Preparation method of Fe-based MOFs glass and its application in advanced oxidation

Abstract

The present invention discloses a preparation method of Fe-based MOFs glass and its application in advanced oxidation. ZIF-62 is obtained by reacting benzimidazole, imidazole and zinc nitrate; ZIF-62 is mixed with a precursor of Fe-N coordination structure, rapidly heated and vitrified, and then cooled and quenched to obtain FeMOFs glass. The FeMOFs glass of the present invention has an active center coordinated by Fe-N, a microstructure with long-range disorder and short-range order and its polarization electric field effect, and a pore confinement effect below 1.9nm, and exhibits an ultra-high degradation efficiency for organic pollutants in wastewater; at the same time, the nanopores enrich the pollutants and oxidants in the pores, thereby improving the utilization rate of free radicals and reducing the amount of oxidants used; in addition, it has a plastic fixed macromorphology and a multi-level pore structure of macropores, mesopores and micropores, can be directly applied in wastewater engineering and is easy to recycle, and has good application prospects.

Description

Technical Field

[0001] The present invention belongs to the research field of using functionalized catalysts for advanced oxidation technology to treat refractory organic pollutants in wastewater, and specifically relates to Fe-based MOFs glass (FeMOFs glass) and its preparation method and application. Background Art

[0002] In fields such as environmental catalysis, catalysts utilize complex active sites to catalyze the removal of organic pollutants from oxidants. This process, through the proton-coupled electron transfer (PCET) reaction, can achieve dramatic acceleration and unparalleled selectivity in pollutant removal, making it a key technology for developing greener, more efficient, and cleaner production.

[0003] The interdependence of proton and electron transfer in the conversion and removal of pollutants brings about a rich reaction mechanism. Through PCET, electrons and protons can be transferred simultaneously and the reactive intermediates only undergo a single reaction transition state, avoiding the formation of high-energy intermediates experienced in the step-by-step degradation pathway, thereby achieving the optimization of the reaction thermodynamics of the pollutant removal process. Therefore, appropriate electron transfer and proton transfer synergy play a core role in PCET. There have been many in-depth studies on the regulation of individual electron transfer processes, such as orbital hybridization to enhance metallicity to promote electron transfer efficiency, built-in electric field to promote interfacial electron directional transfer, etc. However, research on proton transfer processes is still in its infancy. Some researchers have found that the deprotonation process of (100)-oriented double perovskite phase oxides is most likely to occur, resulting in better proton-electron coupling transfer processes observed in the electrochemical tests and calculation results of this orientation. Other scholars have constructed vertical heterostructures to coordinate hydrogen overflow and deprotonation processes. However, the inherent disadvantage of poor mass transfer efficiency of short-lived active hydrogen has not yet been overcome.

[0004] Studies have reported the design of high-surface-area MOFs materials for the catalytic degradation of organic pollutants. The photoelectrons generated by visible light excitation migrate rapidly in the porous MOFs structure. The porous structure with high specific surface area enables adsorption and degradation to proceed alternately, thereby achieving high catalytic performance. However, this clear crystal configuration results in a regular arrangement and alternating combination of active sites and adsorption sites, which cannot form an unbalanced coordination and charge distribution. This structure cannot simultaneously regulate the coordination of electron transfer and proton transfer at the catalytic reaction interface, resulting in the defect that electron and proton transfer cannot react synergistically (Li P, Kim S, Jin J, et al. Efficient photodegradation of volatile organic compounds by iron-based metal-organic frameworks with high adsorption capacity [J]. Applied Catalysis B: Environmental, 2020, 263: 118-284.). Summary of the Invention

[0005] Metal-organic frameworks (MOFs) are popular crystalline materials with ordered structures. However, with the deepening of research, more and more people have come to realize that other unusual physical properties of this family of "soft crystal" materials are also worthy of attention, such as defects, framework flexibility and disorder. At higher temperatures and pressures, zeolitic imidazolate frameworks (ZIFs) can maintain a microporous structure like structurally similar zeolites. If the temperature and pressure are further increased, ZIFs will eventually undergo a phase transition and melt, and then form a new type of glass material after quenching, which contains an amorphous, SiO2-like continuous random network. This type of glass also "inherits" the chemical connectivity, coordination and composition of ZIFs. Therefore, ZIF-62-based MOFs glass has the structural characteristics of long-range order and short-range disorder, and the MOFs glass obtained by the melt-quenching method also has a high porosity. If Fe-N sites with high electron transfer activity are introduced into MOFs glass, the electron transfer process of inert glassy MOFs may be induced; in the glassy state, the ion channels exhibit isotropy, and the microporous nanopores can accelerate proton mass transfer at the nanoscale microscopic reaction interface. Therefore, the proton conduction of MOFs glass is faster, which is conducive to proton conduction to promote the proton-coupled electron transfer process.

[0006] The present invention aims to provide a method for preparing Fe-based MOFs glass (FeMOFs glass) and its application in advanced oxidation processes. The method involves mixing ZIF-62 with an Fe-N coordinated precursor, rapidly heating the mixture to a molten state, and then rapidly cooling and quenching the mixture to produce porous FeMOFs glass with macropores, mesopores, and micropores. The glass is then used in advanced oxidation processes to remove organic pollutants from water. The method utilizes a melt vitrification process, rapidly heating the mixture to a molten state without decomposing it, thereby disrupting the crystal structure of the material and producing a MOFs glass material with long-range disorder, short-range order, and multi-level pores. It has the following characteristics and functions: (1) Due to the long-range disorder and short-range order of the microstructure, the Fe-N coordination of MOFs glass as the active center can undergo electron transfer behavior, and the Fe-NC polarization electric field promotes electron transfer and induces the migration of charged protons at the interface, thereby regulating the proton-coupled electron transfer reaction; (2) Since the FeMOFsglass forms a macroscopic morphology structure after overall melting and quenching, it has good mechanical strength, so it can be easily recycled and reused in wastewater and easy to engineer; (3) Due to the confinement effect of the glassy MOFs pores, the mass transfer rate of pollutants, oxidants, and active species is accelerated, thereby improving the pollutant removal efficiency and oxidant utilization rate, and reducing costs. The most important thing is that the confinement effect of the nanopores below 1.9nm in MOFs glass can constrain protons within the Helmholtz layer of the double electric layer and accelerate their transfer, thereby greatly promoting the proton-coupled electron transfer reaction and showing ultra-high degradation efficiency for organic pollutants.

[0007] In order to achieve the above-mentioned purpose, the present invention adopts the following technical solutions.

