A magnetic nano cobalt-iron-based environment-friendly material, a preparation method and application thereof

Abstract

The application relates to a magnetic nano cobalt-iron-based environment-friendly material and a preparation method and application thereof, and belongs to the technical field of magnetic nano materials, and comprises the following steps: S1: in a glove box, sodium hydroxide powder, sodium hydrosulfite and ferrous chloride are uniformly mixed to obtain a solid mixture, a proper amount of deionized water is sprayed, and a nano zero-valent iron environment-friendly material is prepared under rheological phase conditions; S2: in a water bath, nitrogen is passed for 30 min, a certain amount of cobalt chloride hexahydrate is added, mechanical stirring is carried out until the cobalt chloride hexahydrate is dissolved, and the nano zero-valent iron environment-friendly material prepared in S1 is added; S3: after the reaction is completed, the stirring is stopped, the reaction product is cooled to room temperature after standing, and the reaction product is filtered under the protection of nitrogen; the separated solid product is washed, repeatedly ultrasonically cleaned until neutral, and vacuum dried to prepare the magnetic nano cobalt-iron-based environment-friendly material; the magnetic nano cobalt-iron-based environment-friendly material not only has extremely high organic matter degradation performance, but also has good environmental friendliness, realizes more efficient, low-cost removal and wastewater purification, and is used for treating and recycling cobalt-containing wastewater.

Description

Technical Field

[0001] This invention belongs to the field of magnetic nanomaterials technology, and relates to a magnetically controlled cobalt-iron-based environmentally friendly nanomaterial, its preparation method and application, especially to a magnetically controlled cobalt-iron-based environmentally friendly nanomaterial, its preparation method and its application in treating cobalt-containing wastewater and treating antibiotics. Background Technology

[0002] The sources of cobalt-containing wastewater can be mainly attributed to the following aspects: Lithium battery production: Cobalt-containing wastewater primarily originates from the production process of lithium battery materials such as cobalt tetroxide. In this process, raw materials such as cobalt chloride crystals, ammonium bicarbonate crystals, and pure water undergo specific chemical reactions (e.g., CoCl2 + 2NH4HCO3 → CoCO3↓ + 2NH4Cl + CO2↑) to generate the target product, accompanied by various types of wastewater, including but not limited to cobalt tetroxide mother liquor, cobalt tetroxide washing water, acid and alkali wastewater, copper and manganese precipitation wastewater, cobalt salt wastewater, ammonium chloride wastewater, and cobalt oxide process wastewater. In addition, routine equipment cleaning and cleanroom maintenance also contribute a certain amount of cobalt-containing wastewater. In the electroplating industry, cobalt, as part of the electroplating solution, generates wastewater containing cobalt ions during use. In the production of ceramic products, especially certain special ceramics (such as ceramic pigments or glazes containing cobalt), cobalt-containing wastewater may also be generated. Besides the above-mentioned major industrial production processes, cobalt-containing wastewater may also originate from other fields, such as metal smelting and chemical production. These sectors may use cobalt or its compounds in their production processes, resulting in cobalt-containing wastewater.

[0003] In summary, cobalt-containing wastewater originates from a wide range of sources, primarily involving the production processes of lithium batteries, electroplating, and ceramics industries. This wastewater typically contains high concentrations of cobalt ions, along with potentially accompanying organic matter, heavy metal ions, and other harmful substances, posing a potential threat to the environment and human health. Therefore, the effective treatment of cobalt-containing wastewater is of paramount importance.

[0004] Cobalt-iron alloys possess unique soft magnetic material properties, including high saturation magnetization, high Curie temperature, low coercivity, high permeability, and low magnetic anisotropy constant. As a key magnetic nanomaterial, they have been widely used in strategic fields such as aero-engines, computer read / write heads, microelectromechanical systems (MEMS), magnetic keys, and the automotive industry. Due to quantum size effects, these materials show broad application prospects in fields such as magnetism, catalysis, and electromagnetic wave absorption.

