CN110841714A - Iron-cobalt bimetal-organic framework material based on 2, 5-dihydroxy terephthalic acid ligand and preparation method and application thereof - Google Patents

Abstract

The present invention relates to an iron-cobalt bimetallic-organic framework material based on 2,5-dihydroxyterephthalic acid ligand and a preparation method and application thereof. Cobalt nitrate hexahydrate, ferrous chloride tetrahydrate and 2,5 -Dihydroxyterephthalic acid is dissolved in an organic solvent to obtain a precursor solution; the precursor solution is subjected to a solvothermal reaction at 110-170°C; after the reaction is completed, an iron-cobalt bimetal-organic framework material is obtained by post-treatment. The highly dispersed cobalt and iron active center ions in the iron-cobalt bimetallic-organic framework material can enhance the effective contact of cobalt ions and iron with peroxymonosulfate to generate sulfate radicals with strong oxidizing properties, thereby reducing waste water Removal of refractory organic pollutants. The iron-cobalt bimetal-organic framework material based on the 2,5-dihydroxyterephthalic acid ligand of the invention is suitable for various organic wastewater treatment, has high efficiency, good durability, convenient operation and environmental friendliness, and is difficult to deal with toxic and harmful. Biodegradable organic wastewater offers great prospects.

Description

An iron-cobalt bimetallic-organic bone based on 2,5-dihydroxyterephthalic acid ligand Shelf material, preparation method and application thereof

technical field

The invention belongs to the technical field of water pollution control, and in particular relates to an iron-cobalt bimetallic-organic framework material based on a 2,5-dihydroxyterephthalic acid ligand and a preparation method and application thereof.

Background technique

With the rapid development of industry, the treatment of water pollution environment has become a worldwide problem, and the widespread existence of refractory organic pollutants has made water treatment more and more people's attention. Refractory organic pollutants are difficult to remove by traditional biological, physical and chemical methods due to their complex composition, stable structure and long half-life. And most of the refractory organic pollutants have certain toxicity and are easy to be retained in the organism, resulting in cancer, distortion and feminization of humans and animals. Advanced oxidation technology has the characteristics of rapid, non-selective, and thorough oxidation, and has a good treatment effect on trace refractory organic pollutants and high-concentration organic wastewater in the environment, which improves an effective solution to this environmental problem. . Therefore, advanced oxidation technology has gradually become the preferred method for the treatment of refractory organic pollutants.

In recent years, advanced oxidation technology based on SO ₄ ^-· has attracted more and more researchers' attention and research because of its strong oxidizing ability, wide applicable pH range and simple operation. Using transition metal to activate PS to generate radical SO ₄ ^-· is the most effective way. SO ₄ ^－· is produced by decomposing peroxysulphate (PS) with strong oxidizing ability. With respect to the hydroxyl radical (·OH), SO ₄ ^−· has an oxidation-reduction potential equivalent to that of (·OH, E ₀ =2.6vs.NHE), E ₀ =2.5-3.1vs.NHE, and SO ₄ ^−· in Under neutral conditions, it has better treatment effect on organic wastewater, which makes the advanced oxidation technology based on SO ₄ ^-· more prominent in water treatment. _SO4- ^· can be produced by decomposition of peroxodisulfate (PDS) and peroxymonosulfate (PMS). Radiation, ultraviolet light and high temperature can catalyze the production of SO ₄ ^-· from PMS. However, the transition metal catalysis method does not require external heat source and light source, and the reaction system is simple and has received extensive attention. Metal-Organic Frameworks (MOFs) are a new class of materials with periodic structures obtained by self-assembly of inorganic metal nodes and organic bridging ligands through coordination. Recent studies have shown that MOFs as heterogeneous catalysts have shown outstanding performance in the treatment of polluted environments, especially in the removal of water pollutants, showing great application prospects.

SUMMARY OF THE INVENTION

In order to overcome the fact that the cobalt ions in the cobalt ion-activated peroxymonosulfate reaction system in the prior art cannot be recycled and cause secondary pollution to the environment, it is necessary to further increase treatment processes such as ion exchange, adsorption, precipitation and separation, which increases the treatment cost. To solve the problems and disadvantages, the present invention provides an iron-cobalt bimetallic-organic framework material, a preparation method thereof, and an application in the field of wastewater treatment.

