Composite photocatalytic material, preparation method and application thereof

Abstract

The application discloses a composite photocatalytic material and a preparation method and application thereof, and relates to the technical field of photocatalytic materials. 12 The composite photocatalytic material comprises a bismuth-based composite oxide layer and a phenolic resin layer loaded on the surface of the bismuth-based composite oxide layer; the material of the bismuth-based oxide layer is selected from at least one of Bi2WO6, BiVO4, Bi2Mo3O 12 The phenolic resin layer is irradiated by photon energy, surface-escaping electrons can participate in a water redox reaction to generate H2O2, and then the H2O2 can react with formaldehyde gas to generate formic acid and water, so that the formaldehyde degradation is realized; and the bismuth-based composite oxide layer can promote water splitting to generate oxygen under the action of light, the generated oxygen can promote the redox reaction of the phenolic resin layer, accelerate the generation of H2O2, improve the concentration of H2O2, and thus improve the formaldehyde degradation efficiency, so that the composite photocatalytic material can realize efficient photocatalytic degradation of formaldehyde.

Description

Technical Field

[0001] This invention relates to the field of photocatalytic materials technology, and in particular to a composite photocatalytic material, its preparation method, and its application. Background Technology

[0002] Formaldehyde is considered a potential carcinogen among volatile organic compounds (VOCs) with a typical pungent odor. Its irritant toxicity can damage the human nervous and respiratory systems, posing a serious threat to human health. Current conventional formaldehyde purification methods include adsorption, catalytic combustion, and photocatalysis. Among these, adsorption is the most widely used, with activated carbon (AC) being a highly representative adsorbent. However, adsorption cannot quickly and completely remove formaldehyde. Furthermore, some studies have explored the degradation of gaseous formaldehyde using catalytic combustion. Thermal catalysis often exhibits high catalytic efficiency, but it also suffers from significant energy loss and potential secondary environmental pollution. Photocatalysis converts solar energy into chemical energy without requiring other consumables. Based on the advantages of photocatalysis, strategies for synthesizing photocatalysts have been proposed. These strategies achieve highly efficient catalysis while ensuring a more cost-effective and environmentally friendly catalytic process. Therefore, photocatalysis is currently the best method for eliminating VOCs. However, the traditional method involves forming a photocatalytic film layer using photocatalytic materials. This monolayer structure effectively improves the separation of photogenerated carriers, but at the cost of reduced oxidation capacity, thus inhibiting the catalytic activity of the photocatalyst. Therefore, the photocatalytic performance of existing photocatalytic materials still needs improvement. Summary of the Invention

[0003] This invention aims to solve at least one of the technical problems existing in the prior art. To this end, this invention proposes a composite photocatalytic material, its preparation method, and its application.

[0004] In a first aspect, the present invention provides a composite photocatalytic material comprising a bismuth-based composite oxide layer and a phenolic resin layer supported on the surface of the bismuth-based composite oxide layer; wherein the bismuth-based composite oxide layer is selected from Bi₂WO₆, BiVO₄, and Bi₂Mo₃O₃. 12 At least one of them.

[0005] According to embodiments of the present invention, the composite photocatalytic material has at least the following beneficial effects: The composite photocatalytic material comprises a bismuth-based composite oxide layer and a phenolic resin layer supported on the surface of the bismuth-based composite oxide layer. When the phenolic resin layer is irradiated with photon energy, the electrons escaping from the surface can participate in the redox reaction of water to generate H2O2, which can then react with formaldehyde gas to generate formic acid and water, thereby achieving formaldehyde degradation. Furthermore, under light irradiation, the bismuth-based composite oxide layer can promote the splitting of water reaching the layer to generate oxygen. The generated oxygen can promote the redox reaction of the phenolic resin layer, accelerate the generation of H2O2, increase the concentration of H2O2, and thus improve the formaldehyde degradation efficiency. Therefore, this composite photocatalytic material, through the combination of the bismuth-based composite oxide layer and the phenolic resin layer, can achieve highly efficient photocatalytic degradation of formaldehyde.

[0006] In some embodiments of the present invention, the phenolic resin layer is selected from at least one of resorcinol-formaldehyde resin layer and alcohol-soluble phenolic resin layer.

[0007] In some embodiments of the present invention, the thickness of the phenolic resin layer is 0.5 to 1 μm.

[0008] In some embodiments of the present invention, the thickness of the bismuth-based composite oxide layer is 0.5 to 1 μm.

