High-efficiency water treatment photocatalyst material and preparation method and application thereof

Abstract

The application discloses a kind of high-efficiency water treatment photocatalyst materials and its preparation method and application, comprising the following steps: S1, preparation of zinc activated montmorillonite;S2, preparation of modified montmorillonite;S3, preparation of molybdenum disulfide / titanium dioxide / montmorillonite composite;S4, preparation of high-efficiency water treatment photocatalyst material.The photocatalyst material uses modified montmorillonite as carrier, generates molybdenum disulfide and titanium dioxide in situ on its surface by hydrothermal method, not only can solve the separation problem of titanium dioxide catalyst, and use the strong adsorption of modified montmorillonite, it is beneficial to adsorb organic matter in industrial wastewater on the surface of catalyst, thereby further improve the effect of photocatalytic reaction;It can simultaneously use the photocatalytic capacity of molybdenum disulfide and titanium dioxide and the adsorption capacity of montmorillonite to treat pollutants in water, there are less organic pollutants on the surface of modified montmorillonite after photocatalytic reaction, it is beneficial to long-term use of photocatalytic material.

Description

Technical Field

[0001] This invention belongs to the field of photocatalytic materials technology, specifically relating to a high-efficiency water treatment photocatalyst material, its preparation method, and its application. Background Technology

[0002] With economic development, the total amount of organic wastewater generated by leading industries such as coal coking, metallurgy, chemicals, deep processing of agricultural and sideline products, tobacco, and pharmaceuticals is constantly increasing, and the types of wastewater are complex. The treatment of high-concentration industrial organic wastewater has become a recognized challenge in the wastewater treatment industry both domestically and internationally. This type of wastewater has a high chemical oxygen demand (COD), generally exceeding 2000 mg / L, and in some cases reaching tens of thousands to hundreds of thousands of mg / L. Currently, physical, chemical, and biochemical methods, as well as combinations thereof, are commonly used for the treatment of industrial wastewater. However, due to the special properties of this type of wastewater, conventional treatment technologies generally struggle to achieve satisfactory treatment results.

[0003] Photocatalysis is a widely recognized method for treating wastewater in recent years due to its low cost and lack of secondary pollution. After exposure to light radiation, organic molecules in wastewater are broken down into smaller inorganic molecules. The light source used in photocatalysis can be natural or artificial. Photocatalysis involves the separation of photogenerated charge carriers in a semiconductor material under specific wavelengths of light. The photogenerated electrons and holes then combine with ions or molecules to generate active free radicals with oxidizing or reducing properties. These free radicals degrade large organic molecules into carbon dioxide or other smaller organic molecules, as well as water. During the reaction, the semiconductor material itself, the photocatalyst, remains unchanged. As a highly efficient, safe, and environmentally friendly wastewater purification technology, photocatalysis has gained international recognition for its effectiveness in improving wastewater quality.

[0004] Currently, TiO2 is the most commonly used catalyst in photocatalysis. TiO2 has high catalytic efficiency for dyes, stable chemical properties, relatively mild reaction conditions, and is harmless to the human body. It is very effective in degrading organic pollutants in water, possessing advantages that other traditional water treatment processes cannot match, thus showing broad application prospects. However, it also has shortcomings, such as a wide band gap and low efficiency in utilizing sunlight.

[0005] The main method for improving the photocatalytic performance of TiO2 is doping. Doping can be categorized into metal ion doping and non-metal ion doping. Metal ion doping can reduce the band gap to some extent, expanding the response range of TiO2 to sunlight, but it may affect the thermal stability of TiO2. Non-metal ion doping can maintain the excellent performance of TiO2 itself, reduce the band gap, broaden the response range of visible light, and effectively suppress the recombination of photogenerated carriers, thereby improving its photocatalytic performance. Compared with metal ions, non-metal ions also have advantages such as wide availability and low cost. Therefore, non-metal ion doping is more conducive to improving the photocatalytic performance of TiO2 and gaining market acceptance. Non-metal element doping is mostly done with elements such as B, C, N, F, P, and S.

[0006] Chinese patent application number 200810051025.9 relates to the preparation of inorganic functional materials, particularly the preparation of photocatalysts using microporous minerals as supports and loading wide-bandgap N-type semiconductors. The method involves preparing supports using natural and artificially modified microporous minerals, and then using a sol-gel impregnation method to load N-type semiconductors and composite semiconductors with photocatalytic functions. The resulting catalysts are applied to the photocatalytic degradation of organic pollutants or as fillers in coatings. However, the semiconductors or composite semiconductors prepared by the above method suffer from problems such as uneven particle size, susceptibility to poisoning, poor water resistance, and insufficient catalytic efficiency.

