A fenton-like reaction applied catalytic filter membrane, preparation method, application and water treatment method

Abstract

The application discloses a kind of Fenton-like reaction with catalytic filter membrane, preparation method, application and water treatment method, the catalytic filter membrane is combined by membrane matrix and catalytic component, its preparation process includes catalytic component preparation and filter membrane construction and the like steps;Catalytic component is in-situ self-reduction modified MXene of cobalt, copper bimetallic atom;Filter membrane construction is combined using vacuum auxiliary or coating method catalytic component and membrane matrix.Processing water method is filter membrane in the process of filtering water catalytic Fenton-like reaction water treatment.The filter membrane for catalytic Fenton-like reaction water treatment disclosed in the application has mild preparation condition, and the water treatment process is simple and convenient to operate, efficient in treatment, integrates membrane filtration, adsorption, catalytic oxidation and the like, and is suitable for water pollution control and water deep purification.

Description

Technical Field

[0001] This invention relates to a water treatment material, its preparation method, its application, and a method for treating water, and particularly to a catalytic filter membrane material for Fenton-like reactions, its preparation method, its application, and a method for treating water, belonging to the field of water treatment materials and methods. Background Technology

[0002] In recent decades, water pollution has become a global concern, making water pollution control and effective water purification increasingly urgent. Among various water treatment technologies, Fenton and Fenton-like oxidation processes are considered highly efficient advanced oxidation technologies due to their high efficiency, mild conditions, simple operation, and thorough mineralization. Compared to traditional homogeneous reaction systems, heterogeneous systems are compatible with a wider pH range, do not produce iron sludge, have milder reaction conditions, and significantly reduce economic costs. However, improving mass transfer and catalytic efficiency in heterogeneous Fenton and Fenton-like oxidation processes remains an unresolved issue.

[0003] Membrane-based water treatment utilizes pressure-driven, osmosis-driven, and electro-driven methods to separate and remove substances from water. Membrane filtration systems typically have a small footprint and excellent water purification effects, but are easily limited by membrane fouling. Coupled with advanced oxidation technology, membrane filtration can integrate the advantages of both processes. Membrane filtration can trap and remove impurities and pollutants from water while promoting mass transfer, while advanced oxidation degrades pollutants in situ, reducing membrane fouling. Two-dimensional layered materials like MXene are gaining attention in environmental remediation due to their excellent hydrophilicity, flexibility, and high specific surface area. MXene has potential advantages as a filter membrane material, but further modification is often required to expand its catalytic activity and water flux. Modifying MXene with metals or metal oxides is a common method. However, metal modification of MXene often requires demanding preparation conditions, such as an inert gas environment and high temperature, and the size of the metal catalyst is difficult to control, resulting in low metal utilization. Mild and simple preparation methods are the foundation for widespread application. The key to further optimization and improvement of MXene materials lies in how to select appropriate modification methods, determine suitable components and ratios, construct efficient reaction systems, and improve their water flux, mass transfer efficiency, and catalytic performance. Summary of the Invention

[0004] Objectives of the Invention: To address the problems existing in the prior art, the first objective of this invention is to provide a Fenton reaction catalytic filter membrane, a water treatment material that combines high efficiency in adsorption, membrane separation, and catalytic Fenton reaction, and is suitable for Fenton reaction-like catalysis. The second objective is to provide a method for preparing this Fenton reaction catalytic filter membrane. The third objective is to provide the application of this Fenton reaction catalytic filter membrane in water treatment. The fourth objective is to provide a method for treating water using this Fenton reaction catalytic filter membrane, thus solving the problems of harsh material preparation conditions, low membrane separation efficiency, and poor catalytic activity in the prior art.

[0005] Technical solution: The present invention provides a catalytic filter membrane for Fenton-like reactions, the catalytic filter membrane comprising a membrane matrix and a catalytic component, wherein the membrane matrix is ​​an inorganic porous filter material or an organic porous filter material; and the catalytic component is MXene modified by in-situ self-reduction of cobalt and copper bimetallic atoms.

[0006] Furthermore, when MXene is modified by in-situ self-reduction of cobalt and copper bimetallic atoms, the total loading of cobalt and copper on MXene is 0.5 to 3.0% wt, and the molar ratio of cobalt to copper is 3:7-8:2.

