Axial Co-O coordination modified metalloporphyrin material and its preparation and application

Abstract

The present invention relates to the technical field of halogenated organic matter treatment, and in particular to a kind of axial Co-O coordination modified metal porphyrin material and its preparation and application. The present invention provides a preparation method of axial Co-O coordination modified metal porphyrin material, comprising: mixing porphyrin cobalt powder with reduced iron powder to obtain a mixture, then ball milling under an inert atmosphere, the cobalt atom at the center of the porphyrin cobalt and the oxygen atom on the surface of the reduced iron powder form axial Co-O coordination, and obtain axial Co-O coordination modified metal porphyrin material. The present invention mixes porphyrin cobalt with reduced iron powder, and coordinates the cobalt atom at the center of the porphyrin cobalt with the oxygen atom under the action of mechanical force, thereby obtaining an axial Co-O coordination modified metal porphyrin material, which can be used to solve the treatment problem of high-concentration organic wastewater.

Description

Technical Field

[0001] The present invention relates to the technical field of halogenated organic matter treatment, and in particular to an axial Co-O coordination modified metal porphyrin material and a preparation and application thereof. Background Art

[0002] The halogenated organic 1,2-dichloroethane (1,2-DCA) is one of the most widely produced industrial chemicals worldwide, used extensively in the synthesis of pharmaceuticals, specialty surfactants, and functionalized polymers. Despite its industrial importance, 1,2-DCA poses serious environmental risks as a groundwater contaminant, particularly due to its long-term presence at industrial sites. Exposure to 1,2-DCA is classified as a probable human carcinogen and is associated with neurological disorders, hepatotoxicity, and kidney damage. The high persistence of 1,2-DCA highlights the urgent need for effective pollution control strategies.

[0003] Common reductive dehalogenation methods include physical adsorption, electrochemical dechlorination, bioremediation, and chemical redox. However, these methods have very limited effects on the degradation of 1,2-DCA and are almost incapable of degradation. Among them, electrochemical dechlorination of 1,2-DCA has been shown to be a promising and economical dehalogenation strategy; however, due to its harsh dechlorination conditions, unclear reaction mechanism, and poor selectivity, this method is generally challenging in practice.

[0004] Catalytic conversion is considered an effective and green method. Catalytic materials can facilitate selective dehalogenation, converting C-X bonds to relatively harmless C-H bonds, making it a key environmental remediation approach. However, the selection and development of catalytic materials remains challenging; therefore, exploring more suitable catalytic materials to achieve efficient and green treatment of 1,2-DCA is an urgent issue. Summary of the Invention

[0005] The present invention provides an axially Co-O coordinated modified metalloporphyrin material, its preparation, and application. Based on mechanochemical principles, the method utilizes mechanical shear, impact, and friction forces to mechanically ball-mill the porphyrin cobalt and reduced iron powder. This allows the central cobalt atom of the porphyrin cobalt to coordinate with oxygen atoms on the surface of the reduced iron powder to form Co-O bonds, thereby obtaining a critical iron oxide shell. This helps improve the removal efficiency of halogenated organic compounds such as 1,2-DCA.

[0006] In order to achieve the above object, the present invention provides the following technical solutions:

[0007] The present invention provides a preparation method of an axial Co-O coordination modified metal porphyrin material, comprising: mixing porphyrin cobalt powder and zero-valent iron powder to obtain a mixture, then ball milling the mixture under an inert atmosphere, so that the cobalt atoms located at the center of the porphyrin cobalt form axial Co-O coordination with the oxygen atoms on the surface of the zero-valent iron powder, and post-processing to obtain the axial Co-O coordination modified metal porphyrin material.

[0008] In this invention, cobalt porphyrin powder is mixed with zero-valent iron powder, where it interacts with the iron through mechanochemical interaction, causing the cobalt to coordinate with oxygen to produce an axially Co-O coordinated metalloporphyrin material. Experimental results demonstrate that this axially Co-O coordinated metalloporphyrin material, obtained using the proposed method, effectively enhances the zero-valent iron's ability to degrade 1,2-DCA in water.

[0009] Preferably, the molar ratio of cobalt in the porphyrin cobalt powder to iron in the zero-valent iron powder is 0.006:1 to 0.008:1.

[0010] Preferably, the molar ratio of cobalt in the porphyrin cobalt powder to iron in the zero-valent iron powder is greater than or equal to 0.05:1.

[0011] When the amount of Co is gradually increased to a molar ratio of 0.05:1 between the cobalt in the porphyrin cobalt powder and the iron in the zero-valent iron powder, the degradation of 1,2-DCA is close to 100%, and rapid degradation can be achieved within 1 hour. When the amount of porphyrin cobalt is further increased, its degradation performance will not be significantly improved. Therefore, considering the cost, 0.05:1 is a better choice. However, a molar ratio greater than 0.05:1 is still within the scope of protection of the present invention. In practical applications, the addition ratio can be selected and adjusted according to actual needs.