[0009] In some embodiments of the present invention, a base layer is also included, wherein the bismuth-based composite oxide layer is disposed on the surface of the base layer.

[0010] In some embodiments of the present invention, the base layer is selected from transparent base layers.

[0011] In some embodiments of the present invention, the transparent substrate is selected from either FTO conductive glass or ITO conductive glass; preferably, the composite photocatalytic material is a composite glass material; preferably, the composite glass material is architectural glass material or automotive glass material.

[0012] A second aspect of the present invention provides a method for preparing any of the composite photocatalytic materials proposed in the first aspect of the present invention, comprising the following steps:

[0013] S1. A bismuth-based composite oxide layer is set on the surface of the substrate;

[0014] S2. A phenolic resin layer is deposited on the surface of the bismuth-based composite oxide layer to obtain a composite photocatalytic material.

[0015] In some embodiments of the present invention, in step S1, a bismuth-based composite oxide layer is synthesized on the surface of the substrate by a solvothermal method.

[0016] In some embodiments of the present invention, step S1 involves synthesizing a bismuth-based composite oxide layer on the surface of the substrate using a solvothermal method. Specifically, this includes: mixing a bismuth source, a metal M source, and a surfactant in an organic solvent to obtain a bismuth-based composite oxide precursor solution; and then placing the substrate in the bismuth-based composite oxide precursor solution for a solvothermal reaction; wherein the metal M source is selected from at least one of a tungsten source, a vanadium source, and a molybdenum source.

[0017] Specifically, the bismuth-based composite oxide precursor solution is prepared by mixing a bismuth source, a metal M source, and a surfactant with an organic solvent, and then stirring at a speed of 600–800 rpm for 1–3 hours until completely dissolved to obtain the bismuth-based composite oxide precursor solution.

[0018] A transparent substrate can be used, but the inventors' research and experiments have shown that using conventional glass as a substrate is fragile under high-temperature and high-pressure hydrothermal (or solvothermal) reactions, posing a risk of uneven in-situ growth of the bismuth-based composite oxide layer and the phenolic resin layer. Therefore, it is preferable to use at least one transparent conductive glass, such as FTO conductive glass or ITO conductive glass. These transparent conductive glasses have high hardness and high light transmittance. Using them as a substrate, a uniform bismuth-based composite oxide layer and a phenolic resin layer can be grown in situ on them through the above solvothermal and hydrothermal reactions, respectively. This allows for the simple and rapid preparation of a composite photocatalytic material (i.e., a composite glass material) with light transmittance, high hardness, and formaldehyde degradability, which can then be used to prepare multifunctional glass windows.

[0019] In some embodiments of the present invention, the temperature of the solvothermal reaction is 160–280°C, for example, it can be controlled at 160–180°C, 180–200°C, 200–250°C, or 250–280°C.

[0020] In some embodiments of the present invention, the solvothermal reaction takes 12 to 24 hours.

[0021] In some embodiments of the present invention, the bismuth source is selected from at least one of bismuth pentahydrate, bismuth trioxide, and bismuth carbonate.

[0022] In some embodiments of the present invention, the tungsten source is selected from at least one of sodium tungstate dihydrate and ammonium tungstate, the vanadium source is selected from at least one of sodium vanadate and ammonium vanadate, and the molybdenum source is selected from at least one of sodium molybdate and ammonium molybdate.

[0023] In some embodiments of the present invention, the surfactant is selected from at least one of hexadecyltrimethylammonium bromide, sodium dioctyl succinate sulfonate, and sodium dodecylbenzene sulfonate.

[0024] In some embodiments of the present invention, the organic solvent is selected from at least one of ethylene glycol solution and ethanol.

[0025] In some embodiments of the present invention, in step S2, a phenolic resin layer is synthesized on the surface of the bismuth-based composite oxide layer by a hydrothermal method to obtain a composite photocatalytic material.

[0026] In some embodiments of the present invention, step S2 involves synthesizing a phenolic resin layer on the surface of the bismuth-based composite oxide layer using a hydrothermal method to obtain a composite photocatalytic material. Specifically, this includes: mixing phenolic organic compounds with aldehyde organic compounds, an alkaline catalyst, and a solvent to prepare a phenolic resin precursor solution; then placing the composite material obtained in step S1 into the phenolic resin precursor solution for a hydrothermal reaction to obtain the composite photocatalytic material. Specifically, the phenolic resin precursor solution can be prepared by mixing phenolic organic compounds, aldehyde organic compounds, an alkaline catalyst, and water as a solvent, and stirring at a speed of 550–850 rpm for 30–180 min to obtain the phenolic resin precursor solution.

