Fe-doped MoS2 catalyst-loaded ceramic catalytic membrane as well as preparation method and application thereof

Abstract

The invention provides a Fe-doped MoS2 catalyst-loaded ceramic catalytic membrane as well as a preparation method and application thereof, and belongs to the technical field of water treatment. The ceramic catalytic membrane loaded with the Fe-doped MoS2 catalyst comprises a porous ceramic membrane and the Fe-doped MoS2 catalyst loaded on the surface and in holes of the porous ceramic membrane, wherein the Fe element in the Fe-doped MoS2 catalyst and the S element in MoS2 form a coordination structure.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of water treatment, and particularly relates to a ceramic catalytic membrane loaded with Fe-doped MoS2 catalyst and a preparation method and application thereof. BACKGROUND

[0002] Fenton-like advanced oxidation technology has a wide application in water treatment and water environment remediation, and particularly shows excellent performance in removing refractory organic pollutants in water and disinfection. Among them, Fe-based heterogeneous catalysts have become a research hotspot due to environmental friendliness, recyclability and good Fenton catalytic activity. However, there is a key bottleneck in the Fenton reaction of traditional Fe-based catalysts: low-valence Fe ions are difficult to be effectively regenerated after being gradually oxidized to high-valence state, resulting in significant decrease in catalytic activity and stability.

[0003] To solve the above problems, a common strategy is to introduce a co-catalyst as a reducing agent in the Fe-based catalyst to accelerate the iron ion cycle. As a non-homogeneous co-catalyst with excellent performance, MoS2 can effectively drive the reduction of Fe IV and Mo VI between them can effectively drive the reduction of Fe 3+ , thereby promoting the Fe ion cycle. Further studies have shown that doping Fe atoms into the MoS2 lattice can significantly improve the Fenton catalytic activity and long-term use stability. At the same time, the edge structure of MoS2 nanosheets can realize the bactericidal function by inserting / cutting the cell membrane and promoting phospholipid extraction, further enhancing the disinfection efficiency of the system.

[0004] However, the catalytic system still faces the following key problems in actual water treatment applications: first, the dissolved background organic matter such as protein and humic substance in complex water bodies will consume a large amount of active oxygen species, significantly reducing the pollutant removal efficiency and bactericidal effect; second, the nanocatalyst is easy to be deactivated by agglomeration during the reaction, resulting in increased catalytic cost.

[0005] Fixing Fe-MoS2 nanosheets on a membrane material to construct a catalytic membrane is an important way to solve the above problems. However, the existing MoS2 catalytic membrane uses polyvinylidene fluoride (PVDF), polysulfone and other organic membranes as carriers, and MoS2 nanosheets are fixed on the surface by surface filtration, which has the defects of low catalyst loading, easy falling off and significantly reducing the membrane permeation flux, limiting its practical application. SUMMARY

[0006] In view of the above technical problems, the application provides a ceramic catalytic membrane loaded with Fe-doped MoS2 catalyst and a preparation method and application thereof, in order to at least partially solve the above technical problems, and thus the specific technical solutions provided by the application are as follows.

[0007] As a first aspect of the present application, a ceramic catalytic membrane loaded with Fe-doped MoS2 catalyst is provided, comprising: a porous ceramic membrane, and Fe-doped MoS2 catalyst loaded on the surface and pores of the porous ceramic membrane; wherein in the Fe-doped MoS2 catalyst, Fe element forms a coordination structure with S element in MoS2.

[0008] As a second aspect of the present application, a preparation method of a ceramic catalytic membrane loaded with Fe-doped MoS2 catalyst is provided, comprising: adding a porous ceramic membrane to a mixed solution containing a molybdenum source and a sulfur source, and performing a hydrothermal reaction to synthesize MoS2 in situ on the surface and pores of the porous ceramic membrane, to obtain a porous ceramic membrane loaded with MoS2; and filtering an ethanol aqueous solution containing a soluble iron salt through the porous ceramic membrane loaded with MoS2, to obtain a ceramic catalytic membrane loaded with Fe-doped MoS2 catalyst.

[0009] As a third aspect of the present application, the ceramic catalytic membrane as described above is applied in wastewater treatment.

