Preparation method of photocatalyst for degrading emerging pollutants

Abstract

The invention belongs to the technical field of environmental protection, and particularly relates to a preparation method of a photocatalyst for degrading emerging pollutants, which comprises the following steps: S1, selecting a proper photocatalyst material, S2, carrying out synthesis preparation by adopting a proper photocatalyst synthesis method, S3, carrying out surface modification on the photocatalyst, and S4, carrying out an experiment of photocatalytic degradation of emerging pollutants. S5, reaction conditions are optimized, organic pollutants can be degraded by exciting electrons to generate free radicals under the illumination condition by adopting the modified photocatalyst, the free radicals have strong oxidizing property and can effectively decompose complex organic pollutants and reduce the harm of the complex organic pollutants to the environment, and the degradation process of the modified photocatalyst is carried out at normal temperature and normal pressure, so that the degradation effect is good. Extra chemical additives or a large amount of energy consumption is not needed, and high-temperature and high-pressure conditions required in traditional chemical reactions are reduced. Therefore, the method has remarkable green and environment-friendly properties.

Description

Technical Field

[0001] The invention relates to the technical field of photocatalyst preparation, and in particular to a method for preparing a photocatalyst for degrading emerging pollutants. Background Art

[0002] Emerging pollutants have recently been found to be widely present in the water environment and have been identified as potential environmental or public health risks. However, since most emerging pollutants have extremely low concentrations, conventional detection methods are almost impossible to measure, their hazards are not fully studied, and data are lacking, it is difficult to determine their environmental risks;

[0003] The impact of emerging pollutants on human health and environmental ecosystems is largely unknown. Some studies have shown that even very low exposure doses may have an impact on biological systems. Currently, due to the widespread use of emerging pollutants, these pollutants are continuously discharged into the environment. Therefore, it is urgent to provide a method for preparing photocatalysts for degrading emerging pollutants, so as to partially remove or degrade them through photocatalysts. Summary of the invention

[0004] The object of the present invention is to provide a method for preparing a photocatalyst for degrading emerging pollutants.

[0005] To solve the above technical problems, according to one aspect of the present invention, the present invention provides the following technical solutions:

[0006] A method for preparing a photocatalyst for degrading emerging pollutants comprises the following steps:

[0007] S1. Select appropriate photocatalyst material:

[0008] These include titanium dioxide, zinc oxide, nitrogen doping, carbon quantum dots or sulfides;

[0009] S2. Use a suitable photocatalyst synthesis method for synthesis preparation:

[0010] Common photocatalyst preparation methods include sol-gel method, deposition method, and solvent hydrothermal method;

[0011] S3. Surface modification of photocatalyst:

[0012] Improve the performance of photocatalysts, such as:

[0013] S301, doping elements: adjusting the electronic structure and light absorption capacity of the photocatalyst by doping with non-metals, such as nitrogen, sulfur, carbon, or metal elements, such as cobalt, copper, and iron;

[0014] S302 Carrier modification: Loading the photocatalyst on a porous material or nanostructured carrier to improve the surface activity and light absorption performance of the photocatalyst;

[0015] S303 forms composite materials: such as TiO2 / carbon quantum dots, TiO2 / carbon nitride composite materials, and improves catalytic efficiency through the synergistic effect of the composite materials;

[0016] S4. Experiments on photocatalytic degradation of emerging pollutants;

[0017] S5. Optimize reaction conditions.

[0018] As a preferred embodiment of the method for preparing a photocatalyst for degrading emerging pollutants according to the present invention, in step S2, the sol-gel method comprises the following operations:

[0019] S201, preparing a sol solution, usually by mixing a titanium source and a solvent, wherein the titanium source is tetraisopropyl titanate and the solvent is ethanol;

[0020] S202, adding an appropriate amount of water, adjusting the pH value, and forming a sol;

[0021] S203, stirring the sol at room temperature until it is stable;

[0022] S204, coating the sol on a carrier material, such as glass, fiber, or ceramic surface;

[0023] S205, drying and calcining at high temperature to form TiO2 film or particles.

[0024] As a preferred embodiment of the method for preparing a photocatalyst for degrading emerging pollutants according to the present invention, in step S2, the deposition method includes the following operations:

[0025] P201, select a suitable metal precursor and a solvent to mix, the metal precursor is a metal salt or a metal oxide, and the solvent is water or an alcohol solvent;

[0026] P202, transfer the mixed solution into a sealed container and heat it to react at a certain temperature (usually between 180-300°C);

[0027] P203, after the reaction is completed, cool and remove impurities by washing;

[0028] P204. The product is treated through processes such as drying and calcination to obtain the final catalyst.