[0027] In some embodiments of the present invention, the temperature of the hydrothermal reaction is 180–300°C, for example, it can be controlled at 180–200°C, 200–250°C, 240–260°C, 260–280°C, or 280–300°C.

[0028] In some embodiments of the present invention, the hydrothermal reaction time is 12 to 24 hours.

[0029] In some embodiments of the present invention, the phenolic organic compound is selected from at least one of resorcinol, phenol, and hydroquinone.

[0030] In some embodiments of the present invention, the aldehyde organic compound is selected from at least one of formaldehyde and acetaldehyde.

[0031] In some embodiments of the present invention, the alkaline catalyst is selected from at least one of ammonia and arsenic.

[0032] In some embodiments of the present invention, before step S1, step S0 is included, which involves removing impurities from the substrate.

[0033] In some embodiments of the present invention, the impurity removal treatment includes immersion in an alcohol solution followed by washing with water. The immersion or washing process may be ultrasonically assisted; the alcohol solution may include methanol, anhydrous ethanol, etc. Specifically, the substrate may first be immersed in a methanol solution and ultrasonically sonicated; then immersed in anhydrous ethanol and ultrasonically sonicated; finally washed with water and ultrasonically sonicated; wherein the immersion time in the methanol solution and the ultrasonic time can be controlled within 2–4 hours, the immersion time in the anhydrous ethanol and the ultrasonic time can be controlled within 2–4 hours; the washing and ultrasonic time can be controlled within 30–180 minutes.

[0034] In some embodiments of the present invention, step S2, after the hydrothermal reaction, further includes washing and drying. Specifically, the composite material obtained after the hydrothermal reaction can be first placed in an acetone solution and sonicated for 30–180 min, and then repeatedly washed with pure water and anhydrous ethanol; the drying temperature can be controlled at 60–200°C, and the drying time can be controlled at 12–24 h.

[0035] In a third aspect, the invention proposes the application of any of the composite photocatalytic materials proposed in the first aspect of the invention in the photocatalytic degradation of formaldehyde. Attached Figure Description

[0036] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein:

[0037] Figure 1 This is a schematic diagram of the preparation process of the composite photocatalytic material in Example 1;

[0038] Figure 2 The image shows a SEM image of the composite photocatalyst material prepared in Example 1.

[0039] Figure 3 This is a schematic diagram of the photocatalytic degradation mechanism of formaldehyde by the composite photocatalytic material prepared in Example 1;

[0040] Figure 4 This is a schematic diagram of the formaldehyde degradation mechanism in the simulated environment during the photocatalytic degradation performance test method of the composite photocatalytic material in Example 1.

[0041] Figure 5 The figure shows the test results of the photocatalytic degradation performance of formaldehyde by the composite photocatalytic material in Example 1.

[0042] Figure 6 The graph shows the comparison of the concentration of H2O2 generated by the composite photocatalytic materials of Example 1 and Comparative Example 1 under light irradiation.

[0043] Figure 7 The graph shows the test results of the photocatalytic degradation performance of the composite photocatalytic material in Example 2 for formaldehyde.

[0044] Figure 8 The figure shows the test results of the photocatalytic degradation performance of formaldehyde by the composite photocatalytic material in Example 3. Detailed Implementation

[0045] The following will describe the concept and technical effects of the present invention clearly and completely with reference to embodiments, so as to fully understand the purpose, features and effects of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are all within the scope of protection of the present invention.

[0046] Example 1

[0047] This embodiment prepares a composite photocatalytic material, and the preparation method is as follows: Figure 1 As shown, it specifically includes:

[0048] S1. Take a piece of FTO conductive glass with a length and width of 25mm and a thickness of 2mm; then remove impurities from it by soaking it in methanol solution for 2 hours and sonicating it for 30 minutes; then soak it in anhydrous ethanol for 2 hours and sonicate it for 1 hour; finally, wash it with pure water and sonicate it for 30 minutes.

[0049] S2. Weigh 2 mmol of bismuth nitrate pentahydrate and 1 mmol of sodium tungstate dihydrate using a balance, add them to 16 ml of ethylene glycol solution and 0.01 g of hexadecyltrimethylammonium bromide, mix and stir at 700 rpm for 1 h until completely dissolved to obtain Bi2WO6 precursor solution.

