyvinylpyrrolidone, highly dispersed nano-spherical structure β-MnO2 was synthesized, and its particle size could be uniformly controlled between 50 - 100 nanometers. Using tert-butanol as the solvent, microwave reaction was used to control the production of CeO2 micro-nano sheets coated on the outside of nano-spherical manganese dioxide;

[0008] Preferably, the concentration ratio of potassium permanganate to manganese sulfate is 2:3;

[0009] Preferably, the volume ratio of deionized water to glycerol is (1 - 2):(5 - 8);

[0010] Preferably, the MnO2-CeO2 composite material is a flower-like structure formed by CeO2 nano-sheets coating the periphery of 50 - 100 nm MnO2;

[0011] Preferably, the mass ratio of potassium permanganate to polyvinylpyrrolidone is 1:(0.2 - 0.4);

[0012] The technical effects achieved by this application:

[0013] During the experiment of this application, CeO2 micro-nanosheets are coated on the outside of nano-spherical manganese dioxide. This structure can fully improve the light energy utilization rate. The combination of the two improves the degradation efficiency of the material for many organic pollutants. The heterojunction structure of MnO2-CeO2 is beneficial to improving the separation efficiency of electron-hole pairs of the material. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The drawings constituting a part of this application are used to provide a further understanding of the present invention. The schematic embodiments and descriptions thereof of the present invention are used to explain the present invention and do not constitute an improper limitation to the present invention.

[0015] Figure 1 This is the XRD pattern of MnO2 of this application, and its crystal structure is β-MnO2;

[0016] Figure 2 This is the scanning electron microscope image of MnO2-CeO2 of this application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0017] The present invention will be further described in detail below through specific embodiments. The following embodiments are only descriptive and not restrictive, and the protection scope of the present invention cannot be limited thereby.

[0018] Example 1

[0019] S1: Add 2 mmol of potassium permanganate and 3 mmol of manganese sulfate to 100 ml of deionized water / glycerol and stir to obtain a mixed solution, where the volume of deionized water is 20 ml and the volume of glycerol is 80 ml; add polyvinylpyrrolidone to the mixed solution; wherein, the mass ratio of potassium permanganate to polyvinylpyrrolidone is 1:0.3; after mixing evenly, place it in a microwave reactor (power is 1000 w), react at 165 °C for 0.5 h to obtain a precipitate, and wash the obtained precipitate alternately with deionized water and ethanol;

[0020] S2: Add the precipitate obtained in step S1 to 100 ml of tert-butanol solvent, continue to add 1 mmol of cerium nitrate to the solvent, mix evenly, place it in a microwave reactor (power is 1000 w), react at 160 °C for 0.5 h to obtain a precipitate, and continue to wash the obtained precipitate alternately with deionized water and ethanol 3 times; obtain the MnO2-CeO2 composite material.

[0021] Example 2

[0022] S1: Add 2 mmol of potassium permanganate and 3 mmol of manganese sulfate into 100 ml of deionized water / glycerol and stir to obtain a mixed solution, where the volume of deionized water is 20 ml and the volume of glycerol is 100 ml; add polyvinylpyrrolidone to the said mixed solution; wherein, the mass ratio of potassium permanganate to polyvinylpyrrolidone is 1:0.3; after mixing evenly, place it in a microwave reactor (with a power of 800 w), react at 165 °C for 1 h to obtain a precipitate, and wash the obtained precipitate alternately with deionized water and ethanol;

[0023] S2: Add the precipitate obtained in step S1 into 100 ml of tert-butanol solvent, continue to add 1 mmol of cerium nitrate in the solvent, mix evenly, place it in a microwave reactor (with a power of 800 w), react at 160 °C for 1 h to obtain a precipitate, and continue to wash the obtained precipitate alternately with deionized water and ethanol 3 times; obtain the MnO2-CeO2 composite material.

[0024] Example 3

[0025] S1: Add 2 mmol of potassium permanganate and 3 mmol of manganese sulfate into 100 ml of deionized water / glycerol and stir to obtain a mixed solution, where the volume of deionized water is 20 ml and the volume of glycerol is 100 ml; add polyvinylpyrrolidone to the said mixed solution; wherein, the mass ratio of potassium permanganate to polyvinylpyrrolidone is 1:0.4; after mixing evenly, place it in a microwave reactor (with a power of 1000 w), react at 165 °C for 40 min to obtain a precipitate, and wash the obtained precipitate alternately with deionized water and ethanol;

[0026] S2: Add the precipitate obtained in step S1 into 80 ml of tert-butanol solvent, continue to add 1 mmol of cerium nitrate in the solvent, mix evenly, place it in a microwave reactor (with a power of 1000 w), react at 160 °C for 1 h to obtain a precipitate, and continue to wash the obtained precipitate alternately with deionized water and ethanol 3 times; obtain the MnO2-CeO2 composite material.