[0007] Furthermore, the MXene is Ti3C2T rich in Ti vacancy defects. x -MXene.

[0008] Furthermore, the inorganic porous filter material is a ceramic filter material, a metal or metal oxide sintered filter material.

[0009] Furthermore, the organic porous filter material is a PVDF filter membrane or a PTFE filter membrane.

[0010] Furthermore, the Ti3C2T x -MXene is a Ti3C2T enriched with Ti vacancy defects obtained by acid etching. x -MXene lyophilized tablets.

[0011] The method for preparing the Fenton-like catalytic filter membrane of the present invention includes the following steps:

[0012] (1)Ti3C2T x Preparation of MXene: The Ti3AlC2 precursor was added to a mixed solution of hydrochloric acid and lithium fluoride, etched by heating, washed with hydrochloric acid solution, washed with water and centrifuged until the pH of the supernatant was >6, the precipitate was dissolved in deionized water, and sonicated in an ice bath under argon or nitrogen protection, the supernatant was collected by centrifugation, and the supernatant was freeze-dried to obtain Ti3C2T rich in Ti vacancy defects. x -MXene;

[0013] (2) In-situ self-reduction of cobalt and copper bimetallic atoms to prepare catalytic components: Ti3C2T rich in Ti vacancy defects is used to prepare catalytic components. x MXene was added to an aqueous ethylene glycol solution, and the mixture was sonicated to obtain Ti3C2T. x -MXene alcohol solution, cobalt-modified precursor and copper-modified precursor are added to ethylene glycol, and ultrasonication is performed to obtain a bimetallic atom alcohol solution, Ti3C2T x The MXene alcohol solution and the bimetallic atom alcohol solution were mixed, stirred and sonicated, washed multiple times by centrifugation with ultrapure water, and freeze-dried to obtain the catalytic component.

[0014] (3) Filter membrane preparation: The catalytic components are uniformly loaded or coated onto the membrane matrix by vacuum-assisted or coating method, and then freeze-dried to obtain the catalytic filter membrane.

[0015] Further, in step (1), the mass ratio of lithium fluoride to Ti3AlC2 precursor is 1.5:1-2:1.

[0016] Further, in step (1), the concentration of the hydrochloric acid is 9-12 mol / L.

[0017] Furthermore, in step (1), the temperature of the heating etching is 40-45°C, and the heating etching time is 24-48h.

[0018] Furthermore, in step (1), the freeze-drying time is 24-48 hours.

[0019] Furthermore, in step (2), the cobalt-modified precursor is one of cobalt chloride, cobalt nitrate, and cobalt sulfate.

[0020] Further, in step (2), the copper-modified precursor is one of copper chloride, copper nitrate, and copper sulfate.

[0021] Furthermore, in step (2), the volume concentration of the ethylene glycol aqueous solution is 10%.

[0022] Furthermore, in step (2), the ultrasound time is 30-60 min.

[0023] Furthermore, in step (2), the stirring and ultrasonication time is 30-60 min.

[0024] Furthermore, in step (2), the freeze-drying time is 24-48 hours.

[0025] Furthermore, in step (3), the loading density of the catalytic component on the membrane substrate is 0.4-1.5 mg / cm³. 2 .

[0026] Furthermore, in step (3), the freeze-drying time is 24-48 hours.

[0027] The application of the Fenton-like reaction catalytic filter membrane described in this invention in water purification treatment.

[0028] The present invention also includes a method for treating water using the Fenton-like reaction catalytic filter membrane, which uses the Fenton-like reaction catalytic filter membrane of the present invention as a heterogeneous catalyst for Fenton-like oxidation water treatment, including the following steps: adding hydrogen peroxide or persulfate to the water to be treated, and then filtering it through the Fenton-like reaction catalytic filter membrane of the present invention to obtain purified water.

[0029] Beneficial effects: Compared with the prior art, the present invention has the following significant advantages:

[0030] (1) The present invention uses an in-situ self-reduction method to synthesize diatomic modified MXene catalysts. The process is simple, saves a lot of metal precursors, and has no secondary pollution.

[0031] (2) The catalytic filter membrane for Fenton-like reaction described in this invention, which is loaded with diatomic atoms on its surface, overcomes the drawback of low utilization of traditional metal catalysts. The synergistic effect of the two metals improves the efficiency of Fenton-like catalytic reaction.