[0050] S3. Place the FTO conductive glass cleaned in step S1 into a 20ml polytetrafluoroethylene (PTFE) liner. Then pour the Bi2WO6 precursor solution obtained in step S2 into the PTFE liner, ensuring that the Bi2WO6 precursor solution completely submerges the FTO conductive glass. Next, place the PTFE liner into a stainless steel autoclave and then into a forced-air drying oven. Set the temperature to 180℃ and heat for 16 hours to carry out a solvothermal reaction. After the reaction is complete, air-cool to room temperature to obtain an FTO / Bi2WO6 film.

[0051] S4. Weigh 0.096g of resorcinol powder using a balance and place it in a mixture of 0.135ml formaldehyde, 0.05ml ammonia, and 16ml deionized water. Then stir at 700rpm for 60min until completely dissolved to obtain a phenolic resin precursor solution.

[0052] S5. Place the FTO / Bi2WO6 film obtained in step S3 into a polytetrafluoroethylene (PTFE) liner, then pour the phenolic resin precursor solution obtained in step S4 into the PTFE liner, ensuring the phenolic resin precursor solution completely submerges the FTO / Bi2WO6 film. Next, place the PTFE liner into a stainless steel reactor, then into a forced-air drying oven at 251°C for 24 hours for a hydrothermal reaction. After the reaction is complete, cool to room temperature to obtain the FTO / Bi2WO6 / RF film. Place the film in a beaker containing acetone solution, sonicate for 30 minutes, and finally wash repeatedly with pure water and anhydrous ethanol. Then place it in a vacuum drying oven at 80°C for 12 hours to obtain the composite photocatalytic material, namely the FTO / Bi2WO6 / RF composite photocatalytic material.

[0053] The composite photocatalyst material prepared above was observed using a scanning electron microscope (SEM), and the results are as follows: Figure 2 As shown. By Figure 2 It is known that the prepared composite photocatalytic material includes an FTO conductive glass substrate, a Bi2WO6 layer loaded on the surface of the FTO conductive glass substrate, and a phenolic resin RF layer loaded on the surface of the Bi2WO6 layer.

[0054] The photocatalytic degradation mechanism of formaldehyde by this composite photocatalytic material is as follows: Figure 3 As shown, when the phenolic resin RF layer is irradiated by photon energy, the electrons that escape from the surface can participate in the redox reaction of water to generate H2O2, which can then react with formaldehyde gas to generate formic acid and water, thereby achieving formaldehyde degradation. Furthermore, under the action of light, the Bi2WO6 layer can promote the splitting of water in the layer to generate oxygen. The generated oxygen can promote the redox reaction of the phenolic resin layer, accelerate the generation of H2O2, increase the concentration of H2O2, and thus improve the formaldehyde degradation efficiency.

[0055] To further verify the photocatalytic degradation performance of the above-prepared composite photocatalytic material on formaldehyde, the inventors attached the FTO / Bi2WO6 / RF composite photocatalytic material to the side wall of a 60mm*60mm*60mm cubic sealed box made of six acrylic panels of the same length and width. A 2cm diameter hole was cut into the top panel, a rubber stopper was inserted, and the box was glued shut to maintain a tight seal, creating a specially designed sealed container to simulate indoor conditions, serving as experimental group one. A sealed container with the same structure but without the FTO / Bi2WO6 / RF composite photocatalytic material was used as a blank control group. Formaldehyde gas was then collected using 50mL sampling bottles and injected into the specially designed sealed containers. The determination was based on 0.5 solar intensity (50mW cm⁻¹ at an atmospheric factor of AM 1.5G). -2 An LED light was used as the light source to continuously illuminate the sealed container. Every 15 minutes, 5 mL of gas was taken out using a syringe with a 5 mL range and injected into the formaldehyde colorimetric solution to obtain the test solution. Then, the formaldehyde concentration of the blank control group and experimental group 1 was measured using a UV spectrophotometer.

[0056] In the above simulation scenarios, the sealed container can simulate an indoor environment, and the FTO / Bi2WO6 / RF composite photocatalytic material attached to the side wall of the sealed container can simulate a window for photocatalytic formaldehyde degradation testing. Its mechanism of action is as follows: Figure 4 As shown, under light irradiation, the Bi2WO6 layer can promote the decomposition of water in the layer to produce oxygen. The oxygen produced can promote the redox reaction of the phenolic resin layer, accelerate the generation of H2O2, and then react with formaldehyde gas to produce formic acid and water, thereby achieving formaldehyde degradation.

