Fabric-based bismuth vanadate / tin dioxide composite photocatalytic material and preparation method thereof

Abstract

The invention belongs to the technical field of functional textiles, and particularly relates to a fabric-based bismuth vanadate / stannic oxide composite photocatalytic material and a preparation method thereof. The preparation method comprises the following steps: preparing bismuth vanadate / tin dioxide, preparing the dopamine cotton fabric and loading. The fabric-based bismuth vanadate / stannic oxide composite material is prepared by preparing the bismuth vanadate / stannic oxide composite material through a water bath method, loading the catalyst bismuth vanadate / stannic oxide on the cotton fabric through water bath oscillation by taking dopamine as a cross-linking agent, and the composite material improves the utilization rate of light, can delay the compounding of photon-generated carriers, improves the light utilization rate, improves the light utilization rate, improves the light utilization rate, improves the light utilization rate and improves the light utilization rate. Therefore, the photocatalytic degradation performance of the material is improved; the cotton fabric is used as the substrate, so that adsorption sites can be provided to improve the adsorption performance of the material, the material is convenient to recycle, and the effect of recycling is achieved. And the photocatalyst has excellent photocatalytic performance and recoverability. The preparation method disclosed by the invention is simple to operate, convenient to prepare, low in cost and suitable for industrial large-scale production.

Description

Technical Field

[0001] The invention belongs to the technical field of functional textiles, and in particular relates to a fabric-based bismuth vanadate / tin dioxide composite photocatalytic material and a preparation method thereof. Background Art

[0002] With the rapid development of the textile printing and dyeing industry, the problem of printing and dyeing wastewater pollution has become increasingly prominent and has become a major problem that needs to be solved in the field of environmental protection. Printing and dyeing wastewater has complex components and is rich in a large number of pollutants such as organic matter, suspended solids and dyes. It has the characteristics of high chroma, high toxicity, and high biochemical oxygen demand, which poses a serious threat to the water ecological environment and human health.

[0003] At present, the treatment methods for printing and dyeing wastewater mainly include physical adsorption, chemical precipitation and microbial treatment. Physical adsorption is simple to operate, but the adsorbent is easily saturated and difficult to regenerate; chemical precipitation has high treatment efficiency, but it is easy to produce secondary pollution; microbial treatment is environmentally friendly, but the treatment cycle is long and has high requirements for water quality conditions. Therefore, it is of great significance to develop efficient, environmentally friendly and sustainable printing and dyeing wastewater treatment technology.

[0004] As a new type of advanced oxidation technology, photocatalytic degradation technology has shown great application potential in the field of printing and dyeing wastewater treatment in recent years. This technology utilizes the strong oxidizing active species generated by photocatalysts under light conditions, which can efficiently degrade organic pollutants and has the advantages of a wide range of applications, mild reaction conditions, and no secondary pollution. Among them, bismuth vanadate (BiVO4), as a new type of photocatalytic material, has attracted much attention due to its narrow band gap (about 2.4eV), non-toxicity, and simple preparation process. However, BiVO4 photocatalytic materials still face some challenges in practical applications, such as poor photogenerated charge transfer performance, easy recombination of electron-hole pairs, photocorrosion, etc., which leads to the need to further improve its photocatalytic efficiency and application stability. In addition, BiVO 4 Nanoparticles may cause secondary pollution to water bodies due to agglomeration or loss during use, which also limits their practical application.

[0005] Therefore, continuing to develop efficient, stable and environmentally friendly BiVO4-based photocatalytic materials and exploring their application in printing and dyeing wastewater treatment is of great significance for solving the problem of printing and dyeing wastewater pollution and promoting the green and sustainable development of the textile printing and dyeing industry. Summary of the invention

[0006] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a green, easily recyclable and reusable fabric-based bismuth vanadate / tin dioxide composite photocatalytic material and a preparation method thereof.

