Piezoelectric coupling photo-thermal enhanced flexible photocatalytic porous structure material preparation method and product thereof

Abstract

The invention belongs to the field of functional material preparation, and particularly relates to a piezoelectric coupling photo-thermal enhanced flexible photocatalytic porous structure material preparation method and a product thereof. A photo-thermal material, catalyst powder and an organic piezoelectric material polyvinylidene fluoride (PVDF) are dispersed in a N, N-dimethylformamide (DMF) solution together, granulated sugar blocks are used as a pore forming agent to prepare the photocatalytic material with a flexible photocatalytic porous structure, the coupling effect of a piezoelectric electric field and the photo-thermal effect is achieved, and the photocatalytic performance is remarkably improved.

Description

Technical Field

[0001] The present invention belongs to the field of functional material preparation, and specifically relates to a method for preparing a piezoelectrically coupled photothermally enhanced flexible photocatalytic porous structure material and a product thereof. Background Art

[0002] Semiconductor photocatalysis is playing an important role in environmental energy fields such as carbon dioxide reduction, photocatalytic water splitting, and sewage treatment. From a mechanistic perspective, the photocatalytic reaction is a process in which external photons excite electrons in the valence band of the semiconductor and cause these electrons to jump to the conduction band, leaving holes in the valence band. However, these photogenerated electron-hole pairs excited by photons are very likely to recombine again, thereby reducing the activity of the photocatalytic material. Therefore, how to effectively prevent these recombination is the key to improving the performance of photocatalytic reactions.

[0003] Generally speaking, a built-in electric field can be constructed through heterojunctions and other methods, and the built-in electric field will effectively prevent the recombination of photogenerated carriers, which is a desirable approach. In addition, by using catalysts with piezoelectric properties or other piezoelectric materials, a built-in electric field can also be constructed to separate photogenerated carriers. At the same time, by increasing the temperature of the reaction system, the migration of photogenerated carriers can be accelerated, but it may also aggravate the recombination of carriers. Therefore, by coupling piezoelectricity with photothermal, we can take advantage of the advantages of the photothermal effect while hindering the recombination of carriers, which is a way to kill two birds with one stone.

[0004] At the same time, in terms of structural design, the design of some porous structures can facilitate the deformation characteristics of photocatalytic materials, thereby better utilizing the piezoelectric effect. Therefore, how to design a structure that can effectively utilize both the photothermal effect and the piezoelectric effect is an important way to improve the efficiency of photocatalytic reactions. Summary of the Invention

[0005] Against this backdrop, the present invention proposes a method for preparing a flexible photocatalytic porous structure material with piezoelectrically coupled photothermal enhancement, and its product. By dispersing the photothermal material, catalyst powder, and the organic piezoelectric material polyvinylidene fluoride (PVDF) in an N,N-dimethylformamide (DMF) solution, and using sugar as a pore-forming agent, a flexible photocatalytic porous structure is prepared. This method achieves the coupling of the piezoelectric field and the photothermal effect, significantly enhancing photocatalytic performance.

[0006] In order to overcome at least one of the above-mentioned shortcomings of the prior art, the first aspect of the present invention provides a method for preparing a flexible photocatalytic porous structure material with piezoelectric coupling photothermal enhancement, comprising the following steps:

[0007] Step 1: Disperse the photothermal material and PVDF in DMF and stir for a certain period of time to obtain solution A;

[0008] Step 2: adding a certain amount of photocatalytic material powder and sugar cubes to the solution A in step 1, heating and drying to obtain solid B;

[0009] Step 3, washing the solid B obtained in step 2 with water to obtain a flexible photocatalytic porous structure material C;

[0010] Step 4: immerse the material C obtained in step 3 into a photocatalytic material precursor solution synthesized at room temperature, so that another photocatalytic material grows on its surface to obtain a piezoelectrically coupled photothermally enhanced flexible photocatalytic porous structure material.

