A mofs derivative containing fe-o electronic bridge and preparation and application thereof

Abstract

The present application relates to the field of environmental catalysis technology, and relates to a MOFs derivative containing Fe-O electronic bridge and preparation and application thereof, and comprises the following steps: S1: dispersing zirconium metal salt and terephthalic acid in N, N-dimethylformamide organic solvent, acidizing, and performing hydrothermal reaction to obtain a MOFs material; S2: dissolving iron salt and the MOFs material synthesized in S1 in an organic solvent, heating the obtained solution to evaporation, drying, washing after drying, and then drying again to obtain the MOFs derivative containing Fe-O electronic bridge. Compared with the prior art, the MOFs derivative of the present application presents a regular octahedron shape and has a large specific surface area; under the irradiation of visible light, the MOFs derivative can efficiently degrade bisphenol A in water.

Description

Technical Field

[0001] This invention relates to the field of environmental catalysis technology, and in particular to a MOF derivative containing an Fe-O electron bridge and its preparation and application. Background Technology

[0002] In recent years, due to the over-reliance on and abuse of chemical fertilizers, pesticides, and antibiotics, large amounts of untreated industrial and agricultural wastewater and domestic sewage containing phenols have been discharged into rivers, lakes, and oceans. This has led to a sharp increase in the concentration of phenolic pollutants in natural aquatic environments, making them difficult to degrade naturally in a timely manner, thus posing a significant threat to environmental safety and ecosystems. MOF (metal-organic framework) catalysts, due to their unique structural characteristics and tunability, have been widely studied and applied in the field of photocatalytic degradation.

[0003] MOFs have become a research hotspot in applications such as water splitting for hydrogen production, CO2 reduction, and degradation of organic pollutants. These materials have great potential in the field of photoelectrocatalysis due to their high specific surface area, abundance of metal / organic ligands, large pore volume, and tunable structure and composition. According to previous reports, MOFs used for photocatalysis include: (1) Amino-modified Fe / Cu-MOF: Studies have shown that the introduction of amino groups can significantly improve the photocatalytic performance of MOF catalysts, especially in the degradation of organic dyes such as Rhodamine B. (2) MOF composites based on POMs (polyoxometalates): These composites can enhance the photocatalytic degradation of organic pollutants in the aqueous phase, providing an important method to adjust the photocatalytic activity of MOFs. (3) MOFs / g-C3N4 composite photocatalysts: Composite photocatalysts formed by combining MOFs with graphitic carbon nitride (g-C3N4) have been studied for hydrogen production, CO2 reduction, Cr reduction, and degradation of organic pollutants due to their excellent photocatalytic performance.

[0004] However, MOF derivatives exhibit weak water stability, and most are nanoscale in size, making them prone to damage or loss during water treatment and limiting their long-term recyclability. Furthermore, modifications to MOFs still present some limitations. For instance, the utilization rate of H2O2 in the water treatment process involving Fe-based MOFs-activated degradation of bisphenol A is low; and the process relies on ultraviolet light, exhibiting low utilization of visible light.

[0005] UiO-66 is a zirconium (Zr)-based metal-organic framework (MOF) material. Due to its ultra-large specific surface area, excellent pore structure, and flexible tunability, it shows great promise for applications in catalysis, functional materials, and adsorption. The excellent chemical, mechanical, thermal, and water stability of the UiO-66 series of MOFs greatly enhances their prospects for practical applications. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of the existing technology and provide a MOF derivative containing Fe-O electron bridges, as well as its preparation and application. This invention addresses the deficiencies of current methods for constructing Fe-O electron bridge MOFs in terms of preparation methods, structural regulation, degradation efficiency, and visible light utilization, and provides a simple, easy-to-implement, structurally stable, and highly efficient method for constructing MOF derivatives containing Fe-O electron bridges and its preparation method.