[0057] The photocatalytic degradation performance of the composite photocatalytic material prepared in this embodiment was tested according to the above simulation test method, and the results are as follows. Figure 5 As shown in the figure. Tests revealed that experimental group one achieved a formaldehyde degradation rate of 88.89% within 5 hours.

[0058] The specific formula for calculating the degradation rate is as follows:

[0059]

[0060] in: The average concentration of formaldehyde in a sealed container without the addition of composite photocatalytic material within 5 hours. The average concentration of formaldehyde after degradation within a sealed container containing composite photocatalytic material is measured over 5 hours.

[0061] Comparative Example 1

[0062] This comparative example prepared a composite photocatalytic material. The difference between this comparative example and Example 1 is that: in this comparative example, a Bi2WO6 layer was not set on the surface of the FTO conductive glass substrate, but a phenolic resin RF layer was directly prepared by hydrothermal method; that is, in this comparative example, steps S2 and S3 in Example 1 were omitted, and after completing step S1 in Example 1, step S4 was performed. Then, the FTO conductive film cleaned in step S1 replaced the FTO / Bi2WO6 film in step S5 of Example 1. Following step S5, the composite photocatalytic material, namely the FTO / RF composite photocatalytic material, was obtained.

[0063] The composite photocatalytic material in Example 1 and the composite photocatalytic material in Comparative Example 1 were used to construct a sealed container using a method similar to the formaldehyde photodegradation performance test method in Example 1. Ar gas was introduced into the sealed container to remove the air inside. Then, at a solar intensity of 0.5 (50 mW cm⁻¹ under an atmospheric factor of AM 1.5G), the photocatalytic material was tested. -2 An LED light was used as the light source to continuously illuminate a sealed container, and the concentration of hydrogen peroxide produced was measured. The results are as follows: Figure 6 As shown. By Figure 6 It is evident that the composite photocatalytic material prepared in Example 1 contains an additional Bi2WO6 layer between the FTO conductive glass substrate and the phenolic resin RF layer. This layer enhances the concentration of hydrogen peroxide generated by the phenolic resin RF layer under illumination. Specifically, the Bi2WO6 layer, under illumination, promotes the splitting of water to produce oxygen, which in turn promotes the redox reaction between the phenolic resin RF layer and water to generate hydrogen peroxide, ultimately improving the formaldehyde degradation efficiency.

[0064] Example 2

[0065] This embodiment prepares a composite photocatalytic material, specifically including:

[0066] S1. Take a piece of FTO conductive glass with a length and width of 25mm and a thickness of 2mm; then remove impurities from it by soaking it in methanol solution for 2 hours and sonicating it for 30 minutes; then soak it in anhydrous ethanol for 2 hours and sonicate it for 1 hour; finally, wash it with pure water and sonicate it for 30 minutes.

[0067] S2. Weigh 4 mmol of bismuth nitrate pentahydrate and 2 mmol of sodium tungstate dihydrate using a balance, add them to 12 ml of ethylene glycol solution and 0.01 g of hexadecyltrimethylammonium bromide, mix and stir at 700 rpm for 1 h until completely dissolved to obtain Bi2WO6 precursor solution.

[0068] S3. Place the FTO conductive glass cleaned in step S1 into a 20ml polytetrafluoroethylene (PTFE) liner. Then pour the Bi2WO6 precursor solution obtained in step S2 into the PTFE liner, ensuring that the Bi2WO6 precursor solution completely submerges the FTO conductive glass. Next, place the PTFE liner into a stainless steel autoclave and then into a forced-air drying oven. Set the temperature to 180℃ and heat for 24 hours to carry out a solvothermal reaction. After the reaction is complete, air-cool to room temperature to obtain an FTO / Bi2WO6 film.

[0069] S4. Weigh 0.192g of resorcinol powder using a balance and place it in a mixture of 0.135ml formaldehyde, 0.05ml ammonia, and 16ml deionized water. Then stir at 700rpm for 30min until completely dissolved to obtain a phenolic resin precursor solution.

[0070] S5. Place the FTO / Bi2WO6 film obtained in step S3 into a polytetrafluoroethylene (PTFE) liner, then pour the phenolic resin precursor solution obtained in step S4 into the PTFE liner, ensuring the phenolic resin precursor solution completely submerges the FTO / Bi2WO6 film. Next, place the PTFE liner into a stainless steel reactor, then into a forced-air drying oven at 251°C for 24 hours for a hydrothermal reaction. After the reaction is complete, cool to room temperature to obtain the FTO / Bi2WO6 / RF film. Place the film in a beaker containing acetone solution, sonicate for 30 minutes, and finally wash repeatedly with pure water and anhydrous ethanol. Then place it in a vacuum drying oven at 80°C for 12 hours to obtain the composite photocatalytic material, namely the FTO / Bi2WO6 / RF composite photocatalytic material.