[0012] Preferably, the particle size of the zero-valent iron powder is 2-30 μm.

[0013] Preferably, the zero-valent iron powder is elemental iron powder, reduced iron powder, cast iron powder, pig iron powder or industrial scrap iron containing zero-valent iron.

[0014] Preferably, the ball mill has a rotation speed of 300-500 rpm.

[0015] Preferably, the ball milling time is 2 to 30 h.

[0016] Preferably, the inert atmosphere comprises nitrogen.

[0017] Preferably, the inert gas is nitrogen and / or argon.

[0018] Preferably, the post-processing includes: washing the powder obtained by ball milling.

[0019] Preferably, the cleaning agent is alcohol, acid or water.

[0020] Preferably, the alcohol is ethanol and / or methanol; more preferably, the water content in the alcohol is less than 0.1%.

[0021] Preferably, the acid is a 1M acid; more preferably, the acid is at least one of sulfuric acid, hydrochloric acid or nitric acid.

[0022] Preferably, the water is deionized water or oxygen-free water; more preferably, the water is oxygen-free water.

[0023] The present invention also provides an axial Co-O coordination modified metal porphyrin material prepared by the above method, wherein the axial Co-O coordination modified metal porphyrin material comprises zero-valent iron and an iron oxide shell wrapped on the surface of the zero-valent iron, wherein the iron oxide shell is formed by Co-O coordination between cobalt atoms located at the cobalt center of the porphyrin and oxygen atoms on the surface of the zero-valent iron powder.

[0024] Preferably, the thickness of the iron oxide shell is 5 to 15 nm; based on the mass of the axial Co-O coordinated modified metal porphyrin material, the mass of the zero-valent iron is 70 to 90 wt%.

[0025] Preferably, the particle size of the axial Co-O coordination modified metalloporphyrin material is 1-10 μm.

[0026] The present invention also provides an axial Co-O coordination modified metal porphyrin material prepared by the above method or the use of the above axial Co-O coordination modified metal porphyrin material in repairing and removing halogenated organic matter in high-concentration organic wastewater.

[0027] Preferably, the halogenated organic compound is at least one of 1,2-dichloroethane, tetrachloroethylene, chloroform, trichloroethylene and trans-1,2-dichloroethylene.

[0028] Preferably, the halogenated organic compound is 1,2-dichloroethane.

[0029] Preferably, the concentration of the halogenated organic matter is 10-400 ppm.

[0030] More preferably, the concentration of the halogenated organic matter is 10-200 ppm.

[0031] The present invention also provides a method for repairing and removing halogenated organic matter in organic wastewater, wherein a catalyst is added into the organic wastewater containing the halogenated organic matter, wherein the catalyst is the above-mentioned axial Co-O coordination modified metal porphyrin material.

[0032] Preferably, the dosage of the catalyst is 1-100 g / L; more preferably, the dosage of the catalyst is 5-50 g / L; more preferably, the dosage of the catalyst is 5-10 g / L.

[0033] Therefore, the present invention has the following beneficial effects:

[0034] (1) The present invention mixes porphyrin cobalt with reduced iron powder, and coordinates the cobalt atom at the center of the porphyrin cobalt with the oxygen atom under the action of mechanical force, thereby obtaining an axial Co-O coordinated modified metal porphyrin material.

[0035] (2) The axial Co-O coordination modified metalloporphyrin material synthesized by the method of the present invention has an excellent removal effect on 1,2-DCA and can be used to solve the problem of treating high-concentration organic wastewater.

[0036] (3) The raw materials used in the method of the present invention are widely available and are used in low amounts. The preparation process does not require high temperatures, does not generate wastewater or waste, and is safe to use.

[0037] (4) The technical method of the present invention is simple, highly practical, has mild reaction conditions, is easy to operate, has high productivity, high repeatability, does not have excessively high requirements for equipment, can be used for large-scale experiments, and has significant economic, environmental and social effects. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 This is a SEM-mapping image of the axial Co-O coordinated metalloporphyrin material prepared in Example 1 of the present invention;

[0039] Figure 2 This is a SEM-mapping image of the ordinary iron powder material prepared in Comparative Example 1 of the present invention;

[0040] Figure 3 1,2-DCA removal effect diagram of Example 1 and Comparative Example 1;

[0041] Figure 4 A comparison of the effects of different Co / Fe molar ratios on the degradation of 1,2-DCA by axial Co-O coordinated modified metalloporphyrin materials;

[0042] Figure 5 A comparison of the effects of different washing methods on the degradation of 1,2-DCA by axial Co-O coordinated modified metalloporphyrin materials;

[0043] Figure 6 This is a comparison of the effects of different cobalt precursors on the degradation of 1,2-DCA by axial Co-O coordination modified metalloporphyrin materials;

[0044] Figure 7 This is a diagram showing the removal effect of Example 1 for different 1,2-DCA concentrations. DETAILED DESCRIPTION

[0045] The present invention will be further described below with reference to specific embodiments. Those skilled in the art will be able to implement the present invention based on these descriptions. Furthermore, the embodiments of the present invention described below generally represent only a portion of the present invention, rather than all of the embodiments. Therefore, all other embodiments derived by those skilled in the art based on the embodiments of the present invention without inventive effort should fall within the scope of protection of the present invention.

