Titanium oxide-based photocatalytic material derived from metal organic framework and preparation method and application thereof

Abstract

This invention discloses a TiO2-based photocatalytic material derived from a metal-organic framework (MOF), its preparation method, and its applications, belonging to the field of photocatalysis. Using a titanium-based MOF as a template, a heterojunction photocatalytic material of TiO2 and ZnIn2S4 was prepared via a one-pot method in a ZnIn2S4 synthesis precursor solution. The MOF-derived TiO2 possesses extremely high specific surface area and porosity, significantly promoting O2 capture. Furthermore, the heterojunction material prepared via the one-pot method exhibits excellent interfacial contact between monomers, facilitating the separation of photogenerated carriers and further promoting the photocatalytic reaction. This photocatalytic material, used for the photocatalytic reduction of O2 to H2O2 under visible light, offers advantages such as simple preparation and high visible light catalytic activity, providing a green and sustainable pathway for oxygen reduction to H2O2.

Description

Technical Field

[0001] This invention relates to the field of photocatalysis, specifically to a titanium dioxide-based photocatalytic material derived from a metal-organic framework for the visible light photocatalytic preparation of H2O2. Background Technology

[0002] Metal-organic frameworks (MOFs) are ordered porous materials formed by the self-assembly of metal ions or metal clusters with organic ligands through coordination bonds. Due to the periodic arrangement of metal and oxygen atoms in the MOF structure, metal oxides derived from MOFs can largely retain the high specific surface area and porosity of MOFs. Furthermore, compared to MOFs, metal oxides often possess higher stability and can be applied in harsher environments. Nevertheless, derived metal oxides still face problems such as low utilization of visible light and rapid recombination of photogenerated carriers. Constructing heterojunctions with narrow-bandgap semiconductors is an effective means to solve these problems. ZnIn2S4 is a typical narrow-bandgap semiconductor with a two-dimensional sheet morphology, good visible light absorption, and a suitable band structure. This invention uses a titanium-based metal-organic framework material (ML-125-NH2) as a template to prepare a heterojunction photocatalytic material of titanium oxide (TiO2) and ZnIn2S4 derived from a metal-organic framework material via a one-pot method in a ZnIn2S4 synthesis precursor solution.

[0003] Hydrogen peroxide (H2O2) is a versatile and environmentally friendly oxidant, widely used in environmental remediation, industrial production, and healthcare due to its high reactivity, sustainability, and operational safety. Furthermore, H2O2, as a carbon-neutral liquid fuel alternative, offers a potential solution for mitigating climate change and environmental pollution. However, current industrial production of H2O2 primarily relies on the anthraquinone process, which is energy-intensive, requires large amounts of raw materials, and is environmentally harmful. Visible light accounts for approximately 46% of sunlight; therefore, photocatalytic oxygen reduction reaction to produce H2O2 under visible light is a green and sustainable technology, significant for promoting the application of photocatalysis in energy regeneration. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a catalytic material capable of efficiently photocatalytically generating H2O2 under visible light and its preparation method.

[0005] The technical solution of the present invention is to provide a photocatalytic material, characterized in that: the photocatalytic material is a titanium oxide-based material derived from a metal-organic framework material.

[0006] The present invention also provides a method for preparing the above-mentioned photocatalytic material, comprising the following steps:

[0007] Step 1: Dissolve tetraisopropyl titanate, 2-aminoterephthalic acid and methanol in N,N-dimethylformamide and sonicate for 10-30 min to obtain a mixed solution;

[0008] Step 2: Place the above mixed solution in an oven and carry out a solvothermal reaction at 120-180℃ for 18-30 hours to obtain MIL-125-NH2;

[0009] Step 3: Disperse MIL-125-NH2 in deionized water by sonication for 5-25 min and stir for 5-25 min to obtain solution A;

[0010] Step 4: Add ZnCl2, InCl3·4H2O and thioacetamide to solution A in sequence, stir for 20-40 min to obtain solution B;

[0011] Step 5: Place solution B in an oven for a solvothermal reaction at 150-210℃ for 8-16 hours to obtain the photocatalytic material.

[0012] Specifically, in step 1, tetraisopropyl titanate, 2-aminoterephthalic acid and methanol are dissolved in N,N-dimethylformamide and sonicated for 20 minutes to obtain a mixed solution.

[0013] Step 2: Place the above mixed solution in an oven and perform a solvothermal reaction at 150°C for 24 hours to obtain MIL-125-NH2;

[0014] Step 3: Disperse MIL-125-NH2 in deionized water by sonication for 15 min and stir for 15 min to obtain solution A;

[0015] Step 4: Add ZnCl2, InCl3·4H2O and thioacetamide to solution A in sequence, stir for 30 min to obtain solution B;

[0016] Step 5: Place solution B in an oven for a solvothermal reaction at 180°C for 12 hours to obtain the photocatalytic material.

[0017] In the above technical solution, the molar ratio of tetraisopropyl titanate, 2-aminoterephthalic acid and methanol in step 1 is 1:3:37.