[0007] The object of the present invention is achieved by the following technical solutions: A preparation method of a fabric-based bismuth vanadate / tin dioxide composite photocatalytic material, which comprises the following steps:

[0008] S1. Prepare bismuth vanadate / tin dioxide: Ammonium metavanadate is added to a nitric acid solution of bismuth nitrate pentahydrate, the pH value of the mixed solution is adjusted to 5-6, and then tin dioxide is added, and the reaction is carried out at 120-140 °C for 20-30 h. The obtained product is bismuth vanadate / tin dioxide;

[0009] S2. Prepare dopamine cotton fabric: The cotton fabric soaked in acetone is added to a Tris-HCl buffer solution of dopamine, and shaken at room temperature for 22-26 h under dark conditions. The obtained fabric is dopamine cotton fabric;

[0010] S2. Loading: The dopamine cotton fabric prepared in step S2 is added to an aqueous solution of bismuth vanadate / tin dioxide, and shaken in a water bath at 22-28 °C for 7-9 h. After the cotton fabric is washed and dried, it is a fabric-based bismuth vanadate / tin dioxide composite photocatalytic material.

[0011] As a preferred technical solution, the concentration of the nitric acid solution in step S1 is 1.5-3 mol / L, and the mass-volume ratio of bismuth nitrate pentahydrate to the nitric acid solution is 9-30 mg:1 ml.

[0012] As a preferred technical solution, the mass ratio of bismuth nitrate pentahydrate, ammonium metavanadate and tin dioxide in step S1 is 2-5:1-2:1.

[0013] As a preferred technical solution, after the reaction in step S1, the product is filtered and washed with deionized water and ethanol at room temperature, and finally vacuum dried in an oven at 75-85 °C for 3.5-4.5 h.

[0014] As a preferred technical solution, the tin dioxide in step S1 is prepared by the following method: Tin tetrachloride pentahydrate and ethanol are added to a sodium hydroxide solution, and the reaction is carried out in a reaction kettle at 180-200 °C for 20-26 h. The obtained precipitate is washed 3-4 times with deionized water and ethanol, and then dried at a temperature of 110-130 °C for 20-26 h.

[0015] More preferably, the mass ratio of sodium hydroxide to tin tetrachloride pentahydrate is 1:0.8-2, the concentration of the sodium hydroxide solution is 0.01-0.1 g / ml, and the volume ratio of the sodium hydroxide solution to ethanol is 1:1.

[0016] As a preferred technical solution, the pH value of the mixed solution in step S1 is adjusted with ammonia water.

[0017] As a preferred technical solution, the pH value of the Tris-HCl buffer solution in step S2 is 8.5, the concentration is 10 mmol / L, and the mass-volume ratio of dopamine to the Tris-HCl buffer solution is 1 g: 400-600 ml; the mass ratio of dopamine to the area of the cotton fabric is 4-8 mg / cm 2 .

[0018] As a preferred technical solution, the mass ratio of bismuth vanadate / tin dioxide in step S3 to the area of the dopamine cotton fabric is 8-16 mg / cm 2 .

[0019] The fabric-based bismuth vanadate / tin dioxide composite photocatalytic material prepared by the above method.

[0020] The present invention has the following advantages: The present invention discloses a fabric-based bismuth vanadate / tin dioxide composite photocatalytic material, which prepares the bismuth vanadate / tin dioxide composite material by a water bath method. Using dopamine as a cross-linking agent, the catalyst bismuth vanadate / tin dioxide is loaded onto the cotton fabric through water bath oscillation to prepare a fabric-based bismuth vanadate / tin dioxide composite material. This composite material improves the utilization rate of light and can also delay the recombination of photo-generated carriers, thereby improving the photocatalytic degradation performance of the material; and the cotton fabric as the substrate can not only provide adsorption sites to improve the adsorption performance of the material, but also facilitate recycling, achieving the effect of recycling. It has excellent photocatalytic performance and recyclability. The preparation method disclosed in the present invention is simple in operation, convenient to prepare, low in cost, and suitable for industrial scale production. Description of the Drawings

[0021] Figure 1 It is the UV-Vis diagram of the degradation of methylene blue by the fabric-based BiVO 4 / SnO 2 composite material of the present invention.

[0022] Figure 2 It is the degradation effect diagram of methylene blue by the fabric-based BiVO 4 / SnO 2 composite material of the present invention.

[0023] Figure 3 It is the cyclic degradation effect diagram of methylene blue by the fabric-based BiVO 4 / SnO 2 composite material of the present invention.

