A composite photocatalytic material, its preparation method and application

Abstract

This invention discloses a composite photocatalytic material, its preparation method, and its application, belonging to the field of photocatalysis technology. The photocatalytic material is a ZnIn2S4 / TpPa-Cl2-COF composite material, in which the mass proportion of ZnIn2S4 is 50-70% and the mass proportion of TpPa-Cl2-COF is 30-50%. This invention uses a chlorine-grafted covalent organic framework material as a carrier, and prepares the above-mentioned composite photocatalytic material by in-situ growth of indium zinc sulfide nanosheets on it using a mild oil bath heating method. The presence of chlorine groups promotes the interfacial bonding between the carrier and indium zinc sulfide, thereby effectively improving the separation and transport of photogenerated carriers. The composite photocatalytic material is used to catalytically degrade acid red GR or tetracycline in wastewater under visible light while simultaneously producing hydrogen peroxide. It has the advantages of simple preparation method and high visible light catalytic activity, providing an economical, green, and sustainable approach for wastewater treatment and energy regeneration.

Description

Technical fields:

[0001] This invention relates to the field of photocatalysis technology, specifically to a high-performance ZnIn2S4 / TpPa-Cl2-COF composite material for the simultaneous photocatalytic degradation of water pollutants and H2O2 production. Background technology:

[0002] Covalent organic frameworks (COFs) are a novel class of porous, crystalline, and ordered two- or three-dimensional (2D or 3D) materials, constructed entirely from molecular organic monomers composed of light elements (such as B, C, N, and O) linked by covalent bonds, exhibiting stability and diversity. This superior crystalline porous structure has been extensively studied in various fields, including gas adsorption and separation, heterogeneous catalysis, photodynamic or photothermal therapy, sensing, and photocatalytic applications. In recent years, researchers have made significant efforts to modify COFs, focusing on enhancing their photocatalytic performance through functional group modification and heterostructure construction. Grafting electron-withdrawing groups onto the COF framework can improve COF light absorption and charge transport. Simultaneously, the functional groups grafted onto COFs can act as active sites, binding with guest molecules (such as semiconductors) to form tight heterojunctions, which is beneficial for further improving the separation and transport efficiency of photogenerated carriers. Therefore, to fully enhance the photocatalytic ability of COFs, both modification methods need to be implemented simultaneously.

[0003] Photocatalytic degradation of water pollutants such as Acid Red GR and tetracycline under visible light is a green and environmentally friendly method. Meanwhile, photocatalytic production of hydrogen peroxide (H2O2) is a promising technology that has attracted widespread attention. However, the simultaneous photocatalytic degradation of water pollutants and H2O2 production has been rarely studied. Researchers have focused more on the on-site decomposition of H2O2 produced during the process to promote pollutant degradation, such as the Fenton reaction and Fenton-like reactions. Nevertheless, it is undeniable that photocatalytic degradation of water pollutants and simultaneous H2O2 production also possesses significant economic value and practical significance, enabling the transformation of waste into resources and providing an economical, green, and sustainable approach for wastewater treatment and energy regeneration. Summary of the Invention:

[0004] The technical problem to be solved by the present invention is to provide a catalytic material and its preparation method that can simultaneously and efficiently photocatalytically degrade water pollutants and produce H2O2.

[0005] The technical solution of the present invention is to provide a composite photocatalytic material, wherein the photocatalytic material is a ZnIn2S4 / TpPa-Cl2-COF composite material, wherein the mass ratio of ZnIn2S4 in the ZnIn2S4 / TpPa-Cl2-COF composite material is 50-70%, and the mass ratio of TpPa-Cl2-COF is 30-50%.

[0006] Preferably, the mass ratio of ZnIn2S4 to TpPa-Cl2-COF is any one of 7:3, 6:4, and 5:5.

