A kind of lattice copper and carbon vacancy co-modified zero-valent iron and its preparation method and application in catalytic dechlorination of carbon tetrachloride in water body

Abstract

The application discloses lattice copper and carbon vacancy co-modified zero-valent iron and a preparation method and application thereof in catalyzing dechlorination of carbon tetrachloride in water, and belongs to the technical field of functional catalysts and underground water pollution remediation. The application solves the technical problem of slow and incomplete dechlorination caused by inherent electron competition between carbon tetrachloride and water. Based on an in-situ sacrifice strategy of the iron oxide layer, the application utilizes consumption of the surface iron oxide layer, oxygen volatilization and carbon reduction in a high-temperature ball milling process to induce formation of carbon vacancies, promote lattice doping of copper in the core of the zero-valent iron, promote outward release of iron and inward migration of copper (lattice doping), and prepare the lattice copper and carbon vacancy co-modified zero-valent iron catalyst with a symbiotic structure. The catalyst can realize rapid and complete dechlorination of carbon tetrachloride, the product is a chlorine-free product (methane, carbon monoxide and formic acid), the product recovery rate is greater than 80%, and the dechlorination reaction can occur in a wide pH environment.

Description

Technical Field

[0001] This invention relates to a lattice copper and carbon vacancy co-modified zero-valent iron, its preparation method, and its application in the catalytic dechlorination of carbon tetrachloride in water, belonging to the technical field of functional catalysts and their application in groundwater pollution remediation. Background Technology

[0002] Carbon tetrachloride is ubiquitous in groundwater, posing a significant potential threat to ecological security and human health. However, due to its low electron affinity, carbon tetrachloride requires a high energy barrier for dechlorination. Furthermore, as the dechlorination reaction proceeds, structural saturation due to the reduction in the number of hydrogenated or chlorinated substituents typically leads to a significant decrease in the electron affinity of intermediates, complicating the dechlorination process and potentially increasing the toxicity of dechlorination intermediates, thus raising the risk of re-contamination of water. Therefore, there is an urgent need for sustainable and efficient chemical dechlorination solutions to mitigate secondary pollution after dechlorination treatment of water bodies.

[0003] Zero-valent iron (ZVFe) reduction dechlorination provides an economical, safe, and efficient approach to pollution control and ecological security. However, due to the inherent electron competition between organic matter and water, slow and incomplete dechlorination remains extremely challenging. This is mainly attributed to the hydrophilicity of ZVFe, which makes its selectivity for target pollutants lower than its selectivity for water. Furthermore, the dense structure of the surface iron oxide layer hinders electron transport and interfacial mass transfer. Moreover, ZVFe dechlorination is entirely determined by a direct electron transfer mechanism, while the dechlorination of low-chlorine organic matter is more likely to be dominated by the indirect reduction of active hydrogen. Therefore, the synergistic enhancement of both direct electron transfer and indirect reduction by active hydrogen is crucial for achieving complete dechlorination of carbon tetrachloride by ZVFe. To achieve complete dechlorination of carbon tetrachloride, the iron oxide layer needs to be utilized rationally. Chinese patent application CN116553702A discloses a method for reduction dechlorination using a compound surfactant coupled with a sulfurized micronized ZVFe system, specifically using the compound surfactants HTAB and Tween80 coupled with sulfurized micronized ZVFe materials as a reducing agent to reduce carbon tetrachloride in water. However, due to its limited reducing capacity and single direct electron transfer reduction dechlorination mechanism, carbon tetrachloride is difficult to completely remove in groundwater environments. In order to achieve rapid and complete dechlorination of carbon tetrachloride without generating secondary pollutants, it is still necessary to further develop modified zero-valent iron materials with high hydrophobicity, high electron transfer capacity, and effective utilization of active hydrogen. Summary of the Invention

[0004] This invention addresses the technical problem of slow and incomplete dechlorination caused by the inherent electron competition between carbon tetrachloride and water, by providing a method for preparing lattice copper and carbon vacancy co-modified zero-valent iron and its application in the catalytic dechlorination of carbon tetrachloride in water.

