A modified zirconium-based organic metal framework composite material and preparation method thereof

Abstract

The present invention provides a modified zirconium-based organic metal framework composite material and a preparation method thereof. The present invention uses zirconium tetrachloride, iron disulfide, and dihydroxyterephthalic acid as raw materials, which are dispersed in N,N-dimethylformamide (DMF) respectively. The three solutions are then ultrasonically mixed to obtain a precursor solution, which is then sealed in a stainless steel autoclave and reacted at high temperature for a certain period of time. Finally, the product in the autoclave is removed, washed, and dried to obtain the modified zirconium-based organic metal framework composite material. The method for preparing the zirconium-based organic metal framework composite material of the present invention is simple, the raw materials are readily available, and the cost is low. The composite material exhibits high efficiency in reducing and removing heavy metal ions from water, is easily recyclable, and can be reused multiple times.

Description

Technical Field

[0001] The invention relates to a modified zirconium-based organic metal framework composite material and a preparation method thereof, belonging to the technical field of water treatment. Background Art

[0002] With the rapid development of industrialization, a large number of heavy metal elements are widely used in industrial production and manufacturing processes. These industrial activities, including mining, smelting, electronic waste disposal, and chemical industry, result in the emission and release of large quantities of heavy metals. Heavy metal pollution has serious impacts on the environment and human health. Heavy metals are bioaccumulative and toxic, and long-term exposure or contact to heavy metals can lead to chronic poisoning, neurological diseases, cancer, and other health problems. Therefore, reducing and controlling heavy metal pollution has become a major global task. Governments, research institutions, and businesses around the world are working hard to formulate and implement relevant policies and measures to reduce heavy metal emissions and pollution. Organic metal frameworks (MOFs) are a class of materials composed of organic molecules and metal ions. Due to the flexibility and diversity of organic ligands, MOFs possess rich structural diversity and tunability. These structural characteristics of MOFs endow them with diverse applications. First, their porous structure and surface functional groups can be used to adsorb and store substances such as gases and liquids. Second, MOFs possess catalytic activity, demonstrating excellent catalytic performance in catalytic reactions. In addition, due to their structural tunability, MOFs can also be used to construct functional materials such as optical, electrical, and magnetic materials. Zirconium-based MOFs (Zr-MOFs) have the characteristics of high tunability, large pore volume and porosity, and high stability, which makes them have potential application prospects.

[0003] Iron disulfide, as an adsorbent, can be used to remove heavy metal ions from water or soil. When heavy metal ions are present in water or soil, the surface of the iron disulfide reacts chemically with the ions to form complexes or precipitates, thereby removing the heavy metal ions. This adsorption process can effectively reduce the concentration of heavy metals in the environment. Furthermore, iron disulfide acts as a reducing agent in some redox reactions, reacting with heavy metal ions to reduce them to lower-valence ions or solid forms, reducing their solubility and activity, thereby reducing their toxic effects on the environment. Summary of the Invention

[0004] The present invention aims to provide a modified zirconium-based organic metal framework composite material and a preparation method thereof, so as to solve the problems of high cost, low removal efficiency and poor reusability of existing deep purification of heavy metal pollutants in wastewater.

[0005] A modified zirconium-based organic metal framework composite material and a preparation method thereof, characterized by comprising the following steps:

[0006] 1) A certain amount of zirconium tetrachloride, iron disulfide, and dihydroxyterephthalic acid are dispersed in N,N-dimethylformamide (DMF) to obtain three solutions;

[0007] 2) slowly adding the zirconium tetrachloride and iron disulfide solutions in 1) to the dihydroxy terephthalic acid solution in sequence, and sonicating to obtain a precursor solution;

[0008] 3) The precursor solution in 2) is placed in a stainless steel autoclave lined with polytetrafluoroethylene and sealed, and then placed in a constant temperature oven for high temperature reaction for a certain period of time;

[0009] 4) After the reactor in step 3) is naturally cooled to room temperature, the product in the suspension is collected by centrifugation, washed with N,N-dimethylformamide (DMF) and formic acid, respectively, and vacuum-dried to obtain a modified zirconium-based organometallic framework composite material.

[0010] According to the above scheme, the amount of zirconium tetrachloride is 1-7 mmol.

[0011] According to the above scheme, the molar ratio of the zirconium tetrachloride and dihydroxyterephthalic acid is 1: (0.7~1.5).

[0012] According to the above scheme, the amount of the iron disulfide substance is 1.4~5.6 mmol.

[0013] According to the above scheme, the reaction temperature of the reactor is 80~150℃, and the reaction time is 16~48 hours.

[0014] The invention provides a modified zirconium-based organic metal framework composite material.

[0015] The working principle of the present invention is that the reducing active component iron disulfide is stabilized and dispersed on the zirconium-based organic metal framework, which can promote the reaction of iron disulfide reducing heavy metal ions and realize the effective treatment of heavy metal-containing wastewater.

[0016] The present invention has the following beneficial effects:

[0017] The present invention is synthesized by a one-step solvent thermal method, and the preparation process is simple, environmentally friendly, and low-cost. The material has good reducing properties for heavy metal ions in wastewater, stable performance, and can be reused.