[0011] Furthermore, in step 1, the photothermal material is any one or more combinations of aniline black, carbon nanotubes and graphene.

[0012] Furthermore, in step 1, the mass ratio of the photothermal material to the mass ratio of PVDF is 2-3%, the mass ratio of PVDF to the mass ratio of DMF is 10-30%, and the stirring time is 1-3 hours.

[0013] Furthermore, in step 2, the photocatalytic material is any one or more combinations of piezoelectric photocatalytic materials selected from zinc oxide, lead titanate and barium titanate.

[0014] Furthermore, in step 2, the mass ratio of the photocatalytic material to the mass ratio of DMF is 0.1% to 5%, and the mass ratio of the sugar block to the mass ratio of DMF is 200% to 400%.

[0015] Furthermore, in step 4, the photocatalytic material in the photocatalytic material precursor solution is bismuth oxycarbonate, bismuth oxychloride or bismuth oxybromide.

[0016] Furthermore, step 4 is to pre-disperse the photocatalytic material in an acid solution, recorded as solution D; dissolve Na2CO3 in deionized water, recorded as solution E, and then immerse the flexible photocatalytic porous structure obtained in step 3 in solution D, stir for 1 hour, and then transfer it to solution E and continue stirring for 2 hours to allow bismuth oxycarbonate to grow on its surface. Take it out, rinse it thoroughly with deionized water 3 times, and drain it to obtain a piezoelectrically coupled photothermal enhanced flexible photocatalytic porous structure material.

[0017] A second aspect of the present invention provides a piezoelectrically coupled photothermally enhanced flexible photocatalytic porous structure material prepared by the above method.

[0018] The beneficial effects of the present invention are:

[0019] 1. The present invention focuses on utilizing external physical fields to enhance photocatalytic performance, constructing a built-in electric field through piezoelectric materials and a thermal field through the photothermal effect, ultimately achieving the coupling of the electric and thermal fields, thereby significantly enhancing the photocatalytic performance.

[0020] 2. The present invention solves the problem of easy recombination of photogenerated carriers in photocatalytic reactions by combining piezoelectricity with photothermal energy, while avoiding the deactivation of carriers during migration.

[0021] 3. The piezoelectrically coupled photothermally enhanced flexible photocatalytic porous structure material prepared by the present invention is rich in pores and can undergo reciprocating deformation under stress, which is more conducive to the coupling of piezoelectricity and photothermal. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a comparison chart of the photocatalytic performance of the materials prepared in Examples 1-2 and Comparative Examples 1-3.

[0023] Figure 2 This is a comparison chart of the photocatalytic performance of the materials prepared in Example 1 under different testing conditions. DETAILED DESCRIPTION

[0024] Before discussing the exemplary embodiments in more detail, it should be mentioned that some exemplary embodiments are described as processes or methods depicted as flow charts. Although the flow charts describe the various operations as sequential processes, many of the operations therein can be implemented in parallel, concurrently, or simultaneously. In addition, the order of the various operations can be rearranged. The process can be terminated when its operation is completed, but can also have additional steps not included in the accompanying drawings. The process can correspond to a method, function, procedure, subroutine, subprogram, etc.

[0025] It should be understood that although the terms "first," "second," and the like may be used herein to describe various elements, these elements should not be limited by these terms. These terms are used solely to distinguish one element from another. For example, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element, without departing from the scope of the exemplary embodiments. The term "and / or" as used herein includes any and all combinations of one or more of the listed associated items.

[0026] Example 1

[0027] Step 1: Disperse 0.01 g of the photothermal material aniline black and 0.5 g of the organic piezoelectric material PVDF in 2 mL of DMF solvent and stir for 2 h to obtain solution A.

[0028] Step 2: Add 30 mg of lead titanate powder and 6 g of sugar to solution A in step 1, heat and dry at 65°C for 12 h to obtain solid B.