[0046] The particle size of the reduced iron powder in this part is 30 μm.

[0047] [Example]

[0048] Example 1

[0049] Cobalt porphyrin was mixed with reduced iron powder at a molar ratio of 0.007 (denoted as Co / Fe = 0.007) and placed in a ball mill filled with inert gas. The milling speed was 400 rpm for 20 hours to obtain an axially Co-O coordinated metalloporphyrin material, which was then washed with oxygen-free water and designated as Co-ZVI. The axially Co-O coordinated metalloporphyrin material contained 85 wt% zero-valent iron (ZVI) and had an iron oxide shell thickness of 5–15 nm. The particle size of the axially Co-O coordinated metalloporphyrin material was 5 μm.

[0050] Example 2

[0051] This embodiment is substantially the same as embodiment 1, except that the molar ratio of cobalt to iron is 0.05, denoted as Co / Fe = 0.05.

[0052] Comparative Example 1

[0053] This comparative example is basically the same as Example 1, except that: reduced iron powder with the same total mass as that in Example 1 was ball-milled while other parameters remained unchanged to obtain ordinary iron powder material; denoted as pure-ZVI, in which Co / Fe=0.

[0054] Comparative Example 2

[0055] This comparative example is basically the same as Example 1, except that it was washed with ethanol and recorded as Co-ZVI. ethanol .

[0056] Comparative Example 3

[0057] This comparative example is basically the same as Example 1, except that it was washed with 1 mol / L sulfuric acid and recorded as Co-ZVI. acid .

[0058] Comparative Example 4

[0059] This comparative example is substantially the same as Example 1, except that porphyrin cobalt is replaced by cyclohexanediamine cobalt, and the molar ratio of cobalt to iron is maintained at 0.007.

[0060] Comparative Example 5

[0061] This comparative example is substantially the same as Example 1, except that porphyrin cobalt replaces sulfonated phthalocyanine cobalt, and the molar ratio between cobalt and iron is maintained at 0.007.

[0062] Comparative Example 6

[0063] This comparative example is substantially the same as Example 1, except that the molar ratio of cobalt to iron is 0.003, denoted as Co / Fe = 0.003.

[0064] Comparative Example 7

[0065] This comparative example is substantially the same as Example 1, except that the molar ratio of cobalt to iron is 0.005, denoted as Co / Fe = 0.005.

[0066] Comparative Example 8

[0067] This comparative example is substantially the same as Example 1, except that the molar ratio of cobalt to iron is 0.01, denoted as Co / Fe = 0.01.

[0068]

Performance test

[0069] 1. SEM and XRD

[0070] The materials obtained in Example 1 and Comparative Example 1 were subjected to SEM tests respectively, and the results are as follows: Figures 1 and 2 Observation Figure 1 It can be seen that many rough particles are obviously present on the surface of the Co-ZVI material. These rough particles may be the iron oxide shell formed by axial Co-O coordination. In addition, the Co-ZVI material has a small particle size and therefore a large specific surface area, which provides more reaction sites when treating pollutants, and theoretically has a higher degradation efficiency. In comparison, without the addition of porphyrin cobalt, no Co-O coordination is formed, and thus there is no iron oxide shell. The surface morphology of pure-ZVI is regular and smooth, and the particles are larger than those of the Co-ZVI material. Comparing the SEM results of the two materials, it can be inferred that under the action of mechanical force, the axial Co-O coordination causes a significant change in the particle size and specific surface area of ​​ZVI.

[0071] 2. Degradation efficiency

[0072] The 1,2-DCA degradation experiment was conducted as follows: the material was added to a bottle, followed by HEPEs buffer solution (50 mM, pH 7) and 1,2-DCA, resulting in a material concentration of 10 g / L and a pollutant concentration of 10 ppm. Samples were collected at designated time intervals, and the headspace 1,2-DCA concentration was analyzed using a gas chromatograph.

[0073] The materials prepared in Examples 1-2 and Comparative Examples 1-7 were respectively subjected to the above-mentioned degradation test method to measure the corresponding degradation efficiency, and the results are as follows: Figures 3 to 6 shown.