[0007] Therefore, developing a high-efficiency photocatalyst for industrial wastewater treatment that is more stable, has higher catalytic effect and efficiency, and is inexpensive meets market demand and has broad market value and application prospects. Summary of the Invention

[0008] To address the shortcomings of existing technologies, the present invention aims to provide a high-efficiency water treatment photocatalyst material, its preparation method, and its application. This photocatalyst exhibits excellent catalytic performance and good stability, and can effectively and efficiently adsorb and degrade high-concentration organic pollutants in industrial wastewater, thereby further improving the purification effect of industrial wastewater.

[0009] To achieve the above objectives, the present invention provides the following technical solution:

[0010] A method for preparing a high-efficiency water treatment photocatalyst material includes the following steps:

[0011] S1. Preparation of zinc-activated montmorillonite: Montmorillonite was impregnated in hydrochloric acid. After impregnation, it was filtered, washed, and dried to obtain a solid powder. Then, the solid powder was added to a zinc chloride solution and stirred evenly. Ammonia water was added to adjust the pH to 7 and stirred to react. After the reaction was completed, it was filtered, washed, dried, and calcined to obtain zinc-activated montmorillonite.

[0012] S2. Preparation of modified montmorillonite: The zinc-activated montmorillonite obtained in step S1 is added to deionized water, followed by chitosan acetic acid solution and polyvinyl alcohol. The mixture is subjected to a constant temperature reaction. After the reaction is completed, the mixture is filtered, washed, calcined, and ground to obtain modified montmorillonite.

[0013] S3. Preparation of molybdenum disulfide / titanium dioxide / montmorillonite composite: The modified montmorillonite from step S2 was added to deionized water, ultrasonically dispersed, and then ammonium molybdate, thiourea, tetrabutyl titanate and ethylenediamine were added. After stirring evenly, a hydrothermal reaction was carried out. After the reaction was completed, the mixture was filtered, washed and dried to obtain molybdenum disulfide / titanium dioxide / montmorillonite composite.

[0014] S4. Preparation of high-efficiency water treatment photocatalyst material: The molybdenum disulfide / titanium dioxide / montmorillonite composite obtained in step S3 is impregnated in a mixed solution of nickel nitrate and cobalt nitrate. After impregnation, the material is dried and calcined to obtain the high-efficiency water treatment photocatalyst material.

[0015] Preferably, the hydrochloric acid in step S1 has a mass fraction of 5-8%, the immersion temperature is 40-50°C, and the immersion time is 2-4 hours.

[0016] Preferably, in step S1, the mass-to-volume ratio of the solid powder to the zinc chloride solution is 5-10g:200-300mL, the concentration of the zinc chloride solution is 30-50g / L, the mass fraction of the ammonia water is 5%, the stirring reaction temperature is 60-70℃, and the time is 3-5h; the calcination temperature is 300-400℃, and the time is 2-3h.

[0017] Preferably, in step S2, the mass ratio of zinc-activated montmorillonite, chitosan acetic acid solution, and polyvinyl alcohol is 5-10:100-150:1-2; the isothermal reaction temperature is 70-80℃, and the time is 1-3 hours.

[0018] Preferably, in step S2, the chitosan in the chitosan-acetic acid solution has a chitosan mass fraction of 5%, and the acetic acid in the acetic acid solution has a mass concentration of 10%; the calcination temperature is 600-700℃, and the time is 1-2 hours.

[0019] Preferably, the mass ratio of modified montmorillonite, ammonium molybdate, thiourea, tetrabutyl titanate and ethylenediamine in step S3 is 20:10-20:15-30:30-40:25-35.

[0020] Preferably, the hydrothermal reaction in step S3 is carried out at a temperature of 150-180°C for 4-6 hours.

[0021] Preferably, in step S4, the concentration of nickel nitrate in the mixed solution is 0.1-0.3 mol / L, and the concentration of cobalt nitrate is 0.1-0.3 mol / L; the impregnation temperature is 40-50℃, and the time is 1-2 h; the calcination temperature is 400-500℃, and the time is 3-5 h.

