A metal-organic framework material and its preparation method and application

Abstract

The present invention belongs to the technical field of metal-organic framework materials, and specifically relates to a metal-organic framework material and a preparation method and application thereof. The metal-organic framework material of the present invention is Fe x Cr 3‑x O(BDC)3F y (H2O) 3‑y , wherein BDC is terephthalic acid, x is 2.0-2.4, y is 1.0-1.5, and the material is prepared by a hydrothermal method in one step using stainless steel pickling wastewater and PET plastic. The present invention uses stainless steel pickling wastewater and waste PET plastic as raw materials, fully utilizes metal ions (Fe and Cr), inorganic acids (nitric acid and hydrofluoric acid), water and waste PET plastic in stainless steel pickling wastewater, and realizes the simple synthesis of MOFs by a hydrothermal method in one step, which not only realizes efficient resource utilization of waste, but also reduces the synthesis cost of MOFs materials, and has positive significance for the large-scale synthesis and industrialization progress of MOFs.

Description

Technical Field

[0001] The present invention belongs to the technical field of metal-organic framework materials, and in particular relates to a metal-organic framework material and a preparation method and application thereof. Background Art

[0002] Metal-Organic Frameworks (MOFs) are a new type of porous functional material that has emerged in recent years. Due to their special spatial continuous skeleton structure, MOFs materials have shown a wide range of application value in many fields such as adsorption and separation, catalysis, biomedicine, and sensing. However, the high synthesis cost of MOFs is still the main factor restricting its large-scale production. The raw materials for synthesizing MOFs generally include metal ions, organic ligands, solvents, and inorganic acids. The existing MOFs synthesis raw materials mainly use commercial reagents. Due to their high cost, most MOFs applications remain in the laboratory stage and cannot be applied on a large scale.

[0003] my country is a major stainless steel producer. The components of pickling wastewater generated during stainless steel production mainly include nitric acid, hydrofluoric acid and high concentrations of heavy metal ions such as iron, chromium and nickel. my country's resource utilization of stainless steel pickling wastewater is limited: first, simply recovering metals such as iron in wastewater is of little significance and has high costs. Second, even the method of using wastewater as raw materials to prepare metal oxides or metal salts still lacks economic benefits. With the rise of high value-added materials, stainless steel pickling wastewater has the potential to become one of the raw materials for the synthesis of metal-organic framework materials due to its high concentration of metal ions and acidic properties.

[0004] In addition, my country is also a major user of plastics. Among the many types of plastics, polyethylene terephthalate (PET) is the polyester plastic with the largest current production volume. With the rapid development of the PET industry, the amount of waste PET is increasing day by day. PET can be decomposed under certain conditions to obtain monomers of ethylene glycol and terephthalic acid, the latter of which can be used as an important organic synthetic raw material for metal-organic framework materials.

[0005] In view of this, it is urgent to develop a method that can efficiently utilize stainless steel pickling wastewater and waste PET plastics to successfully synthesize MOFs materials. Summary of the invention

[0006] Based on the above background, the present invention provides a metal-organic framework material and a preparation method and application thereof to solve the problem of high synthesis cost of MOFs in the prior art.

[0007] To achieve the above object, the present invention is implemented through the following technical solutions:

[0008] The present invention provides a metal-organic framework material Fe x Cr 3-x O(BDC) 3 F y (H 2 O) 3-y , wherein BDC is terephthalic acid, x is 2.0 to 2.4, and y is 1.0 to 1.5.

[0009] Preferably, the metal-organic framework material is composed of rod-shaped particles with a length of 1 to 8 μm and a BET specific surface area of ​​10 to 35 m 2 / g, pore volume is 0.09~0.14cm 3 / g. The metal-organic framework material under this preferred embodiment has excellent zirconium ion adsorption performance.

[0010] The present invention also provides a method for preparing the metal-organic framework material, which uses stainless steel pickling wastewater and PET plastic to prepare the metal-organic framework material in one step through a hydrothermal method. In this technical solution, since the stainless steel pickling wastewater contains high concentrations of Fe and Cr ions, nitric acid, hydrofluoric acid, etc., it not only solves the source of metal ions and solvents (water), but also provides a strong acidic environment to smoothly hydrolyze PET into terephthalic acid, and then synthesize MOFs.