[0071] The formaldehyde degradation performance of the composite photocatalytic material prepared in this embodiment was tested according to the method described in Example 1. Specifically, the FTO / Bi2WO6 / RF composite photocatalytic material prepared above was affixed to the side wall of a 60mm*60mm*60mm cubic sealed box made of six acrylic plates of the same length and width. A 2cm diameter circular hole was cut out of the top plate, a rubber stopper was inserted, and the holes were glued together to maintain a seal, thus creating a specially designed sealed container to simulate indoor conditions, serving as experimental group two. A sealed container with the same structure but without the FTO / Bi2WO6 / RF composite photocatalytic material was used as a blank control group. Formaldehyde gas was then collected using 50mL sampling bottles and injected into the specially designed sealed containers. An LED lamp with an intensity of 0.5 times sunlight was used as the light source to continuously illuminate the sealed containers. Every 15 minutes, 5 mL of gas was drawn using a syringe with a 5 mL capacity and injected into the formaldehyde colorimetric solution to obtain the test solution. The formaldehyde concentration in the blank control group and experimental group two was then measured using a UV spectrophotometer. Following the above simulation test method, the photocatalytic degradation performance of the composite photocatalytic material prepared in this embodiment was tested, and the results are as follows: Figure 7 As shown, "Nofilm" represents the blank control group, which was placed in a sealed container without the FTO / Bi2WO6 / RF composite photocatalyst material, while "Contains film" represents experimental group two, which was placed in a sealed container with the FTO / Bi2WO6 / RF composite photocatalyst material. Tests showed that experimental group two achieved an 85% degradation rate of formaldehyde within 5 hours.

[0072] Example 3

[0073] This embodiment prepares a composite photocatalytic material, the preparation method of which includes:

[0074] S1. Take a piece of FTO conductive glass with a length and width of 25mm and a thickness of 2mm; then remove impurities from it by soaking it in methanol solution for 2 hours and sonicating it for 30 minutes; then soak it in anhydrous ethanol for 2 hours and sonicate it for 1 hour; finally, wash it with pure water and sonicate it for 30 minutes.

[0075] S2. Weigh 4 mmol of bismuth nitrate pentahydrate and 3.8 mmol of sodium vanadate using a balance, add them to 12 ml of ethylene glycol solution and 0.01 g of hexadecyltrimethylammonium bromide, mix and stir at 700 rpm for 1 h until completely dissolved to obtain BiVO4 precursor solution.

[0076] S3. Place the FTO conductive glass cleaned in step S1 into a 20ml polytetrafluoroethylene (PTFE) liner, then pour the BiVO4 precursor solution obtained in step S2 into the PTFE liner, ensuring the BiVO4 precursor solution completely submerges the FTO conductive glass; then place the PTFE liner into a stainless steel autoclave, and then into a forced-air drying oven, setting the temperature to 180℃ and heating for 24 hours to carry out a solvothermal reaction; after the reaction is complete, air cool to room temperature to obtain an FTO / BiVO4 film.

[0077] S4. Weigh 0.096g of resorcinol powder using a balance and place it in a mixture of 0.135ml formaldehyde, 0.05ml ammonia, and 16ml deionized water. Then stir at 700rpm for 30min until completely dissolved to obtain a phenolic resin precursor solution.

[0078] S5. Place the FTO / BiVO4 film obtained in step S3 into a polytetrafluoroethylene (PTFE) liner, then pour the phenolic resin precursor solution obtained in step S4 into the PTFE liner, ensuring the phenolic resin precursor solution completely submerges the FTO / BiVO4 film. Next, place the PTFE liner into a stainless steel reactor, then into a forced-air drying oven at 251°C for 24 hours for a hydrothermal reaction. After the reaction is complete, cool to room temperature to obtain the FTO / BiVO4 / RF film. Place the film in a beaker containing acetone solution, sonicate for 30 minutes, and finally wash repeatedly with pure water and anhydrous ethanol. Then place it in a vacuum drying oven at 80°C for 12 hours to obtain the composite photocatalytic material, namely the FTO / BiVO4 / RF composite photocatalytic material.

