Process for the preparation of a gaseous pollutant purification material with photo-fenton activity

Abstract

The present application relates to the pollution purification technology, aims at providing a kind of preparation method of gaseous pollutant purification material with photo-fenton activity. Including: after mixing titanium-containing precursor, tin hydroxide, acid catalyst and dye, reaction is carried out;Modified titanium dioxide nanocrystalline coating film liquid is obtained;After mixing surfactant, ferrous salt aqueous solution and trimesic acid, reaction is carried out, and nanometer iron-based catalytic material dispersion is obtained;Mix two with polyether modified polysiloxane, then put into porous carrier and soak;After taking out, dry, obtain gaseous pollutant purification material with photo-fenton activity.The present application avoids the application limit of traditional high-temperature heat treatment process to organic high polymer and other not heat-resistant film-forming substrate, solves the problem of photo-fenton performance degradation caused by the coating effect of high molecular film-forming material on nanometer catalytic material in traditional method;Can effectively promote the migration and separation of photo-generated carriers, significantly improve photo-fenton reaction efficiency.

Description

Technical Field

[0001] The present invention relates to a pollutant purification technology, and in particular to a method for preparing a gaseous pollutant purification material with photo-Fenton activity. Background Art

[0002] Air pollution caused by indoor renovations and typical industrial emissions has become a new form of pollution. Gaseous pollutants can harm the nervous system, respiratory system, digestive system, nervous system, skin system, vision system, and even cause cancer and blood diseases. Therefore, the control of gaseous pollutants has attracted widespread attention.

[0003] Currently, air pollution is widely addressed through purification technologies such as adsorption, oxidant oxidation, ozone purification, and photocatalysis. However, adsorption technology cannot decompose pollutants and suffers from issues such as saturation, short service life, and secondary pollution. Oxidant oxidation consumes the oxidant during the treatment process, resulting in poor durability. Ozone purification technology is prone to secondary ozone pollution. While photocatalysis offers strong oxidative decomposition capabilities, it still suffers from insufficient purification efficiency when treating high-volume, high-concentration gaseous pollutants. Therefore, the development of new and efficient gaseous pollutant purification technologies is urgently needed.

[0004] As an advanced oxidation process, photo-Fenton technology has the advantages of excellent degradation performance, strong operability and high stability, and has shown great application potential in the field of environmental purification. However, the iron-based catalysts currently in widespread use are mostly iron oxides or modified iron compounds. Although they work well in traditional Fenton processes, they have poor light response performance and are difficult to apply to photo-Fenton processes. In addition, the iron-based catalysts currently available for photo-Fenton processes still have problems such as easy recombination of photogenerated carriers and low quantum efficiency. Therefore, the development of efficient iron-based catalysts that can fully utilize the energy of light to produce active substances has become the focus of photo-Fenton technology research.

[0005] Furthermore, existing iron-based catalysts are mostly in powder form, which poses a problem of powder recovery during application. Supported catalysts typically incorporate catalyst particles into a polymer film-forming material, which then adheres to the substrate surface through the bonding action of the polymer. However, the coating of the catalyst particles by the polymer film can reduce their activity. High-temperature heat treatment (generally above 350°C) can also achieve a strong bond between the catalyst and the substrate surface, but this limits its use on some heat-sensitive polymer substrates.

[0006] Therefore, there is an urgent need to develop a new purification material to solve the above problems. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a method for preparing a gaseous pollutant purification material with photo-Fenton activity.

[0008] In order to solve the above technical problems, the solution of the present invention is:

[0009] A method for preparing a gaseous pollutant purification material having photo-Fenton activity is provided, comprising the following steps:

[0010] (1) adding an acid catalyst to 20 to 25 parts by mass of a tin hydroxide aqueous solution to adjust the pH value of the mixed solution to 3 to 5 and the mass fraction of the tin hydroxide aqueous solution to 5%; dissolving 4 to 6 parts by mass of a titanium-containing precursor in 6 to 10 parts by mass of anhydrous ethanol and adding the precursor dropwise to the mixed solution under stirring in a 90°C water bath; reacting for 12 to 36 hours, adding 0.001 to 0.01 parts by mass of a dye; continuing stirring for 1 hour, and removing part of the solvent by evaporation using a rotary evaporator to obtain a modified titanium dioxide nanocrystalline coating solution with a solid content of 8%;

[0011] (2) 3 to 5 parts by mass of a surfactant and 30 to 50 parts by mass of cyclohexane are mixed, and 0.5 to 2 parts by mass of a ferrous salt aqueous solution is added under stirring at room temperature, wherein the mass fraction of the ferrous salt aqueous solution is 10%; stirring is continued for 1 hour, and 0.5 to 2 parts by mass of a trimesic acid aqueous solution is added, wherein the mass fraction of the trimesic acid aqueous solution is 15%; stirring is continued for 1 hour, and then stirring is continued for another 3 to 5 hours in a 90°C water bath; the resulting suspension is filtered, washed alternately with deionized water and ethanol three times, and then dispersed in anhydrous ethanol to obtain a nano-iron-based catalytic material dispersion with a solid content of 50%;