[0005] The technical solution of this invention:

[0006] One objective of this invention is to provide a method for preparing zero-valent iron co-modified by lattice copper and carbon vacancies, the method comprising the following steps:

[0007] (1) Citric acid was subjected to a first ball milling process under an argon atmosphere to obtain precursor A;

[0008] (2) Add micron-sized zero-valent iron to precursor A and continue ball milling under argon atmosphere to obtain precursor B;

[0009] (3) Add copper powder to the precursor B and continue ball milling in an argon atmosphere to obtain lattice copper and carbon vacancy co-modified zero-valent iron.

[0010] Further specifying, the mass ratio of citric acid, micronized zero-valent iron, and copper powder is 0.0958-0.6182: 2.7830-4.4891: 0.5109-2.2170.

[0011] Further specifying, the particle size of micron-sized zero-valent iron is 30-50 μm.

[0012] Further specifying, the ball-to-material ratio for the first, second, and third ball milling processes is 10:1, with the ratio of 6mm diameter to 10mm diameter zirconia balls being 6:1.

[0013] Further specified, in (1), the first ball milling treatment speed is 550 r / min and the time is 4 h.

[0014] Further specified, in (2) the second ball milling treatment speed is 550 r / min and the time is 2 h.

[0015] Further specified, in (3) the third ball milling treatment speed is 550 r / min and the time is 6 h.

[0016] The second objective of this invention is to provide a lattice copper and carbon vacancy co-modified zero-valent iron prepared by the above method.

[0017] The third objective of this invention is to provide an application of the above-mentioned lattice copper and carbon vacancy co-modified zero-valent iron, specifically for catalyzing the chemical dechlorination of carbon tetrachloride in water.

[0018] The fourth objective of this invention is to provide a method for dechlorinating carbon tetrachloride in groundwater using the above-mentioned lattice copper and carbon vacancy co-modified zero-valent iron catalyst. Specifically, lattice copper and carbon vacancy co-modified zero-valent iron are used as catalysts, and the groundwater containing carbon tetrachloride is catalytically degraded for 1-20 hours at an oscillation rate of 20-25℃ and 200r / min to achieve complete dechlorination of carbon tetrachloride in the groundwater.

[0019] The initial concentration of carbon tetrachloride in groundwater is further limited to 5 mg / L.

[0020] Beneficial effects:

[0021] This invention, based on an in-situ sacrifice strategy for the iron oxide layer, cleverly utilizes the consumption of the surface iron oxide layer, oxygen volatilization, and carbon reduction during high-temperature ball milling to induce the formation of carbon vacancies. This promotes lattice doping of copper in the zero-valent iron core (similar to the Kirkendall effect), facilitating the outward release of iron and the inward migration of copper (lattice doping), thus preparing lattice copper with a symbiotic structure and carbon vacancy-modified zero-valent iron. Compared with existing technologies, it also has at least the following advantages:

[0022] (1) The lattice copper and carbon vacancy co-modified zero-valent iron provided by this invention can achieve rapid and complete dechlorination of carbon tetrachloride, with chlorine-free products (methane, carbon monoxide, formic acid) and a product recovery rate of over 80%. The dechlorination reaction can occur in a wide range of pH environments. In addition, the lattice copper and carbon vacancy co-modified zero-valent iron catalyst material has excellent reusability, providing superior reactivity and long-term stability for deep dechlorination of carbon tetrachloride in sustainable groundwater treatment.