[0005] Therefore, there is a need for a magnetically controlled nano-cobalt-iron based environmentally friendly material that can efficiently and cost-effectively treat cobalt-containing wastewater, in order to achieve the degradation of organic matter in cobalt-containing wastewater and the recycling of cobalt and iron. Summary of the Invention

[0006] In view of this, the present invention provides a magnetically controlled nano-cobalt-iron based environmentally friendly material, its preparation method and application. The preparation method utilizes a rheological phase method, using an environmentally compatible low-sulfite solution as a reducing agent to prepare nano-zero-valent iron environmentally friendly material. Using the prepared nano-iron material as a reducing agent, the magnetically controlled nano-cobalt-iron based environmentally friendly material is obtained by reduction under liquid phase conditions. It not only has extremely high organic matter degradation performance, but also has good environmental friendliness, and can achieve more efficient and low-cost removal and wastewater purification, and can be used to treat and recycle cobalt-containing wastewater.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] A method for preparing a magnetically controlled cobalt-iron nano-based environmentally friendly material includes the following steps:

[0009] S1: In a glove box, sodium hydroxide powder, sodium dithionite and ferrous salt are taken and mixed evenly to obtain a solid mixture. Ionized water is sprayed on the mixture. The mass ratio of sodium hydroxide powder, sodium dithionite and ferrous salt is 1~2:1~2:1, and the mass ratio of deionized water to solid mixture is 0.3~0.5:1. Nano-zero valent iron is obtained under rheological phase conditions.

[0010] S2: In a water bath, purge with nitrogen for 30 min, add cobalt chloride hexahydrate, stir mechanically until fully dissolved, add nano-zero valent iron prepared in step S1, the mass ratio of cobalt chloride hexahydrate to nano-zero valent iron is 4~5:1, keep heating and stirring to ensure that the cobalt salt is fully reduced by iron.

[0011] S3: After the reaction is complete, stop stirring. The cobalt salt reaction product after being fully reduced by iron in step S2 is allowed to stand and cool to room temperature, then filtered under nitrogen protection. The separated solid product is washed, repeatedly ultrasonically cleaned until neutral, and vacuum dried to obtain a layered magnetically controlled nano-cobalt-iron-based environmentally friendly material.

[0012] S4: Place the magnetized nano-cobalt-iron-based environmentally friendly material prepared in step S3 into an external magnetic field with a magnetic field strength of 300-800 kA / m to separate cobalt and iron, and further realize magnetic recycling.

[0013] The beneficial effects of this basic scheme are as follows: Compared with traditional liquid-phase reactions, rheo-phase reactions exhibit significant advantages in terms of condition setting. It cleverly avoids the need for harsh environments such as high temperatures and strong alkalis. This improvement not only greatly enhances the safety performance of the reaction apparatus, allowing the entire reaction process to proceed under milder and more controllable conditions, thereby effectively reducing the safety risks that may be caused by extreme conditions, but also achieves efficient resource utilization and conservation.

[0014] Furthermore, in step S1, the ferrous salt is ferrous chloride or ferrous sulfate.

[0015] Furthermore, in step S1, the ferrous salt is ferrous chloride, the mass ratio of sodium hydroxide powder, sodium dithionite, and ferrous chloride is 1:1:1, and the mass ratio of the amount of deionized water to the mass of the solid mixture formed by mixing sodium hydroxide powder, sodium dithionite, and ferrous chloride is 0.3:1.

[0016] Furthermore, in step S2, the mass ratio of cobalt chloride hexahydrate to nano-zero-valent iron environmentally friendly material is 4:1.

[0017] Furthermore, the temperature of the water bath in step S2 is 50-60 ℃.

[0018] Furthermore, in step S3, the reaction product is washed with oxygen-free distilled water, anhydrous ethanol, or dilute hydrochloric acid until neutral.

[0019] Furthermore, in step S3, the ultrasonic cleaning frequency is 30 kHz-50 kHz, and the power is 650 W-900 W.

[0020] Furthermore, the vacuum drying temperature in step S3 is 65-75 ℃.

