Patent Application
20250002381
This patent application claims the benefit and priority of Chinese Patent Application No. 202310762888.1 filed with the China National Intellectual Property Administration on Jun. 27, 2023, the disclosure of which is incorporated by reference herein in its entirety as part of the present application.
The present disclosure relates to the technical field of materials, and specifically relates to a preparation method and use of a novel copper-metal organic framework (Cu-MOF)-derived magnetic Fe3O4@Cu/C composite.
At present, due to the lack of reasonable treatment mechanisms and strict control measures, the continuous exposure of antibiotics in water bodies has caused many adverse effects on human health and ecosystems. As a preventive antibiotic, oxytetracycline (OTC) is generally used in agricultural production processes such as aquaculture. Due to limited absorption by animals after ingestion, large amounts of OTC are excreted into the natural water environment through excretion. The OTC has chemical stability and biological resistance, such that conventional chlorination and biodegradation processes are difficult to effectively eliminate it, resulting in the continuous accumulation of OTC in the natural environment and causing adverse effect to environment. Therefore, effective removal of OTC from wastewater to reduce its residual in the environmental water bodies is an important demand in the field of environmental protection. Currently, sulfate radical-based advanced oxidation processes (SR-AOPs) are considered to be one of the effective technologies for removing OTC because of its rapid removal with high efficiency. Since activation ability of peroxymonosulfate (PMS) in the sulfate radical-based SR-AOPs processes is a main factor reflecting catalyst efficiency, metals or metal oxides with various structures, crystal sizes, and appearances are considered to be key motivating factors for wastewater treatment by the sulfate radical-based SR-AOPs processes. Among many metals or metal oxides, iron oxides are generally used as a heterogeneous Fenton-type catalyst due to their abundant resources, low cost, and non-toxicity. Common ferric oxide generally faces a limited catalytic ability due to the slow conversion rate of Fe(III) into Fe(II) and poor electrical conductivity. In view of this, there is an urgent need to improve the catalytic activity of iron-based catalysts for PMS activation.
In order to solve the above existing problems, the present disclosure provides a preparation method and use of a novel Cu-MOF-derived magnetic Fe3O4@Cu/C composite.
The objects of the present disclosure can be achieved by the following technical solutions:
The present disclosure provides a copper-metal organic framework (Cu-MOF) material with a novel structure, where the Cu-MOF material has unit cell parameters including: a=8.7292 Å, b=20.4196 Å, c=34.3986 Å, α=β=γ=90°, and V=6131.42 Å3, and belongs to an orthorhombic crystal system and a Pbca space group.
The present disclosure further provides a method for preparing the Cu-MOF material described above, including the following steps:
In some embodiments, a molar ratio of the tris(4-(4H-1,2,4-triazol-4-yl)phenyl)amine, the copper acetate, and the 1,3,5-benzenetricarboxylic acid is in a range of 1:(1-5):(1-5).
In the method described above, the reaction is conducted at a temperature of 145° C. to 165° C.; the gradient cooling is conducted at a speed of 5° C./h to 10° C./h; and the alcohol is selected from the group consisting of methanol and ethanol.
The present disclosure further provides a method for preparing a novel magnetic Fe3O4@Cu/C composite, including the following steps:
In the method for preparing the novel magnetic Fe3O4@Cu/C composite described above, a molar ratio of the Cu-MOF material to the Fe2O3 in the hexagonal structure is in a range of 1:(1-1.5), and the grinding is conducted for 2 h to 4 h; and
the calcination is conducted by programmed heating at a heating rate of 2° C./min to 3° C./min to a calcination temperature of 600° C. to 650° C. and holding at the calcination temperature for 2 h to 4 h, and then subjecting an obtained calcination product to natural cooling to room temperature.
The present disclosure further provides a Fe3O4@Cu/C composite, which is prepared by the method described above.
The present disclosure further provides use of the magnetic Fe3O4@Cu/C composite in antibiotic degradation.
In some embodiments, the magnetic Fe3O4@Cu/C composite cooperates with a persulfate as a catalyst for efficient degradation of an antibiotic pollutant in water.
In some embodiments, the persulfate is sodium peroxymonosulfate (PMS), and the PMS is added in an amount of 0.5 mmol/L to 1.5 mmol/L.
In some embodiments, the antibiotic is OTC, and the antibiotic degradation is conducted under a pH value of 3 to 11 at a temperature of 25° C. to 45° C. for 50 min to 60 min. The composite shows anti-interference when catalytically degrading the OTC, and could still maintain a desirable degradation performance in the presence of inorganic ions such as H2PO4−, NO3−, Cl−, HCO3−, and SO42− as well as humic acid (HA) (
Some embodiments of the present disclosure have the following beneficial effects:
In the present disclosure, the method for preparing the magnetic Fe3O4@Cu/C composite is simple and easy to implement. The composite has a high efficiency in degrading antibiotics. Moreover, the composite shows anti-interference when catalytically degrading the OTC, and could still maintain a desirable degradation performance in the presence of inorganic ions such as H2PO4−, NO3−; Cl−, HCO3−, and SO42− as well as HA (
The present disclosure will be further described below in conjunction with examples, but the scope of the present disclosure is not limited thereto.
