Polyoxometalate-based inorganic-organic hybrid compounds, methods for their preparation and their use in the photocatalytic degradation of antibiotics

Abstract

The application belongs to the field of functional crystalline material preparation, and discloses a polyacid-based inorganic-organic hybrid compound, a preparation method thereof and application of the compound in photocatalytic degradation of antibiotics. 10 The chemical formula of the polyacid-based inorganic-organic hybrid compound is [Cu2Mo2O8(C 12 O 40 After H3[PMo O ]、4,4'-bipy and Cu(NO3)2 are mixed, H2O and DMF are added, and the mixture is stirred and heated to obtain the polyacid-based inorganic-organic hybrid compound. The compound can be used as a catalyst in photocatalytic degradation of antibiotics.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of functional crystalline material preparation, and particularly relates to a polyacid-based inorganic-organic hybrid compound, a preparation method thereof and application thereof in photocatalytic degradation of antibiotics. BACKGROUND

[0002] Antibiotics are praised as one of the major achievements in the history of microbiology due to their excellent therapeutic effect on bacterial infections. Quinolone antibiotics are widely used in clinical practice. However, the excessive and improper use of quinolone antibiotics has led to their residues in animal products, the increase of drug resistance, and the ecological effects on the environment, which have caused widespread concern. Therefore, it is crucial to seek a reasonable method for degrading antibiotics to protect human health and environmental safety. Traditional methods for treating quinolone antibiotics include filtration, biodegradation, reverse osmosis, etc. However, these methods are limited due to high cost or incomplete treatment. Patent (CN202311805915.5) discloses a quinolone antibiotic-degrading bacterium, bacterial agent, and its preparation method and application. The achromobacter has excellent degradation effect on quinolone antibiotics such as levofloxacin, moxifloxacin, and enoxacin. The degradation rate can reach more than 95% within 48 hours under the condition of a concentration of 100-500 mg / L. However, the culture process of achromobacter is complex and costly. Solar energy is a clean and renewable energy source that can fundamentally solve environmental pollution and energy shortage problems. Photocatalytic technology for degrading organic pollutants has the advantages of fast speed, no secondary pollution, and energy saving. The core of photocatalytic technology lies in designing catalysts with excellent performance and stable structure. Currently, catalysts are mainly composite materials. Patent (CN 113398955 B) discloses a preparation method of Sillén-type double-metal oxyhalides for antibiotic degradation. The invention uses brominated 1-hexadecyl-3-methyl imidazole as the bromine source and cadmium acetate dihydrate as the cadmium source to synthesize CdBiO2Br ultra-thin nanosheets through a solvothermal method in a mixed solution of water and mannitol. The product is cooled, filtered, washed, and dried in air to obtain CdBiO2Br ultra-thin nanosheets, which are used for photocatalytic degradation of ciprofloxacin. After 210 minutes of visible light irradiation, the degradation rate of ciprofloxacin is 79.44%. However, the main catalytic site in the catalyst, cadmium ions, poses a threat to water pollution and human health. The catalytic time is long, and the efficiency is low. The existing antibiotic removal technologies also have the disadvantages of incomplete degradation, high cost, and difficulty in recycling. SUMMARY

[0003] The present application aims to at least partially solve the above technical problems, and provides a polyacid-based inorganic-organic hybrid compound, a preparation method thereof and application thereof in photocatalytic degradation of antibiotics. The synthesized polyacid-based inorganic-organic hybrid compound has a three-dimensional cavity structure and excellent photocatalytic degradation performance for antibiotics.

[0004] In a first aspect, the present application provides a polyoxometalate-based inorganic-organic hybrid compound, which has a chemical formula of [Cu2Mo2O8(C 10 N2H8)] and crystallographic parameters of:

[0005] In some embodiments of the present application, the polyoxometalate-based inorganic-organic hybrid compound has a three-dimensional network cavity structure.