[0029] Step 3: Wash the solid B obtained in step 2 with water at a washing temperature of 60° C. to obtain a flexible photocatalytic porous structure material C.

[0030] Step 4: Disperse 0.25 mmol of Bi(NO₃)₃·5H₂O in 10 mL of 1 M nitric acid solution, designated Solution D. Dissolve 0.7 mmol of Na₂CO₃ in 30 mL of deionized water, designated Solution E. Immerse the flexible photocatalytic porous structure obtained in Step 3 in Solution D and stir for 1 hour. Then transfer it to Solution E and continue stirring for 2 hours to allow bismuth oxycarbonate to grow on its surface. Remove the flexible photocatalytic porous structure, rinse thoroughly with deionized water three times, and drain. This results in a piezoelectrically coupled photothermally enhanced flexible photocatalytic porous structure material.

[0031] Example 2

[0032] Step 1: Disperse 0.015 g of the photothermal material aniline black and 0.5 g of the organic piezoelectric material PVDF in 2 mL of DMF solvent and stir for 2 h to obtain solution A.

[0033] Step 2: Add 30 mg of lead titanate powder and 6 g of sugar to solution A in step 1, heat and dry at 65°C for 12 h to obtain solid B.

[0034] Step 3: Wash the solid B obtained in step 2 with water at a washing temperature of 60° C. to obtain a flexible photocatalytic porous structure material C.

[0035] Step 4: Disperse 0.25 mmol of Bi(NO3)3·5H2O in 10 mL of 1 M nitric acid solution, designated as solution D; dissolve 0.7 mmol of Na2CO3 in 30 mL of deionized water, designated as solution E. Immerse the flexible photocatalytic porous structure obtained in step 3 in solution D and stir for 1 hour. Then transfer it to solution E and continue stirring for 2 hours to allow bismuth oxycarbonate to grow on its surface. Remove the flexible photocatalytic porous structure, rinse it thoroughly with deionized water three times, and drain it. A piezoelectrically coupled photothermally enhanced flexible photocatalytic porous structure material is obtained.

[0036] Comparative Example 1

[0037] Step 1: Disperse 0.5 g of organic piezoelectric material PVDF in 2 mL of DMF solvent and stir for 2 h.

[0038] Step 2: Add 30 mg of lead titanate powder and 6 g of sugar cubes to the solution in step 1, and heat and dry at 65°C for 12 hours.

[0039] Step 3: Wash the block obtained in step 2 with water at a washing temperature of 60° C. to obtain a flexible photocatalytic porous structure.

[0040] Step 4: Dissolve 0.25 mmol of Bi(NO₃)₃·5H₂O in 10 mL of 1 M nitric acid solution, designated as Solution D. Dissolve 0.7 mmol of Na₂CO₃ in 30 mL of deionized water, designated as Solution E. Immerse the flexible photocatalytic porous structure material obtained in Step 3 in Solution D and stir for 1 hour. Then transfer it to Solution E and continue stirring for 2 hours to allow bismuth oxycarbonate to grow on its surface. Remove the flexible photocatalytic porous structure, rinse thoroughly with deionized water three times, and drain. This yields a piezoelectrically coupled photothermally enhanced flexible photocatalytic porous structure material.

[0041] Comparative Example 2

[0042] Step 1: Disperse 0.005 g of photothermal material aniline black and 0.5 g of organic piezoelectric material PVDF in 2 mL of DMF solvent and stir for 2 h.

[0043] Step 2: Add 30 mg of lead titanate powder and 6 g of sugar cubes to the solution in step 1, and heat and dry at 65°C for 12 hours.

[0044] Step 3: Wash the block obtained in step 2 with water at a washing temperature of 60° C. to obtain a flexible photocatalytic porous structure.