[0008] A method for preparing Fe-based MOFs glass comprises the following steps:

[0009] (1) Preparation of ZIF-62: Add the metal salt Zn(NO3)2·6H2O and the organic ligands benzyl imidazole and imidazole to N,N-dimethylformamide (DMF) solvent and stir for 30-60 minutes. Transfer the prepared mixture to a polytetrafluoroethylene-lined autoclave and heat at 110-180°C for 24-60 hours. The product is washed with DMF, methanol, and water, purified, and vacuum-dried for 12-15 hours to obtain ZIF-62.

[0010] (2) Preparation of a mixture of ZIF-62 and Fe-N coordinated precursor: ZIF-62 and Fe-N coordinated precursor were mixed uniformly in a mortar to obtain a premixed precursor;

[0011] (3) Preparation of FeMOFs glass: The premixed precursor obtained in step (2) is placed in an inert gas atmosphere and maintained for 20-60 minutes to exclude oxygen, and then rapidly heated to 430-500°C at a heating rate of 10-20°C / min to melt it. After maintaining it for 20-60 minutes, it is rapidly cooled at a cooling rate of 150-250°C / h to vitrify it, thereby obtaining a glassy FeMOFs glass catalyst with Fe-N as the coordination center.

[0012] Furthermore, in step (1), the molar ratio of the amount of imidazole added to the amount of benzimidazole added is 4:1-1:2; the molar ratio of the amount of Zn(NO3)2·6H2O added to the sum of the amounts of imidazole and benzimidazole added is 1:1-1:5; and the molar ratio of the amount of N,N-dimethylformamide added to the amount of Zn(NO3)2·6H2O added is 200:1-50:1.

[0013] Furthermore, in step (2), the Fe-N coordination precursor is one or more of ZIF-8 (Zn, Fe), iron phthalocyanine, Fe-doped g-C3N4, Fe / N-doped graphene, Fe / N-doped carbon nanotubes, Fe / N-doped biomass, and Fe / N-doped biomass carbon.

[0014] Furthermore, in step (2), the mass ratio of ZIF-62 to Fe-N coordination precursor is 20:1-1:2.

[0015] Furthermore, the present invention provides FeMOFs glass prepared by the synthesis method, which has a long-range disordered and short-range ordered coordination structure, a nanopore confinement effect, and a macroscopic morphology structure.

[0016] The present invention also provides the application of the FeMOFs glass in advanced oxidation technology to remove organic pollutants in wastewater. The FeMOFs glass is added to wastewater containing organic pollutants, and then an oxidant is added, and the mixture is placed in a constant temperature shaking incubator for shaking reaction at a reaction temperature of 20-40°C.

[0017] Furthermore, the organic pollutants are new pollutants of the endocrine disruptor class, such as electron-donating phenol pollutants, including bisphenol A (BPA), rhodamine B, methyl orange, etc.

[0018] Furthermore, the oxidant is peroxydisulfate, peroxymonosulfate or H2O2.

[0019] Furthermore, the molar ratio of the organic pollutants to the oxidant is 10:1-1:200, the concentration of FeMOFs glass in the wastewater is 0.1 g / L-5.0 g / L, and the concentration of the organic pollutants in the wastewater is 0.5 mg / L-50 mg / L.

[0020] To address the problem of difficult degradation and removal of new pollutants during advanced wastewater treatment, the present invention discloses a method for preparing Fe-based MOFs glass and its application in treating organic pollutants in wastewater using advanced oxidation technology. The method for preparing Fe-based MOFs glass provided by the present invention has the following advantages and benefits:

[0021] (1) The present invention combines ZIF-62 with a Fe-N coordinated precursor for the first time to construct a glass-like MOFs catalyst with a long-range disorder and short-range order structure. The long-range disorder state of the catalyst makes its topological structure abnormal and has unique amorphous structural properties. The short-range order state based on this allows the formation of a polarization electric field between its local coordination structures, which can promote the directional transport of local electrons, thereby accelerating the Fe cycle of the active site and improving the catalytic performance and selectivity. Due to the long-range disorder and short-range order microstructure, the Fe-N coordination of the MOFs glass as the active center can undergo electron transfer behavior, and the Fe-NC polarization electric field promotes electron transport and induces the migration of charged protons at the interface, thereby regulating the proton-coupled electron transfer reaction.

[0022] (2) The FeMOFs glass provided by the present invention has a pore structure of less than 1.9 nm due to its glassification, so it can confine organic pollutants, oxidants, and active species in the pores, accelerate mass transfer, increase the probability of reaction collisions, and thus accelerate the reaction process. At the same time, the nanopores can prevent macromolecular impurities in wastewater from interfering with the catalytic degradation of organic pollutants, avoid the waste of oxidants and active species, and thus reduce costs. In addition, the pores smaller than 1.9 nm will locally overlap the interfacial double layer structure, thereby enriching hydrogen ions in the double layer and constructing an acidic microenvironment that can maintain the same good reaction effect as acidic solutions in neutral and alkaline solutions. The most important thing is the confinement effect of the nanopores below 1.9 nm in the FeMOFs glass, which can confine protons in the Helmholtz layer of the double layer and accelerate transfer, thereby greatly promoting the proton-coupled electron transfer reaction.

[0023] (3) The preparation method of FeMOFs glass provided by the present invention can directly obtain a catalyst with a macroscopic morphology structure, good mechanical strength and a multi-level pore structure of macropores, mesopores and micropores. It does not require catalyst loading, forming and other treatments and can be directly used in wastewater treatment projects, which is convenient for recycling, reuse and engineering.

[0024] (4) The preparation method of FeMOFs glass proposed in the present invention has simple equipment, mild reaction conditions, easy process control, and no need to add toxic and harmful reagents, which is convenient for the industrialization and engineering application of the catalyst. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a schematic diagram of the preparation principle of FeMOFs glass provided by the present invention.

[0026] Figure 2 This is the X-ray crystal diffraction pattern of FeMOFs glass.

[0027] Figure 3 This is a scanning electron microscope image of the FeMOFs glass catalyst ZIF-62(Fe)-4 in Example 1.

[0028] Figure 4 This is a Fourier transform infrared spectrum of the FeMOFs glass catalyst provided by the present invention.

[0029] Figure 5 This is a structural diagram of the long-range disorder and short-range order of the FeMOFs glass catalyst ZIF-62(Fe)-4.

[0030] Figure 6 This is the potential distribution diagram of the Fe-N coordination center of the FeMOFs glass catalyst ZIF-62(Fe)-4.

[0031] Figure 7 This is the electrochemical impedance spectroscopy diagram of the electron transfer performance of FeMOFs glass catalyst ZIF-62(Fe)-4.

[0032] Figure 8 This is the pore size distribution diagram of FeMOFs glass catalyst ZIF-62(Fe)-4.

[0033] Figure 9 This is the UV-visible-near-infrared absorption spectrum of FeMOFs glass catalyst ZIF-62(Fe)-4.