[0032] (3) The catalytic filter membrane for the Fenton reaction of the present invention has mild preparation conditions, simple operation and high efficiency in water treatment process, and integrates membrane filtration, adsorption and catalytic oxidation, and is suitable for water pollution control and deep water purification. Detailed Implementation

[0033] Example 1

[0034] (1) Add 2g of lithium fluoride to 40mL of 9mol / L hydrochloric acid and stir in an ice-water bath for 10 minutes to dissolve it completely. Then add 1g of Ti3AlC2 in batches. After complete dissolution, stir magnetically at 400rpm for 24h under a 40℃ water bath heating condition. After obtaining the black solution reactant, first centrifuge the black solution reactant at 3500rpm to remove concentrated hydrochloric acid, and then wash it twice with 1mol / L dilute hydrochloric acid to remove excess lithium fluoride. Finally, wash with deionized water at 3500rpm for 5 minutes each time to make the pH of the solution greater than 6. Dissolve the obtained precipitate in 100mL of water, sonicate in an ice bath for 2h under nitrogen protection, and finally centrifuge at 3500rpm for 30min. Collect the supernatant and freeze-dry the obtained supernatant at -60℃ for 48h to obtain Ti3C2T x -MXene powder is ready for use.

[0035] (2) Add 0.1g Ti3C2T xMXene powder was dispersed in 20 mL of ethylene glycol solution and sonicated for 1 h to obtain Ti3C2T x –MXene alcohol solution. Simultaneously, based on a total loading of approximately 2.6% wt and a cobalt to copper molar ratio of approximately 7:3, 7.5 mg CoCl₂·6H₂O and 2.3 mg CuCl₂·2H₂O were weighed and dissolved in 30 mL of ethylene glycol and sonicated for 1 h to obtain a bimetallic atom alcohol solution. Subsequently, this solution was added to a uniformly dispersed Ti₃C₂T₂ solution. x A mixture was obtained by slowly adding a bimetallic atom alcohol solution to an MXene alcohol solution and stirring for 30 min. The mixture was then sonicated for 1 h under nitrogen atmosphere. After washing with ultrapure water and centrifuging three times (3500 rpm), the precipitate was freeze-dried at -60℃ for 48 h to obtain cobalt-copper bimetallic modified Ti3C2T. x MXene material is used as a catalytic component.

[0036] Comparative Example 1

[0037] The catalyst material was designed with a similar total loading, and the preparation process was the same as in Example 1, except that only 10.7 mg of CoCl2·6H2O was added as the precursor salt solution, resulting in cobalt single-atom modified Ti3C2T. x -MXene material.

[0038] Comparative Example 2

[0039] The catalyst material was designed with a similar total loading, and the preparation process was the same as in Example 1, except that only 7.7 mg of CuCl2·2H2O was added as the precursor salt solution, resulting in copper single-atom modified Ti3C2T. x -MXene material.

[0040] The modified Ti3C2T prepared in Example 1 and Comparative Examples 1 and 2 x -MXene materials are used as heterogeneous catalysts for the activation of persulfate treatment, specifically: modified Ti3C2T x -MXene material was added at a concentration of ~100 mg / L, and the water to be treated was an ofloxacin aqueous solution with a concentration of ~60 mg / L. Modified Ti3C2T was then added. x After pre-adsorption of MXene material for 30 min, ~1 mmol / L potassium persulfate was added, and the reaction was carried out for 20 min. Samples were then taken to determine the concentration of ofloxacin in the water. The results are shown in Table 1.

[0041] Table 1 Comparison of persulfate catalytic performance of three catalytic materials

[0042] Material Ofloxacin total removal rate (%) Example 1 ～73.2 Comparative Example 1 ～62.9 Comparative Example 2 ～3.4

[0043] As can be seen from Table 1, the comparative example of total cobalt single-atom modification of Ti3C2T x -MXene material has a certain removal effect on ofloxacin. Comparative Example 2: Copper single-atom modified Ti3C2T x -MXene materials have a weak effect on the removal of ofloxacin, while the cobalt and copper diatomic modified Ti3C2T of this invention... x -MXene material has a better removal effect than cobalt single-atom modified Ti3C2T x -MXene materials and copper single-atom modified Ti3C2T x -MXene material can remove more ofloxacin within 20 minutes.