[0007] The objective of this invention can be achieved through the following technical solutions:

[0008] A method for preparing MOF derivatives containing Fe-O electron bridges includes the following steps:

[0009] Iron salts and MOF materials are mixed in an organic solvent, and the resulting mixture is heated to react until the solvent evaporates and is dried. After drying, the mixture is washed and then dried again to obtain MOF derivatives containing Fe-O electron bridges.

[0010] Furthermore, the iron salt includes one of ferric chloride, ferric sulfate, or ferric nitrate.

[0011] Furthermore, the mass ratio of the iron salt to the MOF material is 1-1.5:1.

[0012] Furthermore, the heating reaction is carried out at a temperature of 70-90°C for 8-12 hours, preferably at 80°C for 12 hours.

[0013] Furthermore, the preparation process of the MOFs material includes: dispersing zirconium metal salt and terephthalic acid in N,N-dimethylformamide organic solvent, acidifying, and carrying out a solvothermal reaction to obtain the MOFs material.

[0014] Furthermore, the mass ratio of the zirconium metal salt to terephthalic acid is (1-2):1.

[0015] Furthermore, the temperature of the solvothermal reaction is 100-200℃, and the reaction time is 24-30h.

[0016] A MOF derivative containing Fe-O electron bridges was prepared by the above-described preparation method, wherein the MOF derivative has an octahedral structure and a particle size of 0.55-1.1 μm.

[0017] Application of a MOF derivative containing an Fe-O electron bridge for the removal of bisphenol A from polluted water.

[0018] Furthermore, this includes the following steps:

[0019] MOF derivatives, hydrogen peroxide, and bisphenol A-contaminated water were mixed and subjected to a degradation reaction under light.

[0020] The amounts of MOF derivatives added per liter of polluted water are 0.1 mg to 1.0 mg; hydrogen peroxide added per liter of polluted water is 0.2 mmol to 2.0 mmol; the initial concentration of bisphenol A in the polluted water is 1 mg / L to 100 mg / L; the initial pH value of the polluted water is 3.0 to 11.0; and the wavelength of light used during illumination is 390 nm to 780 nm.

[0021] A MOF derivative containing Fe-O electron bridges, wherein the MOF derivative has a regular octahedral structure and a particle size of 0.55-1.1 μm.

[0022] Application of a MOF derivative containing an Fe-O electron bridge for the removal of bisphenol A from polluted water.

[0023] Furthermore, this includes the following steps:

[0024] MOF derivatives, hydrogen peroxide, and bisphenol A-contaminated water were mixed and subjected to a degradation reaction under light.

[0025] The amounts of MOF derivatives added per liter of polluted water are 0.1 mg to 1.0 mg; hydrogen peroxide added per liter of polluted water is 0.2 mmol to 2.0 mmol; the initial concentration of bisphenol A in the polluted water is 1 mg / L to 100 mg / L; the initial pH value of the polluted water is 3.0 to 11.0; and the wavelength of light used during illumination is 390 nm to 780 nm.

[0026] This invention employs a strategy to improve the photocatalytic performance of UiO-66 through defect engineering. By introducing defect sites, the photoelectric properties of UiO-66 can be altered, increasing its light absorption and improving charge separation efficiency. This provides additional advantages for iron loading, as the defect sites can serve as anchoring sites for iron nanoparticles. Modification of UiO-66 includes the selection of metal nodes, functionalization of organic linkers, defect engineering, and foreign metal loading, among which foreign metal loading involves loading metals such as iron onto UiO-66 to enhance photocatalytic performance.

[0027] Compared to previously reported catalysts, UiO-66 supported on iron introduces an Fe-O electron bridge. The Fe sites accept photogenerated electrons from the conduction band and react with H₂O₂ to produce a large amount of ·OH. Simultaneously, electrons are transferred to Zr sites via the Fe-O electron bridge. The Zr sites accept photogenerated electrons and transfer them to oxygen molecules to generate ·O₂. - This improves the oxidation capacity of the entire reaction system. It not only enhances the light absorption capacity of UiO-66 but also strengthens the separation and transfer efficiency of its photogenerated charges, thereby improving photocatalytic performance.