[0010] Based on the above technical solution, the ceramic catalytic membrane loaded with Fe-doped MoS2 catalyst and the preparation method and application provided by the present application at least have one of the following beneficial effects.

[0011] (1) In the embodiments of the present application, the ceramic catalytic membrane loaded with Fe-doped MoS2 catalyst provided by the present application cooperates with the coordination active center of the Fe-MoS2 catalyst through the pore channel structure of the porous ceramic membrane, to realize the multifunctional coupling of separation, catalysis and sterilization. On the one hand, the pore channels of the porous ceramic catalytic membrane form a multi-stage screening network, which produces physical interception and surface adsorption of background organic matter in the water body during the filtration process, and exhibits excellent separation performance; on the other hand, the coordination structure of Fe element and S element constructs an “Fe 2+ / Fe 3+ -Mo 4+ / Mo 6+ ” electron transfer chain, activates oxidants to produce active species such as ·OH, not only efficiently degrades organic pollutants, but also exhibits significant sterilization and disinfection capacity on microorganisms such as Escherichia coli by oxidizing and destroying the cell membrane structure of bacteria. In addition, the through-pore channel design of the catalytic membrane realizes in-situ conversion of “adsorption-catalysis-sterilization”, avoids the desorption of pollutants and the reproduction of bacteria, and at the same time, the coordination structure enhances the binding force between the catalyst and the carrier, and the Fe ion dissolution amount is low, solving the problems of catalyst loss and insufficient sterilization efficiency in traditional catalytic systems, and having dual advantages of pollutant removal and microbial control in the field of water purification.

[0012] (2) In the embodiment of the present application, the preparation method combining in-situ synthesis with filtration doping through hydrothermal reaction realizes efficient synergy of separation, catalysis and sterilization. The hydrothermal reaction makes the MoS2 nanosheets uniformly loaded on the surface and in the pores of the porous ceramic membrane, and the formed multi-level pore structure endows the ceramic catalytic membrane material with excellent adsorption performance; the filtration doping process promotes the formation of coordination structure of Fe element and S element in MoS2, and constructs an efficient electron transfer chain. The method precisely controls the distribution state of the catalyst through “in-situ synthesis-directional doping”, so that the Fe element is uniformly dispersed, realizes “adsorption-catalysis-sterilization” in-situ conversion by utilizing the pores of the porous ceramic membrane, and solves the problems of difficult separation of traditional powder catalysts and easy loss of active components, and has both engineering practicability and technical advancement in the field of water treatment.

[0013] (3) In the embodiment of the present application, the ceramic catalytic membrane loaded with Fe-doped MoS2 catalyst realizes the adsorption-catalysis-sterilization synergy in wastewater treatment: the porous structure not only traps organic pollutants, but also blocks microorganisms through screening effect, and the Fe-MoS2 coordination active center in the through pore can activate oxidants to produce strong oxidizing species, synchronously degrading pollutants and destroying bacterial cell membranes. The design not only avoids the desorption of pollutants and the breeding of bacteria through in-situ catalysis, but also solves the problem of loss of traditional catalysts by utilizing the ceramic catalytic membrane carrier, realizes the inactivation of microorganisms such as Escherichia coli while efficiently removing soluble organic matter, and has the dual advantages of environmental governance and engineering application. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 is the X-ray diffraction pattern of the surface of the Fe-MoS2 ceramic catalytic membrane in Example 1 of the present application;

[0015] Figure 2 is the scanning electron microscope image of the surface of the Fe-MoS2 ceramic catalytic membrane in Example 1 of the present application;

[0016] Figure 3 is Figure 2 is a local enlarged view of region A in Example 1 of the present application;

[0017] Figure 4 is the scanning electron microscope image of the cross section of the Fe-MoS2 ceramic catalytic membrane in Example 1 of the present application;

[0018] Figure 5 is Figure 4 is a local enlarged view of region B in Example 1 of the present application;

[0019] Figure 6 is Figure 4 is the energy dispersive X-ray spectrum of the cross section in Example 1 of the present application;

[0020] Figure 7The figure is the adsorption performance of the Fe-MoS2 ceramic catalytic membrane without adding H2O2 in the embodiment 1 of the application on sulfamethoxazole;

[0021] Figure 8 The figure is the catalytic degradation performance change of the Fe-MoS2 ceramic catalytic membrane under different H2O2 concentrations in the embodiment 1 of the application;

[0022] Figure 9 The figure is the sterilization and disinfection performance change of the Fe-MoS2 ceramic catalytic membrane in the embodiment 1 of the application. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical scheme and advantages of the application more clear and obvious, the application is further described in detail below with reference to the specific embodiments and the accompanying drawings.