[0006] In a second aspect, the present application provides a preparation method of the above-mentioned polyoxometalate-based inorganic-organic hybrid compound, which comprises the following steps:

[0007] S1. Dissolving Na2MoO4·2H2O in water, sequentially adding concentrated H3PO4 and concentrated HCl, stirring, then adding diethyl ether, oscillating until completely mixed, cooling and standing until the solution is layered, taking the lower layer solution, extracting and purifying to obtain H3[PMo 12 O 40 ];

[0008] S2. Mixing H3[PMo 12 O 40 ], 4,4'-bipy and Cu(NO3)2, then adding H2O and DMF, stirring until uniform, heating and reacting, and cooling to room temperature to obtain the polyoxometalate-based inorganic-organic hybrid compound.

[0009] In some embodiments of the present application, the extracting and purifying is to remove Na2MoO4·2H2O, H3PO4 and HCl mixed in H3[PMo 12 O 40 ];

[0010] To the lower layer solution, add water, then add diethyl ether, oscillate until mixed and uniform, stand until the solution is layered, and take the lower layer solution.

[0011] To the obtained lower layer solution, add water, slowly drop concentrated HNO3 until the solution color turns yellow, heat and react to obtain the pure product H3[PMo 12 O 40 ];

[0012] In some embodiments of the present application, in step S2 of the above-mentioned preparation method, the mass ratio of H3[PMo 12 O 40 ] to 4,4'-bipy to Cu(NO3)2 is (0.01-0.05):(0.001-0.015):(0.001-0.05).

[0013] In some embodiments of the present application, in step S2 of the preparation method, the heating reaction is specifically carried out at 100-150℃ for 24-56h.

[0014] In some embodiments of the present application, in step S2 of the preparation method, the heating reaction is specifically carried out at 100-150℃ for 24-56h. 12 O 40 The amount ratio of H3[PMo

[0015] In a third aspect of the present application, the application provides a use of the above-mentioned polyoxometalate-based inorganic-organic hybrid compound or the polyoxometalate-based inorganic-organic hybrid compound prepared by the above-mentioned preparation method as a catalyst in photocatalytic degradation of antibiotics.

[0016] In some embodiments of the present application, the photocatalytic degradation of antibiotics is visible light catalytic degradation of antibiotics.

[0017] In a fourth aspect of the present application, the application provides a method for photocatalytic degradation of antibiotics, which comprises adding a catalyst into a solution containing antibiotics, stirring until adsorption-desorption equilibrium is reached, and then performing a photo reaction under visible light irradiation, wherein the catalyst is the above-mentioned polyoxometalate-based inorganic-organic hybrid compound or the polyoxometalate-based inorganic-organic hybrid compound prepared by the above-mentioned preparation method.

[0018] In some embodiments of the present application, the amount ratio of the catalyst to the solution containing antibiotics is 15mg:50mL, and the concentration of antibiotics in the solution containing antibiotics is (10-20)mg / L.

[0019] The polyoxometalate-based inorganic-organic hybrid compound, the preparation method thereof and the use thereof in photocatalytic degradation of antibiotics according to the embodiments of the present application have at least one of the following advantages:

[0020] (1) The polyoxometalate-based inorganic-organic hybrid compound provided by the present application has a three-dimensional network cavity structure, which is helpful for high adsorption of antibiotics.

[0021] (2) The polyoxometalate-based inorganic-organic hybrid compound provided by the present application has a band gap width adjusted by introducing a transition metal regulating material, forming a semiconductor-like structure, which is helpful for improving the separation efficiency of photo-generated electrons / holes, enhancing the photocatalytic efficiency under visible light, and improving the removal rate of antibiotics. BRIEF DESCRIPTION OF DRAWINGS

[0022] These and / or other aspects and advantages of the present application will become apparent and be more readily understood from the following description, taken in conjunction with the accompanying drawings, in which:

[0023] Figure 1A 3D structure diagram of the polyacid-based inorganic-organic hybrid compound provided by the present application;