[0034] Figure 10 Efficiency diagram of FeMOFs glass catalysts prepared using different Fe-N coordination precursors for pollutant degradation.

[0035] Figure 11 This is the outer electron orbital distribution diagram of the FeMOFs glass catalyst ZIF-62(Fe) and the product of Comparative Example 1.

[0036] Figure 12 The X-ray crystal diffraction patterns of FeMOFs glass and several comparative examples are shown.

[0037] Figure 13 This is the catalytic degradation efficiency diagram of pollutants using FeMOFs glass catalyst ZIF-62(Fe).

[0038] Figure 14 This is a diagram of the active species masking experiment of FeMOFs glass catalyst ZIF-62(Fe)-4.

[0039] Figure 15 This is a quantitative detection diagram of active species in FeMOFs glass catalyst ZIF-62(Fe)-4.

[0040] Figure 16 This is a diagram showing the gain effect of FeMOFs glass catalyst ZIF-62(Fe)-4 in catalytic degradation of pollutants under sunlight.

[0041] Figure 17 This is the thermodynamic energy barrier diagram for the catalytic degradation of pollutants by FeMOFs glass catalyst ZIF-62(Fe)-4.

[0042] Figure 18 This is the macroscopic morphology of the FeMOFs glass catalyst ZIF-62(Fe)-4.

[0043] Figure 19 The adsorption capacity and specific surface area of FeMOFs glass catalyst ZIF-62(Fe)-4.

[0044] Figure 20 This is a diagram showing the catalytic degradation of different pollutants by FeMOFs glass catalyst ZIF-62(Fe). DETAILED DESCRIPTION

[0045] This invention provides a method for preparing Fe-based MOFs glass (FeMOFs glass) and its application in advanced oxidation processes. These methods address technical drawbacks of existing catalysts, including poor catalytic efficiency, poor active species selectivity, low electron transfer efficiency, lack of a stable macrostructure, difficulty recovering in wastewater, lack of pores smaller than 2 nm, and poor reaction performance in neutral and alkaline solutions. The FeMOFs glass prepared by this invention exhibits a long-range disordered, short-range ordered structure, pores smaller than 1.9 nm, and a stable macrostructure.

[0046] To solve the above technical deficiencies, the main ideas of the embodiments of the present invention are:

[0047] An embodiment of the present invention provides a method for preparing FeMOFs glass, comprising the following steps:

[0048] Providing an Fe precursor, wherein the Fe precursor includes an Fe-N coordinated material;

[0049] The Fe-N coordinated precursor and ZIF-62 are mixed in a mass ratio of 20:1-1:2 to obtain a mixture; the obtained mixture is rapidly heated to 430-500°C in an inert atmosphere at a heating rate of 10-20°C / min, maintained for 20-60 minutes, and then rapidly cooled at a cooling rate of 150-250°C / min to obtain FeMOFs glass. The principle of this preparation method is as follows Figure 1 As shown, ZIF-62 is combined with a Fe-N coordinated precursor, rapidly melted at high temperature, and then cooled and quenched to obtain a glass-like FeMOFs glass.

[0050] In the embodiment of the present invention, ZIF-62 and Fe-N coordinated precursors are mixed and then rapidly heated to a molten state, and then rapidly cooled to obtain glass-like FeMOFs. By combining the porous ZIF-62 material that can obtain an inert glass-like structure and the material with high catalytic activity Fe-N coordination, a catalyst with a macroscopic morphology structure, an overall inert and stable glassy state, and a high catalytic activity Fe-N center is finally obtained. The structure, morphology and properties of the prepared catalyst are characterized, and bisphenol A is used as a model pollutant to evaluate its catalytic performance in removing organic pollutants in water. The gain effect of the embodiment of the present invention is attributed to the long-range disorder and short-range order glassy structure in the FeMOFs glass, as well as the nanopore confinement effect less than 1.9 nm and the stable macroscopic morphology structure.

[0051] The FeMOFs glass provided by the present invention can catalyze oxidants to degrade organic pollutants in water. The catalyst achieved a degradation rate of 96% for bisphenol A and also achieved the expected degradation effect for other pollutants.

[0052] In order to make the above and other purposes, features, advantages and technical feasibility of the present invention more obvious and easy to understand, the embodiments of the present invention are described in detail below with reference to the accompanying drawings, but the implementation and protection of the present invention are not limited thereto.

[0053] Example 1

[0054] This embodiment provides a method for preparing FeMOFs glass, the main steps of which are as follows:

[0055] (1) Preparation of ZIF-62: 3 mM Zn(NO₃)₂·6H₂O, 6 mM imidazole, and 3 mM phenylimidazole were added to 50 mL of N,N-dimethylformamide (DMF) and stirred for 60 min. The mixture was transferred to a polytetrafluoroethylene-lined autoclave and heated at 130°C for 48 h. The product was washed with DMF, methanol, and water, purified, and vacuum-dried for 15 h to obtain ZIF-62.

[0056] (2) Preparation of ZIF-8(Zn,Fe): 4 g of 2-methylimidazole was dissolved in 60 mL of methanol, which was referred to as the first solution. 1.6 g of Zn(NO3)2·6H2O and 0.08 g of Fe(NO3)3·9H2O were dissolved in 20 mL of methanol, which was referred to as the second solution. The second solution was rapidly added dropwise to the first solution, stirred for 24 h, and then allowed to stand. The precipitate was separated and dried in vacuo at 60°C for 24 h to obtain ZIF-8(Zn,Fe).

[0057] (3) Preparation of premixed precursor: ZIF-62 and ZIF-8 (Zn, Fe) mixture were mixed uniformly in a mortar with a mass ratio of 1:1 to obtain a premixed precursor.

[0058] (4) Preparation of FeMOFs glass: The premixed precursor obtained in step (3) was placed in an inert gas atmosphere for 30 minutes to expel oxygen, then rapidly heated to 500°C at a rate of 10°C / min to melt it, held for 30 minutes, and then rapidly cooled at a cooling rate of 200°C / h to obtain a glass-like FeMOFs material, designated as g-ZIF-62(Fe)-4. Its crystal structure is as follows Figure 2 As shown in Figure 2, g-ZIF-62(Fe)-4 is amorphous, indicating that g-ZIF-62(Fe)-4 is a long-range disordered glass-like structure. Figure 3 As shown, it is an irregular amorphous structure.

[0059] Example 2

[0060] (1) Preparation of ZIF-62: 5 mM Zn(NO₃)₂·6H₂O, 10 mM imidazole, and 5 mM phenylimidazole were added to 60 mL of N,N-dimethylformamide (DMF) and stirred for 40 min. The mixture was transferred to a polytetrafluoroethylene-lined autoclave and heated at 150°C for 24 h. The product was washed with DMF, methanol, and water, purified, and vacuum-dried for 12 h to obtain ZIF-62.

