Zirconium-doped nano zero-valent metal composite material as well as preparation method and application thereof
The preparation of zirconium-doped nano zero-valent metal composite materials by liquid phase in situ reduction co-precipitation method has solved the stability and activity problems of nano zero-valent metals when treating organic chelating agent wastewater, and achieved efficient and stable degradation of organic pollutants and metal ion control, avoiding secondary pollution.
Patent Information
- Application Number
- CN202510634241.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-16
- Publication Date
- 2025-08-19
AI Technical Summary
Nanovalent metals are prone to excessive corrosion when they contain organic chelating agent pollutants in the treatment water, resulting in material deconstruction and metal ions leaching, forming secondary pollution, and existing modification methods have not effectively solved their stability and activity problems.
The zirconium-doped nano zero-valent metal composite material was prepared by liquid phase in situ reduction co-precipitation method. The particle size was reduced through zirconium doping, and a multi-level layered framework was formed to enhance dispersion, and the electron enrichment effect of zirconium and pH changes in the buffer interface of hydroxyl layer were inhibited and the stability was improved.
It realizes efficient treatment of organic chelating agent wastewater, and zirconium-doped nano zero-valent metal composites maintain high stability within a wide pH range, significantly improve the specific surface area and reactive sites, and can efficiently generate reactive oxygen species, degrade organic pollutants and control metal dissolution, avoid secondary pollution.
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Figure CN120502324A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of environmental protection, and in particular relates to a zirconium-doped nanometer zero-valent metal material and a preparation method and application thereof. Background Art
[0002] In recent years, nano-zero-valent metals (nZVMs) have been widely used in water treatment due to their high chemical reactivity. Their unique core-shell structure makes them show great application potential in the field of Fenton-like catalysts. However, in actual applications, nZVMs are very prone to agglomeration and surface passivation. Existing technologies usually modify nZVMs to enhance the dispersibility of nanoparticles while promoting the reactivity of nZVMs to ensure that they have better anti-passivation ability. However, in actual water treatment processes, this type of highly active nZVMs composite material is very likely to cause excessive corrosion of nZVMs, resulting in the deconstruction of the nZVMs composite material, the leaching of large amounts of metal ions, and the formation of secondary pollution, especially when the water contains organic pollutants with strong metal chelating coordination capabilities. Summary of the Invention
[0003] To address the above technical issues, the present invention provides a zirconium-doped nano-zero-valent metal composite material, its preparation method, and its application. The present invention prepares the zirconium-doped nano-zero-valent metal composite material (nZVMs-Zr) via a liquid-phase in-situ reduction co-precipitation method. This composite material exhibits excellent redox activity and high stability. Furthermore, this composite material can be used as a Fenton-like catalyst for the efficient treatment of organic chelating agent-contaminated wastewater.
[0004] To achieve the above object, the technical solution of the present invention is as follows:
[0005] In one aspect, the present invention provides a method for preparing a zirconium-doped nano zero-valent metal composite material, comprising the following steps:
[0006] In an aqueous solution, a transition metal salt and a zirconium source are reacted under the action of a reducing agent to prepare the zirconium-doped nanometer zero-valent metal composite material.
[0007] As a preferred embodiment, the transition metal is selected from at least one of Fe, Cu and Co.
[0008] In the technical solution of the present invention, the Fe salt is soluble Fe 2+ Salt; Cu salt is soluble Cu 2+ Salt; Co salt is soluble Co 2+ Salt.
[0009] In the technical solution of the present invention, the zirconium source is a soluble Zr salt, such as ZrCl4, Zr(NO3)4 and Zr(SO4)2.
[0010] As a preferred embodiment, the molar ratio of the transition metal in the transition metal salt to Zr in the zirconium source is 1:1-5.
[0011] As a preferred embodiment, the reducing agent is at least one of KBH4 and ascorbic acid.
[0012] As a preferred embodiment, the molar ratio of the reducing agent to the metal ions in the reaction system is 4 to 10:1; in the technical solution of the present invention, the metal ions in the reaction system include transition metal ions and zirconium ions.
[0013] As a preferred embodiment, the reaction is carried out in an inert atmosphere.