[0021] Using the above-mentioned method for preparing magnetically controlled cobalt-iron nano-based environmentally friendly materials, a low-sulfite solution is used as a reducing agent to prepare nano-zero-valent iron environmentally friendly materials via a rheological phase method. The prepared nano-iron materials are then used as a reducing agent to reduce the magnetically controlled cobalt-iron nano-based environmentally friendly materials under liquid phase conditions.

[0022] The aforementioned magnetically controlled nano-cobalt iron-based environmentally friendly material can be reused after being repeatedly washed with hydrochloric acid in the recycling of cobalt-containing wastewater and the treatment of antibiotics.

[0023] The beneficial effects of this invention are as follows:

[0024] 1. This invention discloses a method for preparing a magnetically controlled cobalt-iron nano-based environmentally friendly material. The reaction process results in nanoparticles with a zero-valent iron substrate. Using a rheological phase method, an environmentally compatible low-sulfite solution is used as a reducing agent to simultaneously generate the nano-zero-valent iron substrate and modify its surface with sulfur, thereby enhancing its adsorption capacity and selectivity for antibiotic ions. This preparation method is simple, avoids the disadvantages of traditional methods such as toxic byproducts and harsh conditions, has low production costs, and uses widely available raw materials. It has the advantages of low investment and high output, while also reducing the environmental hazards of traditional carbon-loaded reinforced heavy metal ion removal composite material production processes.

[0025] 2. The method for preparing a magnetically controlled cobalt-iron-based environmentally friendly nanomaterial disclosed in this invention significantly enhances the reactivity and pollutant removal efficiency of the zero-valent iron-based material through a meticulously designed metal surface modification strategy. This innovation not only greatly enhances the material's application potential in wastewater treatment, but also significantly reduces the difficulty of treatment and the risk of environmental pollution, particularly for the effective removal of high concentrations of heavy metal ions, persistent organic pollutants, and chemical residues in wastewater.

[0026] 3. The method for preparing a magnetically controlled cobalt-iron nano-based environmentally friendly material disclosed in this invention emphasizes the sustainable use of resources from the source. Through precise metering and an efficient recycling mechanism, it ensures the maximum benefit of raw material use. During the reaction process, unreacted raw materials and byproducts can be appropriately treated and reintroduced into the production process, forming a closed-loop cycle and reducing waste emissions.

[0027] 4. This invention discloses a method for preparing a magnetically controlled nano-cobalt-iron-based environmentally friendly material. It ingeniously uses nano-zero-valent iron as the core matrix and, through a meticulously designed rheological phase process, introduces an environmentally friendly low-sulfite solution as a highly efficient reducing agent. This achieves the simultaneous construction of the nano-zero-valent iron substrate and the precise modification of its surface sulfur elements, ultimately yielding a nanocomposite material with a unique layered structure. This composite material not only inherits the characteristics of nano-zero-valent iron as a powerful reducing agent but also exhibits excellent capture and conversion capabilities for cobalt ions in a liquid environment, promoting the formation of cobalt-iron alloys and providing a novel and efficient solution for wastewater treatment. Particularly noteworthy is that the cobalt-iron alloy composite material prepared in this process, after fulfilling its purpose, can be conveniently and efficiently magnetically recycled and reused due to its excellent magnetic properties, significantly reducing treatment costs and environmental burden. The core advantages of this invention lie in its significant cost-effectiveness, low investment threshold, and feasibility for large-scale production, opening up new avenues for more economical, efficient, and environmentally friendly wastewater purification and wastewater resource recovery.

[0028] Other advantages, objectives, and features of the invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination, or may be learned from practice of the invention. The objectives and other advantages of the invention can be realized and obtained through the following description. Attached Figure Description

[0029] To make the objectives, technical solutions, and advantages of the present invention clearer, the preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, wherein:

[0030] Figure 1 This is a scanning electron microscope image of the magnetron sputtering cobalt-iron based environmentally friendly material prepared in Example 1.

[0031] Figure 2 This is a schematic diagram showing the relationship between the removal rate of TC in wastewater and time when the magnetically controlled cobalt-iron nano-based environmentally friendly material prepared in Example 1 removes a simulated tetracycline (TC) concentration of 30 mg / L.