[0061] (2) Preparation of ZIF-8(Zn,Fe): 4 g of 2-methylimidazole was dissolved in 60 mL of methanol, which was referred to as the first solution. 1.6 g of Zn(NO3)2·6H2O and 0.08 g of Fe(NO3)3·9H2O were dissolved in 20 mL of methanol, which was referred to as the second solution. The second solution was rapidly added dropwise to the first solution, stirred for 24 h, and then allowed to stand. The precipitate was separated and dried in vacuo at 60°C for 24 h to obtain ZIF-8(Zn,Fe).

[0062] (3) Preparation of premixed precursor: ZIF-62 and ZIF-8 (Zn, Fe) mixture was mixed uniformly in a mortar with a mass ratio of 1:2 to obtain a premixed precursor.

[0063] (4) Preparation of FeMOFs glass: The premixed precursor obtained in step (3) was placed in an inert gas atmosphere for 50 minutes to expel oxygen, and then rapidly heated to 500°C at a rate of 10°C / min to melt it. After holding for 30 minutes, it was rapidly cooled at a cooling rate of 200°C / h to obtain a glass-like FeMOFs glass material. It is denoted as g-ZIF-62(Fe)-5. Its ligand structure is as follows Figure 4 As shown in Figure 2, the coordination structure of FeMOFs glass is composed of Fe-N, C=N, methylimidazole, imidazole, and phenylimidazole coordination bonds, indicating that FeMOFs glass is still a short-range ordered coordination structure. Figure 5 As shown, with Fe-N4 as the center, metal and organic ligands are jointly composed, and the overall structure is irregular. Figure 6 It shows that this long-range disorder and short-range order coordination structure causes its local charge to shift, forming a polarization electric field, which can promote the directional transport of local electrons. Figure 7 The electrochemical impedance spectroscopy test shows that the electron transfer rate is significantly increased, which is beneficial to improve the efficiency of the catalytic reaction. Figure 8 As shown in the figure, most of the pores are micropores below 5nm, of which pores smaller than 1.9nm account for the largest proportion. The confinement effect brought by this nanopore can enrich pollutants, oxidants, and active species, enhance the mass transfer process, improve reaction efficiency, and reduce the amount of oxidants used, thereby reducing costs. In addition, Figure 9 It shows that this confinement effect can also enhance light absorption in the near-infrared region and has a plasmon effect, which can greatly promote light absorption and thus promote the catalytic degradation of organic pollutants.

[0064] Example 3

[0065] (1) Preparation of ZIF-62: 5 mM Zn(NO₃)₂·6H₂O, 10 mM imidazole, and 5 mM phenylimidazole were added to 60 mL of N,N-dimethylformamide (DMF) and stirred for 40 min. The mixture was transferred to a polytetrafluoroethylene-lined autoclave and heated at 150°C for 24 h. The product was washed with DMF, methanol, and water, purified, and vacuum-dried for 12 h to obtain ZIF-62.

[0066] (2) Preparation of ZIF-62 and Fe-N coordination mixture: ZIF-62 and iron phthalocyanine were mixed uniformly in a mortar at a mass ratio of 5:1 to obtain a premixed precursor.

[0067] (3) Preparation of FeMOFs glass: The premixed precursor obtained in step (2) was placed in an inert gas atmosphere for 50 minutes to expel oxygen, then rapidly heated to 500°C at a rate of 10°C / min to melt. After holding for 30 minutes, the mixture was rapidly cooled at a rate of 180°C / h to obtain FeMOFs glass material, designated as g-ZIF-62(Fe)(ferrophthalocyanine).

[0068] Example 4

[0069] (1) Preparation of ZIF-62: 5 mM Zn(NO₃)₂·6H₂O, 10 mM imidazole, and 5 mM phenylimidazole were added to 60 mL of N,N-dimethylformamide (DMF) and stirred for 40 min. The mixture was transferred to a polytetrafluoroethylene-lined autoclave and heated at 150°C for 24 h. The product was washed with DMF, methanol, and water, purified, and vacuum-dried for 12 h to obtain ZIF-62.

[0070] (2) Preparation of Fe-doped g-C3N4: Fe salt and cyanamide are uniformly mixed in a mortar and heated in a muffle furnace at a heating rate of 2-10°C / min to 450-550°C for 1-3 hours to obtain Fe-doped g-C3N4. The Fe salt can be one of FeCl3·6H2O, Fe(NO3)2·9H2O, or Fe(CH3COO2)·4H2O. The cyanamide precursor of g-C3N4 can be one of urea, dicyandiamide, or melamine. The mass ratio of Fe salt to cyanamide is 1:100-50:100.

[0071] (3) Preparation of ZIF-62 and Fe-N coordination mixture: ZIF-62 and Fe-doped g-C3N4 were mixed evenly in a mortar with a mass ratio of 5:1 to obtain a premixed precursor.

[0072] (4) Preparation of FeMOFs glass: The premixed precursor obtained in step (3) was placed in an inert gas atmosphere for 50 min to expel oxygen, then rapidly heated to 500°C at a rate of 10°C / min to melt. After holding for 30 min, it was rapidly cooled at a rate of 180°C / h to obtain FeMOFs glass material, designated as g-ZIF-62(Fe) (Fe-doped g-C3N4).

[0073] Example 5

[0074] (1) Preparation of ZIF-62: 5 mM Zn(NO₃)₂·6H₂O, 10 mM imidazole, and 5 mM phenylimidazole were added to 60 mL of N,N-dimethylformamide (DMF) and stirred for 40 min. The mixture was transferred to a polytetrafluoroethylene-lined autoclave and heated at 150°C for 24 h. The product was washed with DMF, methanol, and water, purified, and vacuum-dried for 12 h to obtain ZIF-62.

[0075] (2) Preparation of Fe / N-doped graphene and Fe / N-doped carbon nanotubes: Fe salt, nitrogen source, and graphene or carbon nanotubes are uniformly mixed in a mortar and placed in a muffle furnace and heated to 450-550°C at a heating rate of 2-10°C / min for 1-3 hours to obtain Fe / N-doped graphene or Fe / N-doped carbon nanotubes. The Fe salt can be one of FeCl3·6H2O, Fe(NO3)2·9H2O, and Fe(CH3COO2)·4H2O, and the nitrogen source precursor cyanamide can be one of urea, dicyandiamide, and melamine. The mass ratio of Fe salt to graphene or carbon nanotubes is 1:100-50:100.

[0076] (3) Preparation of ZIF-62 and Fe-N coordination mixture: ZIF-62 was mixed with Fe / N-doped graphene and Fe / N-doped carbon nanotubes in a mortar at a mass ratio of 5:1 to obtain a premixed precursor.