[0014] As a preferred embodiment, the reaction time is 2 to 6 hours.
[0015] In certain specific embodiments, the reducing agent is added to the reaction system in the form of a solution at a flow rate of 5 mL / min; the reaction is carried out under stirring conditions; and the reaction further includes post-processing of centrifugation, washing, and vacuum freeze-drying.
[0016] In another aspect, the present invention provides a zirconium-doped nanometer zero-valent metal composite material obtained by the above preparation method.
[0017] In another aspect, the present invention provides application of the zirconium-doped nano zero-valent metal composite material in the treatment of organic chelating agent wastewater.
[0018] In the technical solution of the present invention, the organic chelating agent is selected from at least one of ethylenediaminetetraacetic acid (EDTA), hydroxyethylidene diphosphonic acid (HEDP), nitrilotriacetic acid (NTA) and citric acid (CA).
[0019] In some specific embodiments, the zirconium-doped nano zero-valent metal composite material is added to organic chelating agent wastewater and reacted for 2 to 6 hours to remove the organic chelating agent in the water; the amount of the zirconium-doped nano zero-valent metal composite material in the organic chelating agent wastewater is 0.5 to 2.0 g / L.
[0020] In some specific embodiments, the concentration of the organic chelating agent in the organic chelating agent wastewater is 10-50 mg / L.
[0021] In certain specific embodiments, the pH of the reaction is 3.0-9.0.
[0022] The present invention has the following advantages:
[0023] (1) The present invention prepares zirconium-doped nano-zero-valent metal composite materials by liquid-phase in-situ reduction co-precipitation method. The particle size of nano-zero-valent metals (nZVMs) is reduced by zirconium doping to form a multi-level layered skeleton, which not only further prevents the agglomeration of nanoparticles but also forms highly dispersed nZVMs, significantly increasing the specific surface area of the composite material and enabling it to expose more reactive sites.
[0024] (2) In the zirconium-doped nano-zero-valent metal composite material prepared by the present invention, the hydroxyl (-OH) layer adsorbed on the zirconium surface can effectively buffer the pH change of the reaction interface of nZVMs in water, providing a suitable interfacial reaction environment for nZVMs at extreme pH.
[0025] (3) In the zirconium-doped nano-zero-valent metal composite prepared by the present invention, the electron enrichment effect of zirconium can significantly change the surface electronic structure of nZVMs, resulting in an increase in the Fermi level of the composite, which to some extent inhibits the electron loss process of nZVMs in the composite. In addition, zirconium doping can form a stronger bonding structure with other transition metals through orbital hybridization, further inhibiting the metal dissolution kinetics rate, ultimately endowing the nZVMs-Zr with extremely high stability while maintaining its own reactivity.
[0026] (4) The zirconium-doped nano-zero-valent metal composite material nZVMs-Zr prepared by the present invention can not only form an interfacial pre-enrichment effect on organic metal chelating agents such as EDTA, NTA, HEDP and CA in water, but also the highly stable nZVMs-Zr can control its reaction interface to undergo 2-electron transfer with dissolved oxygen in the system to efficiently generate H2O2, thereby inducing a Fenton-like reaction in situ to generate reactive oxygen species (ROSs) such as interfacial hydroxyl radicals and singlet oxygen, thereby achieving efficient degradation of organic pollutants enriched at the interface. BRIEF DESCRIPTION OF THE DRAWINGS
[0027] Figure 1 3 is a SEM image of the zirconium-doped nanometer zero-valent metal composite material nZVI-Zr prepared in Example 1 of the present invention.
[0028] Figure 2 This is a SEM image of the zirconium-doped nano zero-valent metal composite material nZVCu-Zr prepared in Example 2 of the present invention.
[0029] Figure 3 This is a SEM image of the zirconium-doped nanometer zero-valent metal composite material nZVCo-Zr prepared in Example 3 of the present invention.
[0030] Figure 4 3 is the XRD pattern of the zirconium-doped nanometer zero-valent metal composite material nZVI-Zr prepared in Example 1 of the present invention.
[0031] Figure 5This is the XRD pattern of the zirconium-doped nanometer zero-valent metal composite material nZVCu-Zr prepared in Example 2 of the present invention.
