A photocatalytic composite material, a preparation method and application thereof

Abstract

The application discloses a kind of photocatalytic composite material and its preparation method and application, it includes carrier, and the resorcinol-formaldehyde resin loaded on carrier;The carrier is modified transparent wood piece;The modified transparent wood piece has pore structure.The application is loaded on the resorcinol-formaldehyde resin of modified transparent wood piece, on one hand, the wood piece after modification has more pore structure and light transmission, so that it is easier to load more and the resorcinol-formaldehyde resin content;On the other hand, using the resorcinol-formaldehyde resin loaded on the modified transparent wood piece stably promotes water oxidation performance, generates H2O2 under natural light, H2O2 is easy to decompose into hydroxyl radical, urea in air and hydroxyl radical react to produce ammonia, carbon dioxide and other substances, and have high degradation efficiency.

Description

Technical Field

[0001] The present invention relates to the field of photocatalysis technology, and in particular to a photocatalytic composite material and a preparation method and application thereof. Background Art

[0002] Urea is an organic substance that readily evaporates into the air along with water vapor, posing a serious threat to human health. It has toxic effects in the body, particularly at relatively high levels, affecting all body systems and organs. Therefore, a technology is needed to directly process urea without damaging the environment.

[0003] Various urea degradation technologies have recently been developed, including bioelectrochemical, biological, photoelectrochemical, electrochemical, and photocatalytic methods. However, photocatalytic urea degradation methods have been less studied. Although there have been studies on bare titanium dioxide (TiO2) photocatalysts and photocatalytic urea degradation, their degradation efficiency is low, reaching 90% degradation efficiency only after 15 hours, which is a low degradation efficiency. In addition, some researchers have studied TiO2 photocatalytic degradation of urea, but this is limited to the degradation of urea in water and has not been applied to the removal of urea in the air. Furthermore, since the existing urea degradation materials are all opaque, their application is limited.

[0004] Therefore, there is an urgent need to develop a composite material that is light-transmissive and can efficiently degrade urea in the air. Summary of the Invention

[0005] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, in a first aspect, the present invention provides a photocatalytic composite material that is light-transmissive and can efficiently degrade urea in the air.

[0006] The second aspect of the present invention also provides a method for preparing the photocatalytic composite material.

[0007] The third aspect of the present invention also provides a window.

[0008] The fourth aspect of the present invention also provides an application of a photocatalytic composite material.

[0009] According to a first aspect of the present invention, a photocatalytic composite material is provided, comprising a carrier and a resorcinol-formaldehyde resin loaded on the carrier; the carrier is a modified transparent wood chip; the modified transparent wood chip has a pore structure.

[0010] The photocatalytic composite material according to the embodiment of the present invention has at least the following beneficial effects:

[0011] The present invention loads resorcinol-formaldehyde resin on modified transparent wood chips. On the one hand, the modified wood chips have more pore structures and light transmittance, so that the resorcinol-formaldehyde resin content loaded is higher and easier to load. On the other hand, the resorcinol-formaldehyde resin loaded on the modified transparent wood chips is used to stably promote water oxidation performance, generating H2O2 under natural light. H2O2 is easily decomposed into hydroxyl radicals. Urea in the air reacts with the hydroxyl radicals to produce substances such as ammonia and carbon dioxide, and has a high degradation efficiency.

[0012] According to some embodiments of the present invention, the mass percentage of the resorcinol-formaldehyde resin in the photocatalytic composite material is 10% to 50%. According to some embodiments of the present invention, the mass percentage of the resorcinol-formaldehyde resin in the photocatalytic composite material is 20% to 40%. According to some embodiments of the present invention, the mass percentage of the resorcinol-formaldehyde resin in the photocatalytic composite material is 10%, 20%, 30%, 40%, 50%, or within a range consisting of any two of the foregoing values. As a result, the photocatalytic composite material has good efficiency in photocatalytic degradation of urea.

[0013] According to some embodiments of the present invention, the thickness of the modified transparent wood sheet is 1.0 mm to 3.0 mm. According to some embodiments of the present invention, the thickness of the modified transparent wood sheet is 1.5 mm to 2.0 mm. According to some embodiments of the present invention, the thickness of the modified transparent wood sheet is 1.0 mm, 1.5 mm, 2.0 mm, 2.5 mm, 3.0 mm, or within a range consisting of any two of the foregoing values. Thus, the modified transparent wood sheet has better light transmittance.