[0024] Figure 4 It is the microscopic electron microscope diagram of the fabric-based BiVO 4 / SnO 2 composite material of the present invention, where a is magnified 1500 times, b is magnified 3000 times, and c is magnified 7500 times.

[0025] Figure 5 For BiVO 4 , SnO 2 and fabric-based BiVO 4 / SnO 2 Degradation effect diagram of methylene blue by the composite material.

[0026] Figure 6 For the degradation effect diagrams of methylene blue in Experimental Examples 1 - 5. Specific implementation mode

[0027] The following further describes the present invention in conjunction with the attached drawings and embodiments. The protection scope of the present invention is not limited to the following: Embodiment 1: A preparation method of a fabric-based bismuth vanadate / tin dioxide composite photocatalytic material, which includes the following steps:

[0028] S1. Preparation of bismuth vanadate / tin dioxide: Bismuth nitrate pentahydrate is dissolved in a nitric acid solution with a concentration of 1.5 mol / L. The mass-volume ratio of bismuth nitrate pentahydrate to the nitric acid solution is 9 mg:1 ml. Ammonium metavanadate is added, and the pH value of the mixed solution is adjusted to 5 with ammonia water. Then, tin dioxide is added. The mass ratio of bismuth nitrate pentahydrate, ammonium metavanadate, and tin dioxide is 2:1:1. React at 120 °C for 30 h. The obtained product is filtered and washed with deionized water and ethanol at room temperature, and finally vacuum-dried in an oven at 75 °C for 4.5 h to obtain bismuth vanadate / tin dioxide;

[0029] Among them, the tin dioxide is prepared by the following method: Sodium hydroxide solution with a concentration of 0.01 g / ml is added with tin tetrachloride pentahydrate and ethanol. The mass ratio of sodium hydroxide to tin tetrachloride pentahydrate is 1:0.8. The volume ratio of the sodium hydroxide solution to ethanol is 1:1. React in a reaction kettle at 180 °C for 26 h. The obtained precipitate is washed 3 times with deionized water and ethanol, and then dried at a temperature of 110 °C for 26 h.

[0030] S3. Preparation of dopamine cotton fabric: The cotton fabric soaked in acetone is added to the Tris-HCl buffer solution of dopamine, and shaken at room temperature for 22 h in the dark. The obtained fabric is the dopamine cotton fabric; among them, the pH value of the Tris-HCl buffer solution is 8.5, the concentration is 10 mmol / L, and the mass-volume ratio of dopamine to the Tris-HCl buffer solution is 1 g:400 ml; the mass ratio of dopamine to the area of the cotton fabric is 4 mg / cm 2 .

[0031] S2. Loading: Add the dopamine cotton fabric prepared in step S2 to the aqueous solution of bismuth vanadate / tin dioxide. The mass ratio of bismuth vanadate / tin dioxide to the area of the dopamine cotton fabric is 8 mg / cm 2, oscillate in a water bath at 22 °C for 7 h. After washing and drying the cotton fabric, it becomes the fabric-based bismuth vanadate / tin dioxide composite photocatalytic material.

[0032] Example 2: A preparation method of a fabric-based bismuth vanadate / tin dioxide composite photocatalytic material, which includes the following steps:

[0033] S1. Prepare bismuth vanadate / tin dioxide: Bismuth nitrate pentahydrate is dissolved in a nitric acid solution with a concentration of 3 mol / L. The mass-volume ratio of bismuth nitrate pentahydrate to the nitric acid solution is 30 mg:1 ml. Ammonium metavanadate is added, and the pH value of the mixed solution is adjusted to 6 with ammonia water. Then tin dioxide is added. The mass ratio of bismuth nitrate pentahydrate, ammonium metavanadate, and tin dioxide is 5:2:1. React at 140 °C for 20 h. The obtained product is filtered and washed with deionized water and ethanol at room temperature, and finally vacuum-dried in an oven at 85 °C for 3.5 h to obtain bismuth vanadate / tin dioxide;

[0034] Among them, the tin dioxide is prepared by the following method: Add tin tetrachloride pentahydrate and ethanol to a sodium hydroxide solution with a concentration of 0.1 g / ml. The mass ratio of sodium hydroxide to tin tetrachloride pentahydrate is 1:2, and the volume ratio of the sodium hydroxide solution to ethanol is 1:1. React in a reaction kettle at 200 °C for 20 h. The obtained precipitate is washed 4 times with deionized water and ethanol, and then dried at 130 °C for 20 h.