[0007] The present invention also provides a method for preparing the above-mentioned photocatalytic material, comprising the following steps:

[0008] Step 1: Mix 2,4,6-tricarboxymethyl phloroglucinol, 2,5-dichloro-1,4-phenylenediamine with acetic acid, mesitylene, and 1,4-dioxane to obtain a homogeneous solution A;

[0009] Step 2: After repeatedly freezing-vacuuming-thawing, solution A is subjected to a solvothermal reaction at 110-130℃ in an oven for 65-80 hours to obtain TpPa-Cl2-COF;

[0010] Step 3: Mix a certain mass of TpPa-Cl2-COF with pure water, and sonicate and stir for more than 0.5 hours to form solution B;

[0011] Step 4: Add ZnCl2, InCl3·4H2O, and C2H5NS to solution B. The ratio of the amounts of the three solid substances added is 1:2:6.

[0012] Step 5: After adjusting the pH value of the mixed solution obtained in step 4 with hydrochloric acid, the solution is subjected to a hydrothermal reaction in an oil bath to obtain the photocatalytic material.

[0013] Specifically, in step 1, 2,4,6-tricarboxymethyl phloroglucinol, 2,5-dichloro-1,4-phenylenediamine, acetic acid, mesitylene, and 1,4-dioxane are mixed to obtain a homogeneous solution A;

[0014] Step 2: After the solution A obtained in Step 1 is subjected to three cycles of freezing-vacuuming-thawing, it is subjected to a solvothermal reaction at 120℃ for 72h in an oven to obtain TpPa-Cl2-COF;

[0015] Step 3: Mix a certain mass of TpPa-Cl2-COF with pure water, and sonicate and stir for 1 hour to form solution B;

[0016] Step 4: Add ZnCl2, InCl3·4H2O, and C2H5NS to solution B. The ratio of the amounts of the three solid substances added is 1:2:6.

[0017] Step 5: After adjusting the pH value of the mixed solution obtained in step 4 with hydrochloric acid, the solution is subjected to a hydrothermal reaction in an oil bath to obtain the photocatalytic material.

[0018] In the above technical solution, the molar ratio of 2,4,6-tricarboxymethyl phloroglucinol and 2,5-dichloro-1,4-phenylenediamine in step 1 is 3:4; the volume ratio of mesitylene and 1,4-dioxane in step 1 is 1:1.

[0019] In the above technical solution, the concentration of acetic acid in step 1 is 3 mol / L.

[0020] In the above technical solution, the mesitylene and 1,4-dioxane in step 1 include anhydrous reagents.

[0021] In the above technical solution, the molar ratio of ZnCl3, InCl3·4H2O and C2H5NS in step 4 is 1:2:6.

[0022] In the above technical solution, the concentration of hydrochloric acid in step 5 is 1 mol / L; the pH value in step 5 is adjusted to 2.5; the temperature of the hydrothermal reaction in step 5 is 80℃, and the hydrothermal reaction time is 6h.

[0023] This invention also provides the application of the above-mentioned composite photocatalytic material in the degradation of acid red GR or tetracycline and the simultaneous production of H2O2.

[0024] Compared with the prior art, the present invention has the following advantages after adopting the above solution:

[0025] The ZnIn2S4 / TpPa-Cl2-COF composite material can effectively separate electron-hole pairs and prolong the survival time of photogenerated carriers, thereby improving the catalytic activity of the photocatalyst. It can be applied to the degradation of Acid Red GR or tetracycline while simultaneously producing H2O2. The photocatalyst material provided by this invention exhibits optimal performance when the mass ratio of ZnIn2S4 / TpPa-Cl2-COF composite material is 6:4. After 120 min of visible light irradiation, the degradation rate of 50 mg / L Acid Red GR is 93%, and the degradation rate of 80 mg / L tetracycline is 95%, while the yields of H2O2 are 936 and 846 μmol·L, respectively. -1 . Attached image description:

[0026] Figure 1 a and b are X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectra of the ZnIn2S4 / TpPa-Cl2-COF composite materials prepared in Examples 1-3, and ZnIn2S4 and TpPa-Cl2-COF, respectively.