[0044] Example 2

[0045] Cobalt and copper diatomic modified Ti3C2T x The preparation method for MXene is the same as in Example 1.

[0046] Furthermore, a vacuum-assisted strategy is adopted to... 10mg Catalytic components cobalt and copper dual-atom modified Ti3C2T x -MXene catalyst was uniformly loaded to a loading of ~12.56 cm⁻¹ using vacuum filtration. 2 The loading density of the catalytic component on the PTFE filter membrane is ~0.8 mg / cm³. 2 The catalytic filter membrane can be obtained by freeze-drying at -60℃ for 48 hours.

[0047] The catalytic filter membrane prepared in this embodiment was used for the treatment of persulfate brine. Specifically, the catalytic filter membrane prepared in this embodiment was placed on a vacuum filtration device, and the vacuum pressure was controlled at 0.6 bar. An aqueous solution containing ~2 mmol / L potassium persulfate and ~40 mg / L ofloxacin was filtered to conduct a membrane filtration coupled with persulfate catalytic oxidation water treatment experiment. The water flux of the catalytic filter membrane and the concentration of the pollutant ofloxacin in the water after membrane filtration were measured, and the treatment efficiency was analyzed. The treatment results are shown in Table 2.

[0048] Comparative Example 3

[0049] The activated persulfate treatment is the same as in Example 2, using unmodified Ti3C2T. x -MXene, i.e., Ti3C2T obtained in step (1) of Example 1. x -MXene is a membrane filter material prepared by filtration onto a PTFE membrane according to the method in Example 2. (Unmodified Ti3C2T) x The loading density of MXene on the PTFE filter membrane is ~0.80 mg / cm³. 2 The processing results are shown in Table 2.

[0050] Table 2 Comparison of persulfate catalytic performance of two catalytic membranes

[0051] Material <![CDATA[Water flux (L / (m 2 ·h))]]> Ofloxacin total removal rate (%) Example 2 ～1303 ～100 Comparative Example 3 ～87 ～67

[0052] As can be seen from Table 2, the cobalt and copper diatomic modified Ti3C2T of this invention... x -MXene filter membrane compared to unmodified Ti3C2T x -MXene filter membranes have significantly improved water flux and pollutant removal efficiency, and the modified filter membrane material has excellent performance.

[0053] Example 3

[0054] Using the catalytic filter membrane prepared in Example 2 and the membrane filter material prepared in Comparative Example 3, the water treatment method in Example 2 was adopted, and ~2 mmol / L potassium persulfate was replaced with ~2 mmol / L H2O2 for treatment. The treatment effect is shown in Table 3.

[0055] Table 3. Treatment methods and effects

[0056] Material <![CDATA[The removal rate of ofloxacin (mg / (m 2 ·min)]]> Example 2 ～718.3 Comparative Example 3 ～53.2

[0057] As can be seen from Table 3, the cobalt and copper diatomic modified Ti3C2T of this invention x -MXene filter membranes also exhibit excellent performance in catalytic hydrogen peroxide-based Fenton reaction systems, with a significant improvement in treatment efficiency compared to the unmodified material, indicating that this material has a wide range of applications in the field of catalytic Fenton water treatment.

Claims

1. A catalytic filter membrane for Fenton-like reactions, characterized in that, The catalytic filter membrane includes a membrane matrix and a catalytic component. The membrane matrix is ​​an inorganic porous filter material or an organic porous filter material. The catalytic component is MXene modified by in-situ self-reduction of cobalt and copper bimetallic atoms. The method for preparing the Fenton-like catalytic filter membrane includes the following steps: (1) Ti3C2T x Preparation of MXene: The Ti3AlC2 precursor was added to a mixed solution of hydrochloric acid and lithium fluoride, etched by heating, washed with hydrochloric acid solution, washed with water and centrifuged until the pH of the supernatant was >6, the precipitate was dissolved in deionized water, and sonicated in an ice bath under argon or nitrogen protection, the supernatant was collected by centrifugation, and the supernatant was freeze-dried to obtain Ti3C2T rich in Ti vacancy defects. x -MXene; (2) In-situ self-reduction of cobalt and copper bimetallic atoms to prepare catalytic components: Ti3C2T rich in Ti vacancy defects is used to prepare catalytic components. x MXene was added to an aqueous ethylene glycol solution and sonicated to obtain Ti3C2T. x -MXene alcohol solution, cobalt-modified precursor and copper-modified precursor are added to ethylene glycol, and ultrasonication is performed to obtain a bimetallic atom alcohol solution, Ti3C2T x The MXene alcohol solution and the bimetallic atom alcohol solution were mixed, stirred and sonicated, washed multiple times by centrifugation with ultrapure water, and freeze-dried to obtain the catalytic component. (3) Filter membrane preparation: The catalytic components are uniformly loaded or coated onto the membrane matrix by vacuum-assisted or coating method, and then freeze-dried to obtain the catalytic filter membrane.