[0035] S2. Prepare dopamine cotton fabric: Add the cotton fabric soaked in acetone to the Tris-HCl buffer solution of dopamine, and oscillate at room temperature in the dark for 26 h. The obtained fabric is the dopamine cotton fabric; among them, the pH value of the Tris-HCl buffer solution is 8.5, the concentration is 10 mmol / L, and the mass-volume ratio of dopamine to the Tris-HCl buffer solution is 1 g:600 ml; the mass ratio of dopamine to the area of the cotton fabric is 8 mg / cm 2 .

[0036] S3. Loading: Add the dopamine cotton fabric prepared in step S2 to the aqueous solution of bismuth vanadate / tin dioxide. The mass ratio of bismuth vanadate / tin dioxide to the area of the dopamine cotton fabric is 16 mg / cm 2 , oscillate in a water bath at 28 °C for 7 - 9 h. After washing and drying the cotton fabric, it becomes the fabric-based bismuth vanadate / tin dioxide composite photocatalytic material.

[0037] Example 3: A preparation method of a fabric-based bismuth vanadate / tin dioxide composite photocatalytic material, which includes the following steps:

[0038] S1. Preparation of bismuth vanadate / tin dioxide: Bismuth nitrate pentahydrate is dissolved in a nitric acid solution with a concentration of 2 mol / L. The mass-volume ratio of bismuth nitrate pentahydrate to the nitric acid solution is 20 mg:1 ml. Ammonium metavanadate is added, and the pH value of the mixed solution is adjusted to 5.5 with ammonia water. Then tin dioxide is added. The mass ratio of bismuth nitrate pentahydrate, ammonium metavanadate, and tin dioxide is 3:1.5:1. The reaction is carried out at 130 °C for 25 h. The obtained product is filtered and washed with deionized water and ethanol at room temperature, and finally vacuum-dried in an oven at 80 °C for 4 h to obtain bismuth vanadate / tin dioxide;

[0039] Among them, the tin dioxide is prepared by the following method: Stannic chloride pentahydrate and ethanol are added to a sodium hydroxide solution with a concentration of 0.05 g / ml. The mass ratio of sodium hydroxide to stannic chloride pentahydrate is 1:1.2, and the volume ratio of the sodium hydroxide solution to ethanol is 1:1. The reaction is carried out in a reaction kettle at 190 °C for 24 h. The obtained precipitate is washed 3 times with deionized water and ethanol, and then dried at 120 °C for 24 h.

[0040] S2. Preparation of dopamine cotton fabric: The cotton fabric soaked in acetone is added to the Tris-HCl buffer solution of dopamine, and shaken at room temperature for 24 h in the dark. The obtained fabric is dopamine cotton fabric; among them, the pH value of the Tris-HCl buffer solution is 8.5, the concentration is 10 mmol / L, and the mass-volume ratio of dopamine to the Tris-HCl buffer solution is 1 g:500 ml; the mass ratio of dopamine to the area of the cotton fabric is 6 mg / cm 2 .

[0041] S3. Loading: The dopamine cotton fabric prepared in step S2 is added to the aqueous solution of bismuth vanadate / tin dioxide. The mass ratio of bismuth vanadate / tin dioxide to the area of the dopamine cotton fabric is 12 mg / cm 2 , and shaken in a water bath at 25 °C for 8 h. After the cotton fabric is washed and dried, it is a fabric-based bismuth vanadate / tin dioxide composite photocatalytic material.