[0022] This invention also protects a high-efficiency water treatment photocatalyst material prepared by the aforementioned preparation method.

[0023] This invention also protects the application of the aforementioned high-efficiency water treatment photocatalyst material in the treatment of high-concentration industrial wastewater.

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

[0025] (1) The high-efficiency water treatment photocatalyst material provided by the present invention uses modified montmorillonite as a carrier and generates molybdenum disulfide and titanium dioxide in situ on its surface by hydrothermal method. This not only solves the separation problem of titanium dioxide catalyst, but also utilizes the strong adsorption properties of modified montmorillonite to adsorb organic matter in industrial wastewater onto the catalyst surface, thereby further improving the photocatalytic reaction effect.

[0026] (2) The high-efficiency water treatment photocatalyst material provided by this invention firstly weakens the interlayer bonding force of montmorillonite by acid treatment, causing the interlayer lattice to crack and the interlayer spacing to increase. After modification, the specific surface area and adsorption capacity of montmorillonite are significantly improved. Then, it is ion-exchanged with zinc chloride solution, allowing zinc ions to enter the interlayer of montmorillonite through ion exchange. After calcination, the zinc ions are converted into stable zinc oxide columns, which expand the interlayer of montmorillonite to form a mesh-like montmorillonite, thereby improving the adsorption performance of montmorillonite. Then, chitosan is used to modify zinc-activated montmorillonite, so that chitosan coats the surface of montmorillonite. After calcination, biochar is formed on the surface of montmorillonite. The calcined chitosan forms porous carbon, which increases the specific surface area of ​​montmorillonite and overcomes the problem that titanium dioxide and molybdenum disulfide can only grow along the layered direction of montmorillonite in subsequent reactions due to the spatial confinement effect, thus leading to the growth of titanium dioxide and molybdenum disulfide. The problem of reduced edge active site density of titanium dioxide and molybdenum disulfide was addressed by increasing the density of edge active sites of titanium dioxide and molybdenum disulfide and improving the utilization efficiency of the montmorillonite surface, thereby enhancing the catalytic activity of the photocatalytic material. Subsequently, ammonium molybdate, thiourea, tetrabutyl titanate, and ethylenediamine were subjected to a hydrothermal reaction with modified montmorillonite, allowing the generated titanium dioxide and molybdenum disulfide to be loaded onto the surface of montmorillonite. Compared with direct blending, this effectively improved the bonding strength between titanium dioxide, molybdenum disulfide, and montmorillonite. Furthermore, molybdenum disulfide has good visible light absorption, and its synergistic effect with titanium dioxide resulted in a wider band gap for the photocatalyst, which can improve the light utilization rate and catalytic activity of the photocatalyst material. Finally, the molybdenum disulfide / titanium dioxide / montmorillonite composite was impregnated in nickel nitrate and cobalt nitrate solutions and calcined to introduce nickel and cobalt ions, further enhancing the catalytic activity of the photocatalyst.

[0027] (3) The high-efficiency water treatment photocatalyst material provided by the present invention can simultaneously utilize the photocatalytic capabilities of molybdenum disulfide and titanium dioxide as well as the adsorption capabilities of montmorillonite to treat pollutants in water. After the photocatalytic reaction is completed, the surface of the modified montmorillonite has fewer organic pollutants, which is conducive to the long-term utilization of the photocatalytic material. Detailed Implementation

[0028] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0029] The montmorillonite was purchased from Shijiazhuang Huabang Mineral Products Co., Ltd., with a mesh size of 400; the polyvinyl alcohol was PVA-1799.

[0030] Example 1

[0031] A method for preparing a high-efficiency water treatment photocatalyst material includes the following steps:

[0032] S1. Preparation of zinc-activated montmorillonite: 50g of montmorillonite was impregnated in 500mL of 7% hydrochloric acid at 45℃ for 3 hours. After impregnation, the mixture was filtered, washed, and dried to obtain a solid powder. Then, 10g of the solid powder was added to 300mL of 30g / L zinc chloride solution and stirred evenly. Ammonia water with a mass fraction of 5% was added to adjust the pH to 7, and the mixture was stirred and reacted at 65℃ for 4 hours. After the reaction was completed, the mixture was filtered, washed, and dried, and then calcined at 350℃ for 2.5 hours to obtain zinc-activated montmorillonite.