[0032] Figure 3 This is a diagram illustrating the recycling effect of the magnetically controlled nano-cobalt-iron-based environmentally friendly material of this invention.

[0033] Figure 4 This is a schematic diagram showing the relationship between the TC removal rate in simulated TC wastewater with a concentration of 50 mg / L when the magnetically controlled cobalt-iron nano-based environmentally friendly material prepared in Example 2 of this invention removes TC from the wastewater. Detailed Implementation

[0034] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0035] Example 1

[0036] Reference Figure 1-3 This embodiment provides a method for preparing a magnetically controlled cobalt-iron nano-based environmentally friendly material, which specifically includes the following steps:

[0037] S1. Weigh 20 g of granular sodium hydroxide powder (NaOH), 20 g of sodium dithionite (Na2S2O4) and 20 g of ferrous chloride in a glove box, mix them evenly to obtain a solid mixture, and after stirring evenly, spray 20-25 ml of deionized water into the solid mixture with a spray bottle while stirring, so that the reactants react in a rheological phase. Filter the cooled reaction product under nitrogen protection, and repeatedly ultrasonically wash the separated solid product with oxygen-free distilled water, anhydrous ethanol or dilute hydrochloric acid until neutral to obtain nano-zero valent iron.

[0038] S2. In a water bath, purge with nitrogen for 30 minutes, add a certain amount of cobalt chloride hexahydrate (CoCl2·6H2O), stir mechanically until fully dissolved, add the above-synthesized nano-zero-valent iron, and keep heating and stirring to ensure that the cobalt salt is fully reduced by the iron.

[0039] S3. After the reaction is complete, stop stirring. Let the reaction product stand and cool to room temperature, then filter under nitrogen protection. The separated solid product is washed with oxygen-free distilled water, anhydrous ethanol or dilute hydrochloric acid. The ultrasonic cleaner has a frequency of 30 kHz and a power of 650 W. The product is washed until the pH is neutral. After vacuum drying, the magnetically controlled nano-cobalt iron-based environmentally friendly material is obtained.

[0040] Scanning electron microscope (SEM) images of the magnetron sputtering cobalt-iron-based environmentally friendly nanomaterials prepared in this embodiment are shown below. Figure 1 As shown, the morphological characteristics of the magnetized cobalt-iron nano-based environmentally friendly material were observed using a scanning electron microscope. Figure 1 The nZVI particles showed a plate-like structure with significantly reduced aggregation, while the magnetically controlled cobalt-iron nano-based environmentally friendly material exhibited a radial morphology. Further magnification revealed that the magnetically controlled cobalt-iron nano-based environmentally friendly material displayed a distinct rod-like structure, with a length between 100 and 2000 nanometers and a thickness of less than 100 nanometers.

[0041] Prepare 500 ml of tetracycline (TC) simulated wastewater with a concentration of 30 mg / L. Then, gradually dilute the stock solution according to the usage conditions, and take 100 mL of the stock solution into a 250 mL Erlenmeyer flask. Place the flask in a constant-temperature shaker set to 20℃ and 200 r / min, and add a certain amount of magnetically controlled nano-cobalt-iron based environmentally friendly material. Samples are taken at regular intervals. After filtering the water samples through a 0.22 μm filter membrane, the TC removal rate is measured using a UV spectrophotometer. Two parallel experiments are performed to correct for potential errors. Adsorption is confirmed when the TC content of each water sample no longer changes; the change in TC removal rate in the wastewater over time is shown in the figure. Figure 2 As shown, by Figure 2 It can be seen that TC in the wastewater was completely removed after 4 hours. After standing for 2 hours, the upper layer of the wastewater became clear, and the magnetically controlled nano-cobalt iron-based environmentally friendly material can be recycled and reused using a magnet.

