Adenine / SDBS / UiO-66 composite catalyst and its preparation method and application

Abstract

The present invention belongs to the field of piezoelectric catalysis technology, and specifically relates to an adenine / SDBS / UiO-66 composite catalyst, a preparation method and an application thereof. Adenine / UiO-66 (AD-U) material was synthesized by adding a connecting agent adenine, and then a surfactant (sodium dodecylbenzene sulfonate, SDBS) was introduced to prepare an adenine / SDBS / UiO-66 (AD-U-S) composite material. The optimized AD-U-S catalyst has an efficiency of up to 98% in degrading DCF in 30 minutes, which is 20 minutes earlier than the AD-U catalyst. Therefore, the AD-U-S catalyst has better piezoelectric response performance, a larger specific surface area and a higher charge transfer efficiency. The preparation conditions of the present invention are easy to control, environmentally friendly, simple in process, and good in operability. The obtained material has the characteristics of high catalytic efficiency, low energy consumption, high stability, and no secondary pollution.

Description

Technical Field

[0001] The invention belongs to the technical field of piezoelectric catalysis, and specifically relates to an adenine / SDBS / UiO-66 composite catalyst and a preparation method and application thereof. Background Art

[0002] Nonsteroidal anti-inflammatory drugs (NSAIDs), one of the most commonly prescribed drugs, have been found to contaminate a wide range of aquatic environments, including rivers, lakes, and surface freshwaters. Global consumption of NSAIDs has resulted in the continuous release of these substances or their metabolites into the environment, making them an emerging pollutant. DCF is commonly used as an analgesic, anti-inflammatory, anti-arthritic, and anti-rheumatic drug, and its global consumption is estimated at 940 tons per year. DCF is commonly detected in water bodies from domestic sewage treatment plants due to limited biodegradation or natural fading.

[0003] The methods for removing antibiotics from sewage are roughly physical adsorption, extraction, biological purification, photocatalytic oxidation, electrocatalytic oxidation and piezoelectric catalysis. In recent years, a piezoelectric catalytic effect has been proposed as a promising strategy to solve the problem of dye pollution. Piezoelectric materials can convert mechanical vibrations into electrical energy. The origin of piezocatalysis is the non-centrosymmetric nature of the material's crystal structure. When external stress is applied to the piezoelectric material, the positive and negative charge centers are displaced from each other; unbound charges accumulate on its surface. The charge displacement produces an aligned dipole moment and generates an internal electric field, namely the piezoelectric potential. The internal piezoelectric potential promotes the immediate separation of excited state carriers after generation, realizing the catalytic degradation of organic pollutants in the dark. Compared with traditional methods, piezoelectric catalysis has the benefit of reducing costs in removing pollutants.

[0004] In recent years, most of the research on piezoelectric materials has focused on inorganic piezoelectric materials, such as Bi2WO3, ZnO, ZnSnO3, BaCO3 and BaTiO3, while there are relatively few studies on the piezoelectricity of inorganic metal framework (MOF) materials. Summary of the invention

[0005] The present invention aims to provide an adenine / SDBS / UiO-66 composite catalyst and a preparation method and application thereof, specifically, by adding a specific surfactant SDBS in the AD-U synthesis process to obtain an AD-US piezoelectric material, thereby increasing the band gap of the AD-US catalyst, generating two active substances, and thereby enhancing the piezoelectric performance. The present invention also uses sodium diclofenac as a target to study the degradation performance of the synthetic material on antibiotics. The catalyst has good stability, and the preparation method is simple, efficient, low-cost, economical and environmentally friendly.

[0006] In order to achieve the purpose of the present invention, the technical solution adopted is:

[0007] The preparation method of adenine / SDBS / UiO-66 (AD-US for short) composite catalyst comprises the following steps:

[0008] Dissolve ZrCl4, H2BDC (terephthalic acid), SDBS and adenine in DMF solution and sonicate until dissolved, then transfer the solution to a hydrothermal reactor for hydrothermal reaction (preferably, the reaction conditions are stored at 120°C for 48 hours), wash the obtained white precipitate with water and anhydrous ethanol, and dry (preferably, the drying conditions are vacuum drying at 60°C for 24 hours) to obtain AD-US.