[0032] Figure 6 3 is the XRD pattern of the zirconium-doped nanometer zero-valent metal composite material nZVCo-Zr prepared in Example 3 of the present invention.
[0033] Figure 7 This is a comparison chart of the production of H2O2 produced by activating dissolved oxygen by nZVI and nZVI-Zr in Example 1 of the present invention.
[0034] Figure 8 This is a comparison chart of the production of H2O2 produced by activating dissolved oxygen by nZVCu and nZVCu-Zr in Example 2 of the present invention.
[0035] Figure 9 This is a comparison chart of the production of H2O2 produced by activating dissolved oxygen by nZVCo and nZVCo-Zr in Example 3 of the present invention. DETAILED DESCRIPTION
[0036] The following embodiments are merely some of the embodiments of the present invention, rather than all of them. Therefore, the detailed description of the embodiments of the present invention provided below is not intended to limit the scope of the claimed invention, but rather merely represents selected embodiments of the present invention. All other embodiments derived by those skilled in the art based on the embodiments of the present invention without creative effort are intended to fall within the scope of protection of the present invention.
[0037] In the present invention, unless otherwise specified, all equipment and raw materials can be purchased from the market or are commonly used in the industry. The methods in the following embodiments, unless otherwise specified, are all conventional methods in the art.
[0038] Example 1:
[0039] This embodiment provides a zirconium-doped nano zero-valent metal composite material nZVI-Zr, the preparation process of which is as follows:
[0040] Mix 50 mL of 0.02 M FeSO4 and 50 mL of 0.02 M ZrCl4 solutions; under argon protection, add 100 mL of 0.08 M KBH4 solution dropwise to the mixed solution at a flow rate of 5 mL / min, and mechanically stir for 2 hours; centrifuge and wash the resulting solid material with ultrapure water and anhydrous ethanol to remove impurities, and then vacuum freeze-dry to obtain the zirconium-doped nano-zero-valent metal composite material nZVI-Zr.
[0041] In this example, nZVI-Zr was used to treat chelating agent-containing wastewater. The specific method was as follows: Using a 250mL beaker as a reactor, simulated wastewater containing 50mg / L of EDTA, NTA, CA, and HEDP was prepared, and 200mL of each was added to the corresponding reaction vessel. 0.5g / L of nZVI-Zr was then added to each reactor. The reactor was placed in a 25°C water bath with mechanical stirring at 300rpm. After 2 hours of reaction, the EDTA, NTA, CA, and HEDP removal efficiencies were calculated for each system under different pH conditions. The results are shown in Table 1. Within the pH range of 3.0-9.0, the degradation and removal efficiencies of EDTA, NTA, CA, and HEDP reached a maximum of 99%, 100%, 100%, and 93%, respectively. Furthermore, the maximum iron ion dissolution rate from nZVI-Zr within the pH range of 3.0-9.0 was only 0.2mg / L.
[0042] This example also tested the degradation and removal of EDTA, NTA, CA, and HEDP by the pure nano-zero-valent metal composite material nZVI under the same conditions. The preparation process of the pure nano-zero-valent metal material nZVI is the same as that of nZVI-Zr, except that ZrCl4 is not added during the preparation process. The test results are shown in Table 1: At the same pH, the degradation and removal rates of EDTA, NTA, CA, and HEDP by nZVI are all lower than those of nZVI-Zr. Furthermore, nZVI suffers from severe excessive corrosion during the reaction, especially under acidic conditions. 2+ The maximum dissolution amount reached 11.90 mg / L, which is about 60 times that of nZVI-Zr.
[0043] In addition, nZVI-Zr has better dissolved oxygen activation ability. During the reaction, nZVI-Zr can generate H2O2 more efficiently through 2 electron transfer, and its H2O2 production is 3 times that of nZVI. Figure 7 shown.
[0044] Table 1
[0045]
[0046] Example 2:
[0047] This embodiment provides a zirconium-doped nano zero-valent metal composite material nZVCu-Zr, the preparation process of which is as follows:
[0048] Mix 50 mL of 0.02 M CuSO4 and 50 mL of 0.08 M ZrCl4 solution; under argon protection, add 100 mL of 0.4 M KBH4 solution dropwise to the mixed solution at a flow rate of 5 mL / min, and mechanically stir for 2 hours; centrifuge and wash the resulting solid material with ultrapure water and anhydrous ethanol to remove impurities, and then vacuum freeze-dry to obtain the zirconium-doped nano-zero-valent metal composite material nZVCu-Zr.