[0014] According to some embodiments of the present invention, the modified transparent wood chip is prepared by the following steps:

[0015] S1. Soaking the wood chips in alkaline solution and hydrogen peroxide in sequence to remove lignin and increase the pore size of the wood chips so that more resorcinol-formaldehyde resin can be attached;

[0016] S2. Irradiating the soaked wood chips with ultraviolet light to obtain modified transparent wood chips, the purpose of which is to remove the original pigments and oxides in the wood chips and make them more transparent.

[0017] According to some embodiments of the present invention, the irradiation time is 2 hours to 10 hours.

[0018] According to some embodiments of the present invention, the wood chips are sequentially soaked in the alkaline solution and the hydrogen peroxide for a period of 12 hours to 24 hours.

[0019] According to some embodiments of the present invention, the wood chips are selected from balsa wood, such as balsa wood in the embodiments of the present invention, so that the wood chips have a higher load capacity.

[0020] According to some embodiments of the present invention, the alkaline solution includes at least one of a sodium hydroxide solution, a sodium hypochlorite solution, and a potassium hydroxide solution.

[0021] According to some embodiments of the present invention, the resorcinol-formaldehyde resin is prepared by the following steps:

[0022] S3. Evenly mix resorcinol, formaldehyde, ammonia water and water, and obtain resorcinol-formaldehyde resin through hydrothermal reaction.

[0023] According to some embodiments of the present invention, the temperature of the hydrothermal reaction is 160°C to 280°C.

[0024] According to some embodiments of the present invention, the hydrothermal reaction time is 12 hours to 24 hours.

[0025] According to some embodiments of the present invention, the molar ratio of resorcinol, formaldehyde and ammonia water is 1:(1-2):(1-3).

[0026] According to some embodiments of the present invention, the hydrothermal reaction is followed by a first drying step.

[0027] According to some embodiments of the present invention, the temperature of the first drying is 60°C to 180°C.

[0028] According to some embodiments of the present invention, the first drying time is 12 hours to 24 hours.

[0029] According to some embodiments of the present invention, the mixing stirring speed is 600 rpm to 700 rpm.

[0030] According to some embodiments of the present invention, the mixing time is 10 min to 120 min.

[0031] According to a second aspect of the present invention, a method for preparing a photocatalytic composite material is provided, comprising the following steps:

[0032] S4, mixing the modified transparent wood chips, resorcinol-formaldehyde resin and water, ultrasonicating, and performing a second drying to obtain the product.

[0033] According to some embodiments of the present invention, the ultrasonic time is 60 min to 120 min.

[0034] According to some embodiments of the present invention, the temperature of the second drying is 60°C to 150°C.

[0035] According to some embodiments of the present invention, the second drying time is 12 hours to 24 hours.

[0036] A third aspect of the present invention provides a wooden window prepared from the above-mentioned photocatalytic composite material.

[0037] A fourth aspect of the present invention provides use of the above-mentioned photocatalytic composite material in photocatalytic degradation of urea.

[0038] Other features and advantages of the present invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the following description of the embodiments with reference to the accompanying drawings, in which:

[0040] Figure 1 is a SEM image of the photocatalytic composite material prepared in Example 1 of the present invention;

[0041] Figure 2 Mechanism diagram of urea degradation by the photocatalytic composite material prepared in an embodiment of the present invention;

[0042] Figure 3 A photo of the photocatalytic composite material prepared in an embodiment of the present invention for degrading urea;

[0043] Figure 4 This is a graph showing the simulated indoor photocatalytic degradation of urea in the embodiments of the present invention and the comparative example;

[0044] Figure 5 This is a transmittance diagram of the photocatalytic composite material prepared in an embodiment of the present invention. DETAILED DESCRIPTION

[0045] The following are specific embodiments of the present invention, and the technical solutions of the present invention are further described in conjunction with the embodiments, but the present invention is not limited to these embodiments.