[0029] As a preferred embodiment of the method for preparing a photocatalyst for degrading emerging pollutants according to the present invention, in step S2, the solvent hydrothermal method comprises the following operations:

[0030] Q301. Mix a metal salt, such as titanium sulfate, with an appropriate amount of water or ethanol;

[0031] Q302, transfer the mixture to a high pressure reactor, set the reaction temperature, usually above 100°C, and heat the reaction;

[0032] Q303, after the reaction is completed, cool the mixture to obtain a precipitate;

[0033] Q304. Wash, dry and calcine the precipitate to obtain a photocatalyst with high crystallinity.

[0034] As a preferred embodiment of the method for preparing a photocatalyst for degrading emerging pollutants according to the present invention, in step S4, the degradation experiment includes the following operations:

[0035] S401, preparing pollutant solution: selecting pollutants to be degraded and preparing a solution of a certain concentration;

[0036] S402, catalyst activation: adding the photocatalyst into the pollutant solution and stirring evenly;

[0037] S403, ultraviolet light or visible light irradiation: irradiate the catalytic system with ultraviolet light or visible light to monitor the reaction progress;

[0038] S404. Sampling and analysis: Take samples at different time intervals and use high performance liquid chromatography, gas chromatography or UV-visible spectrophotometer analysis equipment to detect the degradation of pollutants.

[0039] As a preferred embodiment of the method for preparing a photocatalyst for degrading emerging pollutants according to the present invention, in step S5, optimizing the reaction regulation includes the following:

[0040] S501, catalyst concentration: Properly increasing the catalyst concentration is helpful to increase the reaction rate, and avoiding excessively high catalyst concentration may cause the light transmittance of the reaction system to decrease;

[0041] S502, light intensity: Increasing light intensity can increase the catalytic reaction rate and avoid excessive light intensity causing light saturation on the catalyst surface;

[0042] S503. Solution pH value: Different pH values ​​have different effects on photocatalytic reactions. Optimizing the pH value can improve reaction efficiency.

[0043] Compared with the prior art, the present invention has the following beneficial effects:

[0044] 1. The modified photocatalyst can degrade organic pollutants by exciting electrons to generate free radicals under light conditions. These free radicals have strong oxidizing properties and can effectively decompose complex organic pollutants and reduce their harm to the environment;

[0045] 2. The degradation process of the modified photocatalyst occurs at room temperature and pressure, without the need for additional chemical additives or large amounts of energy consumption, reducing the high temperature and high pressure conditions required in traditional chemical reactions. Therefore, it is significantly green and environmentally friendly;

[0046] 3. The degradation reaction conditions (such as light intensity, catalyst concentration, pH value, etc.) can be optimized and adjusted according to the properties of specific pollutants, with high flexibility, so that photocatalytic technology can adapt to different environmental conditions and pollutant removal needs. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the present invention will be described in detail below in combination with the accompanying drawings and detailed embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative labor. Among them:

[0048] Figure 1 It is a schematic diagram of the preparation steps of the present invention;

[0049] Figure 2 Schematic diagram of the surface modification steps of the photocatalyst of the present invention;

[0050] Figure 3 This is a schematic diagram of the degradation experimental steps of the present invention;

[0051] Figure 4 Schematic diagram of the experimental steps for optimizing the reaction of the present invention. DETAILED DESCRIPTION

[0052] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0053] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0054] Secondly, the present invention is described in detail with reference to schematic diagrams. When describing the embodiments of the present invention in detail, for the sake of convenience, the cross-sectional diagrams showing the device structure will not be partially enlarged according to the general scale, and the schematic diagrams are only examples, which should not limit the scope of protection of the present invention. In addition, in actual production, the three-dimensional dimensions of length, width and depth should be included.

[0055] In order to make the objectives, technical solutions and advantages of the present invention more clear, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0056] The present invention provides a method for preparing a photocatalyst for degrading emerging pollutants. Figure 1 , including the following steps:

[0057] S1. Select appropriate photocatalyst material:

[0058] These include titanium dioxide, zinc oxide, nitrogen doping, carbon quantum dots or sulfides;

[0059] S2. Use a suitable photocatalyst synthesis method for synthesis preparation:

[0060] Common photocatalyst preparation methods include sol-gel method, deposition method, and solvent hydrothermal method;

[0061] S3. Surface modification of photocatalyst:

[0062] Improve the performance of photocatalysts, such as:

[0063] S301, doping elements: adjusting the electronic structure and light absorption capacity of the photocatalyst by doping with non-metals, such as nitrogen, sulfur, carbon, or metal elements, such as cobalt, copper, and iron;

[0064] S302 Carrier modification: Loading the photocatalyst on a porous material or nanostructured carrier to improve the surface activity and light absorption performance of the photocatalyst;