An iron-cobalt bimetallic-organic framework material (FeCo-DHTA) based on 2,5-dihydroxyterephthalic acid ligand, prepared from the following raw material components: cobalt nitrate hexahydrate, chloride tetrahydrate Iron, 2,5-dihydroxyterephthalic acid, the molar ratio of the cobalt nitrate hexahydrate, ferrous chloride tetrahydrate, and 2,5-dihydroxyterephthalic acid is 4:1:2.5～1:4: 2.5.

Preferably, the shape of the iron-cobalt bimetallic-organic framework material based on 2,5-dihydroxyterephthalic acid ligand is a regular hollow polyhedron or rod-like structure.

The present invention also provides the above-mentioned preparation method of the iron-cobalt bimetallic-organic framework material based on 2,5-dihydroxyterephthalic acid ligand, comprising the following steps:

(1) Preparation of precursor solution: dissolving cobalt nitrate hexahydrate, ferrous chloride tetrahydrate and 2,5-dihydroxyterephthalic acid in an organic solvent, and then mixing uniformly to obtain a precursor solution;

(2) Preparation of iron-cobalt bimetallic-organic framework material based on 2,5-dihydroxyterephthalic acid ligand: the precursor solution obtained in step (1) is subjected to solvothermal treatment at a temperature of 110-170 °C reaction; cooling, washing, and drying to obtain an iron-cobalt bimetallic-organic framework material based on a 2,5-dihydroxyterephthalic acid ligand.

Preferably, the organic solvent is N,N-dimethylformamide and absolute ethanol, and the volume ratio of the N,N-dimethylformamide and absolute ethanol is 1:1 or 1:0. The dosage of N,N-dimethylformamide can be effectively reduced, and the environmental friendliness can be improved. In addition, the use of toxic and harmful solvents such as hydrofluoric acid is avoided, the operation is simpler and the environment is more friendly.

Preferably, the solvothermal reaction is carried out in a polytetrafluoroethylene-lined high-pressure reaction kettle, and the solvothermal reaction time is 24-48 h; the washing conditions are: using absolute ethanol, N,N-dimethylformaldehyde The precipitate is washed alternately and repeatedly with methylformamide and deionized water; the drying conditions are: drying at 60-100° C. for 12-24 hours.

In addition, the present invention also provides the application of the above-mentioned iron-cobalt bimetallic-organic framework material based on 2,5-dihydroxyterephthalic acid ligand in the field of wastewater treatment.

Preferably, the application of the iron-cobalt bimetallic-organic framework material based on 2,5-dihydroxyterephthalic acid ligands includes the following steps: adding peroxymonosulfate as an oxidant and as a catalyst into the wastewater 2,5-dihydroxyterephthalic acid ligand-based iron-cobalt bimetallic-organic framework materials for wastewater treatment reactions. The iron-cobalt bimetallic-organic framework material based on the 2,5-dihydroxyterephthalic acid ligand of the invention can efficiently catalyze and activate peroxymonosulfate to rapidly and effectively remove toxic, harmful, and biodegradable organic substances in wastewater.

Preferably, the peroxymonosulfate is sodium peroxymonosulfate or potassium peroxymonosulfate.

Preferably, the molar ratio of the peroxymonosulfate to organic pollutants in the wastewater is 6-300:1, and the iron-cobalt bimetallic-organic framework material based on 2,5-dihydroxyterephthalic acid ligands The dosage is 20 ~ 200mg/L. The dosage of peroxymonosulfate is determined according to the concentration of organic pollutants in the wastewater. The greater the concentration of organic pollutants, the greater the amount of peroxymonosulfate added.

Preferably, the temperature of the wastewater treatment reaction is 20 to 60°C, and the time is 2 to 30 minutes; the wastewater treatment reaction is carried out under stirring or shaking conditions, and the stirring or shaking speed is 50 to 200 rpm; the wastewater is organic wastewater, and the The pH value of the organic wastewater is 3.0 to 11.0.