[0046] Unless otherwise specified, the reagents, methods and equipment used in the present invention are conventional reagents, methods and equipment in the art.

[0047] Example 1

[0048] Example 1 provides a photocatalytic composite material comprising a modified transparent wood chip and a resorcinol-formaldehyde resin supported on the modified transparent wood chip, wherein the resorcinol-formaldehyde resin accounts for 10.9% by weight of the photocatalytic composite material. The preparation method is as follows:

[0049] S1. Take 20 mm long, 2.0 mm thick balsa wood chips and dry them at 60°C for 12 hours. Dissolve 1 g of sodium hydroxide in 10 mL of deionized water to prepare a solution. Soak the chips in this solution at room temperature for 12 hours. Transfer them to hydrogen peroxide and store them at room temperature overnight.

[0050] S2, rinsing the wood chips with deionized water and anhydrous ethanol for multiple times, and finally irradiating them with a high-pressure mercury lamp for 4 hours to obtain modified transparent wood chips;

[0051] S3, take 0.096g resorcinol powder, formaldehyde (0.135mL, 6mol L -1 ), ammonia water (0.050 mL, 16 mol L -1 ) and deionized water, stirred for 30 minutes, and then transferred the mixture into a 20 ml Teflon-lined stainless steel autoclave, heated in a forced air drying oven at 251° C. for 24 hours, and then cooled to room temperature; finally, the resorcinol-formaldehyde resin was obtained by filtration, and dried in a vacuum drying oven at 60° C. for 12 hours;

[0052] S4. Weigh 10 mg of the resorcinol-formaldehyde resin powder prepared above, dissolve it in 30 mL of deionized water, add 65 mg of modified transparent wood chips to the solution, stir for 30 min, then ultrasonicate for 30 min, and finally dry at 80° C. for 12 h.

[0053] The amount of the loaded resorcinol-formaldehyde resin powder was measured to be 8 mg, and the loading amount was calculated using the following formula: 8 mg / (8 mg+65 mg)*100%=10.9%.

[0054] The photocatalytic composite material prepared in Example 1 was subjected to SEM testing, and the results were as follows: Figure 1 As shown, the modified transparent wood chips have a pore size of approximately 30 μm. The particles are resorcinol-formaldehyde resin loaded within the modified transparent wood chips. Furthermore, it was found that the resorcinol-formaldehyde resin prepared in this application is more loaded within the transparent wood chips, which helps increase its loading capacity. The particles have a spherical morphology, approximately 500 nm in diameter, and a smooth and relatively uniform surface.

[0055] Example 2

[0056] Example 2 provides a photocatalytic composite material comprising a modified transparent wood chip and a resorcinol-formaldehyde resin supported on the modified transparent wood chip. The resorcinol-formaldehyde resin accounts for 20.7% by weight of the photocatalytic composite material. The preparation method is as follows:

[0057] S1. Take 20 mm long, 2 mm thick balsa wood chips and dry them at 60°C for 12 hours. Dissolve 1 g of sodium hydroxide in 10 mL of deionized water to prepare a solution. Soak the chips in this solution at room temperature for 12 hours. Transfer them to hydrogen peroxide and store them at room temperature overnight.

[0058] S2, rinsing the wood chips with deionized water and anhydrous ethanol for multiple times, and finally irradiating them with a high-pressure mercury lamp for 4 hours to obtain modified transparent wood chips;

[0059] S3, take 0.096g resorcinol powder, formaldehyde (0.135mL, 6mol L -1 ), ammonia water (0.050 mL, 16 mol L -1 ) and deionized water, stirred for 30 minutes, and then transferred the mixture into a 20 ml Teflon-lined stainless steel autoclave, heated in a forced air drying oven at 251° C. for 24 hours, and then cooled to room temperature; finally, the resorcinol-formaldehyde resin was obtained by filtration, and dried in a vacuum drying oven at 60° C. for 12 hours;

[0060] S4. Weigh 20 mg of the resorcinol-formaldehyde resin powder prepared above, dissolve it in 30 mL of deionized water, add the modified transparent wood chips to the solution, stir for 30 minutes, then ultrasonicate for 30 minutes, and finally dry at 80° C. for 12 hours.