[0018] In the above technical solution, the volume of N,N-dimethylformamide in step 1 is 50 mL;

[0019] In the above technical solution, the volume of deionized water in step 3 is 30 mL;

[0020] In the above technical solution, the molar ratio of ZnCl2, InCl3·4H2O and thioacetamide in step 4 is 1:2:4.

[0021] This invention also provides the application of the above-mentioned photocatalytic material in the photocatalytic preparation of H2O2 under visible light.

[0022] Compared with the prior art, the present invention has the following advantages after adopting the above solution:

[0023] This invention utilizes titanium-based metal-organic frameworks (MOFs) as templates to prepare TiO2-ZnIn2S4 heterojunction photocatalytic materials via a one-pot method in a ZnIn2S4 synthesis precursor solution. Compared to conventional methods using metal salts as precursors to prepare TiO2, MOF-derived TiO2 exhibits significantly higher specific surface area and porosity, greatly promoting O2 capture. Furthermore, the heterojunction materials prepared via the one-pot method possess excellent interfacial contact between monomers, facilitating the separation of photogenerated carriers and further promoting the photocatalytic reaction. The prepared photocatalytic material can be applied to the photocatalytic reduction of O2 to H2O2 under visible light, achieving a maximum H2O2 yield of 1395 μmol·L⁻¹ after 1.5 h of visible light irradiation. -1 These figures are 6.8 and 3.3 times that of TiO2 and ZnIn2S4, respectively. Attached Figure Description

[0024] Figure 1 a and b are the X-ray diffraction (XRD) patterns and N2 adsorption-desorption isotherms of the TiO2 / ZnIn2S4 photocatalytic material, the metal-organic framework-derived TiO2 and ZnIn2S4 prepared in Example 2, respectively.

[0025] Figure 2 Scanning electron microscope (SEM) images of the TiO2 / ZnIn2S4 photocatalytic material prepared in Example 2, and TiO2 and ZnIn2S4 derived from metal-organic framework materials.

[0026] Figure 3 The performance of TiO2 / ZnIn2S4 photocatalytic material, TiO2 and ZnIn2S4 derived from metal-organic framework material prepared in Examples 1-3 in photocatalytic generation of H2O2 under visible light is shown in the figure. Detailed Implementation

[0027] The present invention will be further described below with reference to specific embodiments:

[0028] Example 1

[0029] 1.25 mL of tetraisopropyl titanate, 2.177 g of 2-aminoterephthalic acid, and 6 mL of methanol were dissolved in 50 mL of N,N-dimethylformamide, followed by sonication for 20 min. The mixture was placed in a 100 mL high-pressure reactor and maintained at 150 °C for 24 h. After cooling to room temperature, the sample was washed with N,N-dimethylformamide and methanol, and dried in an oven at 80 °C to obtain the MIL-125-NH2 material. 529 mg of MIL-125-NH2 was placed in a beaker containing 30 mL of deionized water, stirred for 15 min, sonicated for 15 min, and then 34 mg of ZnCl2, 146.5 mg of InCl3·4H2O, and 75.3 mg of thioacetamide were added. After stirring again for 30 minutes, the mixture was placed in a 100 mL high-pressure reactor and kept at 180 °C for 12 h. The sample was washed with deionized water and anhydrous ethanol and dried in an 80 °C oven to obtain TiO2 / ZnIn2S4 material.

[0030] Example 2:

[0031] 1.25 mL of tetraisopropyl titanate, 2.177 g of 2-aminoterephthalic acid, and 6 mL of methanol were dissolved in 50 mL of N,N-dimethylformamide, followed by sonication for 20 min. The mixture was placed in a 100 mL high-pressure reactor and maintained at 150 °C for 24 h. After cooling to room temperature, the sample was washed with N,N-dimethylformamide and methanol, and dried in an oven at 80 °C to obtain the MIL-125-NH2 material. 741 mg of MIL-125-NH2 was placed in a beaker containing 30 mL of deionized water, stirred for 15 min, sonicated for 15 min, and then 34 mg of ZnCl2, 146.5 mg of InCl3·4H2O, and 75.3 mg of thioacetamide were added. After stirring again for 30 minutes, the mixture was placed in a 100 mL high-pressure reactor and kept at 180 °C for 12 h. The sample was washed with deionized water and anhydrous ethanol and dried in an 80 °C oven to obtain TiO2 / ZnIn2S4 material.

[0032] Example 3:

[0033] 1.25 mL of tetraisopropyl titanate, 2.177 g of 2-aminoterephthalic acid, and 6 mL of methanol were dissolved in 50 mL of N,N-dimethylformamide, followed by sonication for 20 min. The mixture was placed in a 100 mL high-pressure reactor and maintained at 150 °C for 24 h. After cooling to room temperature, the sample was washed with N,N-dimethylformamide and methanol, and dried in an oven at 80 °C to obtain the MIL-125-NH2 material. 952 mg of MIL-125-NH2 was placed in a beaker containing 30 mL of deionized water, stirred for 15 min, sonicated for 15 min, and then 34 mg of ZnCl2, 146.5 mg of InCl3·4H2O, and 75.3 mg of thioacetamide were added. After stirring again for 30 minutes, the mixture was placed in a 100 mL high-pressure reactor and kept at 180 °C for 12 h. The sample was washed with deionized water and anhydrous ethanol and dried in an 80 °C oven to obtain TiO2 / ZnIn2S4 material.