[0024] In the process of realizing the concept of the application, it is found that the traditional Fenton-like catalytic system has problems such as easy loss of iron ions, narrow pH application range, difficulty in catalyst recovery and insufficient sterilization efficiency, which limit its engineering application. The research of the application finds that the formation of coordination structure between Fe element and S element in MoS2 can significantly enhance the electron transfer efficiency, construct a “Fe 2+ / Fe 3+ -Mo 4+ / Mo 6+ ” bimetallic active center, which can not only improve the efficiency of the decomposition of oxidizing agent to active oxygen species to degrade organic pollutants, but also can destroy the cell membrane structure of bacteria through active oxygen to realize the synchronous inactivation of microorganisms such as Escherichia coli, and broaden the pH application range to neutral conditions. Further, through the process of in-situ hydrothermal synthesis combined with pressure-driven doping, the catalyst is precisely loaded on the inner wall of the porous ceramic membrane pores, which realizes the physical interception of background organic matter and the screening of microorganisms, and at the same time, the membrane separation function is used to strengthen the catalytic sterilization performance of the catalyst. By adjusting the Fe doping amount and the MoS2 loading form, the synergistic optimization of catalytic activity, membrane flux and sterilization efficiency can be realized, and the problems of solid-liquid separation and microorganism control of the traditional suspended catalytic system are solved.

[0025] As a first aspect of the application, a ceramic catalytic membrane loaded with Fe-doped MoS2 catalyst is provided, comprising: a porous ceramic membrane, and a Fe-doped MoS2 catalyst loaded on the surface and pores of the porous ceramic membrane; wherein the Fe element in the Fe-doped MoS2 catalyst forms a coordination structure with the S element in the MoS2.

[0026] In the embodiments of the present application, the ceramic catalytic membrane loaded with Fe-doped MoS2 catalyst is provided, the Fe-MoS2 catalyst is in-situ grown and fixed on the porous ceramic membrane, the catalyst is uniformly distributed on the surface and inner wall of the pores of the membrane, is firmly combined with the porous ceramic membrane carrier, and the active sites are fully exposed. Through the synergistic catalysis of MoS2 and Fe and the steric hindrance screening effect of the porous ceramic membrane pores on macromolecular organic matters such as proteins and humic substances, the micro-pollutants that are difficult to be removed by conventional microfiltration membranes can be efficiently removed, and the active species such as ·OH generated by activating oxidants can be used to achieve water sterilization and disinfection. The uniform loading of the catalyst ensures the stability of the catalytic performance, solves the problems of agglomeration and loss of traditional powder catalysts, and provides a solution with high efficiency and practicability for the removal of pollutants and the control of microorganisms in wastewater treatment.

[0027] According to the embodiments of the present application, the loading amount of the Fe-doped MoS2 catalyst on the ceramic catalytic membrane is 1-5wt%. The doping amount of Fe element in the Fe-doped MoS2 catalyst is 0.01-1wt%.

[0028] In the embodiments of the present application, by controlling the loading amount of the Fe-doped MoS2 catalyst on the ceramic catalytic membrane to be 1-5wt% and limiting the doping amount of Fe element to be 0.01-1wt%, the synergistic optimization of catalytic activity and membrane separation performance can be achieved. The loading amount range can ensure that the catalyst is uniformly dispersed in the pores of the porous ceramic membrane, form a higher density of active sites to more efficiently activate oxidants, avoid the problems of membrane pore blockage and active component agglomeration and deactivation caused by too high loading amount, and precisely control the Fe doping amount to strengthen the coordination structure stability, reduce the dissolution of metal ions, and solve the technical problems that the catalytic efficiency and material stability are difficult to be considered in the traditional catalyst loading process.

[0029] According to the embodiments of the present application, the pore size of the porous ceramic membrane is 100-500nm. The material of the porous ceramic membrane is any one of alumina, zirconia, titania, and silica.