[0061] Example 3

[0062] Example 3 provides a photocatalytic composite material comprising a modified transparent wood chip and a resorcinol-formaldehyde resin (28.6%) loaded on the modified transparent wood chip. The preparation method thereof is as follows:

[0063] S1. Take 20 mm long, 2 mm thick balsa wood chips and dry them at 60°C for 12 hours. Dissolve 1 g of sodium hydroxide in 10 mL of deionized water to prepare a solution. Soak the chips in this solution at room temperature for 12 hours. Transfer them to hydrogen peroxide and store them at room temperature overnight.

[0064] S2, rinsing the wood chips with deionized water and anhydrous ethanol for multiple times, and finally irradiating them with a high-pressure mercury lamp for 4 hours to obtain modified transparent wood chips;

[0065] S3, take 0.096g resorcinol powder, formaldehyde (0.135mL, 6mol L -1 ), ammonia water (0.050 mL, 16 mol L -1) and deionized water, stirred for 30 minutes, and then transferred the mixture into a 20 ml Teflon-lined stainless steel autoclave, heated in a forced air drying oven at 251° C. for 24 hours, and then cooled to room temperature; finally, the resorcinol-formaldehyde resin was obtained by filtration, and dried in a vacuum drying oven at 60° C. for 12 hours;

[0066] S4. Weigh 30 mg of the resorcinol-formaldehyde resin powder prepared above, dissolve it in 30 mL of deionized water, add the modified transparent wood chips to the solution, stir for 30 minutes, then ultrasonicate for 30 minutes, and finally dry at 80° C. for 12 hours.

[0067] Example 4

[0068] Example 4 provides a photocatalytic composite material, the preparation method and dosage of which are basically the same as those of Example 1, except that the mass percentage of the resorcinol-formaldehyde resin in the photocatalytic composite material is 35.6%.

[0069] Example 5

[0070] Example 5 provides a photocatalytic composite material, the preparation method and dosage of which are basically the same as those of Example 1, except that the mass percentage of the resorcinol-formaldehyde resin in the photocatalytic composite material is 40%.

[0071] Example 6

[0072] Example 6 provides a photocatalytic composite material comprising a modified transparent wood chip and a resorcinol-formaldehyde resin (10.9%) loaded on the modified transparent wood chip. The preparation method is as follows:

[0073] S1. Take 20 mm long, 2 mm thick balsa wood chips and dry them at 60°C for 12 hours. Dissolve 1 g of sodium hydroxide in 10 mL of deionized water to prepare a solution. Soak the chips in this solution at room temperature for 12 hours. Transfer them to hydrogen peroxide and store them at room temperature overnight.

[0074] S2, rinsing the wood chips with deionized water and anhydrous ethanol for multiple times, and finally irradiating them with a high-pressure mercury lamp for 4 hours to obtain modified transparent wood chips;

[0075] S3, take 0.096g resorcinol powder, formaldehyde (0.135mL, 6mol L -1 ), ammonia water (0.1 mL, 16 mol L -1 ) and deionized water, stirred for 30 minutes, and then transferred the mixture into a 20 ml Teflon-lined stainless steel autoclave, heated in a forced air drying oven at 251° C. for 24 hours, and then cooled to room temperature; finally, the resorcinol-formaldehyde resin was obtained by filtration, and dried in a vacuum drying oven at 60° C. for 12 hours;

[0076] S4. Weigh 10 mg of the resorcinol-formaldehyde resin powder prepared above, dissolve it in 30 mL of deionized water, add the modified transparent wood chips to the solution, stir for 30 minutes, then ultrasonicate for 30 minutes, and finally dry at 80° C. for 12 hours.

[0077] Comparative Example 1

[0078] Comparative Example 1 provides a photocatalytic composite material, the preparation method and dosage of which are substantially the same as those of Example 1, except that the wood chips in Comparative Example 1 do not have step S1.

[0079] Comparative Example 2

[0080] Comparative Example 2 provides a photocatalytic composite material, the preparation method and dosage of which are substantially the same as those of Example 1, except that the wood chips in Comparative Example 2 do not have step S2.