[0034] Figure 1 a and b are the XRD patterns and N2 adsorption-desorption isotherms of the TiO2 / ZnIn2S4 photocatalyst material and the TiO2 derived from the metal-organic framework material prepared in Example 2, respectively. As can be seen from the figures, the TiO2-based photocatalyst material derived from the metal-organic framework material was successfully prepared and possesses high specific surface area and porosity.

[0035] Figure 2 The TiO2 / ZnIn2S4 photocatalytic material prepared in Example 2 is shown in the figure. As can be seen from the figure, the interfacial contact between the monomers of the composite material is good.

[0036] The photocatalytic test conditions are as follows:

[0037] Photocatalytic H2O2 generation test: 20 mg of TiO2-based photocatalyst material derived from a metal-organic framework was placed in 20 mL of deionized water. The mixed suspension was stirred in the dark for 30 min, and then the reaction solution was placed under a 300 W xenon lamp (light wavelength range: 400-780 nm) equipped with a filter for photocatalytic reaction. During the photocatalytic reaction, samples were taken at intervals, and the catalyst was filtered through a 0.22 μm nylon 66 filter, and the filtrate samples were collected. The H2O2 concentration was determined at 350 nm using a UV-Vis spectrophotometer via iodometric titration.

[0038] The results of the visible light photocatalytic preparation of H2O2 in the examples show that ( Figure 3 The TiO2-based photocatalytic material derived from the metal-organic framework provided by this invention exhibits excellent photocatalytic performance. In Example 2, after 1.5 hours of visible light irradiation, the yield of H2O2 reached 1395 μmol·L⁻¹. -1 .

[0039] This invention utilizes a titanium-based metal-organic framework (MOF) as a template to prepare a TiO2 / ZnIn2S4 heterojunction photocatalytic material via a one-pot synthesis in a ZnIn2S4 precursor solution. The MOF-derived TiO2 possesses an extremely high specific surface area and porosity, significantly promoting O2 capture. Furthermore, the heterojunction material prepared via the one-pot method exhibits excellent interfacial contact between monomers, facilitating the separation of photogenerated carriers and further promoting the photocatalytic reaction. This photocatalytic material, used for the photocatalytic reduction of O2 to H2O2 under visible light, offers advantages such as simple preparation and high visible light catalytic activity, providing a green and sustainable pathway for oxygen reduction to H2O2.

[0040] 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. A photocatalytic material, characterized in that: The photocatalytic material is a titanium dioxide-based material derived from a metal-organic framework.

2. The method for preparing the photocatalytic material according to claim 1, characterized in that: Includes the following steps, Step 1: Dissolve tetraisopropyl titanate, 2-aminoterephthalic acid and methanol in N,N-dimethylformamide and sonicate for 10-30 min to obtain a mixed solution; Step 2: Place the above mixed solution in an oven and carry out a solvothermal reaction at 120-180℃ for 18-30 hours to obtain MIL-125-NH2; Step 3: Disperse MIL-125-NH2 in deionized water by sonication for 5-25 min and stir for 5-25 min to obtain solution A; Step 4: Add ZnCl2, InCl3·4H2O and thioacetamide to solution A in sequence, stir for 20-40 min to obtain solution B; Step 5: Place solution B in an oven for a solvothermal reaction at 150-210℃ for 8-16 hours to obtain the photocatalytic material.

3. The method for preparing the photocatalytic material according to claim 1, characterized in that: Includes the following steps, Step 1: Dissolve tetraisopropyl titanate, 2-aminoterephthalic acid and methanol in N,N-dimethylformamide and sonicate for 20 min to obtain a mixed solution; Step 2: Place the above mixed solution in an oven and perform a solvothermal reaction at 150°C for 24 hours to obtain MIL-125-NH2; Step 3: Disperse MIL-125-NH2 in deionized water by sonication for 15 min and stir for 15 min to obtain solution A; Step 4: Add ZnCl2, InCl3·4H2O and thioacetamide to solution A in sequence, stir for 30 min to obtain solution B; Step 5: Place solution B in an oven for a solvothermal reaction at 180°C for 12 hours to obtain the photocatalytic material.

4. The method for preparing the photocatalytic material according to claim 3, characterized in that: In step 1, the molar ratio of tetraisopropyl titanate, 2-aminoterephthalic acid, and methanol is 1:3:

37.

5. The method for preparing the photocatalytic material according to claim 3, characterized in that: The volume of N,N-dimethylformamide in step 1 is 50 mL.

6. The method for preparing the photocatalytic material according to claim 3, characterized in that: The volume of deionized water in step 3 is 30 mL.

7. The method for preparing the photocatalytic material according to claim 3, characterized in that: In step 4, the molar ratio of ZnCl2, InCl3·4H2O and thioacetamide is 1:2:

4.

8. The application of a catalyst prepared by the photocatalytic material as described in claim 1 or by the method of preparing the photocatalytic material as described in any one of claims 2-7 in the photocatalytic generation of H2O2 under visible light.

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