[0033] S2. Preparation of modified montmorillonite: 10g of zinc-activated montmorillonite obtained in step S1 was added to 200mL of deionized water, followed by 150g of chitosan-acetic acid solution and 2g of polyvinyl alcohol. The reaction was carried out at a constant temperature of 75℃ for 2 hours. After the reaction was completed, the mixture was filtered, washed, and calcined under a nitrogen atmosphere at 650℃ for 1.5 hours. The mixture was then ground to 200 mesh to obtain modified montmorillonite. The chitosan-acetic acid solution contained 5% chitosan by mass, and the acetic acid solution contained 10% acetic acid by mass.

[0034] S3. Preparation of molybdenum disulfide / titanium dioxide / montmorillonite composite: 20g of modified montmorillonite from step S2 was added to 500mL of deionized water and ultrasonically dispersed. Then, 15g of ammonium molybdate, 25g of thiourea, 35g of tetrabutyl titanate and 30g of ethylenediamine were added. After stirring evenly, a hydrothermal reaction was carried out at 170℃ for 5h. After the reaction was completed, the mixture was filtered, washed and dried to obtain the molybdenum disulfide / titanium dioxide / montmorillonite composite.

[0035] S4. Preparation of high-efficiency water treatment photocatalyst material: 20g of molybdenum disulfide / titanium dioxide / montmorillonite composite obtained in step S3 was impregnated in a mixed solution of nickel nitrate and cobalt nitrate in 300mL. The concentration of nickel nitrate was 0.2mol / L and the concentration of cobalt nitrate was 0.2mol / L. The impregnation temperature was 45℃ and the time was 1.5h. After impregnation, the mixture was dried and calcined under nitrogen at 450℃ for 4h to obtain the high-efficiency water treatment photocatalyst material.

[0036] Example 2

[0037] A method for preparing a high-efficiency water treatment photocatalyst material includes the following steps:

[0038] S1. Preparation of zinc-activated montmorillonite: 50g of montmorillonite was impregnated in 500mL of 6% hydrochloric acid at 45℃ for 3 hours. After impregnation, the mixture was filtered, washed, and dried to obtain a solid powder. Then, 10g of the solid powder was added to 250mL of 40g / L zinc chloride solution and stirred evenly. Ammonia water with a mass fraction of 5% was added to adjust the pH to 7, and the mixture was stirred and reacted at 65℃ for 4 hours. After the reaction was completed, the mixture was filtered, washed, and dried, and then calcined at 350℃ for 3 hours to obtain zinc-activated montmorillonite.

[0039] S2. Preparation of modified montmorillonite: 8g of zinc-activated montmorillonite obtained in step S1 was added to 200mL of deionized water, followed by 130g of chitosan-acetic acid solution and 1.5g of polyvinyl alcohol. The mixture was subjected to a constant-temperature reaction at 75℃ for 2 hours. After the reaction was complete, the mixture was filtered, washed, and calcined under a nitrogen atmosphere at 650℃ for 1.5 hours. The mixture was then ground to 200 mesh to obtain modified montmorillonite. The chitosan-acetic acid solution contained 5% chitosan by mass, and the acetic acid solution contained 10% acetic acid by mass.

[0040] S3. Preparation of molybdenum disulfide / titanium dioxide / montmorillonite composite: 20g of modified montmorillonite from step S2 was added to 500mL of deionized water and ultrasonically dispersed. Then, 15g of ammonium molybdate, 20g of thiourea, 35g of tetrabutyl titanate and 30g of ethylenediamine were added. After stirring evenly, a hydrothermal reaction was carried out at 160℃ for 5h. After the reaction was completed, the mixture was filtered, washed and dried to obtain the molybdenum disulfide / titanium dioxide / montmorillonite composite.

[0041] S4. Preparation of high-efficiency water treatment photocatalyst material: 20g of molybdenum disulfide / titanium dioxide / montmorillonite composite obtained in step S3 was impregnated in a mixed solution of nickel nitrate and cobalt nitrate in 300mL. The concentration of nickel nitrate was 0.2mol / L and the concentration of cobalt nitrate was 0.2mol / L. The impregnation temperature was 45℃ and the time was 2h. After impregnation, the material was dried and calcined under nitrogen at 450℃ for 4h to obtain the high-efficiency water treatment photocatalyst material.