[0023] (2) This invention utilizes copper lattice doping in the zero-valent iron core to disrupt the continuity of the zero-valent iron bcc lattice, inducing the release of core electrons and promoting the reductive transformation from carbon tetrachloride to chloroform and then to dichloromethane. The resulting carbon vacancies act as sites and bridges for the generation of active hydrogen, allowing active hydrogen to spontaneously migrate to the adjacent zero-valent iron and participate in the subsequent dechlorination process from dichloromethane to monochloromethane and then to the chlorine-free product. This symbiotic structure modulates the coupling mechanism between direct electron transfer and indirect reduction of active hydrogen, lowers the reaction energy barrier, and achieves thermodynamically favorable continuous and complete dechlorination. Attached Figure Description

[0024] Figure 1 Comparison of the effects of lattice copper and carbon vacancy co-modified zero-valent iron on the degradation of carbon tetrachloride prepared in Examples 1-4 with different copper-iron molar ratios;

[0025] Figure 2 Comparison of the effects of lattice copper and carbon vacancy co-modified zero-valent iron with different carbon-iron molar ratios prepared in Examples 5-8 on the degradation of carbon tetrachloride;

[0026] Figure 3 The graph shows a comparison of the rates at which lattice copper and carbon vacancy co-modified zero-valent iron prepared in Example 9 degrade carbon tetrachloride at different pH values.

[0027] Figure 4 TEM images and partial magnified views of lattice copper and carbon vacancy co-modified zero-valent iron prepared in Example 10;

[0028] Figure 5The image shows the changes in products during the degradation of carbon tetrachloride by lattice copper and carbon vacancy co-modified zero-valent iron prepared in Example 10. Detailed Implementation

[0029] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the examples in the specification.

[0030] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0031] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that is mutually exclusive with other embodiments.

[0032] Unless otherwise specified, the experimental methods used in the following examples are conventional methods. Unless otherwise specified, all materials, reagents, methods, and instruments used are conventional materials, reagents, methods, and instruments in the art, and can be obtained commercially by those skilled in the art. Furthermore, all solid and liquid reagents used are of analytical grade.

[0033] Example 1

[0034] (1) Weigh 0.1545g of citric acid and add it to a 100mL stainless steel container of a planetary ball mill. Add zirconia balls (the ratio of 6mm diameter and 10mm diameter zirconia balls is 6:1, and the material ratio is 10:1). Grind the mixture at 550r / min for 4h under an argon atmosphere to obtain precursor A.

[0035] (2) Weigh 3.1868 g of micron zero-valent iron, add the above precursor A, and continue to grind it in a 100 mL stainless steel container of a planetary ball mill, and add zirconia balls (the ratio of 6 mm diameter and 10 mm diameter zirconia balls is 6:1, and the material ratio is 10:1). Grind the precursor B at 550 r / min speed for 2 h under an argon atmosphere.

[0036] (3) Weigh 0.3642g of copper powder to make the copper-iron molar ratio 0.1, add the above-mentioned precursor B, and continue to grind in a 100mL stainless steel container of a planetary ball mill with the addition of zirconia balls (the ratio of 6mm diameter and 10mm diameter zirconia balls is 6:1, and the material ratio is 10:1). Grind at 550r / min for 6h under an argon atmosphere to prepare lattice copper with symbiotic structure and carbon vacancy co-modified zero-valent iron, named 0.1.

[0037] Example 2

[0038] (1) Weigh 0.1545g of citric acid and add it to a 100mL stainless steel container of a planetary ball mill. Add zirconia balls (the ratio of 6mm diameter and 10mm diameter zirconia balls is 6:1, and the material ratio is 10:1). Grind the mixture at 550r / min for 4h under an argon atmosphere to obtain precursor A.

[0039] (2) Weigh 3.1868 g of micron zero-valent iron, add the above precursor A, and continue to grind it in a 100 mL stainless steel container of a planetary ball mill, and add zirconia balls (the ratio of 6 mm diameter and 10 mm diameter zirconia balls is 6:1, and the material ratio is 10:1). Grind the precursor B at 550 r / min speed for 2 h under an argon atmosphere.