[0030] In the embodiments of the present application, by selecting the porous ceramic membrane made of alumina, zirconia, titania, or silica with a pore size of 100-500nm, the synergistic optimization of separation precision and mass transfer efficiency can be achieved. The pore size range can provide sufficient loading space and through channels for the Fe-doped MoS2 catalyst, ensure the contact efficiency of pollutants and active sites, and intercept pollutants of different sizes through multi-stage screening. After loading the Fe-doped MoS2 catalyst, the pore size of the ceramic catalytic membrane is 50-200nm, which can realize the interception of macromolecular organic matters such as proteins and humic substances. The high chemical stability and mechanical strength of the ceramic material can withstand the acid-base environment and pressure impact in the catalytic reaction, avoid the dissolution or structural damage of the carrier, and provide support for the long-term stable operation of the catalytic membrane.

[0031] As a second aspect of the application, a method for preparing a ceramic catalytic membrane loaded with Fe-doped MoS2 catalyst is provided, comprising: adding a porous ceramic membrane into a mixed solution containing a molybdenum source and a sulfur source, and performing a hydrothermal reaction to in-situ synthesize MoS2 on the surface and in the pores of the porous ceramic membrane, thereby obtaining a porous ceramic membrane loaded with MoS2; and filtering an ethanol aqueous solution containing a soluble iron salt through the porous ceramic membrane loaded with MoS2, thereby obtaining a ceramic catalytic membrane loaded with Fe-doped MoS2 catalyst.

[0032] In the embodiments of the application, the method for preparing the ceramic catalytic membrane loaded with Fe-doped MoS2 catalyst is realized by combining in-situ synthesis with filtering doping through a hydrothermal reaction, thereby achieving efficient synergy of separation and catalytic functions. The hydrothermal reaction allows MoS2 nanosheets to be uniformly loaded on the surface and in the pores of the porous ceramic membrane, and the multi-level pore structure formed thereby endows the ceramic catalytic membrane with excellent adsorption performance. The filtering doping process promotes the formation of a coordination structure between Fe elements and S elements in MoS2, thereby constructing an efficient electron transfer chain. The method precisely controls the distribution of the catalyst by means of “in-situ synthesis-directional doping”, thereby uniformly dispersing the Fe elements and realizing in-situ conversion of pollutants through “adsorption-catalysis” with the aid of the pores of the porous ceramic membrane, thereby solving the problems of difficult separation of traditional powder catalysts and easy loss of active components, and achieving both engineering practicability and technical advancement in the field of water treatment.

[0033] According to the embodiments of the application, the amount of the porous ceramic membrane added in each liter of the mixed solution containing the molybdenum source and the sulfur source is 100-300 g. The molar ratio of the molybdenum source to the sulfur source is 1:10-50. The molar ratio of the molybdenum source to the soluble iron salt is 1:0.025-0.25.

[0034] In the embodiments of the application, the amount of the porous ceramic membrane added in each liter of the mixed solution, the molar ratio of the molybdenum source to the sulfur source, and the molar ratio of the molybdenum source to the soluble iron salt can be adjusted to precisely control the loading of the catalyst and the active components. The parameter range can ensure uniform growth of MoS2 on the surface and in the pores of the ceramic membrane, and can optimize the coordination structure density by adjusting the amount of the iron salt, thereby avoiding agglomeration and deactivation of the active components, while ensuring the connectivity of the pores of the membrane, thereby solving the technical problems of uneven loading of the catalyst and activity decay in the traditional preparation process.

[0035] According to the embodiments of the application, the concentration of the molybdenum source in the mixed solution is 0.5-40 mmol / L. In the ethanol aqueous solution containing the soluble iron salt, the concentration of the soluble iron salt is 0.005-0.05 mmol / L. In the ethanol aqueous solution, the volume ratio of ethanol to water is 0.5-1.5:1.