[0042] Reference Figure 3 An experiment was conducted to recycle magnetically controlled nano-cobalt-iron-based environmentally friendly materials. To achieve the reuse of these materials, the following steps were taken to regenerate the reacted material: First, the used magnetically controlled nano-cobalt-iron-based environmentally friendly material was removed using a method of wrapping it with a magnet and plastic wrap. Then, it was placed in a beaker containing deionized water and rinsed four times with stirring. Next, the cleaned material was removed using the same method and placed in hydrochloric acid. Based on... Figure 3 As a result, with the increase of regeneration times, the removal rate of TC gradually decreased, and the rate of decrease gradually increased. After the 5th regeneration, the maximum removal rate of TC dropped to 63.63%, demonstrating the outstanding recyclability of the material.

[0043] Example 2

[0044] This embodiment provides a method for preparing a magnetically controlled cobalt-iron nano-based environmentally friendly material, which specifically includes the following steps:

[0045] S1. Weigh 40 g of granular NaOH, 40 g of Na2S2O4 and 400 g of ferrous chloride in a glove box, mix them evenly to obtain a solid mixture, and after stirring evenly, spray 40-45 ml of deionized water into the solid mixture with a spray bottle while stirring, so that the reactants react in a rheological phase. Filter the cooled reaction product under nitrogen protection, and repeatedly ultrasonically wash the separated solid product with oxygen-free distilled water, anhydrous ethanol or dilute hydrochloric acid until neutral to obtain nano zero-valent iron material.

[0046] S2. In a water bath, purge with nitrogen for 30 minutes, add a certain amount of cobalt chloride hexahydrate (CoCl2·6H2O), stir mechanically until fully dissolved, add the synthesized elemental iron, and keep heating and stirring to ensure that the cobalt salt is fully reduced by the iron.

[0047] S3. After the reaction is complete, stop stirring. Let the reaction product stand and cool to room temperature, then filter under nitrogen protection. The separated solid product is washed with oxygen-free distilled water, anhydrous ethanol or dilute hydrochloric acid, and repeatedly ultrasonically cleaned until neutral. The ultrasonic cleaner has a frequency of 30 kHz and a power of 650 W. The product is cleaned until the pH is neutral. After vacuum drying, the magnetically controlled nano-cobalt iron-based environmentally friendly material is obtained.

[0048] Prepare 500 ml of tetracycline (TC) simulated wastewater with a concentration of 50 mg / L. Then, gradually dilute the stock solution according to the usage conditions, and take 100 mL of the stock solution into a 250 mL Erlenmeyer flask. Place the flask in a constant-temperature shaker set to 20℃ and 200 r / min, and add 1 g of magnetically controlled nano-cobalt-iron based environmentally friendly material. Samples are taken at regular intervals. After filtering the water samples through a 0.22 μm filter membrane, the TC removal rate is measured using a UV-Vis spectrophotometer. Two parallel experiments are performed to correct for potential errors. Adsorption is confirmed when the TC content of each water sample no longer changes; the change in TC removal rate in the wastewater over time is shown in the figure. Figure 4 As shown, by Figure 4 It can be seen that the removal rate of TC in the wastewater can reach 83.69% after 4 hours. After standing for 2 hours, the upper layer of the wastewater is clear, and the magnetically controlled nano-cobalt iron-based environmentally friendly material can be recycled and reused using a magnet.

[0049] Figure 3This is an experiment to recycle magnetically controlled nano-cobalt-iron-based environmentally friendly materials. To achieve the reuse of these materials, the following steps were taken to regenerate the reacted material: First, the used magnetically controlled nano-cobalt-iron-based environmentally friendly material was removed using a method of wrapping it with a magnet and plastic wrap. Then, it was placed in a beaker containing deionized water and rinsed four times with stirring. Next, the cleaned material was removed using the same method and placed in hydrochloric acid. According to... Figure 3 As a result, with the increase in the number of regenerations, the removal rate of TC gradually decreased, and the rate of decrease gradually increased. After the 5th regeneration, the maximum removal rate of TC dropped to 56.98%, and the removal effect was as follows: Figure 4 As shown, this material exhibits outstanding recyclability. Utilizing the strong magnetic properties of the magnetron-controlled cobalt-iron nanomaterial, a highly efficient magnetic separation and recycling device was designed to achieve rapid separation and recycling of the material during processing. This not only simplifies subsequent processing steps but also significantly reduces material loss and operating costs, establishing a closed-loop resource recycling model.