[0028] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0029] 1) The Fe-O electron bridge MOF derivative constructed in this invention exhibits a loose and porous structure, with advantages such as large specific surface area, good conductivity, high stability, and strong visible light utilization. The iron sites can enhance the interaction between adjacent active sites of the MOF derivative and H2O2, which is beneficial to the Fe(III) / Fe(II) cycle structure, improves the degradation efficiency of bisphenol A, and can efficiently degrade bisphenol A in water, showing great application prospects in the field of catalysis.

[0030] 2) The preparation process of this invention is simple and convenient, and the chemical reagents used in this invention are all commonly used reagents, which are inexpensive and safe. Attached Figure Description

[0031] Figure 1 The images are scanning electron microscope (SEM) images of UiO-66 and Fe-UiO-66-1 synthesized in Example 1 of this invention.

[0032] Figure 2 The image shows the XRD pattern of Fe-UiO-66-X (X = 0.05-1) synthesized in Example 1 of this invention.

[0033] Figure 3 The image shows the photocatalytic degradation of Fe-UiO-66-X (X=0-2) synthesized in Example 1 of this invention.

[0034] Figure 4The UV-vis DRS image of Fe-UiO-66-X (X = 0.05-1) synthesized in Example 1 of this invention;

[0035] Figure 5 The image shows the photocatalytic degradation of Fe-UiO-66-1 synthesized in Example 1 of this invention at different pH values. Detailed Implementation

[0036] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0037] The following embodiments are implemented based on the above-described technical solution of the present invention, and provide detailed implementation methods and specific operation processes. However, the scope of protection of the present invention is not limited to the following embodiments.

[0038] The following are more detailed implementation examples, which further illustrate the technical solution of the present invention and the technical effects that can be obtained.

[0039] In the following embodiments, the prepared products were characterized structurally using the following methods: X-ray diffraction was performed on a RigakuSmartLab SE X-ray diffractometer (Japan); scanning electron microscope (SEM) images were obtained using a ZEISS Sigma 300 (Germany). The concentration of bisphenol A in the water was determined by high-performance liquid chromatography (HPLC) (carbon-18 column: 2.1 × 150 mm).

[0040] Example 1

[0041] This embodiment provides a MOF derivative containing an Fe-O electron bridge and its preparation.

[0042] Includes the following steps:

[0043] S1: Dissolve 700 mg zirconium chloride and 500 mg terephthalic acid in 60 mL DMF and 10 mL acetic acid to obtain clear solution A;

[0044] S2: Add solution A to the reaction vessel and heat it in a blast furnace at 120°C for 24 hours to obtain UiO-66;

[0045] S3: 0.05 g, 0.1 g, 0.5 g, 1 g, and 2 g of Fe2(SO4)3 were dissolved with 1 g of UiO-66 material in a three-necked flask containing 50 mL of methanol. The resulting solution was heated and stirred at 80 °C in an oil bath for 12 h. The flask was then dried in an oven at 60 °C for 12 h. After drying, the flask was removed and washed to remove excess iron from the surface, and then dried overnight in an oven to obtain the target product Fe-UiO-66-X (X = 0.05-2). The morphology of the obtained MOF derivatives containing Fe-O electron bridges was observed, as follows... Figure 1 As shown, (a) is the SEM image of UiO-66 and (b) is the SEM image of Fe-UiO-66-1. The images show that Fe-UiO-66-1 is octahedral with a particle size of 0.55-1.1 μm. Compared to UiO-66, Fe-UiO-66-1 has surface deposits, which are supported Fe particles. Figure 2 XRD patterns of UiO-66 and Fe-UiO-66-X (X = 0.05-1).