[0042] Example 3

[0043] A method for preparing a high-efficiency water treatment photocatalyst material includes the following steps:

[0044] S1. Preparation of zinc-activated montmorillonite: 50g of montmorillonite was impregnated in 500mL of 5% hydrochloric acid at 40℃ for 4 hours. After impregnation, the mixture was filtered, washed, and dried to obtain a solid powder. Then, 5g of the solid powder was added to 200mL of 50g / L zinc chloride solution and stirred evenly. Ammonia water with a mass fraction of 5% was added to adjust the pH to 7, and the mixture was stirred and reacted at 60℃ for 5 hours. After the reaction was completed, the mixture was filtered, washed, and dried, and then calcined at 300℃ for 3 hours to obtain zinc-activated montmorillonite.

[0045] S2. Preparation of modified montmorillonite: 5g of zinc-activated montmorillonite obtained in step S1 was added to 200mL of deionized water, followed by 100g of chitosan-acetic acid solution and 1g of polyvinyl alcohol. The reaction was carried out at a constant temperature of 70℃ for 3 hours. After the reaction was completed, the mixture was filtered, washed, and calcined under a nitrogen atmosphere at 600℃ for 2 hours. The mixture was then ground to 200 mesh to obtain modified montmorillonite. The chitosan-acetic acid solution contained 5% chitosan by mass, and the acetic acid solution contained 10% acetic acid by mass.

[0046] S3. Preparation of molybdenum disulfide / titanium dioxide / montmorillonite composite: 20g of modified montmorillonite from step S2 was added to 500mL of deionized water and ultrasonically dispersed. Then, 10g of ammonium molybdate, 15g of thiourea, 30g of tetrabutyl titanate and 25g of ethylenediamine were added. After stirring evenly, a hydrothermal reaction was carried out at 150℃ for 6h. After the reaction was completed, the mixture was filtered, washed and dried to obtain the molybdenum disulfide / titanium dioxide / montmorillonite composite.

[0047] S4. Preparation of high-efficiency water treatment photocatalyst material: 20g of molybdenum disulfide / titanium dioxide / montmorillonite composite obtained in step S3 was impregnated in a mixed solution of nickel nitrate and cobalt nitrate in 300mL. The concentration of nickel nitrate was 0.1mol / L and the concentration of cobalt nitrate was 0.3mol / L. The impregnation temperature was 40℃ and the time was 2h. After impregnation, the material was dried and calcined under nitrogen at 400℃ for 5h to obtain the high-efficiency water treatment photocatalyst material.

[0048] Example 4

[0049] A method for preparing a high-efficiency water treatment photocatalyst material includes the following steps:

[0050] S1. Preparation of zinc-activated montmorillonite: 50g of montmorillonite was impregnated in 500mL of 8% hydrochloric acid at 50℃ for 2h. After impregnation, the mixture was filtered, washed, and dried to obtain a solid powder. Then, 10g of the solid powder was added to 300mL of 30g / L zinc chloride solution and stirred evenly. Ammonia water with a mass fraction of 5% was added to adjust the pH to 7, and the mixture was stirred and reacted at 70℃ for 3h. After the reaction was completed, the mixture was filtered, washed, and dried, and then calcined at 400℃ for 2h to obtain zinc-activated montmorillonite.

[0051] S2. Preparation of modified montmorillonite: 10g of zinc-activated montmorillonite obtained in step S1 was added to 200mL of deionized water, followed by 150g of chitosan-acetic acid solution and 2g of polyvinyl alcohol. The mixture was subjected to a constant temperature reaction at 80℃ for 1h. After the reaction was completed, the mixture was filtered, washed, and calcined under a nitrogen atmosphere at 700℃ for 1h. The mixture was then ground to 200 mesh to obtain modified montmorillonite. The chitosan-acetic acid solution contained 5% chitosan by mass, and the acetic acid solution contained 10% acetic acid by mass.

[0052] S3. Preparation of molybdenum disulfide / titanium dioxide / montmorillonite composite: 20g of modified montmorillonite from step S2 was added to 500mL of deionized water and ultrasonically dispersed. Then, 20g of ammonium molybdate, 30g of thiourea, 40g of tetrabutyl titanate and 35g of ethylenediamine were added. After stirring evenly, a hydrothermal reaction was carried out at 180℃ for 4h. After the reaction was completed, the mixture was filtered, washed and dried to obtain the molybdenum disulfide / titanium dioxide / montmorillonite composite.