[0079] The formaldehyde degradation performance of the composite photocatalytic material prepared in this embodiment was tested according to the method described in Example 1. Specifically, the FTO / BiVO4 / RF composite photocatalytic material prepared above was affixed to the side wall of a 60mm*60mm*60mm cubic sealed box made of six acrylic plates of the same length and width. A 2cm diameter circular hole was cut out of the top plate, a rubber stopper was inserted, and the holes were glued together to maintain a seal, thus creating a specially designed sealed container to simulate indoor conditions, serving as experimental group three. A sealed container with the same structure but without the FTO / BiVO4 / RF composite photocatalytic material was used as a blank control group. Formaldehyde gas was then collected using 50mL sampling bottles and injected into the specially designed sealed containers. An LED lamp with an intensity of 0.5 times sunlight was used as the light source to continuously illuminate the sealed containers. Every 15 minutes, 5 mL of gas is taken out using a syringe with a 5 mL range and injected into the formaldehyde colorimetric solution to obtain the test solution. Then, the formaldehyde concentration of the blank control group and experimental group 3 is measured using an ultraviolet spectrophotometer.

[0080] The photocatalytic degradation performance of the composite photocatalytic material prepared in this embodiment was tested according to the above simulation test method, and the results are as follows. Figure 8 As shown, "No film" represents the blank control group, which was sealed without FTO / BiVO4 / RF composite photocatalyst material, while "Contains film" represents experimental group three, which was sealed with FTO / BiVO4 / RF composite photocatalyst material. Tests showed that experimental group three achieved an 80% degradation rate of formaldehyde within 5 hours.

[0081] Analysis of Examples 1, 2, and 3 shows that, in addition to using bismuth tungstate and bismuth vanadate as intermediate layers, we infer that bismuth molybdate can also be used as an intermediate layer, for the following reasons:

[0082] First, Bi2Mo3O 12 BiVO4 and Bi2WO6 are both n-type semiconductors with similar crystal structures; while BiVO4, Bi2WO6 and Bi2Mo3O 12 Bismuth-containing multi-component metal compounds exhibit photocatalytic activity primarily attributed to their crystal structure, and Bi₂Mo₃O₃... 12 As an inorganic catalyst, bismuth molybdate has a wider range of synthesis and applications than the other two. Secondly, bismuth molybdate can be synthesized using methods similar to those for BiVO4 and Bi2WO6. Furthermore, bismuth molybdate is a novel photocatalytic material with many physical and chemical properties, including ionic conductivity, dielectric properties, gas sensing, and catalytic activity. Studies have shown that it exhibits strong absorption and the highest photocatalytic activity in the visible light region, making it suitable for degrading organic dyes under visible light irradiation. Bismuth molybdate can also photocatalytically degrade recalcitrant organic pollutants in water, such as rhodamine, methyl orange, and methyl violet, making it a novel visible-light-responsive bismuth-based composite oxide catalytic material. Additionally, as a typical Olivieris layered compound, bismuth molybdate's unique layered structure facilitates the separation and migration of photogenerated carriers. Using synthesis methods similar to those in Examples 1-3 to prepare bismuth molybdate-based composite materials can improve the efficient generation of hydrogen peroxide from RF resins. In summary, bismuth molybdate shares similar functions with the bismuth-based composite oxides in the above examples, all of which can accelerate the rate of hydrogen peroxide generation from RF resins.

[0083] As described above, in the embodiments above, a bismuth-based composite oxide layer and a phenolic resin layer can be easily and rapidly synthesized on the surface of an FTO conductive glass substrate through solvothermal and hydrothermal reactions, thus obtaining a composite photocatalytic material. The FTO conductive glass substrate possesses high hardness and high light transmittance, making it less prone to breakage during the solvothermal and hydrothermal reactions, ensuring the in-situ uniform growth of the bismuth-based composite oxide layer and the phenolic resin layer. When the phenolic resin layer is irradiated with photon energy, the escaped electrons can participate in the redox reaction of water to generate H2O2, which can then react with formaldehyde gas to generate… Formic acid and water are used to degrade formaldehyde; while the bismuth-based composite oxide layer, under light irradiation, promotes the splitting of water in the layer to produce oxygen. The produced oxygen can promote the redox reaction of the phenolic resin layer, accelerate the generation of H2O2, and increase the concentration of H2O2, thereby improving the formaldehyde degradation efficiency. Therefore, this composite photocatalytic material can be used for the photocatalytic degradation of formaldehyde, achieving highly efficient photocatalytic degradation of formaldehyde. For example, it can be used as a composite glass material in architectural glass, automotive glass, etc., and based on its photocatalytic formaldehyde degradation function, it can be used to prepare multifunctional glass windows and other fields.