[0012] (3) 1 part by mass of nano-iron-based catalytic material dispersion was mixed with 0.5-2 parts by mass of modified titanium dioxide nanocrystal coating liquid, and then 0.01-0.03 parts by mass of polyether-modified polysiloxane was added; after stirring the mixed solution for 1 hour, the porous carrier after plasma surface treatment was immediately immersed in it; after soaking for 30 minutes, it was taken out, placed at room temperature for 10 minutes, and then dried in an 80°C oven for 30 minutes to obtain a gaseous pollutant purification material with photo-Fenton activity.

[0013] As a preferred embodiment of the present invention, the acid catalyst in step (1) is at least one of hydrochloric acid, nitric acid, and glacial acetic acid.

[0014] As a preferred embodiment of the present invention, the titanium-containing precursor in step (1) is at least one of butyl titanate, titanium isopropoxide, and titanium ethylene glycol.

[0015] As a preferred embodiment of the present invention, the dye in step (1) is at least one of sulfonated iron porphyrin, eosin, and terpyridine ruthenium.

[0016] As a preferred embodiment of the present invention, the surfactant in step (2) is at least one of sorbitan trioleate, polyoxyethylene castor oil, and isostearic acid monoglyceride.

[0017] As a preferred embodiment of the present invention, the ferrous salt in step (2) is at least one of ferrous sulfate, ferrous chloride and ferrous nitrate.

[0018] As a preferred embodiment of the present invention, the porous carrier in step (3) is made of an organic polymer material, an inorganic non-metallic material or a metal material.

[0019] As a preferred embodiment of the present invention, the porous carrier after plasma surface treatment in step (3) is prepared by the following method:

[0020] The porous carrier was placed on the sample stage of a low-temperature plasma surface treatment machine and treated with air low-temperature plasma; the treatment conditions were a discharge pressure of 25 Pa, a discharge power of 200 W, and a treatment time of 5 min.

[0021] The implementation principle of the present invention:

[0022] When preparing the modified titanium dioxide nanocrystal coating liquid, the present invention controls the full hydrolysis of the titanium-containing precursor and slowly and orderly polymerizes it under the induction of tin hydroxide, thereby in situ preparing tin oxide-modified titanium dioxide nanocrystals in the liquid phase, which can enhance the charge transfer capacity of the catalyst interface; and through dye sensitization, the catalyst's absorption of visible light can be improved.

[0023] Then, a nanoscale "reactor" was constructed using an oil-in-water emulsion system, and the synthesis reaction of the iron-based catalytic material was confined to the "reactor" to prepare nano-iron-based catalytic materials with relatively uniform sizes.

[0024] After the modified titanium dioxide nanocrystal coating liquid is compounded with the nano-iron-based catalytic material, on the one hand, the film-forming effect of the modified titanium dioxide nanocrystal coating liquid is utilized to fix the nano-iron-based catalytic material into the coating; on the other hand, a heterojunction is formed between titanium dioxide and the nano-iron-based catalytic material to promote the migration and separation of photogenerated carriers and improve the efficiency of the photo-Fenton reaction.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] 1. The present invention prepares the modified titanium dioxide nanocrystalline coating liquid under relatively mild conditions, avoiding the application restrictions of traditional high-temperature heat treatment processes on heat-sensitive film-forming substrates such as organic polymers.

[0027] 2. The present invention uses modified titanium dioxide nanocrystal coating liquid as a bonding material to firmly load the nano-iron-based catalytic material onto the surface of the porous carrier, solving the problem of photo-Fenton performance degradation caused by the coating effect of the polymer film-forming material on the nano-catalytic material in the traditional method.

[0028] 3. The present invention constructs a high-efficiency composite photo-Fenton material system of modified titanium dioxide nanocrystals and nano-iron-based catalytic materials. Compared with traditional photo-Fenton materials, it effectively promotes the migration and separation of photogenerated carriers and accelerates the Fe 3+ / Fe 2+ The photo-Fenton reaction efficiency was significantly improved. DETAILED DESCRIPTION

[0029] The present invention is further described in detail below in conjunction with specific embodiments:

[0030] 1. Preparation of gaseous pollutant purification materials

[0031] A method for preparing a gaseous pollutant purification material having photo-Fenton activity comprises the following steps:

[0032] (1) An acid catalyst is added to 20-25 parts by weight of an aqueous tin hydroxide solution to adjust the pH value of the mixed solution to 3-5; the acid catalyst is at least one of hydrochloric acid, nitric acid, and glacial acetic acid, and the mass fraction of the aqueous tin hydroxide solution is 5%. 4-6 parts by weight of a titanium-containing precursor is dissolved in 6-10 parts by weight of anhydrous ethanol and added dropwise to the mixed solution under stirring in a 90°C water bath; the titanium-containing precursor is at least one of butyl titanate, titanium isopropoxide, and titanium glycolate. After reacting for 12-36 hours, 0.001-0.01 parts by weight of a dye is added; the dye is at least one of sulfonic acid iron porphyrin, eosin, and terpyridine ruthenium. Stirring is continued for 1 hour, and a portion of the solvent is evaporated and removed using a rotary evaporator to obtain a modified titanium dioxide nanocrystalline coating solution with a solid content of 8%.

[0033] (2) 3-5 parts by mass of a surfactant and 30-50 parts by mass of cyclohexane are mixed, and 0.5-2 parts by mass of a ferrous salt aqueous solution is added under stirring at room temperature; the surfactant is at least one of anhydrous sorbitan trioleate, polyoxyethylene castor oil, and isostearic acid monoglyceride, and the ferrous salt is at least one of ferrous sulfate, ferrous chloride, and ferrous nitrate, and the mass fraction of the ferrous salt aqueous solution is 10%. Stirring is continued for 1 hour, and 0.5-2 parts by mass of a trimesic acid aqueous solution is added, and the mass fraction of the trimesic acid aqueous solution is 15%. After stirring for 1 hour, stirring is continued in a 90°C water bath for another 3-5 hours. The resulting suspension is filtered, washed three times alternately with deionized water and ethanol, and then dispersed in anhydrous ethanol to obtain a nano-iron-based catalytic material dispersion with a solid content of 50%.

[0034] (3) Preparing a porous carrier after plasma surface treatment, wherein the material of the porous carrier is an organic polymer material, an inorganic non-metallic material or a metal material; the plasma surface treatment of the porous carrier specifically includes the following steps:

[0035] The porous carrier was placed on the sample stage of a low-temperature plasma surface treatment machine and treated with air low-temperature plasma. The treatment conditions were a discharge pressure of 25 Pa, a discharge power of 200 W, and a treatment time of 5 min.

[0036] 1 part by mass of a nano-iron-based catalytic material dispersion is mixed with 0.5 to 2 parts by mass of a modified titanium dioxide nanocrystal coating liquid, and then 0.01 to 0.03 parts by mass of a polyether-modified polysiloxane is added; after stirring the mixed solution for 1 hour, the porous carrier that has been subjected to plasma surface treatment is immediately immersed therein; after soaking for 30 minutes, the carrier is taken out, placed at room temperature for 10 minutes, and then dried in an 80°C oven for 30 minutes to obtain a gaseous pollutant purification material with photo-Fenton activity.

[0037] The preparation method of the polyether-modified polysiloxane in this embodiment can be referred to the published document "Synthesis, Characterization and Properties of Nonionic Polyether-Modified Trisiloxane Surfactants", Journal of Chemical Industry and Engineering, 2015, 66(6): 2181-2188. The other reagents used are all commercially available products.

[0038] The following examples are intended to provide a more comprehensive understanding of the present invention by those skilled in the art, but are not intended to limit the present invention in any way. Gaseous pollutant purification materials exhibiting photo-Fenton activity were successfully prepared through eight examples. The experimental data for each example is shown in Table 1 below.

[0039] Table 1 Example data table

[0040]

[0041]

[0042] II. Photo-Fenton Activity Evaluation of Gaseous Pollutant Purification Materials: 1. Test Materials and Apparatus

[0043] Purification materials with dimensions of 15 cm (length × width × thickness) × 15 cm (length × width × thickness); hydrogen peroxide; deionized water; toluene; a glove box with dimensions of 60 cm (length × width × thickness) × 80 cm (width × thickness); a downward-blowing fan and a 24W LED white light source installed on the top of the glove box; a microinjector; a glass water tank with dimensions of 20 cm (length × width × thickness) × 20 cm (width × thickness) × 5 cm (height); a micro air pump; and a RIKEN GX-6000 gas detector.

[0044] 2. Test steps

[0045] (1) Place a glass water tank in a glove box, directly below a light source. Measure 1.2 L of deionized water and add it to the glass water tank. Add hydrogen peroxide to a final concentration of 4 mg / L. Finally, immerse the purification material in the water. Insert the outlet hose of the micro air pump into the water in the glass water tank, and place the inlet end inside the glove box. Seal the glove box and inject a certain amount of toluene into the glove box using a microinjector, so that the initial toluene concentration in the glove box remains at a certain value a0 (approximately 200 ppm).