[0053] S4. Preparation of high-efficiency water treatment photocatalyst material: 20g of molybdenum disulfide / titanium dioxide / montmorillonite composite obtained in step S3 was impregnated in a mixed solution of nickel nitrate and cobalt nitrate in 300mL. The concentration of nickel nitrate was 0.3mol / L and the concentration of cobalt nitrate was 0.1mol / L. The impregnation temperature was 50℃ and the time was 1h. After impregnation, the material was dried and calcined under nitrogen at 500℃ for 3h to obtain the high-efficiency water treatment photocatalyst material.

[0054] Comparative Example 1

[0055] A method for preparing a high-efficiency water treatment photocatalyst material includes the following steps:

[0056] S1. Preparation of zinc-activated montmorillonite: 50g of montmorillonite was impregnated in 500mL of 7% hydrochloric acid at 45℃ for 3 hours. After impregnation, the mixture was filtered, washed, and dried to obtain a solid powder. Then, 10g of the solid powder was added to 300mL of 30g / L zinc chloride solution and stirred evenly. Ammonia water with a mass fraction of 5% was added to adjust the pH to 7, and the mixture was stirred and reacted at 65℃ for 4 hours. After the reaction was completed, the mixture was filtered, washed, and dried, and then calcined at 350℃ for 2.5 hours to obtain zinc-activated montmorillonite.

[0057] S2. Preparation of molybdenum disulfide / titanium dioxide / montmorillonite composite: 20g of zinc-activated montmorillonite from step S1 was added to 500mL of deionized water and ultrasonically dispersed. Then, 15g of ammonium molybdate, 25g of thiourea, 35g of tetrabutyl titanate and 30g of ethylenediamine were added. After stirring evenly, a hydrothermal reaction was carried out at 170℃ for 5h. After the reaction was completed, the mixture was filtered, washed and dried to obtain the molybdenum disulfide / titanium dioxide / montmorillonite composite.

[0058] S3. Preparation of high-efficiency water treatment photocatalyst material: 20g of molybdenum disulfide / titanium dioxide / montmorillonite composite obtained in step S2 was impregnated in a mixed solution of nickel nitrate and cobalt nitrate in 300mL. The concentration of nickel nitrate was 0.2mol / L and the concentration of cobalt nitrate was 0.2mol / L. The impregnation temperature was 45℃ and the time was 1.5h. After impregnation, the mixture was dried and calcined under nitrogen at 450℃ for 4h to obtain the high-efficiency water treatment photocatalyst material.

[0059] Comparative Example 2

[0060] A method for preparing a high-efficiency water treatment photocatalyst material includes the following steps:

[0061] S1. Preparation of zinc-activated montmorillonite: 50g of montmorillonite was impregnated in 500mL of 7% hydrochloric acid at 45℃ for 3 hours. After impregnation, the mixture was filtered, washed, and dried to obtain a solid powder. Then, 10g of the solid powder was added to 300mL of 30g / L zinc chloride solution and stirred evenly. Ammonia water with a mass fraction of 5% was added to adjust the pH to 7, and the mixture was stirred and reacted at 65℃ for 4 hours. After the reaction was completed, the mixture was filtered, washed, and dried, and then calcined at 350℃ for 2.5 hours to obtain zinc-activated montmorillonite.

[0062] S2. Preparation of modified montmorillonite: 10g of zinc-activated montmorillonite obtained in step S1 was added to 200mL of deionized water, followed by 150g of chitosan-acetic acid solution and 2g of polyvinyl alcohol. The reaction was carried out at a constant temperature of 75℃ for 2 hours. After the reaction was completed, the mixture was filtered, washed, and calcined under a nitrogen atmosphere at 650℃ for 1.5 hours. The mixture was then ground to 200 mesh to obtain modified montmorillonite. The chitosan-acetic acid solution contained 5% chitosan by mass, and the acetic acid solution contained 10% acetic acid by mass.

[0063] S3. Preparation of titanium dioxide / montmorillonite composite: 20g of modified montmorillonite from step S2 was added to 500mL of deionized water, ultrasonically dispersed, and then 50g of tetrabutyl titanate and 55g of ethylenediamine were added. After stirring evenly, a hydrothermal reaction was carried out at a temperature of 170℃ for 5h. After the reaction was completed, the mixture was filtered, washed, and dried to obtain the titanium dioxide / montmorillonite composite.