[0040] (3) Weigh 1.0926g of copper powder to make the copper-iron molar ratio 0.3, add the above-mentioned precursor B, and continue to grind in a 100mL stainless steel container of a planetary ball mill, and add zirconia balls (the ratio of 6mm diameter and 10mm diameter zirconia balls is 6:1, and the material ratio is 10:1). Grind at 550r / min for 6h under an argon atmosphere to prepare lattice copper with symbiotic structure and carbon vacancy co-modified zero-valent iron, named 0.3.

[0041] Example 3

[0042] (1) Weigh 0.1545g of citric acid and add it to a 100mL stainless steel container of a planetary ball mill. Add zirconia balls (the ratio of 6mm diameter and 10mm diameter zirconia balls is 6:1, and the material ratio is 10:1). Grind the mixture at 550r / min for 4h under an argon atmosphere to obtain precursor A.

[0043] (2) Weigh 3.1868 g of micron zero-valent iron, add the above precursor A, and continue to grind it in a 100 mL stainless steel container of a planetary ball mill, and add zirconia balls (the ratio of 6 mm diameter and 10 mm diameter zirconia balls is 6:1, and the material ratio is 10:1). Grind the precursor B at 550 r / min speed for 2 h under an argon atmosphere.

[0044] (3) Weigh 1.8210g of copper powder to make the copper-iron molar ratio 0.5, add the above-mentioned precursor B, and continue to grind in a 100mL stainless steel container of a planetary ball mill, and add zirconia balls (the ratio of 6mm diameter and 10mm diameter zirconia balls is 6:1, and the material ratio is 10:1). Grind at 550r / min for 6h under an argon atmosphere to prepare lattice copper with symbiotic structure and carbon vacancy co-modified zero-valent iron, named 0.5.

[0045] Example 4

[0046] (1) Weigh 0.1545g of citric acid and add it to a 100mL stainless steel container of a planetary ball mill. Add zirconia balls (the ratio of 6mm diameter and 10mm diameter zirconia balls is 6:1, and the material ratio is 10:1). Grind the mixture at 550r / min for 4h under an argon atmosphere to obtain precursor A.

[0047] (2) Weigh 3.1868 g of micron zero-valent iron, add the above precursor A, and continue to grind it in a 100 mL stainless steel container of a planetary ball mill, and add zirconia balls (the ratio of 6 mm diameter and 10 mm diameter zirconia balls is 6:1, and the material ratio is 10:1). Grind the precursor B at 550 r / min speed for 2 h under an argon atmosphere.

[0048] (3) Weigh 2.5494g of copper powder to make the copper-iron molar ratio 0.7, add the above-mentioned precursor B, and continue to grind in a 100mL stainless steel container of a planetary ball mill, and add zirconia balls (the ratio of 6mm diameter and 10mm diameter zirconia balls is 6:1, and the material ratio is 10:1). Grind at 550r / min for 6h under an argon atmosphere to prepare lattice copper with symbiotic structure and carbon vacancy co-modified zero-valent iron, named 0.7.

[0049] The lattice copper and carbon vacancy-modified zero-valent iron prepared in Examples 1 to 4 above were used to degrade carbon tetrachloride with an initial concentration of 5 mg / L. The amount of lattice copper and carbon vacancy-modified zero-valent iron added was 0.2 g / L. The degradation efficiency of carbon tetrachloride was as follows: Figure 1 As shown, by Figure 1 It can be seen that lattice copper and carbon vacancy co-modified zero-valent iron can completely degrade carbon tetrachloride within 5 hours, and it can be determined that the modified material with a copper-iron molar ratio of 0.5 has the fastest carbon tetrachloride degradation rate and the best performance.

[0050] Example 5

[0051] (1) Weigh 0.1539g of citric acid and add it to a 100mL stainless steel container of a planetary ball mill. Add zirconia balls (the ratio of 6mm diameter and 10mm diameter zirconia balls is 6:1, and the material ratio is 10:1). Grind the mixture at 550r / min for 4h under an argon atmosphere to obtain precursor A.