[0045] Step 4: Disperse 0.25 mmol of Bi(NO₃)₃·5H₂O in 10 mL of 1 M nitric acid solution, designated as Solution D. Dissolve 0.7 mmol of Na₂CO₃ in 30 mL of deionized water, designated as Solution E. Immerse the flexible photocatalytic porous structure material obtained in Step 3 in Solution D and stir for 1 hour. Then transfer it to Solution E and continue stirring for 2 hours to allow bismuth oxycarbonate to grow on its surface. Remove the flexible photocatalytic porous structure, rinse thoroughly with deionized water three times, and drain. This yields a piezoelectrically coupled photothermally enhanced flexible photocatalytic porous structure material.

[0046] Comparative Example 3

[0047] Step 1: Disperse 0.02 g of photothermal material aniline black and 0.5 g of organic piezoelectric material PVDF in 2 mL of DMF solvent and stir for 2 h.

[0048] Step 2: Add 30 mg of lead titanate powder and 6 g of sugar cubes to the solution in step 1, and heat and dry at 65°C for 12 hours.

[0049] Step 3: Wash the block obtained in step 2 with water at a washing temperature of 60° C. to obtain a flexible photocatalytic porous structure.

[0050] Step 4: Disperse 0.25 mmol of Bi(NO₃)₃·5H₂O in 10 mL of 1 M nitric acid solution, designated as Solution D. Dissolve 0.7 mmol of Na₂CO₃ in 30 mL of deionized water, designated as Solution E. Immerse the flexible photocatalytic porous structure material obtained in Step 3 in Solution D and stir for 1 hour. Then transfer it to Solution E and continue stirring for 2 hours to allow bismuth oxycarbonate to grow on its surface. Remove the flexible photocatalytic porous structure, rinse thoroughly with deionized water three times, and drain. This yields a piezoelectrically coupled photothermally enhanced flexible photocatalytic porous structure material.

[0051] The materials prepared in Examples 1 and 2 and Comparative Examples 1 to 3 were subjected to photocatalytic testing using 70 mL of 10 mg / L methyl orange as the target degradation product under the conditions of ultrasound + light irradiation. Figure 1 As shown, Figure 1 The photocatalytic performance comparison diagram of the materials prepared in Examples 1 and 2 and Comparative Examples 1 to 3. Among them, Comparative Example 1 does not add the photothermal material aniline black, the addition amount of Example 1 is 0.01g, the addition amount of Example 2 is 0.015g, the addition amount of Comparative Example 2 is 0.005g, and the addition amount of Comparative Example 3 is 0.02g. It can be seen from the photocatalytic performance diagram that Example 2 can achieve the best performance. Among them, Comparative Example 1 cannot effectively exert the photothermal effect because it does not incorporate the photothermal material aniline black, and Comparative Example 2 has a weak photothermal effect because the amount of photothermal material aniline black incorporated is too small. Comparative Example 3 incorporates a large amount of photothermal material aniline black. Excessive aniline black will affect the flexible deformation of PVDF, reduce its piezoelectric properties, and further affect the photocatalytic performance of the entire structure. Therefore, the moderate amount of photothermal material aniline black added enables Example 1 to achieve the best photocatalytic performance, followed by Example 2.

[0052] Figure 2 This is a comparison chart of the photocatalytic performance of the flexible photocatalytic porous structure material with piezoelectric coupled photothermal enhancement prepared in Example 1 under different conditions. The photocatalytic test conditions were ultrasound + light, light alone, and ultrasound alone. It can be seen that ultrasound + light achieved photocatalytic performance far superior to that of ultrasound alone or light alone. This is because light can only activate the photothermal effect, while ultrasound can only activate the piezoelectric effect. Under the synergistic effect of light and ultrasound, the piezoelectric coupled photothermal effect was achieved, thereby greatly enhancing the photocatalytic performance.