Principle of the present invention: The water treatment technology proposed by the present invention to efficiently activate peroxymonosulfate using iron-cobalt bimetallic-organic framework materials based on 2,5-dihydroxyterephthalic acid ligands is based on 2,5- Iron-Cobalt Bimetallic-Organic Frameworks with Dihydroxyterephthalic Acid Ligands as Heterogeneous Catalysts for Peroxymonosulfate Reacting with organic wastewater to be treated in the presence of framework material and peroxymonosulfate, the iron-cobalt bimetallic-organic framework material based on 2,5-dihydroxyterephthalic acid ligands is uniformly dispersed and iron ions and cobalt Metal ions can efficiently activate peroxymonosulfate to produce strongly oxidizing SO ₄ ^-· , which can achieve the purpose of efficiently removing refractory organic pollutants. The reaction can be carried out in a wide pH range, and the catalyst dosage is small, the reaction time is short, and the catalytic oxidation rate is high, the equipment is simple, the operation is convenient, the environment is friendly, and the catalyst is easy to recycle. The field has great application potential.

Compared with the prior art, the present invention has beneficial effects as follows:

(1) The preparation method of the iron-cobalt bimetallic-organic framework material provided by the present invention is simple, the reaction conditions are mild, there is no special requirement for external environmental conditions, the operation is simple, the repeatability is strong, and it is easy to realize;

(2) The iron-cobalt bimetallic-organic framework material provided by the present invention based on 2,5-dihydroxyterephthalic acid ligand can be used as a heterogeneous catalyst for activating peroxymonosulfate salt, and can be applied to wastewater treatment for the first time. The iron-cobalt bimetallic-organic framework material of 2,5-dihydroxyterephthalic acid ligand is applied to the reaction of the advanced oxidation method based on sulfate radicals for the treatment of organic pollutants; Iron ions and cobalt ions in the iron-cobalt bimetallic-organic framework material of phthalic acid ligands are uniformly dispersed in the framework material, which can significantly improve the catalytic activity. The present invention makes full use of iron based on 2,5-dihydroxyterephthalic acid ligands. The highly dispersed cobalt and iron active center ions in cobalt bimetallic-organic framework materials enhance the effective contact between transition metal ions and peroxymonosulfate salts and enhance the generation of sulfate radicals with strong oxidizing properties, thereby accelerating the difficulty of wastewater treatment. Oxidative degradation of organic pollutants; highly catalytically active 2,5-dihydroxyterephthalic acid ligand iron-cobalt bimetallic-organic framework material enables peroxymonosulfate to effectively decompose to generate sulfate radicals, free radicals High utilization rate, short reaction time and good removal of pollutants;

(3) The present invention adopts the iron-cobalt bimetallic-organic framework material as a heterogeneous catalyst to catalyze the peroxymonosulfate, which has high catalytic activity in the range of pH 3.0 to 11.0, making it suitable for treatment The pH value of the wastewater is greatly broadened, which effectively reduces the cost of acid-base adjustment;

(4) The present invention adopts the iron-cobalt bimetallic-organic framework material based on 2,5-dihydroxyterephthalic acid ligand as a heterogeneous catalyst with high activity and low dosage, and can be used at room temperature without illumination and other conditions. High-efficiency catalysis of peroxymonosulfate reduces the cost of sewage treatment, and the catalyst after the reaction can be easily recovered and reused from the solution without secondary pollution;

(5) the present invention is simple to operate, easy to control the conditions, high catalytic efficiency, economical and feasible, and is suitable for advanced treatment of various organic waste water;

(6) The present invention still maintains a high pollutant removal rate under higher pH conditions, and in addition, the present invention is suitable for various organic wastewater treatment, with high efficiency, good durability, convenient operation, and environmental friendliness. The efficient removal of toxic and harmful pollutants in wastewater within the pH range provides a broad prospect for the treatment of toxic and harmful organic wastewater that is difficult to biodegrade.

Description of drawings

Fig. 1 is the scanning electron microscope image that the magnification of the iron-cobalt bimetallic-organic framework material based on 2,5-dihydroxyterephthalic acid ligand prepared under the condition of 150 ° of the present invention is 10 million times;

Fig. 2 is the scanning electron microscope image of the iron-cobalt bimetallic-organic framework material based on 2,5-dihydroxyterephthalic acid ligand prepared by the present invention at 110° with a magnification of 5 million times;

Fig. 3 is the scanning electron microscope image of the iron-cobalt bimetallic-organic framework material based on 2,5-dihydroxyterephthalic acid ligand prepared under the condition of 170° of the present invention with a magnification of 10 million times;

Fig. 4 X-ray crystal diffraction pattern of the iron-cobalt bimetallic-organic framework material prepared under the condition of 150° of the present invention based on 2,5-dihydroxyterephthalic acid ligand;

Fig. 5 is the infrared spectrum of the iron-cobalt bimetallic-organic framework material prepared under the condition of 150° of the present invention based on 2,5-dihydroxyterephthalic acid ligand.