[0052] (2) Weigh 4.4891 g of micron zero-valent iron to make the carbon-iron molar ratio 0.06, add the above precursor A, and continue to grind in a 100 mL stainless steel container of a planetary ball mill, and add zirconia balls (the ratio of 6 mm diameter and 10 mm diameter zirconia balls is 6:1, and the material ratio is 10:1). Grind in an argon atmosphere at a speed of 550 r / min for 2 h to obtain precursor B.

[0053] (3) Weigh 1.8132g of copper powder, add the above precursor B, and continue to grind it in a 100mL stainless steel container of a planetary ball mill with the addition of zirconia balls (the ratio of 6mm diameter and 10mm diameter zirconia balls is 6:1, and the material ratio is 10:1). Grind the mixture at 550r / min for 6h under an argon atmosphere to prepare lattice copper with a symbiotic structure and carbon vacancy co-modified zero-valent iron, named 0.06.

[0054] Example 6

[0055] (1) Weigh 0.3078g of citric acid and add it to a 100mL stainless steel container of a planetary ball mill. Add zirconia balls (the ratio of 6mm diameter and 10mm diameter zirconia balls is 6:1, and the material ratio is 10:1). Grind the mixture at 550r / min for 4h under an argon atmosphere to obtain precursor A.

[0056] (2) Weigh 4.4891 g of micron zero-valent iron to make the carbon-iron molar ratio 0.12, add the above precursor A, and continue to grind in a 100 mL stainless steel container of a planetary ball mill, and add zirconia balls (the ratio of 6 mm diameter and 10 mm diameter zirconia balls is 6:1, and the material ratio is 10:1). Grind in an argon atmosphere at a speed of 550 r / min for 2 h to obtain precursor B.

[0057] (3) Weigh 1.8132g of copper powder, add the above precursor B, and continue to grind in a 100mL stainless steel container of a planetary ball mill, and add zirconia balls (the ratio of 6mm diameter and 10mm diameter zirconia balls is 6:1, and the material ratio is 10:1). Grind at 550r / min for 6h under an argon atmosphere to prepare lattice copper with symbiotic structure and carbon vacancy co-modified zero-valent iron, named 0.12.

[0058] Example 7

[0059] (1) Weigh 0.4617g of citric acid and add it to a 100mL stainless steel container of a planetary ball mill. Add zirconia balls (the ratio of 6mm diameter and 10mm diameter zirconia balls is 6:1, and the material ratio is 10:1). Grind the mixture at 550r / min for 4h under an argon atmosphere to obtain precursor A.

[0060] (2) Weigh 4.4891 g of micron zero-valent iron to make the carbon-iron molar ratio 0.18, add the above precursor A, and continue to grind in a 100 mL stainless steel container of a planetary ball mill, and add zirconia balls (the ratio of 6 mm diameter and 10 mm diameter zirconia balls is 6:1, and the material ratio is 10:1). Grind in an argon atmosphere at a speed of 550 r / min for 2 h to obtain precursor B.

[0061] (3) Weigh 1.8132g of copper powder, add the above precursor B, and continue to grind it in a 100mL stainless steel container of a planetary ball mill with the addition of zirconia balls (the ratio of 6mm diameter and 10mm diameter zirconia balls is 6:1, and the material ratio is 10:1). Grind the mixture at 550r / min for 6h under an argon atmosphere to prepare lattice copper with a symbiotic structure and carbon vacancy co-modified zero-valent iron, named 0.18.

[0062] Example 8

[0063] (1) Weigh 0.6156g of citric acid and add it to a 100mL stainless steel container of a planetary ball mill. Add zirconia balls (the ratio of 6mm diameter and 10mm diameter zirconia balls is 6:1, and the material ratio is 10:1). Grind the mixture at 550r / min for 4h under an argon atmosphere to obtain precursor A.