[0042] The beneficial effects of the present invention are illustrated by the following experiments:

[0043] Experiment 1: Degradation effect of fabric-based bismuth vanadate / tin dioxide composite material on methylene blue

[0044] (1) Experimental object:

[0045] Experimental Example 1: A preparation method of a fabric-based bismuth vanadate / tin dioxide composite photocatalytic material, which includes the following steps:

[0046] (1) Preparation of tin dioxide: Dissolve 1.4 g of sodium hydroxide in 40 mL of deionized water. After stirring until it is completely dissolved, add 1.5 g of tin(IV) chloride pentahydrate. Continue stirring for 10 min, then add 40 mL of ethanol. After that, transfer it to a reaction kettle and react at 190 °C for 24 h. Then wash the precipitate 4 times with a mixture of deionized water and ethanol, and finally dry it at 120 °C for 24 h;

[0047] (2) Preparation of bismuth vanadate / tin dioxide: Dissolve 1.7252 g of bismuth nitrate pentahydrate in a 2 mol / L nitric acid solution. Stir magnetically until it is completely dissolved, then add 0.3509 g of ammonium metavanadate, and slowly dropwise add ammonia water to adjust the pH to 5. After stirring for 30 min, add 0.32 g of tin dioxide and continue stirring for 10 min. Then put it into a reaction kettle and react at 130 °C for 24 h. After it cools down, filter and wash it with deionized water and ethanol, and finally put it into an oven at 80 °C for vacuum drying for 4 h;

[0048] (3) Preparation of dopamine cotton fabric: Add 0.1 g of dopamine to 50 mL of 10 mmol / L Tris-HCl buffer solution with a pH of 8.5, and ultrasonically mix. Then immerse the 2×2 cm cotton fabric treated with acetone into the above solution and oscillate at room temperature in the dark for 24 h;

[0049] (4) Loading: Place 0.2 g of bismuth vanadate / tin dioxide in 50 mL of deionized water and ultrasonicate for 15 min, then add the dopamine cotton fabric. Put it into a water bath at 25 °C and oscillate for 8 h. After that, take out the sample, wash it with deionized water, and dry it in vacuum for 4 h. Repeat the treatment 3 times.

[0050] (2) Experimental method:

[0051] A. Prepare a 10 mg / mL methylene blue aqueous solution. Immerse the 2×2 cm fabric-based bismuth vanadate / tin dioxide composite material in 100 mL of the methylene blue aqueous solution. After 30 min of dark treatment at room temperature, use a 300 W xenon lamp to simulate sunlight for photocatalytic degradation experiments, and take samples every 20 min to obtain the ultraviolet-visible absorption curves of the methylene blue aqueous solution at different times.

[0052] B. After the experiment, take out the sample, rinse it, and dry it at 60 °C. Then repeat the experiment 2 more times.

[0053] C. Take the points at 664 nm in the curve obtained from the first experiment, a total of ten points, to draw the degradation effect diagram of the material on methylene blue; the same is true for subsequent repeated experiments. Organize the data of the three experiments to obtain the cyclic degradation diagram.

[0054] Measure the relative residual liquid concentration (C / C of the methylene blue solution at different times 0) and calculate its degradation rate ΔC / C 0 .

[0055] C / C 0 The calculation formula for C / C 0 = A / A 0 . Where C is the concentration of the methylene blue residual solution, C 0 is the concentration of the methylene blue stock solution, A is the absorbance of the methylene blue residual solution, and A 0 is the absorbance of the methylene blue stock solution. The calculation formula for the degradation rate is: ΔC / C 0 = (A 0 - A) / A 0 .

[0056] (3) Experimental results:

[0057] As Figure 1 shown, it is the UV-Vis diagram (ultraviolet-visible light absorption curve) of the fabric-based BiVO 4 / SnO 2 composite material degrading methylene blue. The maximum absorption wavelength of methylene blue is 664 nm, corresponding to Figure 1 the peak of each curve. Therefore, the degree of degradation of methylene blue can be seen from the change of the peak of the curve, and the degradation effect of methylene blue at different times can be calculated through the absorbance at 664 nm.

[0058] As Figure 2 shown, Figure 2 it is the degradation effect diagram of the fabric-based BiVO 4 / SnO 2 composite material on methylene blue. Each point corresponds to the point at 664 nm in the UV-vis at different times. Figure 2 In the first 30 minutes, the whole system was shielded from light to make the material reach saturated adsorption. In the following 160 minutes, xenon lamp was used to simulate sunlight to excite the catalyst to oxidize and decompose methylene blue under the condition of passing condensed water. It can be seen that after 190 minutes of adsorption and degradation, the removal rate of methylene blue in the water body reached 90.8%, indicating that the prepared composite material has strong photocatalytic performance.