Detailed ways

The present invention will be further described below with reference to the accompanying drawings and specific embodiments, but the scope of protection of the present invention is not limited thereto.

Cobalt nitrate hexahydrate (Co(NO ₃ ) ₂ ·6H ₂ O), ferrous chloride tetrahydrate (Cu(NO ₃ ) ₂ ), 2,5-dihydroxyterephthalic acid used in the examples of the present invention (C ₈ H ₆ O ₆ ), N,N-dimethylformamide (DMF, C ₃ H ₇ NO), absolute ethanol (C ₂ H ₆ O), potassium hydrogen peroxymonosulfate, etc. are all analytically pure, Methylene blue is chromatographically pure, and all water used is deionized water.

According to statistics, there are more than 100,000 types of commercial dyes, and the world's annual output of dyes is about 800,000 to 900,000 tons, while my country's annual output of dyes is about 150,000 tons, ranking the forefront of the world's dye output. 10% to 15% of the dyes are released into the environment during production and use. Most of the dyes are extremely stable and difficult to degrade naturally after entering the water body, which not only increases the chromaticity of the polluted water area and affects the amount of incident light, but also further affects the normal life activities of aquatic animals and plants in the water body and destroys the ecology of the water environment. balance. What's more serious is that most dyes have carcinogenic and teratogenic effects, and their discharge into the water environment will cause great harm to humans and other organisms. The present invention takes into account that dyes are widely used in industries such as medicine, food, printing and dyeing, and cosmetic manufacturing. Therefore, in the present invention, methylene blue (MB), which is widely used, is selected as the representative of pollutants, and the decolorization and degradation of MB can represent the degradation of refractory organic wastewater to a certain extent. Therefore, the organic waste water in the following examples is selected from MB solution.

The organic waste water containing methylene blue (MB) is treated by the method of the invention.

Example 1

Preparation of Iron-Cobalt Bimetallic-Organic Framework Materials

(1) Preparation of precursor solution: 0.873 g (3 mM) Co(NO ₃ ) ₂ ·6H ₂ O, 0.596 g (3 mM) FeCl ₂ ·4H ₂ O and 0.498 g (3 mM) 2,5-dihydroxyl pair Phthalic acid (DTPA) was dissolved in 60 mL of N,N-dimethylformamide (DMF) and ethanol mixture (DMF:ethanol=1:1), and the mixture was stirred until completely dissolved to obtain a precursor solution;

(2) Iron-cobalt bimetallic-organic framework material based on 2,5-dihydroxyterephthalic acid ligand: The precursor solution obtained in step (1) was transferred to a 100 mL polytetrafluoroethylene-lined autoclave , put the reaction kettle into a program-controlled oven, and solvothermally react at 150 °C for 24 hours; cooled, naturally cooled to room temperature, filtered with a vacuum pump, and repeated with absolute ethanol, N,N-dimethylformamide (DMF) and deionized water. Wash to obtain brown precipitate; put the precipitate into a vacuum drying oven at 100°C for 12 hours to obtain black solid powder, which is an iron-cobalt bimetallic-organic framework material based on 2,5-dihydroxyterephthalic acid ligand.

The above-mentioned iron-cobalt bimetallic-organic framework material is characterized by scanning electron microscope, X-ray crystal diffraction and infrared, wherein, Fig. 1 is a scanning electron microscope image with a magnification of 10 million times of iron-cobalt bimetallic-organic framework material in the present embodiment. Fig. 4 is the X-ray crystal diffraction diagram of the iron-cobalt bimetallic-organic framework material in this embodiment, and FIG. 5 is the infrared spectrum diagram of the iron-cobalt bimetallic-organic framework material in this embodiment. It can be seen from the above diagram that the present invention has indeed prepared an iron-cobalt bimetallic-organic framework material, which is in the form of a regular polyhedral crystal, and the detection results of ICP-MS show that the cobalt and iron elements in the material obtained by the preparation method are The molar ratio is close to 1:1, indicating the successful preparation of iron-cobalt bimetallic-organic framework materials.