[0011] Preferably, the volume ratio of the mass of the PET plastic to the stainless steel pickling wastewater is 50 to 300 g / L.

[0012] Preferably, the hydrothermal reaction temperature is 200-220° C., and the reaction time is 12-36 hours.

[0013] The present invention also provides application of the metal-organic framework material in treating wastewater containing zirconium ions.

[0014] Preferably, the application specifically comprises: adding metal-organic framework material to wastewater containing zirconium ions, adsorbing in a constant temperature shaker, and measuring the zirconium ion concentration in the solution after filtering through a filter membrane.

[0015] Preferably, the rotation speed of the constant temperature shaker is 155 rpm, the temperature is 303 K, and the adsorption time is 24 h.

[0016] Preferably, the amount of the metal-organic framework material is 5 mg, the volume of the zirconium ion solution is 10 mL, and the concentration of the zirconium ion solution is 10 mg / L.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] (1) The present invention uses stainless steel pickling wastewater and waste PET plastic as all raw materials, water in the wastewater as solvent, iron chromium ions as metal sources, inorganic acid as regulator and PET degradation catalyst, and PET decomposition monomer terephthalic acid as organic ligand to prepare MOF materials in one step through a hydrothermal method, thus truly realizing the full waste synthesis of MOF materials. The present invention not only realizes the efficient resource utilization of waste, but also reduces the synthesis cost of MOF materials, which has positive significance for the large-scale synthesis and industrialization progress of MOFs.

[0019] (2) The traditional method of preparing MOF materials using PET as raw material includes two steps: the first step is to decompose PET into terephthalic acid in a strong acid or strong base environment; the second step is to use the collected terephthalic acid to react with metal ions to prepare MOF materials. Compared with the traditional method, the present invention combines the PET hydrolysis reaction and the MOF synthesis reaction into one under hydrothermal conditions by taking advantage of the strong acidity of stainless steel pickling wastewater, which greatly reduces the operation difficulty and reaction time and improves the preparation efficiency.

[0020] (3) The metal-organic framework material prepared in the present invention has good zirconium ion adsorption performance. At room temperature, the removal rate of 10 mg / L zirconium ions can reach more than 95% within 24 hours. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is the XRD spectrum of the metal-organic framework material of Example 1 of the present invention;

[0022] Figure 2 This is a SEM image of the metal-organic framework material of Example 1 of the present invention;

[0023] Figure 3 This is the nitrogen adsorption-desorption curve of the metal-organic framework material of Example 1 of the present invention at 77K;

[0024] Figure 4 This is a diagram showing the adsorption effect of the metal-organic framework material on zirconium ions in Example 1 of the present invention;

[0025] Figure 5 This is the XRD spectrum of the metal-organic framework material of Example 2 of the present invention;

[0026] Figure 6 This is a SEM image of the metal-organic framework material of Example 2 of the present invention;

[0027] Figure 7 This is the nitrogen adsorption-desorption curve of the metal-organic framework material of Example 2 of the present invention at 77K;

[0028] Figure 8 This is a diagram showing the adsorption effect of the metal-organic framework material on zirconium ions according to Example 2 of the present invention;

[0029] Fig. 9 This is the XRD spectrum of the metal-organic framework material of Example 3 of the present invention;

[0030] Fig.10 This is a SEM image of the metal-organic framework material of Example 3 of the present invention;

[0031] Fig.11 This is the nitrogen adsorption-desorption curve of the metal-organic framework material of Example 3 of the present invention at 77K;

[0032] Fig.12 This is a diagram showing the adsorption effect of the metal-organic framework material on zirconium ions in Example 3 of the present invention;

[0033] Fig.13 This is the XRD spectrum of the metal-organic framework material of Example 4 of the present invention;

[0034] Fig.14 This is a SEM image of the metal-organic framework material of Example 4 of the present invention;

[0035] Fig.15 This is the nitrogen adsorption-desorption curve of the metal-organic framework material of Example 4 of the present invention at 77K;

[0036] Fig.16 This is a diagram showing the adsorption effect of the metal-organic framework material of Example 4 of the present invention on zirconium ions. DETAILED DESCRIPTION

[0037] The examples described below are implemented based on the technical solution of the present invention, and provide detailed implementation methods and specific operating procedures, but do not limit the protection scope of the patent of the present invention. Any technical solution obtained in the form of equivalent replacement or equivalent transformation should fall within the protection scope of the present invention.