[0064] S4. Preparation of high-efficiency water treatment photocatalyst material: 20g of titanium dioxide / montmorillonite composite obtained in step S3 was added to 300mL of a mixed solution of nickel nitrate and cobalt nitrate for impregnation. The concentration of nickel nitrate was 0.2mol / L and the concentration of cobalt nitrate was 0.2mol / L. The impregnation temperature was 45℃ and the time was 1.5h. After impregnation, the material was dried and calcined under nitrogen at 450℃ for 4h to obtain the high-efficiency water treatment photocatalyst material.

[0065] Comparative Example 3

[0066] A method for preparing a high-efficiency water treatment photocatalyst material includes the following steps:

[0067] S1. Preparation of zinc-activated montmorillonite: 50g of montmorillonite was impregnated in 500mL of 7% hydrochloric acid at 45℃ for 3 hours. After impregnation, the mixture was filtered, washed, and dried to obtain a solid powder. Then, 10g of the solid powder was added to 300mL of 30g / L zinc chloride solution and stirred evenly. Ammonia water with a mass fraction of 5% was added to adjust the pH to 7, and the mixture was stirred and reacted at 65℃ for 4 hours. After the reaction was completed, the mixture was filtered, washed, and dried, and then calcined at 350℃ for 2.5 hours to obtain zinc-activated montmorillonite.

[0068] S2. Preparation of modified montmorillonite: 10g of zinc-activated montmorillonite obtained in step S1 was added to 200mL of deionized water, followed by 150g of chitosan-acetic acid solution and 2g of polyvinyl alcohol. The reaction was carried out at a constant temperature of 75℃ for 2 hours. After the reaction was completed, the mixture was filtered, washed, and calcined under a nitrogen atmosphere at 650℃ for 1.5 hours. The mixture was then ground to 200 mesh to obtain modified montmorillonite. The chitosan-acetic acid solution contained 5% chitosan by mass, and the acetic acid solution contained 10% acetic acid by mass.

[0069] S3. Preparation of molybdenum disulfide / montmorillonite composite: 20g of modified montmorillonite from step S2 was added to 500mL of deionized water, ultrasonically dispersed, and then 50g of ammonium molybdate and 55g of thiourea were added. After stirring evenly, a hydrothermal reaction was carried out at a temperature of 170℃ for 5h. After the reaction was completed, the mixture was filtered, washed, and dried to obtain the molybdenum disulfide / montmorillonite composite.

[0070] S4. Preparation of high-efficiency water treatment photocatalyst material: 20g of molybdenum disulfide / montmorillonite composite obtained in step S3 was impregnated in a mixed solution of nickel nitrate and cobalt nitrate in 300mL. The concentration of nickel nitrate was 0.2mol / L and the concentration of cobalt nitrate was 0.2mol / L. The impregnation temperature was 45℃ and the time was 1.5h. After impregnation, the material was dried and calcined under nitrogen at 450℃ for 4h to obtain the high-efficiency water treatment photocatalyst material.

[0071] The photocatalytic performance of the high-efficiency water treatment photocatalyst materials prepared in Examples 1-4 and Comparative Examples 1-3 was tested. The specific steps are as follows: 10g of the prepared high-efficiency water treatment photocatalyst material was added to 1L of methylene blue wastewater with a concentration of 500mg / L, and irradiated under a 350W mercury lamp light source for 1 hour. The residual methylene blue was detected by UV-Vis absorption spectroscopy, and the removal rate was calculated. 10g of the prepared high-efficiency water treatment photocatalyst material was added to 1L of aniline wastewater with a concentration of 200mg / L, and irradiated under a 350W mercury lamp light source for 1 hour. The residual methylene blue was detected by UV-Vis absorption spectroscopy, and the removal rate was calculated. The test results are shown in Table 1 below.

[0072] Table 1

[0073] Methylene blue removal rate / % Aniline removal rate / % Example 1 96.3 92.4 Example 2 95.2 91.5 Example 3 95.8 90.7 Example 4 96.5 91.8 Comparative Example 1 80.6 71.2 Comparative Example 2 81.5 74.7 Comparative Example 3 76.3 70.5

[0074] As can be seen from Table 1 above, the high-efficiency water treatment photocatalyst material prepared by this invention has a good degradation effect on methylene blue and aniline.