[0077] (4) Preparation of FeMOFs glass: The premixed precursor obtained in step (3) was placed in an inert gas atmosphere for 50 minutes to expel oxygen, and then rapidly heated to 500°C at a rate of 10°C / min to melt it. After holding for 30 minutes, it was rapidly cooled at a cooling rate of 180°C / h to obtain FeMOFs glass material. These materials were designated as g-ZIF-62(Fe) (Fe / N-doped graphene) and g-ZIF-62(Fe) (Fe / N-doped carbon nanotubes), respectively.

[0078] Example 6

[0079] (1) Preparation of ZIF-62: 5 mM Zn(NO₃)₂·6H₂O, 10 mM imidazole, and 5 mM phenylimidazole were added to 60 mL of N,N-dimethylformamide (DMF) and stirred for 40 min. The mixture was transferred to a polytetrafluoroethylene-lined autoclave and heated at 150°C for 24 h. The product was washed with DMF, methanol, and water, purified, and vacuum-dried for 12 h to obtain ZIF-62.

[0080] (2) Preparation of Fe / N-doped biomass carbon: Fe salt, nitrogen source, and biomass are uniformly mixed in a mortar and placed in a muffle furnace and heated to 450-550°C at a heating rate of 2-10°C / min for 1-3 hours to obtain Fe / N-doped biomass carbon. The Fe salt can be one of FeCl3·6H2O, Fe(NO3)2·9H2O, and Fe(CH3COO2)·4H2O. The nitrogen source precursor cyanamide can be one of urea, dicyandiamide, and melamine. The biomass can be one of sawdust, straw, waste paper, and discarded leaves. The mass ratio of Fe salt to biomass is 1:100-50:100.

[0081] (3) Preparation of ZIF-62 and Fe-N coordination mixture: ZIF-62 was mixed with Fe / N-doped biomass and Fe / N-doped biomass carbon in a mortar at a mass ratio of 5:1 to obtain a premixed precursor.

[0082] (4) Preparation of FeMOFs glass: The premixed precursor obtained in step (3) was placed in an inert gas atmosphere for 50 min to expel oxygen, then rapidly heated to 500°C at a rate of 10°C / min to melt. After holding for 30 min, the mixture was rapidly cooled at a rate of 180°C / h to obtain FeMOFs glass material, designated as g-ZIF-62(Fe) (Fe / N-doped biomass carbon).

[0083] The catalytic effects of the products prepared in Examples 1 to 6 on removing organic pollutants from water are as follows: Figure 10 As shown in the figure, more than 80% of bisphenol A can be removed within 30 minutes, indicating that various Fe-N coordination precursors such as ZIF-8 (Zn, Fe), iron phthalocyanine, Fe-doped g-C3N4, Fe / N-doped graphene, Fe / N-doped carbon nanotubes, Fe / N-doped biomass, and Fe / N-doped biomass carbon can be used to prepare FeMOFs glass for advanced oxidation reactions.

[0084] Example 7

[0085] This embodiment provides a method for preparing FeMOFs glass, the main steps of which are as follows:

[0086] (1) Preparation of ZIF-62: 1 mM Zn(NO₃)₂·6H₂O, 2 mM imidazole, and 1 mM phenylimidazole were added to 70 mL of N,N-dimethylformamide (DMF) and stirred for 30 min. The mixture was transferred to a polytetrafluoroethylene-lined autoclave and heated at 110°C for 60 h. The product was washed with DMF, methanol, and water, purified, and vacuum-dried for 12 h to obtain ZIF-62.

[0087] (2) Preparation of ZIF-8(Zn,Fe): 4 g of 2-methylimidazole was dissolved in 60 mL of methanol, which was referred to as the first solution. 1.6 g of Zn(NO3)2·6H2O and 0.08 g of Fe(NO3)3·9H2O were dissolved in 20 mL of methanol, which was referred to as the second solution. The second solution was rapidly added dropwise to the first solution, stirred for 24 h, and then allowed to stand. The precipitate was separated and dried in vacuo at 60°C for 24 h to obtain ZIF-8(Zn,Fe).

[0088] (3) Preparation of premixed precursor: ZIF-62 and ZIF-8 (Zn, Fe) mixture was mixed uniformly in a mortar with a mass ratio of 20:1 to obtain a premixed precursor.

[0089] (4) Preparation of FeMOFs glass: The premixed precursor obtained in step (3) was placed in an inert gas atmosphere for 50 min to expel oxygen, then rapidly heated to 500°C at a rate of 20°C / min to melt it, maintained for 30 min, and then rapidly cooled at a cooling rate of 150°C / h to obtain a glass-like FeMOFs material.

[0090] Example 8

[0091] This embodiment provides a method for preparing FeMOFs glass, the main steps of which are as follows:

[0092] (1) Preparation of ZIF-62: 3 mM Zn(NO₃)₂·6H₂O, 6 mM imidazole, and 3 mM phenylimidazole were added to 50 mL of N,N-dimethylformamide (DMF) and stirred for 60 min. The mixture was transferred to a polytetrafluoroethylene-lined autoclave and heated at 180°C for 24 h. The product was washed with DMF, methanol, and water, purified, and vacuum-dried for 12 h to obtain ZIF-62.

[0093] (2) Preparation of ZIF-8(Zn,Fe): 4 g of 2-methylimidazole was dissolved in 60 mL of methanol, which was referred to as the first solution. 1.6 g of Zn(NO3)2·6H2O and 0.08 g of Fe(NO3)3·9H2O were dissolved in 20 mL of methanol, which was referred to as the second solution. The second solution was rapidly added dropwise to the first solution, stirred for 24 h, and then allowed to stand. The precipitate was separated and dried in vacuo at 60°C for 24 h to obtain ZIF-8(Zn,Fe).

[0094] (3) Preparation of premixed precursor: ZIF-62 and ZIF-8 (Zn, Fe) mixture was mixed uniformly in a mortar with a mass ratio of 1:2 to obtain a premixed precursor.

[0095] (4) Preparation of FeMOFs glass: The premixed precursor obtained in step (3) was placed in an inert gas atmosphere for 30 min to expel oxygen, then rapidly heated to 430°C at a rate of 20°C / min to melt it, maintained for 60 min, and then rapidly cooled at a cooling rate of 250°C / h to obtain a glass-like FeMOFs material.

[0096] Example 9

[0097] This embodiment provides a method for preparing FeMOFs glass, the main steps of which are as follows:

[0098] (1) Preparation of ZIF-62: 3 mM Zn(NO₃)₂·6H₂O, 6 mM imidazole, and 3 mM phenylimidazole were added to 30 mL of N,N-dimethylformamide (DMF) and stirred for 30 min. The mixture was transferred to a polytetrafluoroethylene-lined autoclave and heated at 130°C for 60 h. The product was washed with DMF, methanol, and water, purified, and vacuum-dried for 15 h to obtain ZIF-62.