A method for preparing hexagonal Fe2O3 was performed by the following procedures:
1.0 mmol of FeCl3·6H2O was dissolved in 30 mL of ethanol, and 1 mL of water was added thereto; after complete dissolution, 0.8 g of sodium acetate was added, and then stirred vigorously for 1 h to obtain a solution. The solution was transferred to a polytetrafluoroethylene (PTFE) liner, heated to 180° C. for 12 h, and then cooled to room temperature to obtain a suspension. The suspension was centrifuged at a rotating speed of 10,000 rpm, and a resulting product was then washed repeatedly with water and ethanol, and dried in an oven at a temperature of 60° C. to obtain the hexagonal Fe2O3.
A magnetic Fe3O4@Cu/C composite was synthesized in two steps as follows:
45.0 g (0.1 mol) of tris(4-(4H-1,2,4-triazol-4-yl)phenyl)amine, 42.1 g (0.2 mol) of 1,3,5-benzenetricarboxylic acid, and 57.5 g (0.3 mol) of copper acetate were added into a mixture of water and ethanol to obtain a reaction solution, where a mass of the water was 75 g (4.1 mol) and a mass of the methanol was 50 g (1.6 mol). A pH value of the reaction solution was adjusted to 6.5. A resulting solution was stirred for 15 min to obtain a mixed solution of reactants. The mixed solution was feed into a reactor, and crystallized at a temperature of 150° C. for 72 h to obtain a reaction product. After the reaction, the reaction product was subjected to gradient cooling at a speed of 10° C./h to a temperature of 80° C., then natural cooling to room temperature, and a resulting cooled product was filtered to obtain a blue transparent crystal, namely the novel Cu-MOF material. The blue transparent crystal was washed with a methanol solution until the surface of the crystal was free of impurities, and dried to obtain a compound with a novel structure. The obtained Cu-MOF material has a purity of 95% and a yield of 88%. According to results of the X-ray single crystal diffraction test, the crystal structure parameters of the Cu-MOF material show that its crystal system belongs to an orthorhombic crystal system and a Pbca space group. Specific unit cell parameters are: a=8.7292 Å, b=20.4196 Å, c=34.3986 Å, α=β=γ=90°, and V=6131.42 Å3. There are two-dimensional layered structural features in the crystal structure.
(2) Synthesis of Magnetic Fe3O4@Cu/C Composite
7.4 g (0.01 mol) of the Cu-MOF prepared in step (1) and 1.9 g (0.012 mol) of the hexagonal Fe2O3 were mixed, and ground for 2.5 h until the materials were evenly composited to obtain a composite Cu-MOF@Fe2O3. The composite Cu-MOF@Fe2O3 was transferred to a tubular furnace, and subjected to programmed calcination (the temperature was set to 600° C., and the heating rate was controlled to 2° C./h) under a nitrogen atmosphere for 3 h and then natural cooling to room temperature to obtain the novel magnetic Fe3O4@Cu/C composite. This composite could still maintain a hexagonal lamellar appearance and a large specific surface area, which are conducive to the dispersion of active sites during catalytic reactions (
(3) Performance Test of Antibiotic Degradation by Magnetic Fe3O4@Cu/C Composite
The magnetic Fe3O4@Cu/C composite prepared in Example 1 was used to cooperatively excite PMS to degrade OTC, as follows:
5 mg of Fe3O4@Cu/C composite was weighed and placed in a 100 mL glass bottle, 50 mL of OTC (initial concentration was 20 mg/L) solution was added thereto, and the PMS was added thereto in an amount of 1 mmol/L. The degradation test was conducted in a constant-temperature water bath shaker at 180 rpm/min. At regular intervals, 2 mL of a reaction solution was taken and filtered with a 0.45 μm filter membrane, and quenched by 20 mM Na2S2O3, where the test was conducted for 50 min. A concentration change of the reaction solution was measured with a UV-visible spectrophotometer. A degradation rate was calculated according to a formula c0−c/c0×100%, where c0 and c are mass concentrations of the solution before and after degradation, respectively, in mg/L.
Under the condition that the composite prepared in Example 1 was used to degrade OTC, the degradation rate could reach 95% within 50 min (
During the degradation performance test in 1), 50 mmol/L of interfering ions (H2PO4−, NO3−, Cl−, HCO3−; and SO42−) or 50 mg/L of humic acid were added. For OTC, the degradation efficiency only dropped by about 10%, proving that the composite has strong anti-interference ability (
In the example of degrading OTC in 1), the pH value of the reaction system solution was adjusted to 3 to 11, and the Fe3O4@Cu/C composite could still exert a desirable catalytic degradation effect (
After each test run was completed, the Fe3O4@Cu/C composite was separated from the reaction solution using an external magnetic field (
5) The composite recovered in 4) was cleaned and dried for 12 h for a recyclable test.
The composite was recycled 5 times, and its degradation rate of OTC could still reach 82% (
| Number | Date | Country | Kind |
|---|---|---|---|
| 202310762888.1 | Jun 2023 | CN | national |