[0049] In this example, nZVCu-Zr was used to treat chelating agent-containing wastewater. The specific method was as follows: Using a 250mL beaker as a reactor, simulated wastewater containing 10mg / L of EDTA, NTA, CA, and HEDP was prepared, and 200mL of each was added to the corresponding reaction vessel. Then, 1.0g / L of nZVCu-Zr was added to each reactor. The reactor was placed in a 25°C water bath and mechanically stirred at 300rpm. After 4 hours of reaction, the EDTA, NTA, CA, and HEDP removal efficiencies were calculated under different pH conditions. The results are shown in Table 2. Within the pH range of 3.0-9.0, the degradation and removal efficiencies of EDTA, NTA, CA, and HEDP reached a maximum of 100%, 96%, 100%, and 100%, respectively. Furthermore, the maximum copper ion dissolution rate of nZVCu-Zr within the pH range of 3.0-9.0 was only 0.3mg / L.
[0050] This example also tested the degradation and removal of EDTA, NTA, CA, and HEDP by the pure nano-zero-valent metal composite material nZVCu under the same conditions. The preparation process of the pure nano-zero-valent metal material nZVCu was similar to that of nZVCu-Zr, except that ZrCl4 was not added during the preparation process. The test results are shown in Table 1: At the same pH, the degradation and removal rates of EDTA, NTA, CA, and HEDP by nZVCu were all lower than those of nZVCu-Zr. Furthermore, nZVCu underwent severe over-corrosion during the reaction, especially under acidic conditions. 2+ The maximum dissolution amount reached 20.53 mg / L, which is about 68 times that of nZVI-Zr.
[0051] In addition, nZVCu-Zr has better dissolved oxygen activation ability. During the reaction, nZVCu-Zr can generate H2O2 more efficiently through 2 electron transfer, and its H2O2 production is more than 3 times that of nZVCu. Figure 8 shown.
[0052] Table 2
[0053]
[0054] Example 3:
[0055] This embodiment provides a zirconium-doped nano zero-valent metal composite material nZVCo-Zr, the preparation process of which is as follows:
[0056] Mix 50 mL of 0.02 M CoCl2 and 50 mL of 0.10 M ZrCl4 solutions; under argon protection, add 100 mL of 0.6 M KBH4 solution dropwise to the mixed solution at a flow rate of 5 mL / min, and mechanically stir for 6 hours; centrifuge, wash the resulting solid material with ultrapure water and anhydrous ethanol to remove impurities, and then vacuum freeze-dry to obtain the zirconium-doped nano-zero-valent metal composite material nZVCo-Zr.
[0057] In this example, nZVCo-Zr was used to treat chelating agent-containing wastewater. The specific method was as follows: Using a 250mL beaker as a reactor, simulated wastewater containing 30mg / L of EDTA, NTA, CA, and HEDP was prepared, and 200mL of each was added to the corresponding reaction vessel. Then, 2.0g / L of nZVCo-Zr was added to each reactor. The reactor was placed in a 25°C water bath with mechanical stirring at 300rpm. After 4 hours of reaction, the EDTA, NTA, CA, and HEDP removal efficiencies were calculated under different pH conditions. The results are shown in Table 3. Within the pH range of 3.0-9.0, the degradation and removal efficiencies of EDTA, NTA, CA, and HEDP reached a maximum of 95%, 92%, 97%, and 87%, respectively. Furthermore, the cobalt ion dissolution rate of nZVCo-Zr was less than 0.1mg / L within the pH range of 3.0-9.0.