Example 2

(1) Preparation of precursor solution: 0.873 g (3 mM) Co(NO ₃ ) ₂ ·6H ₂ O, 0.596 g (3 mM) FeCl ₂ ·4H ₂ O and 0.498 g (3 mM) 2,5-dihydroxyl pair Phthalic acid (DTPA) was dissolved in 60 mL of N,N-dimethylformamide (DMF) and ethanol mixture (DMF:ethanol=1:1), and the mixture was stirred until completely dissolved to obtain a precursor solution;

(2) Iron-cobalt bimetallic-organic framework material based on 2,5-dihydroxyterephthalic acid ligand: The precursor solution obtained in step (1) was transferred to a 100 mL polytetrafluoroethylene-lined autoclave , put the reaction kettle into a program-controlled oven, and solvothermally react at 110 °C for 24 hours; cooled, naturally cooled to room temperature, filtered by a vacuum pump, and repeated with absolute ethanol, N,N-dimethylformamide (DMF) and deionized water. Wash to obtain brown precipitate; put the precipitate into a vacuum drying oven at 100°C for 12 hours to obtain black solid powder, which is an iron-cobalt bimetallic-organic framework material based on 2,5-dihydroxyterephthalic acid ligand.

The above iron-cobalt bimetallic-organic framework material is characterized by scanning electron microscope, wherein, FIG. 2 is a scanning electron microscope image of the iron-cobalt bimetallic-organic framework material in this embodiment with a magnification of 5 million times.

Example 3

(1) Preparation of precursor solution: 0.873 g (3 mM) Co(NO ₃ ) ₂ ·6H ₂ O, 0.596 g (3 mM) FeCl ₂ ·4H ₂ O and 0.498 g (3 mM) 2,5-dihydroxyl pair Phthalic acid (DTPA) was dissolved in 60 mL of N,N-dimethylformamide (DMF) and ethanol mixture (DMF:ethanol=1:1), and the mixture was stirred until completely dissolved to obtain a precursor solution;

(2) Iron-cobalt bimetallic-organic framework material based on 2,5-dihydroxyterephthalic acid ligand: The precursor solution obtained in step (1) was transferred to a 100 mL polytetrafluoroethylene-lined autoclave , put the reaction kettle into a program-controlled oven, solvothermally react at 170 °C for 24 hours; cool, naturally cool to room temperature, filter with a vacuum pump and repeat with absolute ethanol, N,N-dimethylformamide (DMF) and deionized water. Wash to obtain brown precipitate; put the precipitate into a vacuum drying oven at 100°C for 12 hours to obtain black solid powder, which is an iron-cobalt bimetallic-organic framework material based on 2,5-dihydroxyterephthalic acid ligand.

The above iron-cobalt bimetallic-organic framework material is characterized by scanning electron microscope, wherein, FIG. 3 is a scanning electron microscope image of the iron-cobalt bimetallic-organic framework material in this embodiment with a magnification of 10 million times.

Example 4

Addition of iron-cobalt bimetallic-organic framework materials based on 2,5-dihydroxyterephthalic acid ligands and potassium hydrogen peroxymonosulfate, iron-cobalt bimetallic-organic frameworks based on 2,5-dihydroxyterephthalic acid ligands Removal rate of MB under the condition of framework material or potassium hydrogen persulfate

The conical flask was used as the reactor, the reaction volume of the wastewater was 100 mL, the initial concentration of methylene blue in the wastewater was 0.2 mM, and the pH was 6.1; three treatment groups were set up: among them, treatment group 1 was added to the reaction flask at the same time based on 2,5- The iron-cobalt bimetallic-organic framework material of dihydroxyterephthalic acid ligand (prepared by the method of Example 1) and potassium hydrogen peroxymonosulfate (final concentrations were 0.05 g/L and 2 mM, respectively), treatment group 2 was added separately based on 2,5-Dihydroxyterephthalic acid ligand iron-cobalt bimetallic-organic framework material (final concentration 0.1g/L), no need to add potassium hydrogen peroxymonosulfate; treatment group 3 added potassium hydrogen peroxymonosulfate alone (final concentration is 2mM), no need to add iron-cobalt bimetallic-organic framework material based on 2,5-dihydroxyterephthalic acid ligand; the reaction flasks of the above three treatment groups were placed in a shaking bed, and the rotation speed was The reaction was carried out at 100 rpm and a temperature of 25 °C, and the MB content in the reaction system was detected regularly to calculate the MB removal rate; the comparison results of the MB removal rate of different treatment groups are shown in Table 1.