[0074] Figure 3 The Co-ZVI and pure-ZVI materials obtained in Example 1 and Comparative Example 1 were observed. Figure 3 The results show that there is a significant difference in the degradation effects of Co-ZVI material and pure-ZVI material on 1,2-DCA, indicating that the degradation efficiency of Co-ZVI material on 1,2-DCA is greatly improved under the action of axial Co-O coordination.

[0075] Figure 4 The following figure shows the 1,2-DCA degradation efficiency of materials prepared at different cobalt-iron molar ratios. It can be observed that when the cobalt-iron molar ratio is 0.007, the Co-ZVI material achieves the best degradation of 1,2-DCA. When the cobalt-iron molar ratio increases to 0.05, degradation can be completed within 1 hour.

[0076] also, Figure 5 The 1,2-DCA degradation efficiency of the materials prepared under different washing methods is shown in the figure. It can be observed that when the material is washed with oxygen-free water, the CO-ZVI material achieves the best degradation effect on 1,2-DCA.

[0077] Figure 6 Figure 1 shows the 1,2-DCA degradation efficiency of materials prepared from different cobalt precursors. Cobalt cyclohexanediamine and cobalt sulfonate phthalocyanine share a central cobalt coordination structure similar to porphyrin cobalt, but the catalytic materials prepared from these three structurally similar and similarly performing cobalt precursors exhibit significant performance differences. This indicates that only porphyrin cobalt forms an axial Co-O coordination with oxygen atoms on the surface of the reduced iron powder. It can be observed that the Co-ZVI material achieves the best 1,2-DCA degradation efficiency when porphyrin cobalt is used as the cobalt source.

[0078] 3. Effect of 1,2-DCA concentration on degradation efficiency

[0079] The degradation experiments were conducted on 1,2-DCA at concentrations of 10 ppm, 40 ppm, 200 ppm, and 400 ppm using the Co-ZVI prepared in Example 1. The HEPEs buffer solution was replaced with a simulated surface water solution (pH = 7.65) prepared separately. The other degradation conditions were exactly the same as those provided in the "2. Degradation Efficiency" section. The results are recorded in Figure 7 Observation Figure 7 It was found that as the concentration of 1,2-DCA increased, the corresponding degradation rate would decrease; generally speaking, high concentration of 1,2-DCA did not significantly inhibit the degradation of Co-ZVI, that is, the Co-ZVI series materials provided by the present invention have wide applicability for the degradation of 1,2-DCA in high-concentration wastewater.

Claims

1. Application of axial Co-O coordination modified metalloporphyrin materials in the repair and removal of halogenated organic matter in organic wastewater, characterized in that: The preparation method of the axial Co-O coordination modified metal porphyrin material includes: mixing porphyrin cobalt powder and zero-valent iron powder to obtain a mixture, then ball milling under an inert atmosphere, so that the cobalt atoms located at the center of the porphyrin cobalt form axial Co-O coordination with the oxygen atoms on the surface of the zero-valent iron powder, and post-processing to obtain the axial Co-O coordination modified metal porphyrin material.

2. The use according to claim 1, characterized in that The molar ratio of cobalt in the porphyrin cobalt powder to iron in the zero-valent iron powder is 0.006:1 to 0.008:1, or the molar ratio of cobalt in the porphyrin cobalt powder to iron in the zero-valent iron powder is greater than or equal to 0.05:

1.

3. The use according to claim 1, characterized in that The particle size of the zero-valent iron powder is 2-30 μm.

4. The use according to claim 1, wherein The ball mill has a rotation speed of 300-500 rpm.

5. The use according to claim 1, characterized in that The post-processing includes: washing the powder obtained by ball milling.

6. The use according to claim 1, wherein The axial Co-O coordinated modified metal porphyrin material includes zero-valent iron and an iron oxide shell wrapped on the surface of the zero-valent iron. The iron oxide shell is formed by axial Co-O coordination between cobalt atoms located at the center of the porphyrin cobalt and oxygen atoms on the surface of the reduced iron powder.

7. The use according to claim 6, characterized in that The thickness of the iron oxide shell is 5-15 nm; based on the mass of the axial Co-O coordinated modified metal porphyrin material, the mass of the zero-valent iron is 70-90 wt%; and the particle size of the axial Co-O coordinated modified metal porphyrin material is 1-10 μm.

8. The use according to claim 1, wherein The halogenated organic compound is at least one of 1,2-dichloroethane, tetrachloroethylene, chloroform, trichloroethylene and trans-1,2-dichloroethylene.

9. A method for repairing and removing halogenated organic matter in organic wastewater, characterized in that: The catalyst is added into organic wastewater containing halogenated organic matter, wherein the catalyst is the axial Co-O coordination modified metal porphyrin material used in any one of claims 1 to 7.

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