[0027] Figure 2 a and b are scanning electron microscope (SEM) and transmission electron microscope (TEM) images of the ZnIn2S4 / TpPa-Cl2-COF composite material prepared in Example 2, respectively.

[0028] Figure 3 a and b are the performance graphs of the photocatalytic degradation of Acid Red GR and the simultaneous production of H2O2 by the ZnIn2S4 / TpPa-Cl2-COF composite materials prepared in Examples 1-3, respectively;

[0029] Figure 4 a and b are performance graphs of the photocatalytic degradation of tetracycline and simultaneous H2O2 production of the ZnIn2S4 / TpPa-Cl2-COF composite materials prepared in Examples 1-3, respectively. Detailed implementation method:

[0030] The present invention will be further described below with reference to specific embodiments:

[0031] Example 1

[0032] 63 mg of 2,4,6-tricarboxymethyl phloroglucinol and 80 mg of 2,5-dichloro-1,4-phenylenediamine were added to a solution containing 1.5 mL of mesitylene, 1.5 mL of dioxane, and 0.5 mL of acetic acid (3 mol·L⁻¹). -1 The mixture was placed in a high-temperature, pressure-resistant tube. The mixture was sonicated for 30 minutes to obtain a uniform dispersion. Subsequently, the tube was rapidly frozen at 77K (liquid N2), degassed through three freeze-thaw cycles, sealed, and then statically heated in an oven at 120℃ for 3 days. The red product was then collected by centrifugation and washed with anhydrous acetone. The resulting powder was vacuum-dried overnight at 180℃ to obtain the corresponding TpPa-Cl2-COF. 181 mg of the above TpPa-Cl2-COF was added to 100 mL of deionized water, sonicated, and stirred for 1 h to obtain a uniform suspension. Then, 137 mg of ZnCl2, 587 mg of InCl3·4H2O, and 451 mg of C2H5NS were added to the suspension, and the mixture was heated at 1 mol·L⁻¹. -1 The pH was adjusted to 2.5 with HCl. The mixture was then stirred in an oil bath at 80°C for 6 hours. Finally, the sample was centrifuged, washed with water and ethanol, and dried overnight at 80°C. The ZnIn2S4 / TpPa-Cl2-COF composite material was obtained.

[0033] Example 2:

[0034] 63 mg of 2,4,6-tricarboxymethyl phloroglucinol and 80 mg of 2,5-dichloro-1,4-phenylenediamine were added to a solution containing 1.5 mL of mesitylene, 1.5 mL of dioxane, and 0.5 mL of acetic acid (3 mol·L⁻¹). -1The mixture was placed in a high-temperature, pressure-resistant tube. The mixture was sonicated for 30 minutes to obtain a uniform dispersion. Subsequently, the tube was rapidly frozen at 77K (liquid N2), degassed through three freeze-thaw cycles, sealed, and then statically heated in an oven at 120℃ for 3 days. The red product was then collected by centrifugation and washed with anhydrous acetone. The resulting powder was vacuum-dried overnight at 180℃ to obtain the corresponding TpPa-Cl2-COF. 282 mg of the above TpPa-Cl2-COF was added to 100 mL of deionized water, sonicated, and stirred for 1 h to obtain a uniform suspension. Then, 137 mg of ZnCl2, 587 mg of InCl3·4H2O, and 451 mg of C2H5NS were added to the suspension, and the mixture was heated at 1 mol·L⁻¹. -1 The pH was adjusted to 2.5 with HCl. The mixture was then stirred in an oil bath at 80°C for 6 hours. Finally, the sample was centrifuged, washed with water and ethanol, and dried overnight at 80°C. The ZnIn2S4 / TpPa-Cl2-COF composite material was obtained.