[0064] (2) Weigh 4.4891 g of micron zero-valent iron to make the carbon-iron molar ratio 0.24, add the above precursor A, and continue to grind in a 100 mL stainless steel container of a planetary ball mill, and add zirconia balls (the ratio of 6 mm diameter and 10 mm diameter zirconia balls is 6:1, and the material ratio is 10:1). Grind in an argon atmosphere at a speed of 550 r / min for 2 h to obtain precursor B.

[0065] (3) Weigh 1.8132g of copper powder, add the above precursor B, and continue to grind it in a 100mL stainless steel container of a planetary ball mill with the addition of zirconia balls (the ratio of 6mm diameter and 10mm diameter zirconia balls is 6:1, and the material ratio is 10:1). Grind the mixture at 550r / min for 6h under an argon atmosphere to prepare lattice copper with a symbiotic structure and carbon vacancy co-modified zero-valent iron, named 0.24.

[0066] The lattice copper and carbon vacancy-modified zero-valent iron prepared in Examples 5-8 were used to degrade carbon tetrachloride with an initial concentration of 5 mg / L. The amount of lattice copper and carbon vacancy-modified zero-valent iron added was 0.3 g / L. The degradation efficiency of carbon tetrachloride was as follows: Figure 2 As shown, by Figure 2 It can be determined that the modified material with a carbon-iron molar ratio of 0.12 has the fastest degradation rate and the best performance in carbon tetrachloride.

[0067] Example 9

[0068] (1) Weigh 0.3291g of citric acid and add it to a 100mL stainless steel container of a planetary ball mill. Add zirconia balls (the ratio of 6mm diameter and 10mm diameter zirconia balls is 6:1, and the material ratio is 10:1). Grind the mixture at 550r / min for 4h under an argon atmosphere to obtain precursor A.

[0069] (2) Weigh 3.7275 g of micron zero-valent iron, add the above precursor A, and continue to grind it in a 100 mL stainless steel container of a planetary ball mill, and add zirconia balls (the ratio of 6 mm diameter and 10 mm diameter zirconia balls is 6:1, and the material ratio is 10:1). Grind the precursor B at 550 r / min speed for 2 h under an argon atmosphere.

[0070] (3) Weigh 1.8132g of copper powder, add the above precursor B, and continue to grind in a 100mL stainless steel container of a planetary ball mill, and add zirconia balls (the ratio of 6mm diameter and 10mm diameter zirconia balls is 6:1, and the material ratio is 10:1). Grind at 550r / min for 6h under an argon atmosphere to prepare lattice copper with symbiotic structure and carbon vacancy co-modified zero-valent iron.

[0071] The lattice copper and carbon vacancy co-modified zero-valent iron prepared in this example was used to degrade carbon tetrachloride with an initial concentration of 5 mg / L. The amount of lattice copper and carbon vacancy co-modified zero-valent iron added was 0.3 g / L, and the pH of the carbon tetrachloride solution was adjusted to 3, 5, 7, 9, and 11 using hydrochloric acid or sodium hydroxide, respectively. The efficiency of carbon tetrachloride degradation is as follows: Figure 3 As shown, by Figure 3 It can be determined that the dechlorination reaction can occur in a wide range of pH environments, especially at pH 3, where the degradation rate of carbon tetrachloride is the fastest and the performance is the best.

[0072] Example 10

[0073] (1) Weigh 0.6182g of citric acid and add it to a 100mL stainless steel container of a planetary ball mill. Add zirconia balls (the ratio of 6mm diameter and 10mm diameter zirconia balls is 6:1, and the material ratio is 10:1). Grind the mixture at 550r / min for 4h under an argon atmosphere to obtain precursor A.

[0074] (2) Weigh 3.1868 g of micron zero-valent iron, add the above precursor A, and continue to grind it in a 100 mL stainless steel container of a planetary ball mill, and add zirconia balls (the ratio of 6 mm diameter and 10 mm diameter zirconia balls is 6:1, and the material ratio is 10:1). Grind the precursor B at 550 r / min speed for 2 h under an argon atmosphere.