[0009] Preferably, the mass ratio of ZrCl4, H2BDC, SDBS and adenine is 3.2:2.3:2.8, and the molar ratio of SDBS to H2BDC is 0.2-0.3.

[0010] The present invention also provides a piezoelectric degradation experiment of DCF: for piezoelectric catalytic degradation of DCF, the method comprises the following steps: dispersing the composite catalyst in a DCF solution, placing the solution in a dark place and stirring the solution continuously.

[0011] Specifically: The piezoelectric catalytic performance of the catalyst was verified by the degradation of DCF. Usually, 0.02g of piezoelectric catalyst was dispersed in a DCF solution (10mg·L -1 , 60mL), placed in a dark place (25℃), and stirred continuously for 50min. Collect quantitative solution at the designed time, and filter DCF with a 0.22μm polytetrafluoroethylene (PTFE) membrane. Determine the content of DCF in the filtrate by liquid chromatography (HPLC).

[0012] The use of the present invention has the following advantages:

[0013] (1) The specially selected surfactant SDBS of the present invention can not only change the pore size of the material but also increase the band gap of the AD-US catalyst, thereby generating two active substances, which has a significant contribution to enhancing the piezoelectric properties of the material. During the synthesis process, the SDBS surfactant acts as a template to form mesoporous channels, while enhancing the connection between the template and the metal ions, thereby enhancing the catalytic performance of the material.

[0014] (2) The catalyst provided by the present invention is an adenine / SDBS / UiO-66 composite catalyst, which has the characteristics of simple synthesis conditions, easy operation, rapid and efficient, energy-saving and environmentally friendly, and good stability.

[0015] (3) For the first time, the adenine / SDBS / UiO-66 composite catalyst was applied to the piezoelectric degradation of DCF, showing ultra-high piezoelectric catalytic activity. Compared with the AD-U material, the AD-US catalyst has better piezoelectric response performance, larger specific surface area and higher charge transfer efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 1 is the XRD diagram of the AD-US catalysts with different SDBS contents in Examples 1-5 and the AD-U catalyst in Comparative Example 1.

[0017] Figure 2 This is the transmission electron microscopy of the AD-US catalyst in Example 1.

[0018] Figure 3 is the pore size distribution diagram of the AD-US catalyst in Example 1.

[0019] Figure 4 This is the pore size distribution diagram of the AD-U catalyst prepared in Control Example 1.

[0020] Figure 5 It is a piezoelectric degradation DCF performance diagram of AD-US catalysts with different SDBS contents in Examples 1-5 and the AD-U catalyst in Control Example 1.

[0021] Figure 6 1 is the piezoelectric degradation kinetic curve of the AD-US catalysts with different SDBS contents in Examples 1-5 and the AD-U catalyst in Control Example 1.

[0022] Figure 7 : is the equilibrium curve diagram of the addition of different capture agents on the degradation of DCF by the catalyst in Examples 6, 7 and 8.

[0023] Figure 8 This is the stability performance diagram of the AD-US catalyst degrading DCF in Example 1.

[0024] Fig. 9 It is a comparison chart of the band gaps of AD-U, AD-UC prepared in Example 1 and Comparative Example 5. DETAILED DESCRIPTION

[0025] The present invention is not limited to the following specific embodiments. A person skilled in the art can implement the present invention by adopting other various specific embodiments according to the contents disclosed in the present invention, or any simple changes or modifications made by adopting the design structure and ideas of the present invention fall within the protection scope of the present invention. It should be noted that the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict. The present invention is described in detail below in conjunction with specific embodiments.

[0026] The degradation efficiency is calculated according to the following formula:

[0027] R=(C-C0) / C0*100%

[0028] R: Degradation efficiency

[0029] C0: initial concentration

[0030] C: Concentration after degradation reaction.