[0035] Figure 2 The images show scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images of the ZnIn2S4 / TpPa-Cl2-COF composite material prepared in Example 2. The ZnIn2S4 / TpPa-Cl2-COF composite material prepared in Example 2 has a good microstructure, with ZnIn2S4 nanosheets tightly wrapped around the surface of TpPa-Cl2-COF, indicating a good interfacial contact between ZnIn2S4 and TpPa-Cl2-COF.

[0036] Example 3:

[0037] 63 mg of 2,4,6-tricarboxymethyl phloroglucinol and 80 mg of 2,5-dichloro-1,4-phenylenediamine were added to a solution containing 1.5 mL of mesitylene, 1.5 mL of dioxane, and 0.5 mL of acetic acid (3 mol·L⁻¹). -1 The mixture was placed in a high-temperature, pressure-resistant tube. The mixture was sonicated for 30 minutes to obtain a homogeneous dispersion. Subsequently, the tube was rapidly frozen at 77K (liquid N2), degassed through three freeze-thaw cycles, sealed, and then statically heated in an oven at 120℃ for 3 days. The red product was then collected by centrifugation and washed with anhydrous acetone. The resulting powder was vacuum-dried overnight at 180℃ to obtain the corresponding TpPa-Cl2-COF. 423 mg of the above TpPa-Cl2-COF was added to 100 mL of deionized water, sonicated, and stirred for 1 h to obtain a homogeneous suspension. Then, 137 mg of ZnCl2, 587 mg of InCl3·4H2O, and 451 mg of C2H5NS were added to the suspension, and the mixture was heated at 1 mol·L⁻¹. -1The pH was adjusted to 2.5 with HCl. The mixture was then stirred in an oil bath at 80°C for 6 hours. Finally, the sample was centrifuged, washed with water and ethanol, and dried overnight at 80°C. The ZnIn2S4 / TpPa-Cl2-COF composite material was obtained.

[0038] Figure 1 The images show the X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectra of the ZnIn2S4 / TpPa-Cl2-COF composite materials prepared in Examples 1-3. It can be seen that the ZnIn2S4 / TpPa-Cl2-COF composite materials prepared in Examples 1-3 contain both ZnIn2S4 and TpPa-Cl2-COF.

[0039] The photocatalytic test conditions are as follows:

[0040] Simultaneous H2O2 production test during Acid Red degradation: At room temperature, 20 mg of catalyst sample was dispersed in a 50 mg / L Acid Red GR solution. The mixed solution was stirred in the dark for 1 h (300 r / min) to reach adsorption-desorption equilibrium. Then, the photocatalytic reaction solution was placed under a 300 W xenon lamp and stirred with a magnetic stirrer. During the photocatalytic degradation of Acid Red GR, 3 mL samples were taken every 30 min, filtered through a 0.22 μm nylon 66 filter, and the filtrate was collected. The absorbance was measured at 509 nm using a UV-Vis spectrophotometer to obtain degradation rate data, which was then analyzed. Simultaneously, 1 mL of the filtrate was used to determine the H2O2 concentration at 350 nm using the iodometric method.

[0041] Simultaneous H2O2 production test during tetracycline degradation: At room temperature, 20 mg of catalyst sample was dispersed in an 80 mg / L tetracycline solution. The mixed solution was stirred in the dark for 1 h (300 r / min) to reach adsorption-desorption equilibrium. Then, the photocatalytic reaction solution was placed under a 300 W xenon lamp and stirred with a magnetic stirrer. During the photocatalytic degradation of tetracycline, 3 mL samples were taken every 30 min, filtered through a 0.22 μm nylon 66 filter, and the filtrate was collected. The absorbance was measured at 357 nm using a UV-Vis spectrophotometer to obtain degradation yield data, which was then analyzed. Simultaneously, 1 mL of the filtrate was used to determine the H2O2 concentration at 350 nm using the iodometric method.