[0038] In the present invention, unless otherwise specified, the stainless steel pickling wastewater all comes from a stainless steel production enterprise in Taiyuan, Shanxi, and the waste PET plastics all come from the same type of mineral water bottles.

[0039] Example 1

[0040] A method for preparing a metal-organic framework material comprises the following steps:

[0041] 3 g of waste PET plastic was mixed with 20 mL of stainless steel pickling wastewater (the ratio of the two was 150 g / L), placed in a reactor, and reacted in an oven at 200 ° C for 12 h to obtain the metal-organic framework material Fe 2.1 Cr 0.9 O(BDC) 3 F 1.3 (H 2 O) 1.7.

[0042] The XRD pattern of the metal-organic framework material prepared above is shown in Figure 1 The material has characteristic diffraction peaks at 8.8°, 10.1°, 14.8°, 17.7°, 21.1° and 26.8°, which correspond to the MIL-88B crystal structure. Figure 2 As shown in Figure 1, the material is composed of thin rod-shaped particles with a particle size of about 1 to 8 μm. Figure 3 As shown in Figure 2, the BET specific surface area of ​​the material calculated using the nitrogen adsorption-desorption curve at 77K is 34.6 m 2 / g, pore volume 0.13cm 3 / g.

[0043] The metal-organic framework material prepared above is used for zirconium ion adsorption, and the specific process is as follows:

[0044] 5 mg of metal-organic framework material was mixed with 10 mL of 10 mg / L zirconium ion aqueous solution and placed in a constant temperature shaker for 24 h at a speed of 155 rpm and a temperature of 303 K. A clear and transparent solution was obtained by filtering with a filter membrane, and the zirconium ion concentration in the solution was determined. Figure 4 As shown, the removal rate of zirconium ions by the material within 24 hours is 96.3%.

[0045] Example 2

[0046] A method for preparing a metal-organic framework material comprises the following steps:

[0047] 3 g of waste PET plastic was mixed with 20 mL of stainless steel pickling wastewater (the ratio of the two was 150 g / L), placed in a reactor, and reacted in an oven at 220 ° C for 12 h to obtain the metal-organic framework material Fe 2.0 Cr 1.0 O(BDC) 3 F 1.5 (H 2 O) 1.5 .

[0048] The XRD pattern of the metal-organic framework material prepared above is shown in Figure 5 The material has characteristic diffraction peaks at 8.8°, 10.1°, 14.8°, 17.7°, 21.1° and 26.8°, which correspond to the MIL-88B crystal structure. Figure 6 As shown in Figure 1, the material is composed of thin rod-shaped particles with a particle size of about 1 to 8 μm. Figure 7 As shown in Figure 2, the BET specific surface area of ​​the material was calculated using the nitrogen adsorption-desorption curve at 77K to be 25.0 m 2 / g, pore volume 0.14cm 3 / g.

[0049] The metal-organic framework material prepared above is used for zirconium ion adsorption, and the specific process is the same as in Example 1, such as Figure 8 As shown, the removal rate of zirconium ions by the material within 24 hours is 97.5%.

[0050] Example 3

[0051] A method for preparing a metal-organic framework material comprises the following steps:

[0052] 1g of waste PET plastic was mixed with 20mL of stainless steel pickling wastewater (the ratio of the two was 50g / L), placed in a reactor, and reacted in an oven at 220℃ for 36h to obtain the metal-organic framework material Fe 2.4 Cr 0.6 O(BDC) 3 F 1.0 (H 2 O) 2.0 .