[0024] Figure 2 A chemical structure diagram of the polyacid-based inorganic-organic hybrid compound provided by the present application;

[0025] Figure 3 An infrared spectrum diagram of the polyacid-based inorganic-organic hybrid compound prepared by the embodiment 1 of the present application;

[0026] Figure 4 A photocatalytic degradation diagram of the polyacid-based inorganic-organic hybrid compound in the test example 2. DETAILED DESCRIPTION

[0027] The technical solutions of the present application are further specifically explained below by embodiments and in conjunction with the drawings. In the description, the same or similar reference numerals indicate the same or similar components. The following description of the embodiments of the present application is intended to explain the general inventive concept of the present application, and should not be understood as a limitation of the present application.

[0028] The raw materials used in the following embodiments are all commercially available products, wherein the concentration of the concentrated H3PO4 is 85wt%, and the concentration of the concentrated HCl is 37wt%.

[0029] Embodiment 1

[0030] 1. 10.5g of Na2MoO4·2H2O was weighed and dissolved in 21mL of distilled water, stirred until completely dissolved, 1mL of concentrated H3PO4 was added, and then 10mL of concentrated HCl was added, and stirred for 40min.

[0031] 2. The solution was transferred to a 250mL separatory funnel, 15mL of ether was measured and manually shaken for 30min until the solution was completely mixed, cooled and placed for 20min, the solution was layered, and the lower layer was separated.

[0032] 3. 10mL of distilled water was added to the lower layer solution obtained in step 2, shaken for 3min, and then 8mL of ether was added, shaken for 30min, and placed, the solution was layered, and the lower layer was separated.

[0033] 4. 2mL of distilled water was added to the lower layer solution obtained in step 3, a blue color appeared in the solution, concentrated HNO3 was slowly added until it turned yellow, and a large amount of yellow solid was produced in a 80℃ water bath for 30min, separated and dried to obtain the pure product H3[PMo 12 O 40 ].

[0034] 5. 0.024g of H3[PMo 12 O 400.009 g 4,4'-bipy, 0.011 g Cu(N03)2 were put into a Teflon bottle, 5 mL H20 and 1 mL DMF were added. After stirring for 30 min, it was put into a hydrothermal synthesis reactor, and then into an oven for reaction at 120 °C for 48 h. The product was obtained as grass green crystals after cooling to room temperature.

[0035] Example 2

[0036] 1. 10.5 g Na2Mo04-2H20 was weighed and dissolved in 21 mL distilled water, stirred until completely dissolved, 1 mL concentrated H3P04was added, and then 10 mL concentrated HC1 was added, and stirred for 40 min.

[0037] 2. The solution was transferred to a 250 mL separatory funnel, 15 mL ether was measured and manually shaken for 30 min until the solution was completely mixed, cooled and stood for 20 min, the solution was layered, and the lower layer was separated.

[0038] 3. 10 mL distilled water was added to the lower layer solution obtained in step 2, shaken for 3 min, then 8 mL ether was added, shaken for 30 min, and stood, the solution was layered, and the lower layer was separated.

[0039] 4. 2 mL distilled water was added to the lower layer solution obtained in step 3, blue appeared in the solution, concentrated HN03was slowly added until it turned yellow, and a large amount of yellow solid was produced in a 80 °C water bath for 30 min, which was separated and dried to obtain the product H3[PMo 12 O 40 ].

[0040] 5. 0.024 g H3[PMo 12 O 40 ], 0.018 g 4,4'-bipy, 0.011 g Cu(N03)2 were put into a Teflon bottle, 5 mL H20 and 1 mL DMF were added. After stirring for 30 min, it was put into a hydrothermal synthesis reactor, and then into an oven for reaction at 120 °C for 48 h. The product was obtained as grass green crystals after cooling to room temperature.