[0018] It has broad application prospects in the fields of governance, material chemistry, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1This is a scanning electron microscope (SEM) image of the modified zirconium-based organic metal framework composite material prepared in Example 1;

[0020] Figure 2 The X-ray powder diffraction (XRD) spectrum of the modified zirconium-based organic metal framework composite material prepared in Example 1;

[0021] Figure 3 This is an X-ray photoelectron spectroscopy (XPS) graph of the modified zirconium-based organic metal framework composite material prepared in Example 1;

[0022] Figure 4 This is a curve showing the change in the efficiency of removing hexavalent chromium with reaction time of the modified zirconium-based organic metal framework composite material (FeS2@UIO66-(OH)2) and the zirconium-based organic metal framework material (UIO66-(OH)2) prepared in Example 1. Implementation Method

[0023] The technical solution of the present invention is not limited to the specific embodiments listed below, but also includes any combination of the specific embodiments. Example 1

[0024] 1) Under magnetic stirring, disperse 7 mmol of zirconium tetrachloride, 7 mmol of dihydroxyterephthalic acid, and 1.4 mmol of iron disulfide in three beakers containing 40 mL of N,N-dimethylformamide (DMF) to obtain three solutions.

[0025] 2) While continuing magnetic stirring, slowly add the zirconium tetrachloride and iron disulfide solutions to the dihydroxyterephthalic acid solution to obtain a precursor solution;

[0026] 3) The precursor solution was placed in a 100 mL polytetrafluoroethylene-lined stainless steel autoclave, sealed, and then placed in a constant temperature oven at 120°C for 24 h.

[0027] 4) After the reactor in step 3) is naturally cooled to room temperature, the product in the suspension is collected by centrifugation, washed three times with N,N-dimethylformamide and methanol, and vacuum dried at 80°C for 12 h to obtain a composite material. Example 2

[0028] This embodiment differs from embodiment 1 in that the amount of iron disulfide in step 1) is 2.8 mmol. Other aspects are the same as those in embodiment 1. Example 3

[0029] This embodiment differs from embodiment 1 in that the amount of iron disulfide in step 1) is 4.2 mmol. Other aspects are the same as those in embodiment 1. Example 4

[0030] This embodiment differs from embodiment 1 in that the amount of iron disulfide in step 1) is 5.6 mmol. Other aspects are the same as those in embodiment 1. Example 5

[0031] This embodiment differs from embodiment 1 in that the amount of zirconium tetrachloride in step 1) is 1 mmol. Other aspects are the same as those in embodiment 1. Example 6

[0032] This embodiment differs from Example 1 in that the amount of dihydroxyterephthalic acid in step 1) is 9.1 mmol. Other steps are the same as those in Example 1. Example 7

[0033] This embodiment differs from Example 1 in that the amount of dihydroxyterephthalic acid in step 1) is 10.5 mmol. Other aspects are the same as those in Example 1. Example 8

[0034] This embodiment differs from embodiment 1 in that the reaction temperature of the reactor in step 3) is 80° C. and the heating reaction time is 48 h. Other aspects are the same as those in embodiment 1. Example 9

[0035] This embodiment differs from embodiment 1 in that the reaction temperature of the reactor in step 3) is 100° C. and the heating reaction time is 36 h. Other aspects are the same as those in embodiment 1. Example 10

[0036] This embodiment differs from embodiment 1 in that the reaction temperature of the reactor in step 3) is 150° C. and the heating reaction time is 16 h. Other aspects are the same as those in embodiment 1.

[0037] The reduction performance of the modified zirconium-based organic metal framework composite materials obtained in Examples 2 to 10 is comparable to that of the modified zirconium-based organic metal framework composite material obtained in Example 1.

[0038] As can be seen from the above examples, the present invention provides a method for preparing a modified zirconium-based organometallic framework composite material. This method is simple, low-cost, and characterized by zero secondary pollution and low energy consumption during operation. The composite material can rapidly reduce hexavalent chromium to trivalent chromium within 3 hours, achieving a removal rate exceeding 95%. Furthermore, it can be recycled multiple times, making it a potentially excellent wastewater treatment material.

[0039] The above descriptions are only preferred and representative embodiments of the present invention. The upper and lower limits and interval values of various raw materials and process methods can realize the present invention, and the embodiments are not listed one by one here.

Claims

1. A method for preparing a modified zirconium-based organic metal framework composite material, characterized in that: The following steps are involved: 1) A certain amount of zirconium tetrachloride, iron disulfide, and dihydroxyterephthalic acid are dispersed in N,N-dimethylformamide (DMF) to obtain three solutions; 2) slowly adding the zirconium tetrachloride and iron disulfide solutions prepared in step 1 to the dihydroxy terephthalic acid solution to obtain a precursor solution; 3) The precursor solution in 2) is placed in a stainless steel autoclave lined with polytetrafluoroethylene and sealed, and then placed in a constant temperature oven for high temperature reaction for a certain period of time; 4) After the reactor in step 3) is naturally cooled to room temperature, the product in the suspension is collected by centrifugation, washed with N,N-dimethylformamide (DMF) and methanol, respectively, and vacuum-dried to obtain a modified zirconium-based organometallic framework composite material.

2. The method for preparing a composite material according to claim 1, wherein: The amount of zirconium tetrachloride is 1 to 7 mmol.

3. The preparation method according to claim 1, characterized in that The molar ratio of the zirconium tetrachloride to dihydroxyterephthalic acid is 1:(0.7-1.5).

4. The preparation method according to claim 1, characterized in that The amount of the iron disulfide is 1.4 to 5.6 mmol.

5. The preparation method according to claim 1, characterized in that The reaction temperature of the reactor is 80-150°C, and the reaction time is 16-48 hours.

6. A modified zirconium-based organic metal framework composite material obtained according to the preparation method according to any one of claims 1 to 5.

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