[0075] (3) Weigh 2.2170 copper powder, add the above precursor B, and continue to grind in a 100mL stainless steel container of a planetary ball mill, and add zirconia balls (the ratio of 6mm diameter and 10mm diameter zirconia balls is 6:1, and the material ratio is 10:1). Grind at 550r / min for 6h under an argon atmosphere to prepare lattice copper with symbiotic structure and carbon vacancy co-modified zero-valent iron.

[0076] The microstructure of the lattice copper and carbon vacancy co-modified zero-valent iron prepared in this embodiment was characterized, and the results are as follows: Figure 4 As shown, a lattice “continuity break” corresponding to the Fe(110) facet was observed by aberration-corrected high-angle annular dark-field transmission electron microscopy. This may correspond to a Kirkendall-like effect of asymmetric displacement between iron and copper, and shows an abundance of carbon vacancies and topological carbon defects.

[0077] The lattice copper and carbon vacancy co-modified zero-valent iron prepared in this embodiment were used to degrade carbon tetrachloride with an initial concentration of 5 mg / L. The amount of lattice copper and carbon vacancy co-modified zero-valent iron added was 0.3 g / L. The products of carbon tetrachloride degradation were as follows: Figure 5 As shown, by Figure 5 It can be confirmed that lattice copper and carbon vacancy co-modification of zero-valent iron achieves rapid and complete dechlorination of carbon tetrachloride, with chlorine-free products consisting of 69% methane, 12% carbon monoxide, and 5% formic acid, and a recovery rate of over 80%.

[0078] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Anyone skilled in the art can make various modifications and alterations without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be determined by the claims.

Claims

1. Use of a crystal lattice copper and carbon vacancy co-modified zero-valent iron, characterized in that, The preparation method of the lattice copper and carbon vacancy co-modified zero-valent iron comprises the following steps: (1) performing first ball milling treatment on citric acid under an argon atmosphere to obtain a precursor A; (2) adding micron zero-valent iron into the precursor A and continuing to perform second ball milling treatment under the argon atmosphere to obtain a precursor B; (3) adding copper powder into the precursor B and continuing to perform third ball milling treatment under the argon atmosphere to obtain the lattice copper and carbon vacancy co-modified zero-valent iron; The mass ratio of the citric acid, the micron zero-valent iron and the copper powder is 0.0958-0.6182:2.7830-4.4891:0.5109-2.2170; The obtained lattice copper and carbon vacancy co-modified zero-valent iron is used for catalyzing chemical dechlorination of carbon tetrachloride in water, and complete dechlorination of carbon tetrachloride in groundwater is realized.

2. Use according to claim 1, characterized in that, The particle size of the micron zero-valent iron is 30-50 μm.

3. Use according to claim 1, characterized in that, The ball-to-material ratio of the first ball milling, the second ball milling and the third ball milling is 10:1, wherein the ratio of the zirconium oxide balls with a diameter of 6 mm and the zirconium oxide balls with a diameter of 10 mm is 6:

1.

4. Use according to claim 1, characterized in that, In the first ball milling treatment, the rotating speed is 550 r / min, and the time is 4 h.

5. The use according to claim 1, characterized in that, In the second ball milling treatment, the rotating speed is 550 r / min, and the time is 2 h.

6. Use according to claim 1, characterized in that, In the third ball milling treatment, the rotating speed is 550 r / min, and the time is 6 h.

7. Use according to claim 1, characterized in that, With the lattice copper and carbon vacancy co-modified zero-valent iron as the catalyst, the groundwater containing carbon tetrachloride is catalytically degraded at a shaking speed of 200 r / min and a temperature of 20-25 ℃ for 1-20 h, and complete dechlorination of carbon tetrachloride in the groundwater is realized.

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