[0053] The above is only an embodiment of the present invention. Common knowledge such as the known specific structures and characteristics in the scheme is not described in detail here. Ordinary technicians in the field are aware of all common technical knowledge in the technical field of the invention before the application date or priority date, can obtain all existing technologies in the field, and have the ability to apply conventional experimental means before that date. Ordinary technicians in the field can improve and implement this scheme in combination with their own abilities under the inspiration given by this application. Some typical known structures or known methods should not become obstacles for ordinary technicians in the field to implement this application. It should be pointed out that for those skilled in the art, without departing from the structure of the present invention, several variations and improvements can be made, which should also be regarded as the scope of protection of the present invention. These will not affect the effect of the implementation of the present invention and the practicality of the patent. The scope of protection required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to interpret the content of the claims.

Claims

1. A method for preparing a flexible photocatalytic porous structure material with piezoelectric coupling and photothermal enhancement, characterized in that: Includes the following steps Step 1: Disperse the photothermal material and PVDF in DMF and stir for a certain period of time to obtain solution A; Step 2: adding a certain amount of photocatalytic material powder and sugar cubes to the solution A in step 1, heating and drying to obtain solid B; Step 3, washing the solid B obtained in step 2 with water to obtain a flexible photocatalytic porous structure material C; Step 4: immerse the material C obtained in step 3 into a photocatalytic material precursor solution synthesized at room temperature, so that another photocatalytic material grows on its surface to obtain a piezoelectrically coupled photothermally enhanced flexible photocatalytic porous structure material.

2. The method for preparing a flexible photocatalytic porous structure material with piezoelectric coupling and photothermal enhancement according to claim 1, characterized in that: In step 1, the photothermal material is any one or more combinations of aniline black, carbon nanotubes and graphene.

3. The method for preparing a flexible photocatalytic porous structure material with piezoelectric coupling and photothermal enhancement according to claim 1, characterized in that: In the step 1, the mass ratio of the photothermal material to the mass ratio of PVDF is 2-3%, the mass ratio of PVDF to the mass ratio of DMF is 10-30%, and the stirring time is 1-3 hours.

4. The method for preparing a flexible photocatalytic porous structure material with piezoelectric coupling and photothermal enhancement according to claim 1, characterized in that: In step 2, the photocatalytic material is any one or more combinations of piezoelectric photocatalytic materials selected from zinc oxide, lead titanate, and barium titanate.

5. The method for preparing a flexible photocatalytic porous structure material with piezoelectric coupling photothermal enhancement according to claim 1, characterized in that: In step 2, the mass ratio of the photocatalytic material to the mass ratio of DMF is 0.1% to 5%, and the mass ratio of the sugar block to the mass ratio of DMF is 200% to 400%.

6. The method for preparing a flexible photocatalytic porous structure material with piezoelectric coupling and photothermal enhancement according to claim 1, characterized in that: In step 3, the detergent is water, and the washing temperature is 50-80°C.

7. The method for preparing a flexible photocatalytic porous structure material with piezoelectric coupling and photothermal enhancement according to claim 1, characterized in that: In step 4, the photocatalytic material in the photocatalytic material precursor solution is bismuth oxycarbonate, bismuth oxychloride or bismuth oxybromide.

8. The method for preparing a flexible photocatalytic porous structure material with piezoelectric coupling and photothermal enhancement according to claim 1, characterized in that: The step 4 is to disperse the photocatalytic material in an acid solution in advance, which is recorded as solution D; dissolve Na2CO3 in deionized water, which is recorded as solution E; and then immerse the flexible photocatalytic porous structure obtained in step 3 in solution D, stir for 1 hour, and then transfer it to solution E and continue stirring for 2 hours to allow bismuth oxycarbonate to grow on its surface. The flexible photocatalytic porous structure is taken out, rinsed with deionized water three times, and drained to obtain a piezoelectrically coupled photothermal enhanced flexible photocatalytic porous structure material.

9. A piezoelectrically coupled photothermally enhanced flexible photocatalytic porous structure material, characterized in that: The invention is prepared by any one of the methods of claims 1 to 8.

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