[0042] The results of the examples show (e.g.) Figure 3 and Figure 4The photocatalyst material provided by this invention exhibits optimal catalyst performance when the mass ratio of the ZnIn2S4 / TpPa-Cl2-COF composite material is 6:4. After 120 min of visible light irradiation, the degradation rate of 50 mg / L Acid Red GR is 93%, and the degradation rate of 80 mg / L Tetracycline is 95%, while the yields of H2O2 are 936 and 846 μmol·L, respectively. -1 .

[0043] This invention utilizes a chlorine-grafted covalent organic framework material as a carrier to prepare the aforementioned composite photocatalytic material by in-situ growth of indium zinc sulfide nanosheets onto it using a mild oil bath heating method. The presence of chlorine groups promotes interfacial bonding between the carrier and indium zinc sulfide, thereby effectively improving the separation and transport of photogenerated carriers. This composite photocatalytic material is used to catalytically degrade acid red GR or tetracycline in wastewater under visible light, simultaneously producing hydrogen peroxide. It has the advantages of simple preparation method and high visible light catalytic activity, providing an economical, green, and sustainable approach for wastewater treatment and energy regeneration.

[0044] The above description only illustrates preferred embodiments of the present invention and should not be construed as limiting the scope of the claims. Any equivalent structural or procedural modifications made using this specification are included within the patent protection scope of the present invention.

Claims

1. The application of a composite photocatalytic material in the degradation of Acid Red GR or tetracycline while simultaneously producing H2O2, characterized in that, The composite photocatalytic material is a ZnIn2S4 / TpPa-Cl2-COF composite material, wherein the mass percentage of ZnIn2S4 in the composite photocatalytic material is 50-70%, and the mass percentage of TpPa-Cl2-COF is 30-50%. The preparation method of the composite photocatalytic material includes the following steps. Step 1: Mix 2,4,6-tricarboxymethyl phloroglucinol, 2,5-dichloro-1,4-phenylenediamine with acetic acid, mesitylene, and 1,4-dioxane to obtain a homogeneous solution A; Step 2: After repeatedly freezing-vacuuming-thawing, solution A is subjected to a solvothermal reaction at 110-130 °C for 65-80 h in an oven to obtain TpPa-Cl2-COF; Step 3: Mix a certain mass of TpPa-Cl2-COF with pure water, and sonicate and stir for more than 0.5 hours to form solution B; Step 4: Add ZnCl2, InCl3·4H2O, and C2H5NS to solution B. The ratio of the amounts of the three solid substances added is 1:2:

6. Step 5: After adjusting the pH value of the mixed solution obtained in step 4 with hydrochloric acid, the solution is subjected to a hydrothermal reaction in an oil bath to obtain the composite photocatalytic material.

2. The application of the composite photocatalytic material according to claim 1 in the degradation of Acid Red GR or tetracycline while simultaneously producing H2O2, characterized in that: The mass ratio of ZnIn2S4 to TpPa-Cl2-COF is any one of 7:3, 6:4, and 5:

5.

3. The application of the composite photocatalytic material according to claim 1 in the degradation of Acid Red GR or tetracycline while simultaneously producing H2O2, characterized in that: The molar ratio of 2,4,6-tricarboxymethyl phloroglucinol to 2,5-dichloro-1,4-phenylenediamine is 3:4; the volume ratio of mesitylene to 1,4-dioxane is 1:

1.

4. The application of the composite photocatalytic material according to claim 1 in the degradation of Acid Red GR or tetracycline while simultaneously producing H2O2, characterized in that: The concentration of acetic acid in step 1 is 3 mol / L.

5. The application of the composite photocatalytic material according to claim 1 in the degradation of Acid Red GR or tetracycline while simultaneously producing H2O2, characterized in that: In step 5, the concentration of hydrochloric acid is 1 mol / L, the pH value is adjusted to 2.5, the hydrothermal reaction temperature is 80℃, and the hydrothermal reaction time is 6 h.

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