[0046] (2) Turn on the light source, fan and micro air pump. After 2 hours of photo-Fenton reaction, test the toluene gas concentration in the glove box. t ; The target gas removal rate P can be calculated by the following formula to characterize the photo-Fenton purification performance of the purification material.

[0047]

[0048] 3. Test using existing purification materials as a comparative example:

[0049] (1) Using titanium dioxide and nano-iron-based catalytic materials commonly used in existing public literature as comparative examples, a photo-Fenton activity evaluation test was carried out according to the above steps.

[0050] The titanium dioxide is P25 titanium dioxide nanopowder from Evonik Degussa, Germany. The preparation method of the nano-iron-based catalytic material is based on the document "Preparation and Performance Study of ZnFe2O4 Heterogeneous Photo-Fenton Catalyst", Chemical Research and Applications, 2022, 34(7): 1620-1625.

[0051] (2) Under the same test conditions, the toluene removal rate of titanium dioxide was 50.3%; the toluene removal rate of nano-iron-based catalytic material was 65.7%.

[0052] It can be seen that the toluene removal rate of the purification materials prepared in each embodiment of the present invention (data shown at the end of Table 1) is significantly better than that of the above existing materials.

[0053] Finally, it should be noted that the above examples are merely specific implementation examples of the present invention. Obviously, the present invention is not limited to the above examples and is subject to numerous variations. All variations that can be directly derived or conceived by a person of ordinary skill in the art from the disclosure of the present invention should be considered within the scope of protection of the present invention.

Claims

1. Application of a gaseous pollutant purification material in photo-Fenton, characterized in that: The preparation method of the purification material comprises the following steps: (1) An acid catalyst is added to 20-25 parts by mass of a tin hydroxide aqueous solution to adjust the pH value of the mixed solution to 3-5 and the mass fraction of the tin hydroxide aqueous solution to 5%; 4-6 parts by mass of a titanium-containing precursor is dissolved in 6-10 parts by mass of anhydrous ethanol and added dropwise to the mixed solution under stirring in a 90°C water bath; after reacting for 12-36 hours, 0.001-0.01 parts by mass of a dye is added; stirring is continued for 1 hour, and a portion of the solvent is evaporated and removed by a rotary evaporator to obtain a modified titanium dioxide nanocrystalline coating solution with a solid content of 8%; (2) 3-5 parts by mass of a surfactant and 30-50 parts by mass of cyclohexane were mixed, and 0.5-2 parts by mass of a ferrous salt aqueous solution was added under stirring at room temperature, with the mass fraction of the ferrous salt aqueous solution being 10%; the stirring was continued for 1 hour, and 0.5-2 parts by mass of a trimesic acid aqueous solution was added, with the mass fraction of the trimesic acid aqueous solution being 15%; the stirring was continued for 1 hour, and then the stirring was continued for another 3-5 hours in a 90°C water bath; the suspension obtained was filtered, washed alternately with deionized water and ethanol three times, and then dispersed in anhydrous ethanol to obtain a nano-iron-based catalytic material dispersion with a solid content of 50%; (3) Mix 1 part by mass of nano-iron-based catalytic material dispersion with 0.5-2 parts by mass of modified titanium dioxide nanocrystal coating liquid, and then add 0.01-0.03 parts by mass of polyether-modified polysiloxane; stir the mixed solution for 1 hour, and immediately soak the porous carrier after plasma surface treatment into it; take it out after soaking for 30 minutes, leave it at room temperature for 10 minutes, and then dry it in an oven at 80°C for 30 minutes to obtain a gaseous pollutant purification material with photo-Fenton activity.

2. The use according to claim 1, characterized in that The acid catalyst in step (1) is at least one of hydrochloric acid, nitric acid, and glacial acetic acid.

3. The use according to claim 1, characterized in that The titanium-containing precursor in step (1) is at least one of butyl titanate, titanium isopropoxide, and titanium ethylene glycol.

4. The use according to claim 1, characterized in that The dye in step (1) is at least one of sulfonated iron porphyrin, eosin, and terpyridine ruthenium.

5. The use according to claim 1, characterized in that The surfactant described in step (2) is at least one of sorbitan trioleate, polyoxyethylene castor oil, and isostearic acid monoglyceride.

6. The use according to claim 1, characterized in that The ferrous salt described in step (2) is at least one of ferrous sulfate, ferrous chloride, and ferrous nitrate.

7. The use according to claim 1, characterized in that The material of the porous carrier described in step (3) is an organic polymer material, an inorganic non-metallic material or a metal material.

8. The use according to claim 1, characterized in that The porous carrier after plasma surface treatment in step (3) is prepared by the following method: placing the porous carrier on the sample stage of a low-temperature plasma surface treatment machine and treating the porous carrier with air low-temperature plasma; the treatment conditions are a discharge pressure of 25 Pa, a discharge power of 200 W, and a treatment time of 5 min.

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