[0099] (2) Preparation of ZIF-8(Zn,Fe): 4 g of 2-methylimidazole was dissolved in 60 mL of methanol, which was referred to as the first solution. 1.6 g of Zn(NO3)2·6H2O and 0.08 g of Fe(NO3)3·9H2O were dissolved in 20 mL of methanol, which was referred to as the second solution. The second solution was rapidly added dropwise to the first solution, stirred for 24 h, and then allowed to stand. The precipitate was separated and dried in vacuo at 60°C for 24 h to obtain ZIF-8(Zn,Fe).

[0100] (3) Preparation of premixed precursor: ZIF-62 and ZIF-8 (Zn, Fe) mixture was mixed uniformly in a mortar with a mass ratio of 20:1 to obtain a premixed precursor.

[0101] (4) Preparation of FeMOFs glass: The premixed precursor obtained in step (3) was placed in an inert gas atmosphere for 30 min to expel oxygen, then rapidly heated to 480°C at a rate of 15°C / min to melt it, maintained for 30 min, and then rapidly cooled at a cooling rate of 150°C / h to obtain a glass-like FeMOFs material.

[0102] Comparative Example 1

[0103] (1) Preparation of ZIF-62: 4 mM Zn(NO₃)₂·6H₂O, 8 mM imidazole, and 4 mM phenylimidazole were added to 40 mL of N,N-dimethylformamide (DMF) and stirred for 20 min. The prepared mixture was transferred to a polytetrafluoroethylene-lined autoclave and heated at 140°C for 36 h. The product was washed with DMF, methanol, and water, purified, and vacuum-dried for 13 h to obtain ZIF-62.

[0104] (2) Preparation of MOFs glass: ZIF-62 was placed in an inert gas atmosphere for 50 minutes to expel oxygen, and then rapidly heated to 500°C at a rate of 15°C / min to melt it. After holding for 30 minutes, it was rapidly cooled at a cooling rate of 200°C / h to obtain a glass-like MOFs glass (g-ZIF-62glass). The outermost electron orbital distribution is as follows Figure 11 As shown, compared with g-ZIF-62(Fe) prepared in an embodiment of the present invention, g-ZIF-62glass has no Fe-N coordination center, and its outer electron orbits are less distributed near the Fermi level, which indicates that its metallicity is weak and its electron transition ability is weak, and it cannot effectively stimulate electron transition to catalyze oxidants and thus degrade organic pollutants.

[0105] Comparative Example 2

[0106] (1) Preparation of ZIF-62: 4 mM Zn(NO₃)₂·6H₂O, 8 mM imidazole, and 4 mM phenylimidazole were added to 40 mL of N,N-dimethylformamide (DMF) and stirred for 20 min. The prepared mixture was transferred to a polytetrafluoroethylene-lined autoclave and heated at 130°C for 48 h. The product was washed with DMF, methanol, and water, purified, and vacuum-dried for 13 h to obtain ZIF-62.

[0107] (2) Preparation of ZIF-8(Zn,Fe): 4 g of 2-methylimidazole was dissolved in 60 mL of methanol, which was referred to as the first solution. 1.6 g of Zn(NO3)2·6H2O and 0.08 g of Fe(NO3)3·9H2O were dissolved in 20 mL of methanol, which was referred to as the second solution. The second solution was rapidly added dropwise to the first solution, stirred for 24 h, and then allowed to stand. The precipitate was separated and dried in vacuo at 60°C for 24 h to obtain ZIF-8(Zn,Fe).

[0108] (3) Preparation of premixed precursor: ZIF-62 and ZIF-8 (Zn, Fe) mixture were mixed uniformly in a mortar with a mass ratio of 1:5 to obtain a premixed precursor.

[0109] (4) Preparation of FeMOFs: The premixed precursor obtained in step (3) was placed in an inert gas atmosphere to expel oxygen for 30 minutes. The temperature was then rapidly increased to 500°C at a rate of 10°C / min to melt the mixture. After holding the mixture for 30 minutes, the mixture was rapidly cooled at a rate of 200°C / h to obtain a crystalline, non-glassy FeMOF material. The ratio was denoted as ZIF-62:ZIF-8 = 1:5. Figure 12 The peaks characteristic of ZIF-8 decomposition dominate, rather than those of FeMOFs glass. This suggests that the ZIF-62 content is too low to form FeMOFs glass. This suggests that controlling the mixing ratio of ZIF-62 to the Fe-N coordination precursor within an appropriate range is crucial for preparing FeMOFs glass.

[0110] Comparative Example 3

[0111] (1) Preparation of ZIF-62: 4 mM Zn(NO₃)₂·6H₂O, 8 mM imidazole, and 4 mM phenylimidazole were added to 40 mL of N,N-dimethylformamide (DMF) and stirred for 20 min. The prepared mixture was transferred to a polytetrafluoroethylene-lined autoclave and heated at 130°C for 48 h. The product was washed with DMF, methanol, and water, purified, and vacuum-dried for 13 h to obtain ZIF-62.

[0112] (2) Preparation of ZIF-8(Zn,Fe): 4 g of 2-methylimidazole was dissolved in 60 mL of methanol, which was referred to as the first solution. 1.6 g of Zn(NO3)2·6H2O and 0.08 g of Fe(NO3)3·9H2O were dissolved in 20 mL of methanol, which was referred to as the second solution. The second solution was rapidly added dropwise to the first solution, stirred for 24 h, and then allowed to stand. The precipitate was separated and dried in vacuo at 60°C for 24 h to obtain ZIF-8(Zn,Fe).

[0113] (3) Preparation of premixed precursor: ZIF-62 and ZIF-8 (Zn, Fe) mixture were mixed uniformly in a mortar with a mass ratio of 1:1 to obtain a premixed precursor.

[0114] (4) Preparation of FeMOFs: The premixed precursor obtained in step (3) was placed in an inert gas atmosphere for 30 min to expel oxygen, and then rapidly heated to 400°C or 600°C at a rate of 10°C / min. After holding for 30 min, it was rapidly cooled at a rate of 200°C / h to obtain crystalline, non-glassy FeMOFs materials, designated as ZIF-62(Fe)400°C and ZIF-62(Fe)600°C, respectively. Figure 12The material heated at 400°C still retained the characteristic peaks of ZIF-62 and did not vitrify. The material heated at 600°C showed peaks of Fe compounds, indicating that the high temperature caused the FeMOFs glass to decompose. These results indicate that temperatures below 430°C prevent the FeMOFs from melting and vitrifying, preventing the formation of glassy FeMOFs glass. Temperatures above 500°C cause the FeMOFs to decompose. These results indicate that maintaining an appropriate heating temperature of 430-500°C is crucial for the successful preparation of FeMOFs glass.