[0046] Application Example 1:

[0047] 0.2 g of the MOF derivative Fe-UiO-66-X (X = 0.1, 0.5, 1, 2) prepared in Example 1 and 2 mmol of hydrogen peroxide were added to 1 L of polluted water with an initial pH of 1 and an initial bisphenol A concentration of 10 mg / L. The degradation reaction was carried out in a 50 mL photoreactor under visible light using a xenon lamp (300 W). During the degradation reaction, the mixture was uniformly stirred using an electric mechanical stirrer, and the temperature was maintained at 25°C through water circulation. The mechanical stirring speed was 450 rpm, and the reaction time was 30 min. The results are as follows: Figure 3 As shown, the removal rates of bisphenol A by UiO-66 and Fe-UiO-66-X (X = 0.1, 0.5, 1, 2) in water were 10%, 65%, 100%, 100%, and 100%, respectively. Figure 4 The image shows the UV-vis diagrams of UiO-66 and Fe-UiO-66-X (X = 0.1, 0.5, 1, 2).

[0048] Application Example 2:

[0049] 0.2 g of the MOF derivative Fe-UiO-66-1 prepared in Example 1 and 2 mmol of hydrogen peroxide were added to 1 L of polluted water with an initial bisphenol A concentration of 10 mg / L and initial pH values ​​of 1, 3, 5, 7, 9, and 11, respectively. The degradation reaction was carried out in a 50 mL photoreactor under visible light using a xenon lamp (300 W). During the degradation reaction, the mixture was uniformly stirred using an electric mechanical stirrer, and the temperature was maintained at 25°C through water circulation. The mechanical stirring speed was 450 rpm, and the reaction time was 30 min. The results are as follows: Figure 5 As shown, when the initial pH values ​​were 3, 5, 7, and 9, the removal rate of bisphenol A by Fe-UiO-66-1 was 100%, when the initial pH value was 11, the removal rate of bisphenol A by Fe-UiO-66-1 was 12%, and when the initial pH value was 1, the removal rate of bisphenol A by Fe-UiO-66-1 was 90%.

[0050] The above description of the embodiments is provided to enable those skilled in the art to understand and use the invention. It will be apparent to those skilled in the art that various modifications can be made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present invention is not limited to the above embodiments, and any improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the invention should be within the protection scope of the present invention.

Claims

1. An application of a MOF derivative containing an Fe-O electron bridge, characterized in that, The method for preparing the MOF derivatives includes the following steps: Iron salts and MOF materials are mixed in an organic solvent. The resulting mixture is heated and reacted until the solvent evaporates and is dried. After drying, the mixture is washed and then dried again to obtain MOF derivatives containing Fe-O electron bridges. The iron salt is ferric sulfate, the MOF material is UIO-66, and the mass ratio of the iron salt to the MOF material is 1-1.5:

1. The MOFs derivatives have an octahedral structure and a particle size of 0.55-1.1 µm; The MOFs derivatives are used to remove bisphenol A from polluted water, including the following steps: MOF derivatives, hydrogen peroxide, and bisphenol A-contaminated water were mixed and subjected to a degradation reaction under light. The following parameters were specified: 0.2 g of MOF derivatives were added per liter of polluted water; 2.0 mmol of hydrogen peroxide was added per liter of polluted water; the initial concentration of bisphenol A in the polluted water was 10 mg / L; the initial pH of the polluted water was 3.0-9.0; and the wavelength of light used during illumination was 390 nm-780 nm.

2. The application of the MOFs derivative containing the Fe-O electron bridge according to claim 1, characterized in that, The heating reaction is carried out at a temperature of 70-90 °C for 8-12 h.

3. The application of the MOFs derivative containing the Fe-O electron bridge according to claim 1, characterized in that, The preparation process of the MOFs material includes: dispersing zirconium metal salt and terephthalic acid in N,N-dimethylformamide organic solvent, acidifying, and carrying out a solvothermal reaction to obtain MOFs material.

4. The application of the MOFs derivative containing the Fe-O electron bridge according to claim 3, characterized in that, The mass ratio of zirconium metal salt to terephthalic acid is (1~2):

1.

5. The application of the MOFs derivative containing the Fe-O electron bridge according to claim 3, characterized in that, The temperature of the solvothermal reaction is 100-200 °C, and the reaction time is 24-30 h.

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