[0059] As Figure 3 shown, it is the cyclic degradation effect diagram of the fabric-based BiVO 4 / SnO 2 composite material on methylene blue (corresponding to 3 repeated experiments of this sample). Figure 3The degradation effects of the composite material on methylene blue were recorded three times. After each use, the material needs to be rinsed and dried. It can be seen that the degradation rate reached 90.8% for the first time, 87.9% for the second time, and 82.8% for the third time, indicating that the prepared photocatalytic composite material has good cyclic stability.

[0060] Experiment 2: Fabric-based BiVO 4 / SnO 2 Microstructure of the composite material

[0061] (1) Experimental method:

[0062] The fabric-based BiVO 4 / SnO 2 composite material prepared in Experimental Example 1 was subjected to electron microscopy scanning under an electron microscope at 1500, 3000, and 7500 magnifications.

[0063] (2) Experimental results:

[0064] As Figure 4 shown, from Figure 4 (a), it can be clearly seen that a large number of particles and needle-like tin dioxide are loaded on the cotton fabric. Figure 4 (b) and 4(c) show rice-grain-shaped bismuth vanadate and a small amount of flower-shaped tin dioxide, and the bismuth vanadate is closely connected to the tin dioxide, which can delay the recombination of carriers during catalysis and thus improve the catalytic efficiency; at the same time, it can be seen from 4(c) that the surface of the cotton fabric is relatively smooth, indicating that dopamine forms a film on the surface of the cotton fabric to adhere the bismuth vanadate and tin dioxide to the fabric surface.

[0065] Experiment 3: Comparison of degradation experiments between single catalyst and composite catalyst

[0066] (1) Experimental objects:

[0067] Experimental Example 1 and Comparative Example 1 and Comparative Example 2, where:

[0068] Comparative Example 1:

[0069] 3 mmol of bismuth nitrate pentahydrate was dissolved in 2 mol / L nitric acid solution, and it was completely dissolved by magnetic stirring. Then, 3 mmol of ammonium metavanadate was added, and ammonia water was slowly added dropwise to adjust the pH to 5. After stirring for 30 min, it was put into a reaction kettle and reacted at 130 °C for 24 h. After it cooled down, it was filtered and washed with deionized water and ethanol, and finally vacuum dried in an oven at 80 °C for 4 h.

[0070] Comparative Example 2:

[0071] Dissolve 1.4 g of sodium hydroxide in 40 mL of deionized water. After stirring until it is completely dissolved, add 1.5 g of stannous chloride pentahydrate. Continue stirring for 10 min, then add 40 mL of ethanol. After that, transfer it to a reaction kettle and react at 190 °C for 24 h. Then wash the precipitate 3 - 4 times with a mixture of deionized water and ethanol, and finally dry it at 120 °C for 24 h.

[0072] (2) Experimental method:

[0073] Prepare an aqueous solution of methylene blue with a concentration of 10 mg / mL. Immerse 20 mg of BiVO 4 (Comparative Example 1) and SnO 2 (Comparative Example 2) separately in 100 mL of the methylene blue aqueous solution. After 30 min of dark treatment at room temperature, use a 300 W xenon lamp to simulate sunlight for the photocatalytic degradation experiment. Take samples every 20 min to obtain the ultraviolet-visible absorption curves of the methylene blue aqueous solution at different times, and take points at 664 nm on each curve to plot the degradation effect diagram.

[0074] (3) Experimental results:

[0075] As Figure 5 shown, it can be seen from Figure 5 that the adsorption and degradation effects of SnO 2 are slightly lower than those of BiVO 4 , while the adsorption and degradation effects of the prepared composite materials have been significantly improved. This is because BiVO 4 is mainly excited in the visible light region, while SnO 2 is mainly excited in the ultraviolet light region. After the two are combined, it can expand the range of light excitation, improve the utilization rate of light, and at the same time delay the recombination of photo-generated carriers, thereby improving the photocatalytic degradation performance of the material; and the cotton fabric as the substrate can not only provide adsorption sites to improve the adsorption performance of the material, but also facilitate recycling, achieving the effect of recycling.