[0115] Comparative Example 4

[0116] (1) Preparation of ZIF-62: 4 mM Zn(NO₃)₂·6H₂O, 8 mM imidazole, and 4 mM phenylimidazole were added to 40 mL of N,N-dimethylformamide (DMF) and stirred for 20 min. The prepared mixture was transferred to a polytetrafluoroethylene-lined autoclave and heated at 130°C for 48 h. The product was washed with DMF, methanol, and water, purified, and vacuum-dried for 13 h to obtain ZIF-62.

[0117] (2) Preparation of ZIF-8(Zn,Fe): 4 g of 2-methylimidazole was dissolved in 60 mL of methanol, which was referred to as the first solution. 1.6 g of Zn(NO3)2·6H2O and 0.08 g of Fe(NO3)3·9H2O were dissolved in 20 mL of methanol, which was referred to as the second solution. The second solution was rapidly added dropwise to the first solution, stirred for 24 h, and then allowed to stand. The precipitate was separated and dried in vacuo at 60°C for 24 h to obtain ZIF-8(Zn,Fe).

[0118] (3) Preparation of premixed precursor: ZIF-62 and ZIF-8 (Zn, Fe) mixture were mixed uniformly in a mortar with a mass ratio of 1:1 to obtain a premixed precursor.

[0119] (4) Preparation of FeMOFs: The premixed precursor obtained in step (3) was placed in an inert gas atmosphere to expel oxygen for 30 minutes, then heated to 500°C at a rate of 5°C / min. After holding for 30 minutes, it was rapidly cooled at a rate of 200°C / h to obtain a crystalline, non-glassy FeMOF material. This was designated as ZIF-62(Fe)5°C / min. Figure 12 The material also shows the diffraction peak of ZIF-62 crystal, indicating that a heating rate lower than 10℃ / min will cause FeMOFs to fail to vitrify and form glassy FeMOFs glass. This shows that rapid quenching with a heating rate of more than 10℃ / min is the key to the successful preparation of FeMOFsglass.

[0120] Application Example 1

[0121] Application Example 1 compares the catalytic degradation performance of ZIF-62 and FeMOFs glass in organic pollutants.

[0122] According to the preparation method of the present invention, FeMOFs glass prepared by selecting ZIF-62 and ZIF-8 (Zn, Fe) in a mass ratio of 10:0, 10:1, 10:2, 10:5, 1:1, and 1:2, namely ZIF-62glass (Comparative Example 1), g-ZIF-62(Fe)-1, g-ZIF-62(Fe)-2, g-ZIF-62(Fe)-3, g-ZIF-62(Fe)-4, and g-ZIF-62(Fe)-5, explore the catalytic degradation performance of organic pollutants by ZIF-62(Fe)-4 prepared in Example 1. The catalyst concentration is 0.5 g / L, the pollutant (bisphenol A) concentration is 5 g / L, and the oxidant concentration is 200 mg / L. Different catalysts are added to 50 mL of the above mixed solution, and the reaction solution is placed in stirring and mixing. The speed is controlled at 500 rpm and the temperature is 25 ° C. Sampling and detection are carried out at different time nodes of the reaction.

[0123] The degradation performance of the above catalysts on pollutants is as follows Figure 13 As shown, g-ZIF-62(Fe)-4 can achieve a degradation rate of 86% for the target pollutant bisphenol A, while ZIF-62glass, g-ZIF-62(Fe)-1, g-ZIF-62(Fe)-2, g-ZIF-62(Fe)-3, and g-ZIF-62(Fe)-5 also have degradation rates of 2%, 8%, 23%, 47%, and 77%, respectively. This indicates that the FeMOFsglass prepared by the present invention has good catalytic performance. The degradation rate of ZIF-62(Fe)glass for pollutants is very low, with almost no pollutants being degraded within 60 minutes, indicating that MOFs glass without Fe-N coordination centers cannot effectively remove organic pollutants in water, reflecting the benefit of mixing ZIF-62 with Fe-N coordination precursors in the present invention.

[0124] Application Example 2

[0125] Application Example 2 studies the main active species of the g-ZIF-62(Fe)-4 catalyst prepared in Example 1 in catalytic degradation of organic pollutants.

[0126] The g-ZIF-62 (Fe) -4 catalyst prepared in Example 1 is explored for its main active species in degrading pollutants by adding quenchers of different active species. The applied simulated sunlight wavelength range is 400-2200nm, the catalyst concentration is 0.5g / L, the pollutant concentration is 5g / L, the oxidant concentration is 200mg / L, the quencher is 100mM, and g-ZIF-62 (Fe) -4 catalyst is added to 50mL of the above mixed solution, and the reaction solution is placed in a beaker container mixed by magnetic stirring, the speed is controlled at 500rpm, the temperature is 25°C, and sampling is performed at different reaction time nodes. Ethanol (EtOH) can quench the hydroxyl radical and sulfate radical in the system, N2 can exclude dissolved oxygen in the reaction system, and disodium ethylenediaminetetraacetic acid (EDTA) can quench the holes in the reaction system. Figure 14 The results showed that neither EtOH nor EDTA had an inhibitory effect on pollutant removal, and only N2 showed a significant inhibitory effect, which indicates that hydroxyl radicals, sulfate radicals, and holes are not the main active species for pollutant degradation, and dissolved oxygen may be the active species involved in pollutant degradation. In addition, dimethyl sulfoxide was used as a molecular probe to detect Fe(IV)=O in the reaction system. Figure 15 The results showed that the specific product of Fe(IV)=O oxidation of dimethyl sulfoxide was obviously produced, indicating that Fe(IV)=O may be the main active species for pollutant degradation.

[0127] Application Example 3

[0128] Application Example 3 Comparison of the Gain Effect of Sunlight on Pollutant Degradation of the g-ZIF-62(Fe)-4 Catalyst Prepared in Example 1 under Sunlight

[0129] By irradiating simulated sunlight, the gain effect of the g-ZIF-62(Fe)-4 catalyst prepared in Example 1 on the degradation of pollutants under light was explored. The wavelength range of the applied simulated sunlight was 400-2200nm, the catalyst concentration was 0.5g / L, the pollutant concentration was 5g / L, and the oxidant concentration was 200mg / L. The g-ZIF-62(Fe)-4 catalyst was added to 50mL of the above mixed solution, and the reaction solution was placed in a beaker container with magnetic stirring and mixing. The speed was controlled at 500rpm and the temperature was 25°C. Sampling and detection were carried out at different time points of the reaction. The results are as follows. Figure 16 As shown in Figure 2, the degradation rate of pollutants under sunlight conditions was significantly increased to 0.0332 min. -1 Compared with the condition without light, the degradation rate increased by 3.7 times. In addition, when there is only light without oxidant, the degradation efficiency of pollutants is not high, only 0.00385min -1These results indicate that sunlight can enhance the catalytic degradation of organic pollutants by oxidants by this catalyst, by photoexciting the catalyst to produce photogenerated electrons and holes, where the photogenerated electrons can promote Fe cycling and reduce the oxidants to produce active species to enhance pollutant degradation.