[0031] Example 1

[0032] 0.32g ZrCl4, 0.23g H2BDC, 0.15g SDBS and 0.28g adenine were dissolved in 70mL DMF solution by ultrasonication until dissolved (the molar ratio of SDBS to H2BDC was 0.30). The solution was then transferred to a hydrothermal autoclave and stored at 120°C for 48 hours. The white precipitate was washed with water and anhydrous ethanol and dried under vacuum at 60°C for 24 hours to obtain AD-US catalyst.

[0033] Usually, 0.02 g of piezoelectric catalyst is dispersed in DCF solution (10 mg·L -1 ,60mL), placed in a dark place (25℃), and stirred continuously for 50min. Collect quantitative solution at the designed time, and filter DCF with a 0.22μm polytetrafluoroethylene (PTFE) membrane. The content of DCF in the filtrate is determined by liquid chromatography (HPLC). The degradation efficiency of the catalyst for DCF solution is 98.3%.

[0034] Table 1 Specific surface area, pore size and pore volume data of AD-US (0.3) and AD-U materials

[0035]

[0036] Example 2

[0037] Compared with Example 1, the difference is that the molar ratio of SDBS to H2BDC in the preparation process is 0.10, and the other preparation methods are the same as Example 1.

[0038] The application method is the same as that of Example 1. The adenine / SDBS / UiO-66 composite catalyst prepared in Example 2 is used for the DCF solution (10 mg·L -1 ,60mL) degradation efficiency was 93.2%.

[0039] Example 3

[0040] Compared with Example 1, the difference is that the molar ratio of SDBS to H2BDC in the preparation process is 0.15, and the other preparation methods are the same as Example 1.

[0041] The application method is the same as that of Example 1. The adenine / SDBS / UiO-66 composite catalyst prepared in Example 3 is used for the DCF solution (10 mg·L -1 ,60mL) degradation efficiency was 94.3%.

[0042] Example 4

[0043] Compared with Example 1, the difference is that the molar ratio of SDBS to H2BDC in the preparation process is 0.20, and the other preparation methods are the same as Example 1.

[0044] The application method is the same as that of Example 1. The adenine / SDBS / UiO-66 composite catalyst prepared in Example 4 is used for the DCF solution (10 mg·L -1 ,60mL) degradation efficiency was 94.9%.

[0045] Example 5

[0046] Compared with Example 1, the difference is that the molar ratio of CTAB to H2BDC in the preparation process is 0.25, and the other preparation methods are the same as Example 1.

[0047] The application method is the same as that of Example 1. The adenine / SDBS / UiO-66 composite catalyst prepared in Example 5 is used for the DCF solution (10 mL·L -1 ,60mL) degradation efficiency was 97.7%.

[0048] Example 6

[0049] To test the active groups of the piezoelectric degradation and reduction processes, a capture experiment was performed. The specific steps are as follows:

[0050] Weigh 20 mg of the catalyst of Example 1 and 0.372 g of disodium ethylenediaminetetraacetate, disperse in 60 mL of 10 mg / L DCF solution, place in a dark place (25° C.), and stir continuously for 40 min. Collect quantitative solution according to the designed time, and filter DCF with a 0.22 μm polytetrafluoroethylene (PTFE) membrane. Use liquid chromatography (HPLC) to determine the content of DCF in the filtrate. Calculate the degradation efficiency, and the degradation efficiency is 31.5% after analysis and calculation.

[0051] Example 7

[0052] Compared with Example 6, the difference is that 100 μL of isopropanol is added during the reaction, and the other preparation methods are the same as Example 6. The degradation efficiency of the adenine / SDBS / UiO-66 composite catalyst prepared in Example 1 for 60 mL of 10 mg / L DCF is 79.4%.

[0053] Example 8

[0054] Compared with Example 6, the difference is that 0.18 g of p-benzoquinone is added during the reaction, and the other preparation methods are the same as Example 6. The degradation efficiency of the adenine / SDBS / UiO-66 composite catalyst prepared in Example 1 for 60 mL of 10 mg / L DCF is 95.5%.