[0027] Comparative Example 1

[0028] S1: Add 2 mmol of potassium permanganate and 3 mmol of manganese sulfate into 100 ml of deionized water / glycerol and stir to obtain a mixed solution, where the volume of deionized water is 20 ml and the volume of glycerol is 80 ml; add polyvinylpyrrolidone to the said mixed solution; wherein, the mass ratio of potassium permanganate to polyvinylpyrrolidone is 1:0.3; after mixing evenly, place it in a microwave reactor (with a power of 1000 w), react at 165 °C for 0.5 h to obtain a precipitate, and wash the obtained precipitate alternately with deionized water and ethanol; obtain MnO2.

[0029] Comparative Example 2

[0030] Add 1 mmol of cerium nitrate to 100 ml of tert-butanol solvent. After mixing evenly, place it in a microwave reactor (with a power of 1000 w) and react at 160 °C for 0.5 h to obtain a precipitate. Then continue to wash the obtained precipitate alternately with deionized water and ethanol three times; CeO2 is obtained.

[0031] Comparative Example 3

[0032] S1: Add 2 mmol of potassium permanganate and 3 mmol of manganese sulfate to 100 ml of deionized water / glycerol and stir to obtain a mixed solution, where the volume of deionized water is 80 ml and the volume of glycerol is 20 ml; add polyvinylpyrrolidone to the said mixed solution; wherein, the mass ratio of potassium permanganate to polyvinylpyrrolidone is 1:0.3; after mixing evenly, place it in a microwave reactor (with a power of 1000 w) and react at 165 °C for 0.5 h to obtain a precipitate, and wash the obtained precipitate alternately with deionized water and ethanol;

[0033] S2: Add the precipitate obtained in step S1 to 100 ml of tert-butanol solvent, and continue to add 1 mmol of cerium nitrate to the solvent. After mixing evenly, place it in a microwave reactor (with a power of 1000 w) and react at 160 °C for 0.5 h to obtain a precipitate. Then continue to wash the obtained precipitate alternately with deionized water and ethanol three times; MnO2-CeO2 composite material is obtained.

[0034] Comparative Example 4

[0035] S1: Add 2 mmol of potassium permanganate and 3 mmol of manganese sulfate to 100 ml of deionized water / glycerol and stir to obtain a mixed solution, where the volume of deionized water is 20 ml and the volume of glycerol is 80 ml; after mixing evenly, place it in a microwave reactor (with a power of 1000 w) and react at 165 °C for 0.5 h to obtain a precipitate, and wash the obtained precipitate alternately with deionized water and ethanol;

[0036] S2: Add the precipitate obtained in step S1 to 100 ml of tert-butanol solvent, and continue to add 1 mmol of cerium nitrate to the solvent. After mixing evenly, place it in a microwave reactor (with a power of 1000 w) and react at 160 °C for 0.5 h to obtain a precipitate. Then continue to wash the obtained precipitate alternately with deionized water and ethanol three times; MnO2-CeO2 composite material is obtained.

[0037] Prepare 50 mL of organic polluted water of rhodamine B, tetracycline, and methyl orange with a concentration of 50 ppm respectively. Add 30 mg of the materials prepared in Examples 1-4 or Comparative Examples 1-4 to the simulated sewage. After stirring and mixing evenly for 30 min, turn on a 400w xenon lamp for photocatalytic reaction. After 3 h, test the removal rates of rhodamine B, tetracycline, and methyl orange by the materials prepared in different Examples / Comparative Examples. The results can be seen in the following table.

[0038]

[0039]

[0040] From the degradation of organic matter by different catalysts in Examples 1-4 and Comparative Examples 1-4 above, the MnO2-CeO2 in Examples 1-4 showed overall better catalytic efficiency.

[0041] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. A preparation method of a water purification material, characterized in that S1: Add potassium permanganate and manganese sulfate to deionized water / glycerol and stir to obtain a mixed solution; add polyvinylpyrrolidone to the mixed solution; after mixing evenly, place it in a microwave reactor and react at 165-180 °C for 0.5-2 h to obtain a precipitate, and wash the obtained precipitate alternately with deionized water and ethanol 3 times; the volume ratio of deionized water to glycerol is (1-2):(5-8); S2: Add the precipitate obtained in step S1 to tert-butanol solvent, continue to add cerium nitrate in the solvent, after mixing evenly, place it in a microwave reactor and react at 160 °C - 180 °C for 0.5-2 h to obtain a precipitate, and continue to wash the obtained precipitate alternately with deionized water and ethanol 3 times; obtain the MnO2-CeO2 composite material; the MnO2-CeO2 composite material is a flower-like structure formed by CeO2 nanosheets coating the periphery of β-MnO2 nanospheres.

2. The preparation method of a water purification material according to claim 1, wherein the concentration ratio of potassium permanganate to manganese sulfate is 2:

3.

3. The preparation method of a water purification material according to claim 1, wherein the mass ratio of potassium permanganate to polyvinylpyrrolidone is 1:(0.2-0.4).

4. A water purification material, characterized in that, Prepared by using any one of the methods of claims 1-3.

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