[0058] This example also tested the degradation and removal effects of pure nano-zero-valent metal composite material nZVCo on EDTA, NTA, CA, and HEDP under the same conditions. The preparation process of pure nano-zero-valent metal material nZVCo is the same as that of nZVCo-Zr, except that ZrCl4 is not added during the preparation process. The test results are shown in Table 1: nZVCo has similar degradation and removal rates for EDTA, NTA, CA, and HEDP under acidic and neutral conditions, but the degradation and removal of each pollutant is significantly inhibited under alkaline conditions. Furthermore, nZVCo suffers from severe excessive corrosion during the reaction, especially under acidic conditions. 2+ The maximum dissolution amount reached 6.70 mg / L, which is 67 times that of nZVCo.
[0059] In addition, nZVCo-Zr has better dissolved oxygen activation ability. During the reaction, nZVCo-Zr can generate H2O2 more efficiently through 2 electron transfer, and its H2O2 production is 5 times that of nZVCo. Figure 9 shown.
[0060] Table 3
[0061]
[0062]
[0063] Figure 1-3 Shown are SEM images of the zirconium-doped nano-zero-valent metal composite materials prepared in Examples 1-3 of the present invention. It can be seen from the figures that a large number of nano-zero-valent metal particles grow on the zirconium oxide skeleton and form a large number of three-dimensional porous structures.
[0064] Figure 4-6 Shown are the XRD patterns of the zirconium-doped nano-zero-valent metal composite materials prepared in Examples 1-3 of the present invention, respectively. It can be seen from the figure that the diffraction peak at a diffraction angle of 28° belongs to the characteristic peak of amorphous ZrO2, and characteristic diffraction peaks belonging to nano-zero-valent metal are also observed, proving that the zirconium-doped nano-zero-valent metal composite material was successfully prepared.
[0065] In summary, the zirconium-doped nano-zero-valent metal composite material (nZVMs-Zr) prepared by the present invention has high chemical stability and can effectively degrade and remove a variety of organic pollutants with strong metal coordination and chelation capabilities in water over a wide pH range (3.0-9.0), including EDTA (69%-100%), NTA (83%-100%), CA (90%-100%), and HEDP (65%-100%). In addition, nZVMs-Zr has better dissolved oxygen activation performance. Compared with pure nZVMs without zirconium doping, nZVMs-Zr can more efficiently produce H2O2 through a two-electron transfer process.
[0066] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.
Claims
1. A method for preparing a zirconium-doped nano zero-valent metal composite material, characterized in that: The following steps are involved: In an aqueous solution, a transition metal salt and a zirconium source are reacted under the action of a reducing agent to prepare the zirconium-doped nanometer zero-valent metal composite material.
2. The preparation method according to claim 1, characterized in that The transition metal is selected from at least one of Fe, Cu and Co; And / or, the reducing agent is selected from at least one of KBH4 and ascorbic acid; And / or, the zirconium source is a soluble Zr salt.
3. The preparation method according to claim 1, characterized in that Fe salt is soluble Fe 2+ Salt; Cu salt is soluble Cu 2+ Salt; Co salt is soluble Co 2+ Salt.
4. The preparation method according to claim 1, characterized in that The molar ratio of the transition metal in the transition metal salt to the Zr in the zirconium source is 1:1 to 5; And / or, the molar ratio of the reducing agent to the metal ions in the reaction system is 4 to 10:
1.
5. The preparation method according to claim 1, characterized in that The reaction is carried out in an inert atmosphere; And / or, the reaction time is 2 to 6 hours.
6. The zirconium-doped nano zero-valent metal composite material obtained by the preparation method according to any one of claims 1 to 5.
7. Use of the zirconium-doped nano zero-valent metal composite material according to claim 6 in the treatment of organic chelating agent wastewater.
8. The use according to claim 7, characterized in that The organic chelating agent is selected from at least one of ethylenediaminetetraacetic acid, hydroxyethylidene diphosphonic acid, nitrilotriacetic acid and citric acid.
9. The use according to claim 7, characterized in that The zirconium-doped nanometer zero-valent metal composite material is added into organic chelating agent wastewater and subjected to reaction treatment for 2 to 6 hours.
10. The use according to claim 9, characterized in that The dosage of the zirconium-doped nano zero-valent metal composite material in organic chelating agent wastewater is 0.5-2.0 g / L; and / or, the concentration of the organic chelating agent in the organic chelating agent wastewater is 10 to 50 mg / L; And / or, the pH of the reaction is 3.0 to 9.0.