[0041] Example 3

[0042] 1. 10.5 g Na2Mo04-2H20 was weighed and dissolved in 21 mL distilled water, stirred until completely dissolved, 1 mL concentrated H3P04was added, and then 10 mL concentrated HC1 was added, and stirred for 40 min.

[0043] 2. The solution was transferred to a 250 mL separatory funnel, 15 mL ether was measured and manually shaken for 30 min until the solution was completely mixed, cooled and stood for 20 min, the solution was layered, and the lower layer was separated.

[0044] 3. To the lower solution obtained in step 2, 10 mL of distilled water was added, shaken for 3 min, then 8 mL of ether was added, shaken for 30 min, left to stand, the solution was separated into two layers, and the lower layer was separated.

[0045] 4. To the lower solution obtained in step 3, 2 mL of distilled water was added, a blue color appeared in the solution, concentrated HNO3 was slowly added until it turned yellow, and a large amount of yellow solid was produced at 80°C for 30 min, which was separated and dried to obtain the product H3[PMo 12 O 40 ].

[0046] 5. 0.048 g of H3[PMo 12 O 40 ], 0.018 g of 4,4'-bipy, and 0.011 g of Cu(NO3)2 were weighed into a polytetrafluoroethylene bottle, 5 mL of H2O and 1 mL of DMF were added, and the mixture was stirred for 30 min. Then it was placed in a hydrothermal synthesis reactor and placed in an oven at 120°C for 48 h. After cooling to room temperature, the product was obtained as a grass green crystal.

[0047] Test Example 1

[0048] A single crystal of the polyacid-based inorganic-organic hybrid compound prepared in Example 1 (denoted as Compound 1) with a size of 10*12*15 mm was mounted on glass fibers or sealed in a glass tube, and then directly transferred to a Gemini A Ultra diffractometer equipped with a 293(2) K graphite monochromatic Mo Kα absorption correction was performed using the SADABS program. The structure was solved by the direct method and refined by full-matrix least squares using the SHELX 97 program package. The crystals obtained in Examples 2 and 3 were tested for unit cell, and the results were consistent with the unit cell of the crystal obtained in Example 1, indicating that they were the same structure.

[0049] The detailed crystallographic data of the compound are shown in Table 1, and the crystal structure is shown in Figure 1 and 2 The structure of the compound was further characterized by infrared spectroscopy Figure 3 ). The absorption peaks in the range of 1000-500 cm -1 are mainly characteristic absorption peaks of the polyacid skeleton. The peaks at 935, 887, 817, 791, 734, and 648 cm -1 can be attributed to Mo-O, Mo-O-Mo, Mo-O-Cu, etc. The absorption peaks in the range of 3300-1000 cm -1 , such as 3099, 3053, 3016, 2362, 1614, 1535, 1494, 1413, 1224, and 1076 cm -1The peak at 3464 cm -1 There is a wide and weak absorption band, which is the absorption band of crystal water.

[0050] Crystallographic parameters of the compounds of table 1

[0051]

[0052]

[0053] Test example 2

[0054] With ofloxacin as the substrate antibiotic, the synthesized compound 1, H3[PMo 12 O 40 ], 4,4'-bipy, Cu(NO3)2 as the photocatalyst, the degradation experiment was carried out in a 100mL quartz photo reactor, the circulating water device was opened to keep the system temperature at 25±0.5℃, and the rotating speed was adjusted. The light source was a 300W xenon lamp. 15mg of photocatalyst (sample 1) was added to 50mL of 10mg·L -1 of ofloxacin solution. After stirring in the dark for 30min to reach the adsorption-desorption equilibrium, the photo reaction was carried out under the irradiation of the light source. Every 30min, 3mL of the suspension was taken out, centrifuged and filtered through a 0.22μm filter head to remove the catalyst particles. The concentration of the degraded antibiotic was determined by high performance liquid chromatography Figure 4 ). Among them, a C18 column was used. The wavelength of the UV-vis detector was set to 288nm, the mobile phase was methanol (A) and 1‰ formic acid aqueous solution (B), the volume ratio was 15:85, the flow rate was 1.0mL·min -1 , and the injection amount was 10μL. The comparison results show that the compound 1 provided by the application has excellent photocatalytic degradation activity of ofloxacin antibiotic