[0036] In the embodiment of the present application, by controlling the concentration of the molybdenum source and the soluble iron salt, and the volume ratio of ethanol to water in the aqueous ethanol solution, the precise control of catalyst synthesis and loading can be realized. This concentration system can not only ensure the uniform nucleation and growth of MoS2 on the surface of the ceramic membrane, but also promote the directional penetration of iron ions into the interlayer of MoS2 through the ethanol-water system, optimize the formation efficiency of the coordination structure, avoid the agglomeration or uneven loading of the catalyst caused by the imbalance of the solvent ratio, and ensure the synergistic improvement of the adsorption and catalytic performance of the catalytic membrane.

[0037] According to the embodiment of the present application, the molybdenum source includes any one of ammonium molybdate and sodium molybdate. The sulfur source includes any one of thiourea and L-cysteine. The soluble iron salt includes any one of ferric chloride, ferric sulfate and ferric nitrate.

[0038] In the embodiment of the present application, the water solubility and dissociation of the molybdenum source ensure the uniform supply of Mo, the mild sulfur release characteristics of the sulfur source promote the ordered growth of MoS2 layered structure, and the ionic form of the soluble iron salt cooperates with the ethanol-water system to promote the directional doping of Fe ions into the MoS2 lattice to form a stable coordination structure, providing a raw material basis for the efficient activity and structural stability of the catalytic membrane.

[0039] According to the embodiment of the present application, the temperature of the hydrothermal reaction is 180-230℃, and the time of the hydrothermal reaction is 8-48h.

[0040] In the embodiment of the present application, by controlling the temperature and time of the hydrothermal reaction, the directional growth and crystal optimization of MoS2 on the surface and pores of the ceramic membrane can be realized. This temperature and time range can not only promote the reaction of the molybdenum source and the sulfur source to form MoS2 nanosheets with good crystallinity, but also avoid the agglomeration of crystal grains or the blockage of membrane pores caused by high temperature (>230℃) and long time (>48h) reaction, ensuring that the catalyst is loaded in the porous ceramic membrane carrier in a highly dispersed state, laying a foundation for the subsequent formation of stable coordination structure by Fe doping and the adsorption-catalysis synergistic performance of the catalytic membrane.

[0041] As a third aspect of the present application, a ceramic catalytic membrane provided by the above-mentioned ceramic catalytic membrane is provided for application in wastewater treatment.

[0042] In the embodiment of the present application, the ceramic catalytic membrane loaded with Fe-doped MoS2 catalyst of the present application realizes the adsorption-catalysis-sterilization synergy in wastewater treatment: the porous structure traps pollutants and microorganisms, the coordination active centers in the through pores activate oxidants to generate oxidizing species, and the pollutants and bacterial cell membranes are simultaneously degraded. In-situ catalysis avoids the desorption of pollutants and the breeding of bacteria, the ceramic carrier solves the loss of the catalyst, efficiently removes organic matter and inactivates microorganisms, and has both environmental and engineering advantages.

[0043] The application exemplarily provides a preparation method of a ceramic catalytic membrane loaded with Fe-doped MoS2 catalyst, and assembles and applies it in wastewater treatment, and the specific operation is as follows.

[0044] (1) Preparation of the ceramic catalytic membrane loaded with Fe-doped MoS2 catalyst: the molybdenum source and the sulfur source are dissolved in ultrapure water, and after being fully stirred, they are poured into the inner container of a polytetrafluoroethylene hydrothermal kettle, then the porous ceramic membrane is immersed in the solution in the hydrothermal kettle, and after being sealed, it is reacted in an oven at 180-230℃ for 8-48h to obtain the porous ceramic membrane loaded with MoS2, and after the ceramic membrane is taken out and washed, the ethanol aqueous solution containing soluble iron salt is filtered through the membrane by using a peristaltic pump, and after being washed with pure water, the ceramic catalytic membrane loaded with Fe-doped MoS2 catalyst (Fe-MoS2 ceramic catalytic membrane) is obtained.

[0045] (2) Application of the catalytic membrane in wastewater treatment: the Fe-MoS2 ceramic catalytic membrane prepared above is placed in a dead-end filtration membrane tank, the feed liquid is the wastewater to be treated with dissolved oxidant, and the feed liquid is driven to pass through the Fe-MoS2 ceramic catalytic membrane by using a peristaltic pump to realize wastewater treatment. The oxidant includes peroxymonosulfate (PMS), peroxydisulfate (PDS) and H2O2. The addition amount of the oxidant can be determined according to the content of the pollutants in the wastewater, and the application is not limited thereto.