[0053] The XRD pattern of the metal-organic framework material prepared above is shown in Fig. 9 The material has characteristic diffraction peaks at 8.8°, 10.1°, 14.8°, 17.7°, 21.1° and 26.8°, which correspond to the MIL-88B crystal structure. Fig.10 As shown in Figure 1, the material is composed of thin rod-shaped particles with a particle size of about 1 to 8 μm. Fig.11 As shown in Figure 2, the BET specific surface area of ​​the material was calculated using the nitrogen adsorption-desorption curve at 77K to be 17.0 m 2 / g, pore volume 0.11cm 3 / g.

[0054] The metal-organic framework material prepared above is used for zirconium ion adsorption, and the specific process is the same as in Example 1, such as Fig.12 As shown, the removal rate of zirconium ions by the material within 24 hours is 98.9%.

[0055] Example 4

[0056] A method for preparing a metal-organic framework material comprises the following steps:

[0057] 6 g of waste PET plastic was mixed with 20 mL of stainless steel pickling wastewater (the ratio of the two was 300 g / L), placed in a reactor, and reacted in an oven at 200 ° C for 24 h to obtain the metal-organic framework material Fe 2.2 Cr 0.8 O(BDC) 3 F 1.2 (H 2 O) 1.8 .

[0058] The XRD pattern of the metal-organic framework material prepared above is shown in Fig.13 The material has characteristic diffraction peaks at 8.8°, 10.1°, 14.8°, 17.7°, 21.1° and 26.8°, which correspond to the MIL-88B crystal structure. Fig.14 As shown in Figure 1, the material is composed of thin rod-shaped particles with a particle size of about 1 to 6 μm. Fig.15 As shown in Figure 2, the BET specific surface area of ​​the material was calculated using the nitrogen adsorption-desorption curve at 77K to be 10.0 m 2 / g, pore volume is 0.09cm 3 / g.

[0059] The metal-organic framework material prepared above is used for zirconium ion adsorption, and the specific process is the same as in Example 1, such as Fig.16 As shown, the removal rate of zirconium ions by the material within 24 hours is 95.6%.

Claims

1. Application of a metal-organic framework material in the treatment of wastewater containing zirconium ions, characterized in that: The metal-organic framework material is Fe x Cr 3-x O(BDC)3F y (H2O) 3-y , where BDC is terephthalic acid, x is 2.0~2.4, and y is 1.0~1.5; The preparation method of the metal-organic framework material comprises: using stainless steel pickling wastewater and waste PET plastic to prepare the metal-organic framework material in one step through a hydrothermal method.

2. The use of the metal-organic framework material according to claim 1 in the treatment of wastewater containing zirconium ions, characterized in that: The metal-organic framework material is composed of rod-shaped particles with a length of 1 to 8 μm and a BET specific surface area of ​​10 to 35 m 2 / g, pore volume is 0.09~0.14 cm 3 / g.

3. The use of the metal-organic framework material according to claim 1 in the treatment of wastewater containing zirconium ions, characterized in that: The volume ratio of the mass of the waste PET plastic to the stainless steel pickling wastewater is 50-300 g / L.

4. The use of the metal-organic framework material according to claim 1 in the treatment of wastewater containing zirconium ions, characterized in that: The hydrothermal reaction temperature is 200-220°C and the reaction time is 12-36 h.

5. The use of the metal-organic framework material according to claim 1 in the treatment of wastewater containing zirconium ions, characterized in that: The application specifically includes: adding metal-organic framework material to wastewater containing zirconium ions, adsorbing in a constant temperature shaker, and measuring the zirconium ion concentration in the solution after filtering through a filter membrane.

6. The use of the metal-organic framework material according to claim 5 in the treatment of wastewater containing zirconium ions, characterized in that: The rotation speed of the constant temperature shaker is 155 rpm, the temperature is 303 K, and the adsorption time is 24 h.

7. The use of the metal-organic framework material according to claim 5 in the treatment of wastewater containing zirconium ions, characterized in that: The amount of the metal-organic framework material used is 5 mg, the volume of the zirconium ion solution is 10 mL, and the concentration of the zirconium ion solution is 10 mg / L.

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