[0065] S303 forms composite materials: such as TiO2 / carbon quantum dots, TiO2 / carbon nitride composite materials, and improves catalytic efficiency through the synergistic effect of the composite materials;

[0066] S4. Experiments on photocatalytic degradation of emerging pollutants;

[0067] S5. Optimize reaction conditions;

[0068] Further: In step S2, the sol-gel method includes the following operations:

[0069] S201, preparing a sol solution, usually by mixing a titanium source and a solvent, wherein the titanium source is tetraisopropyl titanate and the solvent is ethanol;

[0070] S202, adding an appropriate amount of water, adjusting the pH value, and forming a sol;

[0071] S203, stirring the sol at room temperature until it is stable;

[0072] S204, coating the sol on a carrier material, such as glass, fiber, or ceramic surface;

[0073] S205, drying and calcining at high temperature to form TiO2 film or particles;

[0074] Further: In step S2, the deposition method includes the following operations:

[0075] P201, select a suitable metal precursor and a solvent to mix, the metal precursor is a metal salt or a metal oxide, and the solvent is water or an alcohol solvent;

[0076] P202, transfer the mixed solution into a sealed container and heat it to react at a certain temperature (usually between 180-300°C);

[0077] P203, after the reaction is completed, cool and remove impurities by washing;

[0078] P204, treating the product through processes such as drying and calcination to obtain the final catalyst;

[0079] Further: In step S2, the solvent hydrothermal method includes the following operations:

[0080] Q301. Mix a metal salt, such as titanium sulfate, with an appropriate amount of water or ethanol;

[0081] Q302, transfer the mixture to a high pressure reactor, set the reaction temperature, usually above 100°C, and heat the reaction;

[0082] Q303, after the reaction is completed, cool the mixture to obtain a precipitate;

[0083] Q304, washing, drying and calcining the precipitate to obtain a photocatalyst with high crystallinity;

[0084] Further: In step S4, the degradation experiment includes the following operations:

[0085] S401, preparing pollutant solution: selecting pollutants to be degraded and preparing a solution of a certain concentration;

[0086] S402, catalyst activation: adding the photocatalyst into the pollutant solution and stirring evenly;

[0087] S403, ultraviolet light or visible light irradiation: irradiate the catalytic system with ultraviolet light or visible light to monitor the reaction progress;

[0088] S404, sampling and analysis: sampling at different time intervals, using high performance liquid chromatography, gas chromatography or UV-visible spectrophotometer analysis equipment to detect the degradation of pollutants;

[0089] Further: In step S5, optimizing the reaction adjustment includes the following:

[0090] S501, catalyst concentration: Properly increasing the catalyst concentration is helpful to increase the reaction rate. Note that too high a catalyst concentration may result in a decrease in the light transmittance of the reaction system.

[0091] S502, light intensity: Increasing light intensity can increase the catalytic reaction rate and avoid excessive light intensity causing light saturation on the catalyst surface;

[0092] S503, solution pH value: different pH values ​​have different effects on photocatalytic reactions, and optimizing the pH value can improve reaction efficiency;

[0093] Example:

[0094] The comparative example is a common carbon fiber loaded with titanium dioxide photocatalyst purchased on the market;

[0095] Experimental Test:

[0096] 500 ml of titanium dioxide photocatalyst purchased from the market was added to test the photocatalytic performance of the emerging pollutant carbamazepine (the concentration of carbamazepine was 5 mg / L, the addition amount of titanium dioxide photocatalyst was 20 g / L, and the photocatalysis was carried out for 40 minutes);

[0097] Comparative Example: The photocatalytic performance of the emerging pollutant carbamazepine was tested by using the prepared photocatalyst (500 ml) (the concentration of carbamazepine was 5 mg / L, the addition amount of titanium dioxide photocatalyst was 20 g / L, and the photocatalysis was 40 min):

[0098] Processing Operation:

[0099] Add the modified photocatalyst into the pollutant solution and stir evenly;

[0100] UV or visible light irradiation: Use UV or visible light to irradiate the catalytic system and monitor the reaction progress;

[0101] Sampling and analysis: Sampling is performed at different time intervals and the degradation of pollutants is detected using HPLC, GC or UV-visible spectrophotometer analysis equipment:

[0102] By comparing the embodiment and the comparative example, it can be seen that the catalytic performance of the comparative example photocatalyst decreases significantly after a long period of catalytic treatment of sewage, while the catalytic performance of the photocatalyst of the present invention remains basically unchanged after a long period of sewage treatment, and the photocatalytic performance is relatively stable;

[0103] Under light conditions, photocatalysts can degrade organic pollutants, including emerging pollutants (such as drug residues, pesticides, industrial waste, etc.) by exciting electrons to produce free radicals. These free radicals have strong oxidizing properties and can effectively decompose complex organic pollutants and reduce their harm to the environment.