[0046] The application is further illustrated by the following examples and related test experiments. In the following detailed description, many specific details are set forth in order to provide a thorough understanding of the embodiments of the application. However, it is apparent that one or more embodiments can be practiced without these specific details. In addition, the details in each of the following embodiments can be combined with each other as long as there is no conflict.

[0047] Example 1

[0048] In this example 1, the ceramic catalytic membrane loaded with Fe-doped MoS2 catalyst is prepared by the following method, and its structure is characterized and its performance is tested.

[0049] Alumina porous ceramic membrane discs with a diameter of 35 mm (pore size of 80-500 nm) were placed vertically in the inner container of a 50 mL hydrothermal kettle. 22.9 mg of thiourea and 12.4 mg of ammonium molybdate were dissolved in 35 mL of ultrapure water, and the solution was stirred magnetically for 30 min. After the solution was clear, it was poured into the inner container of the hydrothermal kettle. After the hydrothermal kettle was sealed, it was placed in an oven at 200°C for 24 h to obtain a porous ceramic membrane loaded with MoS2. After the hydrothermal kettle cooled to room temperature, the porous ceramic membrane loaded with MoS2 was removed, rinsed with pure water and ethanol, and dried at 60°C. A 50 mL solution of 0.02 mg / L FeCl3 in a mixture of ethanol and water (ethanol:water = 1:1) was filtered through the above porous ceramic membrane loaded with MoS2 at a speed of 10 LMH, washed and dried to obtain a ceramic catalytic membrane loaded with Fe-doped MoS2 catalyst (Fe-MoS2 ceramic catalytic membrane).

[0050] Figure 1 Figure 1 is a surface XRD pattern of the Fe-MoS2 ceramic catalytic membrane in Example 1 of the present application.

[0051] Figure 2 is a surface SEM image of the Fe-MoS2 ceramic catalytic membrane in Example 1 of the present application. Figure 1 As can be seen, the characteristic peaks of the surface XRD diffraction spectrum of the Fe-MoS2 ceramic catalytic membrane correspond to the standard card peaks of MoS2 (PDF #74-0932) and Al2O3 (PDF #78-2426), and there are no other impurity peaks, which indicates that MoS2 has been successfully synthesized and the phase of the alumina porous ceramic membrane has not been changed; at the same time, no characteristic peaks of Fe-related phases are observed, because the amount of Fe doping is low, and exists in an amorphous, highly dispersed coordination structure, without forming a detectable independent Fe phase crystal.

[0052] Figure 2 Figure 3 is a surface SEM image of the Fe-MoS2 ceramic catalytic membrane in Example 1 of the present application. Figure 3 Figure 4 is a local enlarged view of region A in Figure 3. Figure 2 Figure 5 is a cross-sectional SEM image of the Fe-MoS2 ceramic catalytic membrane in Example 1 of the present application. Figure 4 Figure 6 is a local enlarged view of region B in Figure 5. Figure 5 Figure 7 is an energy dispersive X-ray spectrum of the cross-section in Figure 5. Figure 4 Figure 8 is an energy dispersive X-ray spectrum of the cross-section in Figure 6. Figure 6 Figure 9 is a surface XRD pattern of the Fe-MoS2 ceramic catalytic membrane in Example 2 of the present application. Figure 4 Figure 10 is a surface SEM image of the Fe-MoS2 ceramic catalytic membrane in Example 2 of the present application. Figure 11 is a surface SEM image of the Fe-MoS2 ceramic catalytic membrane in Example 2 of the present application.

[0053] Figure 12 is a surface SEM image of the Fe-MoS2 ceramic catalytic membrane in Example 2 of the present application. Figures 2-6It can be seen that the scanning electron microscope (SEM) image presents the synthesized MoS2 nanosheet attached to the surface of the alumina ceramic particle in a sheet cluster form, not only on the surface of the membrane but also inside the membrane hole, penetrating through the entire ceramic membrane; from the images of different magnifications and different observation surfaces (surface and cross section), the distribution state of the MoS2 nanosheet can be seen, which assists in verifying the attachment of the MoS2 nanosheet on the surface of the membrane and in the hole. The energy dispersive X-ray spectroscopy (EDS Mapping) image shows that the elements Mo, S and Fe are uniformly distributed on the ceramic membrane. Compared with the elements Mo and S, the content of the element Fe is obviously lower, because the Fe exists in the form of doping on the MoS2 nanosheet, and thus the loading amount is lower.