Table 1

The results in Table 1 show that both the iron-cobalt bimetallic-organic framework materials based on 2,5-dihydroxyterephthalic acid ligand alone and the potassium hydrogen peroxymonosulfate system alone failed to effectively degrade and remove MB, while those based on 2, 5-dihydroxyterephthalic acid ligand iron-cobalt bimetallic-organic framework material activated potassium hydrogen persulfate system in the treatment effect of MB is very significant, after 30min of reaction, the removal rate of MB reached 98.2%, indicating the present invention It can quickly and effectively treat difficult-to-biochemical wastewater.

Example 5

Removal of MB under acidic, neutral and alkaline conditions by using iron-cobalt bimetallic-organic frameworks based on 2,5-dihydroxyterephthalic acid ligands to activate potassium peroxymonosulfate

The conical flask was used as the reactor, the reaction volume of the wastewater was 100 mL, and the initial concentration of MB in the wastewater was 0.2 mM; four treatment groups were set: among them, the reaction began to go to the reaction flask and potassium hydrogen persulfate was added to make the concentration 2 mM, The pH value of the wastewater was adjusted to 3.0 (treatment group 1), 5.0 (treatment group 2), 7.0 (treatment group 3), 9.0 (treatment group 4) and 11.0 (treatment group 5), and then poured into the reaction flask. Add the iron-cobalt bimetallic-organic framework material based on 2,5-dihydroxyterephthalic acid ligand (prepared by the method of Example 1) to make the reaction concentration 0.05g/L, and place the reaction flask in the shaking bed , under the condition of rotating speed of 100rpm and temperature of 25℃, the MB content in the reaction system was detected regularly, and the MB removal rate was calculated; Table 2 shows the effect of metal-organic framework activated potassium peroxymonosulfate on MB degradation.

Table 2

The results in Table 2 show that the iron-cobalt bimetallic-organic framework material activated potassium hydrogen persulfate oxidation method can have a very good degradation effect on MB under acidic and near-neutral conditions, saving the cost of acid feeding and ensuring the high-grade Efficiency of oxidation technology. The treatment effect is the best under the condition of pH=5.0, and the iron-cobalt bimetallic-organic framework material based on 2,5-dihydroxyterephthalic acid ligand has less dosage and high activation efficiency.

Example 6

Effects of different dosages of Fe-Co bimetallic-organic framework based on 2,5-dihydroxyterephthalic acid ligand on MB removal rate

The conical flask was used as the reactor, the reaction volume of the wastewater was 100 mL, the initial concentration of MB in the wastewater was 0.2 mM, and the pH was 6.1. The reaction began to go to the reaction flask and potassium hydrogen persulfate was added to make the concentration 2 mM, and four treatments were set. Group: wherein, the iron-cobalt bimetallic-organic framework material based on 2,5-dihydroxyterephthalic acid ligand (prepared by the method of Example 3) was added to the reaction flask to make the reaction concentration 0.05g/L (treatment Group 1), 0.1g/L (treatment group 2), 0.2g/L (treatment group 3) and 0.3g/L (treatment group 4), and finally the reaction flask was placed in a shaking bed, and the rotating speed was 100 rpm and the temperature was 100 rpm. The reaction was carried out under the condition of 25 °C and the MB content in the reaction system was detected regularly to calculate the MB removal rate; Table 3 shows the effect of potassium bisulfate on the degradation of MB.

table 3

The results in Table 3 show that the concentration of iron-cobalt bimetallic-organic framework materials based on 2,5-dihydroxyterephthalic acid ligands has a certain effect on the degradation of MB by activated potassium peroxymonosulfate. With the increase of its concentration, MB The degradation rate of 2,5-dihydroxyterephthalic acid ligand-based iron-cobalt bimetallic-organic framework material was the highest when the concentration of 0.1 g/L was 0.1 g/L, and 100% of MB was degraded within 10 min. It shows that the iron-cobalt bimetallic-organic framework material based on 2,5-dihydroxyterephthalic acid ligand has high activity and low dosage. Therefore, it has broad application prospects in organic wastewater that is difficult to biochemically treat.