[0076] Experiment 4: Degradation effect of fabric-based bismuth vanadate / tin dioxide composite materials with different ratios on methylene blue (1) Experimental object:

[0077] Experimental Examples 1 to 5, where:

[0078] Experimental Example 2: The same as Experimental Example 1, the difference in step (2) is:

[0079] Dissolve 1.7252 g of bismuth nitrate pentahydrate in a 2 mol / L nitric acid solution, and completely dissolve it by magnetic stirring. Then add 0.3509 g of ammonium metavanadate, and slowly add ammonia water dropwise to adjust the pH to 5. After stirring for 30 min, add 0.48 g of tin dioxide and continue stirring for 10 min. Then put it into a reaction kettle and react at 130 °C for 24 h. After it cools down, filter and wash it with deionized water and ethanol by suction filtration, and finally put it into an oven at 80 °C for vacuum drying for 4 h.

[0080] Experimental Example 3: The same as Experimental Example 1, the difference is that step (2) is as follows:

[0081] Dissolve 0.5751 g of bismuth nitrate pentahydrate in a 2 mol / L nitric acid solution, and completely dissolve it by magnetic stirring. Then add 0.1170 g of ammonium metavanadate, and slowly add ammonia water dropwise to adjust the pH to 5. After stirring for 30 min, add 0.32 g of tin dioxide and continue stirring for 10 min. Then put it into a reaction kettle and react at 130 °C for 24 h. After it cools down, filter and wash it with deionized water and ethanol by suction filtration, and finally put it into an oven at 80 °C for vacuum drying for 4 h.

[0082] Experimental Example 4: The same as Experimental Example 1, the difference is that step (2) is as follows:

[0083] Dissolve 0.4313 g of bismuth nitrate pentahydrate in a 2 mol / L nitric acid solution, and completely dissolve it by magnetic stirring. Then add 0.0877 g of ammonium metavanadate, and slowly add ammonia water dropwise to adjust the pH to 5. After stirring for 30 min, add 0.48 g of tin dioxide and continue stirring for 10 min. Then put it into a reaction kettle and react at 130 °C for 24 h. After it cools down, filter and wash it with deionized water and ethanol by suction filtration, and finally put it into an oven at 80 °C for vacuum drying for 4 h.

[0084] Experimental Example 5: The same as Experimental Example 1, the difference is that step (2) is as follows:

[0085] Dissolve 0.4313 g of bismuth nitrate pentahydrate in a 2 mol / L nitric acid solution, and completely dissolve it by magnetic stirring. Then add 0.0877 g of ammonium metavanadate, and slowly add ammonia water dropwise to adjust the pH to 5. After stirring for 30 min, add 0.72 g of tin dioxide and continue stirring for 10 min. Then put it into a reaction kettle and react at 130 °C for 24 h. After it cools down, filter and wash it with deionized water and ethanol by suction filtration, and finally put it into an oven at 80 °C for vacuum drying for 4 h.

[0086] (2) Experimental method:

[0087] Prepare an aqueous solution of methylene blue at a concentration of 10 mg / mL. Immerse a 2×2 cm fabric-based bismuth vanadate / tin dioxide composite material in 100 mL of the methylene blue aqueous solution. After 30 minutes of dark treatment at room temperature, use a 300 W xenon lamp to simulate sunlight for the photocatalytic degradation experiment. Take samples every 20 minutes to obtain the ultraviolet-visible absorption curves of the methylene blue aqueous solution at different times, and take points at 664 nm on each curve to plot the degradation effect diagram.

[0088] (3) Experimental results:

[0089] As Figure 6 shown, it can be seen from Figure 6 that the degradation effect of methylene blue in Experimental Example 1 is the best, indicating that the synergistic effect between bismuth vanadate and tin dioxide is the best at this time. As the proportion of tin dioxide increases, the adsorption performance of the material changes, which is related to the surface change after the two are compounded; the effect of Experimental Example 4 is the worst, indicating that the proportion of bismuth vanadate is too low at this time, causing agglomeration between tin dioxides, thus affecting the final catalytic degradation effect.