[0075] The high-efficiency water treatment photocatalyst materials prepared in Example 1 and Comparative Examples 1-3 were used to treat high-concentration dyeing and printing wastewater. The high-concentration wastewater had a COD concentration of 3000 mg / L and an ammonia nitrogen content of 1000 mg / L. The amount of high-efficiency water treatment photocatalyst material added was 10 g / L. Under stirring conditions, the wastewater was irradiated for 6 hours under a 500 W mercury lamp light source. Samples were taken to measure the COD and ammonia nitrogen content after treatment. The removal rates and COD and ammonia nitrogen removal test results are shown in Table 2 below.

[0076] Table 2

[0077] COD removal rate / % Ammonia nitrogen removal rate / % Example 1 87.4 82.5 Comparative Example 1 63.7 60.1 Comparative Example 2 66.2 62.9 Comparative Example 3 61.5 55.6

[0078] As can be seen from Table 2, the high-efficiency water treatment photocatalytic material prepared by this invention has a good catalytic effect on high-concentration dyeing and printing wastewater.

[0079] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for preparing a high-efficiency water treatment photocatalyst material, characterized in that, Includes the following steps: S1. Preparation of zinc-activated montmorillonite: Montmorillonite was impregnated in hydrochloric acid. After impregnation, it was filtered, washed, and dried to obtain a solid powder. Then, the solid powder was added to a zinc chloride solution and stirred evenly. Ammonia water was added to adjust the pH to 7 and stirred to react. After the reaction was completed, it was filtered, washed, dried, and calcined to obtain zinc-activated montmorillonite. S2. Preparation of modified montmorillonite: The zinc-activated montmorillonite obtained in step S1 is added to deionized water, followed by chitosan acetic acid solution and polyvinyl alcohol. The mixture is subjected to a constant temperature reaction. After the reaction is completed, the mixture is filtered, washed, calcined, and ground to obtain modified montmorillonite. S3. Preparation of molybdenum disulfide / titanium dioxide / montmorillonite composite: The modified montmorillonite from step S2 was added to deionized water, ultrasonically dispersed, and then ammonium molybdate, thiourea, tetrabutyl titanate and ethylenediamine were added. After stirring evenly, a hydrothermal reaction was carried out. After the reaction was completed, the mixture was filtered, washed and dried to obtain molybdenum disulfide / titanium dioxide / montmorillonite composite. S4. Preparation of high-efficiency water treatment photocatalyst material: The molybdenum disulfide / titanium dioxide / montmorillonite composite obtained in step S3 is added to a mixed solution of nickel nitrate and cobalt nitrate for impregnation. After impregnation, the material is dried and calcined to obtain the high-efficiency water treatment photocatalyst material. In step S3, the mass ratio of modified montmorillonite, ammonium molybdate, thiourea, tetrabutyl titanate, and ethylenediamine is 20:10-20:15-30:30-40:25-35, and the hydrothermal reaction temperature is 150-180℃ for 4-6 hours.

2. The preparation method according to claim 1, characterized in that, In step S1, the hydrochloric acid has a mass fraction of 5-8%, the immersion temperature is 40-50℃, and the time is 2-4 hours.

3. The preparation method according to claim 1, characterized in that, In step S1, the mass-to-volume ratio of the solid powder to the zinc chloride solution is 5-10g:200-300mL, and the concentration of the zinc chloride solution is 30-50g / L; the mass fraction of the ammonia water is 5%; the stirring reaction temperature is 60-70℃ and the time is 3-5h; the calcination temperature is 300-400℃ and the time is 2-3h.

4. The preparation method according to claim 1, characterized in that, In step S2, the mass ratio of zinc-activated montmorillonite, chitosan acetic acid solution, and polyvinyl alcohol is 5-10:100-150:1-2; the isothermal reaction temperature is 70-80℃, and the time is 1-3 hours.

5. The preparation method according to claim 1, characterized in that, In step S2, the chitosan in the acetic acid solution has a chitosan mass fraction of 5% and the acetic acid in the acetic acid solution has a mass concentration of 10%; the calcination temperature is 600-700℃ and the time is 1-2h.

6. The preparation method according to claim 1, characterized in that, In step S4, the concentration of nickel nitrate in the mixed solution is 0.1-0.3 mol / L, and the concentration of cobalt nitrate is 0.1-0.3 mol / L; the impregnation temperature is 40-50℃, and the time is 1-2 h; the calcination temperature is 400-500℃, and the time is 3-5 h.

7. A high-efficiency water treatment photocatalyst material prepared by the preparation method according to any one of claims 1-6.

8. The application of the high-efficiency water treatment photocatalyst material as described in claim 7 in the treatment of high-concentration industrial wastewater.