The above-mentioned embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited by the above-mentioned embodiments, and any other changes, modifications, substitutions, combinations, The simplification should be equivalent replacement manners, which are all included in the protection scope of the present invention.

Claims (10)

1. a kind of iron-cobalt bimetallic-organic framework material based on 2,5-dihydroxyterephthalic acid ligand, it is characterized in that being prepared by following raw material components: cobalt nitrate hexahydrate, chloride tetrahydrate Iron, 2,5-dihydroxyterephthalic acid, the molar ratio of the cobalt nitrate hexahydrate, ferrous chloride tetrahydrate, and 2,5-dihydroxyterephthalic acid is 4:1:2.5～1:4 : 2.5. 2. The iron-cobalt bimetallic-organic framework material based on 2,5-dihydroxyterephthalic acid ligand according to claim 1, wherein the iron-cobalt bimetallic-organic framework material has a regular shape The hollow polyhedron or rod-like structure. 3. the preparation method of the iron-cobalt bimetallic-organic framework material based on 2,5-dihydroxyterephthalic acid ligand according to claim 1, is characterized in that comprising the following steps: (1) Preparation of precursor solution: dissolving cobalt nitrate hexahydrate, ferrous chloride tetrahydrate and 2,5-dihydroxyterephthalic acid in an organic solvent, and then mixing uniformly to obtain a precursor solution; (2) Preparation of iron-cobalt bimetallic-organic framework material based on 2,5-dihydroxyterephthalic acid ligand: the precursor solution obtained in step (1) is subjected to solvothermal treatment at a temperature of 110-170 °C reaction; cooling, washing, and drying to obtain an iron-cobalt bimetallic-organic framework material based on a 2,5-dihydroxyterephthalic acid ligand. 4. the preparation method of the iron-cobalt bimetallic-organic framework material based on 2,5-dihydroxyterephthalic acid ligand according to claim 3, is characterized in that: described organic solvent is N,N-dimethyl Formamide and absolute ethanol, the volume ratio of the N,N-dimethylformamide and absolute ethanol is 1:1 or 1:0. 5. the preparation method of the iron-cobalt bimetallic-organic framework material based on 2,5-dihydroxyterephthalic acid ligand according to claim 3, is characterized in that: described solvothermal reaction is lined with polytetrafluoroethylene The solvothermal reaction time is 24-48h; the washing conditions are: using absolute ethanol, N,N-dimethylformamide and deionized water to alternately and repeatedly wash the precipitate; the The drying conditions are: drying at 60-100°C for 12-24 hours. 6. The application of the iron-cobalt bimetallic-organic framework material based on 2,5-dihydroxyterephthalic acid ligand according to claim 1 in the field of wastewater treatment. 7. according to the application of the iron-cobalt bimetallic-organic framework material based on 2,5-dihydroxyterephthalic acid ligand according to claim 6, it is characterized in that comprising the following steps: adding in the waste water as an oxidant Hydrogen sulfate and iron-cobalt bimetallic-organic frameworks based on 2,5-dihydroxyterephthalic acid ligands as catalysts for wastewater treatment reactions. 8. according to the application of the iron-cobalt bimetallic-organic framework material based on 2,5-dihydroxyterephthalic acid ligand according to claim 7, it is characterized in that: described peroxymonosulfate is sodium peroxymonosulfate or potassium hydrogen peroxymonosulfate. 9. according to the application of the iron-cobalt bimetallic-organic framework material based on 2,5-dihydroxyterephthalic acid ligand according to claim 8, it is characterized in that: the organic pollutants of described hydrogen peroxymonosulfate and waste water The molar ratio is 6-300:1, and the dosage of the iron-cobalt bimetallic-organic framework material based on the 2,5-dihydroxyterephthalic acid ligand is 20-200 mg/L. 10. The application of the iron-cobalt bimetallic-organic framework material based on 2,5-dihydroxyterephthalic acid ligand according to claim 7, characterized in that: the temperature of the wastewater treatment reaction is 20-60°C, and the time is 2 to 30 minutes; the wastewater treatment reaction is carried out under stirring or shaking conditions, and the rotating speed of stirring or shaking is 50-200 rpm; the wastewater is organic wastewater, and the pH value of the organic wastewater is 3.0-11.0.

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