[0055] Comparative Example 1

[0056] 0.32 g ZrCl4, 0.23 g H2BDC and 0.28 g adenine were dissolved in 70 mL DMF solution by ultrasonication until dissolved (the molar ratio of adenine to H2BDC was 1.5). The solution was then transferred to a hydrothermal autoclave and stored at 120°C for 48 hours. The white precipitate was washed with water and anhydrous ethanol and dried under vacuum at 60°C for 24 hours to obtain AD-U material.

[0057] Usually, 0.02 g of piezoelectric catalyst is dispersed in DCF solution (10 mg·L -1 ,60mL), placed in a dark place (25℃), and stirred continuously for 50min. Collect quantitative solution at the designed time, and filter DCF with a 0.22μm polytetrafluoroethylene (PTFE) membrane. The content of DCF in the filtrate was determined by liquid chromatography (HPLC). The degradation efficiency of the catalyst for DCF solution was 81.1%.

[0058] Comparative Example 2

[0059] Compared with Control Example 1, the difference is that the molar ratio of adenine to H2BDC in the preparation process is 0.8, and the other preparation methods are the same as Control Example 1.

[0060] The application method is the same as that of control example 1. The adenine / UiO-66 composite catalyst prepared in control example 2 is used for the DCF solution (10 mg·L -1 ,60mL) degradation efficiency was 85.2%.

[0061] Comparative Example 3

[0062] Compared with the control example 1, the difference is that the molar ratio of adenine to H2BDC in the preparation process is 1.2, and the other preparation methods are the same as the control example 1.

[0063] The application method is the same as that of control example 1. The adenine / UiO-66 composite catalyst prepared in control example 3 is used for the DCF solution (10 mg·L -1 ,60mL) degradation efficiency was 83.6%.

[0064] Comparative Example 4

[0065] Compared with Control Example 1, the difference is that the molar ratio of adenine to H2BDC in the preparation process is 2.0, and the other preparation methods are the same as Control Example 1.

[0066] The application method is the same as that of control example 1. The adenine / UiO-66 composite catalyst prepared in control example 4 is used for the DCF solution (10 mg·L -1 ,60mL) degradation efficiency was 82.3%.

[0067] Comparative Example 5

[0068] The composite catalyst AD-UC was obtained by replacing the SDBS in Example 1 with hexadecyltrimethylammonium bromide (CTAB) in an equal molar amount, and its degradation efficiency for DCF solution was 88.4%.

[0069] The present invention is based on the selection of a surfactant (sodium dodecylbenzene sulfonate, SDBS), and in the synthesis process of AD-U, the SDBS surfactant is introduced to obtain AD-US. Compared with AD-U, AD-US has a wider band gap structure and abundant surface active sites, and effectively improves the piezoelectric catalytic degradation performance of the material.

[0070] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical solutions and concepts of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A method for preparing an adenine / SDBS / UiO-66 composite catalyst, characterized in that: The composite catalyst is used for piezoelectric material, and the preparation method comprises the following steps: Dissolve ZrCl4, H2BDC, SDBS and adenine in a DMF solution and perform ultrasonication until dissolved, then transfer the solution to a hydrothermal reactor for hydrothermal reaction to obtain a white precipitate, wash it with water and anhydrous ethanol, and dry it to obtain the composite catalyst; The mass ratio of ZrCl4, H2BDC and adenine is 3.2:2.3:2.8, and the molar ratio of SDBS to H2BDC is 0.2-0.

3.

2. The method for preparing the adenine / SDBS / UiO-66 composite catalyst according to claim 1, characterized in that: The hydrothermal reaction conditions were: storage at 120°C for 48 hours.

3. An adenine / SDBS / UiO-66 composite catalyst prepared according to the method described in claim 1 or 2.

4. The use of the adenine / SDBS / UiO-66 composite catalyst according to claim 3, characterized in that: The method is used for piezoelectric catalytic degradation of DCF, and comprises the following steps: dispersing the composite catalyst in a DCF solution, placing the solution in a dark place and stirring the solution continuously.

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