[0130] Application Example 4

[0131] Application Example 4 confirms the influence of the pore confinement effect of the g-ZIF-62(Fe)-4 catalyst prepared in Example 1 of the present invention and the polarization electric field promoting electron / proton transfer on the energy barrier of catalytic degradation of pollutants.

[0132] The Fe-N4-centered catalyst was structurally optimized together with peroxydisulfate, and the transition state was retrieved and the energy barriers of the reactants, products, and transition states were calculated using Gaussian 09. Figure 17 As shown in the figure, due to the confinement effect of the nanopores and the regulation of the polarization electric field, the reaction energy barrier is reduced from 1.54eV to 0.51eV, and the product energy is also reduced from -0.028eV to -0.92eV. This shows that the nanopore confinement effect of FeMOFs glass and the polarization electric field regulation of active species such as electrons and protons can synergistically significantly reduce the thermodynamic reaction energy barrier, thereby enhancing the catalytic degradation reaction of pollutants.

[0133] Application Example 5

[0134] Application Example 5 confirms that the g-ZIF-62(Fe)-4 catalyst prepared in Example 1 of the present invention has a glass-like state with high mechanical strength and porous macroscopic morphology after preparation.

[0135] The g-ZIF-62(Fe)-4 catalyst prepared in Example 1 was taken out to directly obtain a catalyst having a macroscopic morphology structure, such as Figure 18 As shown, the catalyst has a macroscopic shape and millimeter-scale macropores visible to the naked eye. Combined with the pore size distribution results, it can be found that it has a multi-level pore structure of macropores-mesopores-micropores (micropore diameter <2nm; mesopore diameter 2~50nm; macropore diameter >50nm). Figure 19 The FeMOFs glass multi-level pore structure has a large adsorption capacity and a high specific surface area (13.5474m 2 / g), demonstrating its excellent pollutant adsorption capacity. Therefore, the FeMOFs glass preparation method provided by the present invention can directly produce a macroscopic catalyst without further complex operations such as catalyst shaping and loading. This catalyst can be directly used in wastewater treatment projects and is easy to recover.

[0136] Application Example 6

[0137] Application Example 6 confirms that the g-ZIF-62(Fe)-4 catalyst prepared in Example 1 of the present invention has excellent removal effect on various organic pollutants in water.

[0138] The g-ZIF-62(Fe)-4 catalyst prepared in Example 1 was used to catalyze the degradation of organic pollutants by peroxydisulfate under light. Figure 19 As shown, bisphenol A, rhodamine B, and methyl orange were all rapidly degraded, with degradation rates of 79%, 92%, and 97%, respectively. Therefore, the FeMOFs glass provided by the present invention can be directly used to remove various organic pollutants in water without the need for special treatment, with good treatment effects and easy recycling.

[0139] Although preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they are aware of the basic inventive concepts. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the invention. Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the invention. Thus, the present invention is intended to include such changes and modifications as fall within the scope of the claims and their equivalents.

Claims

1. A method for preparing Fe-based MOFs glass, characterized in that: The steps include: (1) Preparation of ZIF-62: Metal salt Zn(NO3)2·6H2O and organic ligands benzyl imidazole and imidazole were added to N,N-dimethylformamide solvent and stirred. The mixture was transferred to an autoclave and heated. The product was washed with N,N-dimethylformamide, methanol, and water, respectively, and dried to obtain ZIF-62. (2) ZIF-62 and Fe-N coordinated precursors were mixed uniformly in a mortar to obtain a premixed precursor; (3) placing the premixed precursor in an atmosphere furnace with an inert gas atmosphere, rapidly heating it to a molten state, and then rapidly cooling and quenching it to vitrify it, thereby obtaining a glassy FeMOFs glass catalyst with Fe-N as the coordination center; In step (2), the mass ratio of ZIF-62 to Fe-N coordination precursor is 20:1-1:2; In step (3), the rapid heating rate is 10-20°C / min; the heating temperature is 430-500°C.

2. The method for preparing Fe-based MOFs glass according to claim 1, wherein: The Fe-N coordination precursor in step (2) is one or more of ZIF-8 (Zn, Fe), iron phthalocyanine, Fe-doped g-C3N4, Fe / N-doped graphene, Fe / N carbon nanotubes, Fe / N-doped biomass, and Fe / N-doped biomass carbon; the inert gas in step (3) is one of nitrogen and argon.

3. The method for preparing Fe-based MOFs glass according to claim 1, wherein: In step (1), the molar ratio of the benzimidazole to the imidazole is 2:1-1:4; the molar ratio of the organic ligand to the metal salt is 5:1-1:1; and the molar ratio of the metal salt to the N,N-dimethylformamide solvent is 1:50-1:

200.

4. The method for preparing Fe-based MOFs glass according to claim 1, wherein: In step (1), the stirring time in the solvent is 30-60 minutes; the temperature of the high-pressure reactor is set at 110-180° C., and the heating time is 24-60 hours.

5. The method for preparing Fe-based MOFs glass according to claim 1, wherein: In step (3), the time for passing the inert gas is 20-60 min; the heating time is 20-60 min; and the cooling rate is 150-250° C. / h.

6. Fe-based MOFs glass prepared by the preparation method according to any one of claims 1 to 5.

7. Use of the Fe-based MOFs glass according to claim 6 in removing organic pollutants in water using advanced oxidation technology.

8. The use according to claim 7, characterized in that Fe-based MOFs glass is added to wastewater containing organic pollutants, and then an oxidant is added, mixed and reacted, and the reaction temperature is 20-40°C.

9. The use according to claim 7, characterized in that The advanced oxidation technology is a peroxodisulfate system, a peroxomonosulfate system or an H2O2 system; the added oxidant is sodium peroxodisulfate, potassium hydrogen peroxomonosulfate or H2O2; the organic pollutants are electron-donating phenol pollutants; the molar ratio of the organic pollutants to the oxidants is 10:1-1:200; the concentration of Fe-based MOFs glass in the wastewater is 0.1g / L-5.0g / L, and the concentration of organic pollutants in the wastewater is 0.5mg / L-50mg / L.

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