[0090] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, makes equivalent substitutions or changes, and all are covered by the protection scope of the present invention.

Claims

1. A method for preparing a fabric-based bismuth vanadate / tin dioxide composite photocatalytic material, characterized in that: It includes the following steps: S1. Preparation of bismuth vanadate / tin dioxide: adding ammonium metavanadate to a nitric acid solution of bismuth nitrate pentahydrate, adjusting the pH value of the mixed solution to 5-6, and then adding tin dioxide, reacting at 120-140° C. for 20-30 hours, and the resulting product is bismuth vanadate / tin dioxide; S2. Preparation of dopamine cotton fabric: adding the cotton fabric soaked in acetone to a Tris-HCl buffer solution of dopamine, shaking at room temperature in the dark for 22 to 26 hours, and obtaining a dopamine cotton fabric; S3. Loading: Add the dopamine cotton fabric prepared in step S2 to the aqueous solution of bismuth vanadate / tin dioxide, oscillate in a water bath at 22-28° C. for 7-9 hours, and wash and dry the cotton fabric to obtain a fabric-based bismuth vanadate / tin dioxide composite photocatalytic material.

2. The method for preparing a fabric-based bismuth vanadate / tin dioxide composite photocatalytic material according to claim 1, characterized in that: The concentration of the nitric acid solution in step S1 is 1.5-3 mol / L, and the mass volume ratio of bismuth nitrate pentahydrate to the nitric acid solution is 9-30 mg:1 ml.

3. The method for preparing a fabric-based bismuth vanadate / tin dioxide composite photocatalytic material according to claim 1, characterized in that: The mass ratio of bismuth nitrate pentahydrate, ammonium metavanadate and tin dioxide in step S1 is 2-5:1-2:

1.

4. The method for preparing a fabric-based bismuth vanadate / tin dioxide composite photocatalytic material according to claim 1, characterized in that: After the reaction in step S1 is completed, the product is filtered and washed with deionized water and ethanol at room temperature, and finally vacuum dried in an oven at 75 to 85° C. for 3.5 to 4.5 hours.

5. The method for preparing a fabric-based bismuth vanadate / tin dioxide composite photocatalytic material according to claim 1, characterized in that: The tin dioxide in step S1 is prepared by the following method: adding tin tetrachloride pentahydrate and ethanol to a sodium hydroxide solution, reacting in a reactor at 180-200° C. for 20-26 hours, washing the resulting precipitate with deionized water and ethanol for 3-4 times, and then drying at a temperature of 110-130° C. for 20-26 hours.

6. The method for preparing a fabric-based bismuth vanadate / tin dioxide composite photocatalytic material according to claim 5, characterized in that: The mass ratio of the sodium hydroxide to the tin tetrachloride pentahydrate is 1:0.8-2, the concentration of the sodium hydroxide solution is 0.01-0.1 g / ml, and the volume ratio of the sodium hydroxide solution to ethanol is 1:

1.

7. The method for preparing a fabric-based bismuth vanadate / tin dioxide composite photocatalytic material according to claim 1, characterized in that: In step S1, the pH value of the mixed solution is adjusted with aqueous ammonia.

8. The method for preparing a fabric-based bismuth vanadate / tin dioxide composite photocatalytic material according to claim 1, characterized in that: The pH value of the Tris-HCl buffer solution in step S2 is 8.5, the concentration is 10 mmol / L, the mass volume ratio of dopamine to the Tris-HCl buffer solution is 1 g:400-600 ml; the mass ratio of dopamine to the area of ​​the cotton fabric is 4-8 mg / cm 2 .

9. The method for preparing a fabric-based bismuth vanadate / tin dioxide composite photocatalytic material according to claim 1, characterized in that: The mass ratio of bismuth vanadate / tin dioxide to the area ratio of dopamine cotton fabric in step S3 is 8-16 mg / cm 2 .

10. A fabric-based bismuth vanadate / tin dioxide composite photocatalytic material prepared by the method according to any one of claims 1 to 9.

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