2. The catalytic filter membrane for Fenton-like reactions according to claim 1, characterized in that, When MXene is modified by in-situ self-reduction of cobalt and copper bimetallic atoms, the total loading of cobalt and copper on MXene is 0.5~3.0%wt, and the molar ratio of cobalt to copper is 3:7-8:

2.

3. The catalytic filter membrane for Fenton-like reactions according to claim 1, characterized in that, The MXene is a Ti3C2T rich in Ti vacancy defects. x -MXene, wherein the inorganic porous filter media is ceramic filter media, metal or metal oxide sintered filter media, and the organic porous filter media is PVDF filter membrane or PTFE filter membrane.

4. The method for preparing the Fenton-like catalytic filter membrane according to any one of claims 1-3, characterized in that, Includes the following steps: (1) Ti3C2T x Preparation of MXene: The Ti3AlC2 precursor was added to a mixed solution of hydrochloric acid and lithium fluoride, etched by heating, washed with hydrochloric acid solution, washed with water and centrifuged until the pH of the supernatant was >6, the precipitate was dissolved in deionized water, and sonicated in an ice bath under argon or nitrogen protection, the supernatant was collected by centrifugation, and the supernatant was freeze-dried to obtain Ti3C2T rich in Ti vacancy defects. x -MXene; (2) In-situ self-reduction of cobalt and copper bimetallic atoms to prepare catalytic components: Ti3C2T rich in Ti vacancy defects is used to prepare catalytic components. x MXene was added to an aqueous ethylene glycol solution and sonicated to obtain Ti3C2T. x -MXene alcohol solution, cobalt-modified precursor and copper-modified precursor are added to ethylene glycol, and ultrasonication is performed to obtain a bimetallic atom alcohol solution, Ti3C2T x The MXene alcohol solution and the bimetallic atom alcohol solution were mixed, stirred and sonicated, washed multiple times by centrifugation with ultrapure water, and freeze-dried to obtain the catalytic component. (3) Filter membrane preparation: The catalytic components are uniformly loaded or coated onto the membrane matrix by vacuum-assisted or coating method, and then freeze-dried to obtain the catalytic filter membrane.

5. The preparation method according to claim 4, characterized in that, In step (1), the mass ratio of lithium fluoride to Ti3AlC2 precursor is 1.5:1-2:1, the concentration of hydrochloric acid solution is 9-12 mol / L, the temperature of heating etching is 40-45 °C, the heating etching time is 24-48 h, and the freeze-drying time is 24-48 h.

6. The preparation method according to claim 4, characterized in that, In step (2), the cobalt-modified precursor is one of cobalt chloride, cobalt nitrate, and cobalt sulfate, and the copper-modified precursor is one of copper chloride, copper nitrate, and copper sulfate.

7. The preparation method according to claim 4, characterized in that, In step (2), the volume concentration of the ethylene glycol aqueous solution is 10%, the ultrasonic time is 30-60 min, the stirring and ultrasonic time is 30-60 min, and the freeze-drying time is 24-48 h.

8. The preparation method according to claim 4, characterized in that, In step (3), the loading density of the catalytic component on the membrane substrate is 0.4-1.5 mg / cm³. 2 The freeze-drying time is 24-48 h.

9. The application of the Fenton-like catalytic filter membrane according to any one of claims 1-3 in water treatment.

10. A method for treating water using a Fenton-like reaction catalytic membrane according to any one of claims 1-3, characterized in that, Using the Fenton-like reaction catalytic filter membrane according to any one of claims 1-3 as a heterogeneous catalyst for Fenton-like oxidation water treatment includes the following steps: adding hydrogen peroxide or persulfate to the water to be treated, and then filtering it through the Fenton-like reaction catalytic filter membrane according to any one of claims 1-3 to obtain purified water.