[0081] Performance Testing

[0082] The photocatalytic composite materials prepared in Examples 1 to 6 and Comparative Examples 1 to 2 were subjected to urea degradation tests. Figure 2 It is the urea degradation mechanism diagram of Examples 1 to 6 of the present invention. Figure 2 Look, water and oxygen in the air generate hydrogen peroxide on the surface of the composite material. Hydrogen peroxide reacts with urea in the air under light, and finally degrades it into organic matter such as titanium dioxide.

[0083] The urea degradation test procedure is as follows: Prepare a sealed 60mm x 60mm x 60mm cubic box and inject toilet gas into the box to simulate indoor urea degradation. After applying light, extract the gas from the box and test for a specified period of time to calculate the urea degradation concentration.

[0084] like Figure 3 As shown, Figure 3 This is a real picture simulating indoor urea degradation; the specific steps are: take 60mL of gas in the toilet and inject it into the prepared device, then take out 5mL of gas sample every 15 minutes under a fluorescent lamp, use an ultraviolet spectrophotometer to measure the urea concentration of the blank control group, Examples 1 to 6 and Comparative Examples 1 to 2, and calculate the degradation rate.

[0085]

[0086] Where C0 represents the initial concentration, C t represents the concentration at time t.

[0087] The results are as follows Figure 4 As shown in Table 1, the degradation rate of urea in the air by the photocatalytic composite material of Example 1 reached 100% within one hour.

[0088] Furthermore, the light transmittance of the photocatalytic composite material of Example 1 was tested by placing a transparent wood chip in a cuvette of an ultraviolet spectrophotometer and using the transmission function of the ultraviolet spectrophotometer to test the light transmittance of the transparent wood. Figure 5 As shown in Table 1, Figure 5 The left figure shows that the best light transmittance is up to about 75%, which is sample 3 (Example 1). Samples 1 and 2 are Examples 2 and 3 respectively. Figure 5 The right picture shows the actual light transmission effect.

[0089] Table 1

[0090]

[0091]

[0092] As shown in Examples 1-5, the amount of resorcinol-formaldehyde resin loaded affects the light transmittance of the photocatalytic composite material. Example 6 shows that increasing the amount of ammonia affects the performance of resorcinol-formaldehyde synthesis, reducing hydrogen peroxide production and thus affecting its degradation rate. Comparative Examples 1 and 2 show that the absence of Steps S1 or S2 results in a lack of light transmittance and a significantly reduced degradation rate.

[0093] The above is a detailed description of the embodiments of the present invention, but the present invention is not limited to the above embodiments. Various changes can be made within the knowledge of ordinary technicians in the relevant technical field without departing from the scope of the present invention.

Claims

1. Application of a photocatalytic composite material in photocatalytic degradation of urea in air, characterized in that: The photocatalytic composite material includes a carrier and a resorcinol-formaldehyde resin loaded on the carrier; the carrier is a modified transparent wood chip; the modified transparent wood chip has a pore structure; The mass percentage of the resorcinol-formaldehyde resin in the photocatalytic composite material is 10% to 50%; The modified transparent wood chip is prepared by the following steps: S1. Soaking wood chips in alkaline solution and hydrogen peroxide in sequence; S2. Irradiating the soaked wood chips under ultraviolet light to obtain modified transparent wood chips.

2. The use according to claim 1, characterized in that The thickness of the modified transparent wood chip is 1.0 mm to 3.0 mm.

3. The use according to claim 1, characterized in that The alkaline solution includes at least one of a sodium hydroxide solution, a sodium hypochlorite solution, and a potassium hydroxide solution.

4. The use according to claim 1, characterized in that The irradiation time is 2h~10h.

5. The use according to claim 1, characterized in that The resorcinol-formaldehyde resin is prepared by the following steps: Resorcinol, formaldehyde, ammonia water and water are uniformly mixed and subjected to a hydrothermal reaction to obtain a resorcinol-formaldehyde resin.

6. The use according to claim 5, characterized in that The temperature of the hydrothermal reaction is 160°C to 280°C.

7. The use according to claim 1, characterized in that The photocatalytic composite material is prepared by the following steps: The modified transparent wood chips, resorcinol-formaldehyde resin and water are mixed, ultrasonicated and subjected to secondary drying to obtain the product.

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