[0054] Further, the catalytic degradation performance of the Fe-MoS2 ceramic catalytic membrane is tested by the following method.

[0055] Specifically, the test process includes: placing the Fe-MoS2 ceramic catalytic membrane prepared above in a dead-end filtration membrane cell with an effective diameter of 35 mm, using a peristaltic pump to drive the feed liquid to pass through the ceramic catalytic membrane at a constant flow rate (50 LMH), and obtaining the treated permeate. First, filter for 1 h to make the ceramic catalytic membrane adsorb SMX to reach an adsorption-desorption equilibrium state, and then add H2O2 to the feed liquid. Every interval, a fixed amount of permeate is taken and added to methanol to stop the reaction, and the content of SMX in the permeate is detected by high performance liquid chromatography.

[0056] The adsorption capacity of the Fe-MoS2 ceramic catalytic membrane for SMX in the feed liquid without adding H2O2, and the catalytic degradation performance of the Fe-MoS2 ceramic catalytic membrane under different H2O2 concentrations are tested by the above method.

[0057] Figure 7 The adsorption performance of the Fe-MoS2 ceramic catalytic membrane for SMX without adding H2O2 in Example 1 of the present application is shown in the figure.

[0058] From Figure 7 It can be seen that the Fe-MoS2 ceramic catalytic membrane has a significant adsorption capacity for SMX in the feed liquid without adding H2O2: within the first 10 minutes of filtration, the SMX adsorption removal rate is over 90%, and the relative concentration of SMX in the permeate is extremely low; as time goes on, the adsorption is basically saturated after 60 minutes, and the relative concentration of SMX in the permeate tends to be close to that of the feed liquid, indicating that the adsorption sites of the ceramic catalytic membrane are gradually occupied, and the adsorption reaches equilibrium, which shows that the Fe-MoS2 ceramic catalytic membrane has a rapid and strong initial adsorption performance for SMX, and the subsequent adsorption capacity gradually weakens with saturation, and tends to be non-adsorption.

[0059] Figure 8A graph of the catalytic degradation performance of the Fe-MoS2 ceramic catalytic membrane in Example 1 of the present application under different H2O2 concentrations.

[0060] From Figure 8 It can be seen that different H2O2 concentrations affect the degradation effect of the Fe-MoS2 ceramic catalytic membrane on SMX: when the H2O2 concentration is 5 mM, SMX can be continuously and efficiently removed, and the removal rate is still 99% after 40 minutes, showing excellent catalytic performance; with the decrease of H2O2 concentration, the removal capacity decreases, such as 1 hour, when the H2O2 concentration is 10 mM and 5 mM, the removal rate is more than 99%, and when the H2O2 concentration is 2 mM and 1 mM, only 67% and 38%, indicating that the oxidant dosage is directly related to the pollutant removal effect, and a suitable concentration (such as 5 mM) can make the Fe-MoS2 ceramic catalytic membrane activate H2O2 to fully exert the advantage of degrading organic pollutants.

[0061] Further, the sterilization and disinfection performance of the Fe-MoS2 ceramic catalytic membrane was tested by using E. coli.

[0062] Specifically, the test process includes: using LB medium to culture E. coli to the logarithmic phase, washing twice with deionized water (DI), dispersing in deionized water, putting the Fe-MoS2 ceramic catalytic membrane synthesized in Example 1 into the bacterial suspension for 1 hour, the volume of the bacterial solution is 20 mL, and the initial optical density value (OD) of E. coli is 0.2. The flat plate coating method is used to measure the concentration of living bacteria at different times. Each sample is serially diluted, and each dilution is inoculated on agar LB plates in duplicate and incubated at 37°C for 18 hours. By counting the number of individual bacteria on the LB plate, the number of living E. coli in the actual bacterial solution is calculated.

[0063] Figure 9 A graph of the sterilization and disinfection performance of the Fe-MoS2 ceramic catalytic membrane in Example 1 of the present application.