[0104] Although the present invention has been described above with reference to the embodiments, various modifications may be made thereto and parts thereof may be replaced by equivalents without departing from the scope of the present invention. In particular, as long as there is no structural conflict, the various features in the embodiments disclosed in the present invention may be used in combination with each other in any manner, and the fact that these combinations are not exhaustively described in this specification is only for the sake of omitting space and saving resources. Therefore, the present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A method for preparing a photocatalyst for degrading emerging pollutants, characterized in that: The steps are as follows: S1. Select appropriate photocatalyst material: These include titanium dioxide, zinc oxide, nitrogen doping, carbon quantum dots or sulfides; S2. Use a suitable photocatalyst synthesis method for synthesis preparation: Common photocatalyst preparation methods include sol-gel method, deposition method, and solvent hydrothermal method; S3. Surface modification of photocatalyst: Improve the performance of photocatalysts, such as: S301, doping elements: adjusting the electronic structure and light absorption capacity of the photocatalyst by doping with non-metals, such as nitrogen, sulfur, carbon, or metal elements, such as cobalt, copper, and iron; S302 Carrier modification: Loading the photocatalyst on a porous material or nanostructured carrier to improve the surface activity and light absorption performance of the photocatalyst; S303 forms composite materials: such as TiO2 / carbon quantum dots, TiO2 / carbon nitride composite materials, and improves catalytic efficiency through the synergistic effect of the composite materials; S4. Experiments on photocatalytic degradation of emerging pollutants; S5. Optimize reaction conditions.

2. The method for preparing a photocatalyst for degrading emerging pollutants according to claim 1, characterized in that: In step S2, the sol-gel method includes the following operations: S201, preparing a sol solution, usually by mixing a titanium source and a solvent, wherein the titanium source is tetraisopropyl titanate and the solvent is ethanol; S202, adding an appropriate amount of water, adjusting the pH value, and forming a sol; S203, stirring the sol at room temperature until it is stable; S204, coating the sol on a carrier material, such as glass, fiber, or ceramic surface; S205, drying and calcining at high temperature to form TiO2 film or particles.

3. The method for preparing a photocatalyst for degrading emerging pollutants according to claim 2, characterized in that: In step S2, the deposition method includes the following operations: P201, select a suitable metal precursor and a solvent to mix, the metal precursor is a metal salt or a metal oxide, and the solvent is water or an alcohol solvent; P202, transfer the mixed solution into a sealed container and heat it to react at a certain temperature (usually between 180-300°C); P203, after the reaction is completed, cool and remove impurities by washing; P204. The product is treated through processes such as drying and calcination to obtain the final catalyst.

4. The method for preparing a photocatalyst for degrading emerging pollutants according to claim 3, characterized in that: In step S2, the solvent hydrothermal method includes the following operations: Q301. Mix a metal salt, such as titanium sulfate, with an appropriate amount of water or ethanol; Q302, transfer the mixture to a high pressure reactor, set the reaction temperature, usually above 100°C, and heat the reaction; Q303, after the reaction is completed, cool the mixture to obtain a precipitate; Q304. Wash, dry and calcine the precipitate to obtain a photocatalyst with high crystallinity.

5. The method for preparing a photocatalyst for degrading emerging pollutants according to claim 4, characterized in that: In step S4, the degradation experiment includes the following operations: S401, preparing pollutant solution: selecting pollutants to be degraded and preparing a solution of a certain concentration; S402, catalyst activation: adding the photocatalyst into the pollutant solution and stirring evenly; S403, ultraviolet light or visible light irradiation: irradiate the catalytic system with ultraviolet light or visible light to monitor the reaction progress; S404. Sampling and analysis: Take samples at different time intervals and use high performance liquid chromatography, gas chromatography or UV-visible spectrophotometer analysis equipment to detect the degradation of pollutants.

6. The method for preparing a photocatalyst for degrading emerging pollutants according to claim 5, characterized in that: In step S5, optimizing the reaction adjustment includes the following: S501, catalyst concentration: Properly increasing the catalyst concentration is helpful to increase the reaction rate, and avoiding excessively high catalyst concentration may cause the light transmittance of the reaction system to decrease; S502, light intensity: Increasing light intensity can increase the catalytic reaction rate and avoid excessive light intensity causing light saturation on the catalyst surface; S503. Solution pH value: Different pH values ​​have different effects on photocatalytic reactions. Optimizing the pH value can improve reaction efficiency.

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