[0050] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A method for preparing a magnetically controlled nano-cobalt-iron based environmentally friendly material, characterized in that, Includes the following steps: S1: In a glove box, sodium hydroxide powder, sodium dithionite and ferrous salt are taken and mixed evenly to obtain a solid mixture. Ionized water is sprayed on the mixture. The mass ratio of sodium hydroxide powder, sodium dithionite and ferrous salt is 1~2:1~2:1, and the mass ratio of deionized water to solid mixture is 0.3~0.5:

1. Nano-zero valent iron is obtained under rheological phase conditions. S2: In a water bath, purge with nitrogen for 30 min, add cobalt chloride hexahydrate, stir mechanically until fully dissolved, add nano-zero valent iron prepared in step S1, the mass ratio of cobalt chloride hexahydrate to nano-zero valent iron is 4~5:1, keep heating and stirring to ensure that the cobalt salt is fully reduced by iron. S3: After the reaction is complete, stop stirring. The cobalt salt reaction product after being fully reduced by iron in step S2 is allowed to stand and cool to room temperature, then filtered under nitrogen protection. The separated solid product is washed, repeatedly ultrasonically cleaned until neutral, and vacuum dried to obtain a layered magnetically controlled nano-cobalt-iron-based environmentally friendly material. S4: Place the magnetized nano-cobalt-iron-based environmentally friendly material prepared in step S3 into an external magnetic field with a magnetic field strength of 300-800 kA / m to separate cobalt and iron, and further realize magnetic recycling.

2. The method for preparing the magnetically controlled cobalt-iron nano-based environmentally friendly material as described in claim 1, characterized in that, In step S1, the ferrous salt is either ferrous chloride or ferrous sulfate.

3. The preparation method of the magnetically controlled nano-cobalt-iron based environmentally friendly material as described in claim 2, characterized in that, In step S1, the ferrous salt is ferrous chloride, the mass ratio of sodium hydroxide powder, sodium dithionite and ferrous chloride is 1:1:1, and the mass ratio of deionized water to the mass of the solid mixture formed by mixing sodium hydroxide powder, sodium dithionite and ferrous chloride is 0.3:

1.

4. The method for preparing the magnetron-controlled nano-cobalt-iron-based environmentally friendly material as described in claim 1, characterized in that, In step S2, the mass ratio of cobalt chloride hexahydrate to nano-zero-valent iron environmentally friendly material is 4:

1.

5. The preparation method of the magnetically controlled nano-cobalt-iron based environmentally friendly material as described in claim 4, characterized in that, The temperature of the water bath in step S2 is 50-60 ℃.

6. The method for preparing the magnetron-controlled cobalt-iron nano-based environmentally friendly material as described in claim 1, characterized in that, In steps S1 and S3, the reaction products are washed with anaerobic distilled water, anhydrous ethanol, or dilute hydrochloric acid until neutral.

7. The method for preparing the magnetically controlled cobalt-iron nano-based environmentally friendly material as described in claim 6, characterized in that, In step S3, the ultrasonic cleaning frequency is 30 kHz-50 kHz and the power is 650 W-900 W.

8. The method for preparing the magnetically controlled cobalt-iron nano-based environmentally friendly material as described in claim 7, characterized in that, The vacuum drying temperature in step S3 is 65-75 ℃.

9. A magnetically controlled cobalt-iron-based environmentally friendly material prepared by the method described in any one of claims 1-8.

10. The application of the magnetically controlled nano-cobalt iron-based environmentally friendly material as described in claim 9 in the recycling of cobalt-containing wastewater and the treatment of antibiotics, wherein the magnetically controlled nano-cobalt iron-based environmentally friendly material after treating cobalt wastewater and antibiotics can be reused after being washed multiple times with hydrochloric acid.

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