[0064] From Figure 9 It can be seen that in the 2-hour sterilization and disinfection experiment, the number of living E. coli cells (CFU / mL) gradually decreases with time (0-120 minutes), and after 2 hours, the number of living bacteria is about 1 / 4 of the initial value, which intuitively shows that the Fe-MoS2 ceramic catalytic membrane has sterilization and disinfection ability and can effectively reduce the number of living E. coli cells.

[0065] In summary, the MoS2 nanosheet with complete crystal form and uniform size (200-300 nm) can be prepared by the hydrothermal synthesis method under the low-temperature liquid phase environment at 180-230 ℃ for 8-48 h without high-temperature treatment, which reduces the energy consumption, in-situ loads the MoS2 nanosheet on the surface and inner wall of the ceramic membrane, increases the exposure amount of active sites and avoids agglomeration. The filtration doping process promotes the formation of coordination structure of Fe element and S element in MoS2, and MoS2 can promote the valence cycle of Fe 2+ / Fe 3+ , significantly improves the activation efficiency of the catalyst to the oxidant and the Fenton catalytic activity. The catalytic membrane can intercept macromolecular pollutants such as natural organic matter (NOM) in the water body, and the Fe-MoS2 catalytic system loaded in the pore can produce active oxygen species by activating H2O2 and other oxidants, which can specifically degrade small molecule micro-pollutants, solves the problem of background organic matter interference in the traditional Fenton reaction, and realizes the deep removal of pollutants in the permeate. In addition, the ceramic catalytic membrane combines the Fenton catalytic oxidation characteristics and the structural advantages of MoS2 nanosheet, simultaneously realizes the dual functions of pollutant degradation and water disinfection, effectively improves the treatment efficiency and microbial control performance.

[0066] The above specific embodiments further illustrate the purpose, technical solutions and advantages of the present application, and it should be understood that the above description is only a specific embodiment of the present application and is not used to limit the present application, and any modification, equivalent replacement, improvement, etc. within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. A ceramic catalytic membrane loaded with Fe-doped MoS2 catalyst, characterized in that, The application relates to a ceramic catalytic membrane loaded with Fe-doped MoS2 catalyst. In the Fe-doped MoS2 catalyst, Fe elements form a coordination structure with S elements in MoS2. The loading amount of the Fe-doped MoS2 catalyst on the ceramic catalytic membrane is 1-5 wt%.

2. The ceramic catalytic membrane of claim 1, wherein, The pore size of the porous ceramic membrane is 100-500 nm.

3. The ceramic catalytic membrane of claim 1, wherein, The material of the porous ceramic membrane is any one of alumina, zirconia, titania and silica. The application relates to a ceramic catalytic membrane loaded with Fe-doped MoS2 catalyst.

4. A method for producing a ceramic catalytic membrane as claimed in any one of claims 1 to 3, characterized in that, The application relates to a ceramic catalytic membrane loaded with Fe-doped MoS2 catalyst. The adding amount of the porous ceramic membrane in each liter of the mixed solution containing a molybdenum source and a sulfur source is 100-300 g. The molar ratio of the molybdenum source to the sulfur source is 1:10-50.

5. The production method according to claim 4, characterized by, The molar ratio of the molybdenum source to the soluble iron salt is 1:0.025-0.

25. The concentration of the molybdenum source in the mixed solution is 0.5-40 mmol / L. In the ethanol aqueous solution containing the soluble iron salt, the concentration of the soluble iron salt is 0.005-0.05 mmol / L.

6. The preparation method according to claim 5, characterized in that, In the ethanol aqueous solution, the volume ratio of ethanol to water is 0.5-1.5:

1.

7. The preparation method according to claim 5, characterized in that, The molybdenum source includes any one of ammonium molybdate and sodium molybdate. The sulfur source includes any one of thiourea and L-cysteine.

8. The preparation method according to claim 5, characterized in that, The soluble iron salt includes any one of ferric chloride, ferric sulfate and ferric nitrate. The temperature of the hydrothermal reaction is 180-230 DEG C, and the time of the hydrothermal reaction is 8-48 h.

10. The application of the ceramic catalytic membrane according to any one of claims 1-3 in wastewater treatment.

9. The preparation method according to claim 4, characterized in that, ​ ​

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