[0055] The polyacid-based inorganic-organic hybrid compound, the preparation method thereof and the application thereof in photocatalytic degradation of antibiotics according to the embodiments of the application have at least one of the following advantages:

[0056] The polyacid-based inorganic-organic hybrid compound, the preparation method thereof and the application thereof in photocatalytic degradation of antibiotics according to the embodiments of the application have at least one of the following advantages:

[0057] (1) The polyacid-based inorganic-organic hybrid compound provided by the application has a three-dimensional network cavity structure, and the cavity structure is helpful for high adsorption of antibiotics.

[0058] (2) The multi-acid-based inorganic-organic hybrid compound provided by the application can adjust the band gap width by introducing transition metals, form a semiconductor structure, improve the separation efficiency of photo-generated electrons / holes, enhance the photocatalytic efficiency under visible light, and improve the removal rate of antibiotics.

Claims

1. A polyacid-based inorganic-organic hybrid compound, characterized by, The chemical formula of the polyacid-based inorganic-organic hybrid compound is [Cu2Mo2O8(C 10 N2H8)], with crystallographic parameters of: a = 7.4451(11) Å; b = 9.2318(13) Å; c = 13.856(2) Å; V = 864.4(2) Å 3 .

2. The polyox acid-based inorganic-organic hybrid compound according to claim 1, characterized by The polyacid-based inorganic-organic hybrid compound has a three-dimensional network cavity structure.

3. A method for producing the polyacid-based inorganic-organic hybrid compound according to claim 1, characterized by, The preparation method comprises the following steps: S1. Dissolve Na2MoO4.2H2O in water, add concentrated H3PO4 and concentrated HCl in turn, stir, then add ether, shake until completely mixed, cool and stand until the solution separates into layers, take the lower layer solution, extract and purify to obtain H3[PMo 12 O 40 ]; S2. H3[PMo 12 O 14 ], 4,4' -bipy and Cu(N03)2 were mixed, H20 and DMF were added, after stirring homogeneously, the reaction was heated, cooled to room temperature to obtain the polyacid-based inorganic-organic hybrid compound.

4. The production method according to claim 3, characterized by, In step S2, H3[PMo 12 O 40 The mass ratio of H3[PMo12O40], 4,4'-bipy and Cu(NO3)2 is (0.01-0.05):(0.001-0.015):(0.001-0.05).

5. The preparation method according to claim 3, characterized in that, In step S2, the heating reaction is specifically 100-150 DEG C for 24-56 h.

6. The preparation method according to claim 4, characterized in that, In step S2, H3[PMo 12 O 40 The ratio of the amounts of H3[PMo12O40]·xH2O, H2O and DMF is (0.01-0.05) g:5 mL:1 mL.

7. Application of the polyacid-based inorganic-organic hybrid compound in claim 1 or 2 or prepared by the preparation method in any one of claims 3-6 as a catalyst in photocatalytic degradation of antibiotics.

8. Use according to claim 7, characterized in that, The photocatalytic degradation of antibiotics is visible light catalytic degradation of antibiotics.

9. A method of photocatalytic degradation of antibiotics, characterized by, The method is: adding the catalyst into a solution containing antibiotics, stirring until adsorption-desorption equilibrium, and then performing a photo reaction under visible light irradiation, wherein the catalyst is the polyacid-based inorganic-organic hybrid compound in claim 1 or 2 or prepared by the preparation method in any one of claims 3-6.

10. The method of claim 9, wherein, The dosage ratio of the catalyst to the solution containing antibiotics is 15 mg:50 mL, and the concentration of antibiotics in the solution containing antibiotics is (10-20) mg / L.

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