[0084] The embodiments described above are merely examples of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention.

Claims

1. The application of a composite glass material in the photocatalytic degradation of formaldehyde, characterized in that, The composite glass material includes a bismuth-based composite oxide layer and a phenolic resin layer supported on the surface of the bismuth-based composite oxide layer; the material of the bismuth-based composite oxide layer is selected from Bi2WO6, BiVO4, and Bi2Mo3O. 12 At least one of the following, the phenolic resin layer is prepared by a method comprising the following steps: mixing phenolic organic compounds, aldehyde organic compounds, alkaline catalysts and solvent water to prepare a phenolic resin precursor solution, placing a bismuth-based composite oxide layer in the phenolic resin precursor solution, and growing the phenolic resin layer in situ on the surface of the bismuth-based composite oxide layer by hydrothermal reaction. The composite glass material is configured for photocatalytic degradation of formaldehyde. When the phenolic resin layer is irradiated with photon energy, the electrons escaping from the surface can participate in the redox reaction of water to generate H2O2, thereby degrading formaldehyde. Furthermore, under light irradiation, the bismuth-based composite oxide layer can promote the splitting of water reaching the bismuth-based composite oxide layer to generate oxygen. The oxygen promotes the redox reaction of the phenolic resin layer, accelerates the generation of H2O2, increases the concentration of H2O2, and improves the formaldehyde degradation efficiency.

2. The application according to claim 1, characterized in that, The phenolic resin layer is selected from at least one of resorcinol-formaldehyde resin layer and alcohol-soluble phenolic resin layer.

3. The application according to claim 1 or 2, characterized in that, It also includes a base layer, wherein the bismuth-based composite oxide layer is disposed on the surface of the base layer.

4. The application according to claim 3, characterized in that, The base layer is selected from transparent base layers.

5. The application according to claim 4, characterized in that, The transparent substrate is selected from either FTO conductive glass or ITO conductive glass.

6. The application according to claim 1, characterized in that, The composite glass material is prepared by a method comprising the following steps: S1. A bismuth-based composite oxide layer is set on the surface of the substrate; S2. A phenolic resin layer is deposited on the surface of the bismuth-based composite oxide layer by a hydrothermal method to prepare a composite photocatalytic material, thereby obtaining a composite glass material; specifically, this includes: preparing a phenolic resin precursor solution by mixing phenolic organic compounds with aldehyde organic compounds, an alkaline catalyst, and water as a solvent. The composite material obtained in step S1 is then placed in a phenolic resin precursor solution for a hydrothermal reaction to obtain a composite glass material.

7. The application according to claim 6, characterized in that, In step S1, a bismuth-based composite oxide layer is synthesized on the surface of the substrate by a solvothermal method.

8. The application according to claim 7, characterized in that, Step S1 specifically includes: mixing and dissolving a bismuth source, a metal M source, and a surfactant in an organic solvent to obtain a bismuth-based composite oxide precursor solution; then placing the substrate in the bismuth-based composite oxide precursor solution for a solvothermal reaction; the metal M source is selected from at least one of tungsten source, vanadium source, and molybdenum source.

9. The application according to claim 8, characterized in that, The temperature of the solvothermal reaction is 160~280℃.

10. The application according to claim 8, characterized in that, The bismuth source is selected from at least one of bismuth nitrate pentahydrate, bismuth trioxide, and bismuth carbonate; the tungsten source is selected from at least one of sodium tungstate dihydrate and ammonium tungstate; the vanadium source is selected from at least one of sodium vanadate and ammonium vanadate; the molybdenum source is selected from at least one of sodium molybdate and ammonium molybdate; and the surfactant is selected from at least one of hexadecyltrimethylammonium bromide, sodium dioctyl succinate sulfonate, and sodium dodecylbenzene sulfonate.

11. The application according to claim 6, characterized in that, In step S2, the temperature of the hydrothermal reaction is 180~300℃.

12. The application according to claim 6, characterized in that, The phenolic organic compound is selected from at least one of resorcinol, phenol, and hydroquinone; the aldehyde organic compound is selected from at least one of formaldehyde and acetaldehyde; and the alkaline catalyst is selected from at least one of ammonia and arsenic.

13. The application according to claim 6, characterized in that, Before step S1, step S0 is also included, which involves removing impurities from the substrate.

14. The application according to claim 13, characterized in that, The impurity removal process includes immersion in an alcohol solution followed by washing with water.

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