A TiO2@MXene ceramic membrane, its preparation method, and its application in emulsification or demulsification.

Abstract

The application discloses a TiO2@MXene ceramic membrane, a preparation method and application in milk preparation or demulsification, wherein the preparation method comprises the following steps: at least one layer of MXene nanosheet is prepared by using a wet chemical etching method; and a TiO2@MXene ceramic membrane with a 0D-2D structure is prepared on a ceramic support by using a high-temperature in-situ oxidation method or a self-assembly method; the TiO2@MXene ceramic membrane has a unique 0D-2D sandwich structure, the transmission path of a dispersed phase is enlarged, and the transmission resistance of a separated phase between layers is reduced, which is of great significance for a hydrophilic membrane to be used in membrane emulsification for preparing monodisperse W / O emulsion with controllable particle size; meanwhile, the TiO2@MXene ceramic membrane exhibits excellent oil stain resistance and a low flux decay rate in an oil-water separation process, and is also of great significance for realizing a high-stable oil-water separation process.

Description

Technical Field

[0001] This invention relates to a TiO2@MXene ceramic membrane, its preparation method, and its application in emulsification or demulsification, belonging to the field of membrane separation technology. Background Technology

[0002] Emulsified oil has been regarded as a new type of petroleum product alternative fuel. Membrane emulsification technology has attracted widespread attention due to its advantages such as simple operation, low energy consumption, and ease of control. However, it also suffers from problems such as difficulty in controlling emulsion particle size, low membrane emulsification flux, and membrane fouling. Ceramic membranes have the characteristics of high temperature resistance and high mechanical strength, making them more suitable for the harsh service environment in membrane emulsification production. High temperature resistance allows ceramic membranes to maintain good performance even at high temperatures, which is beneficial to improving membrane stability and service life. High mechanical strength means that ceramic membranes can withstand greater mechanical impact, thus preventing cracking or damage during use. In the membrane emulsification process, the emulsion needs to withstand extreme conditions such as high temperature and high-speed flow. Ceramic membranes can meet these harsh environmental requirements and ensure the stability of the emulsion. In addition, ceramic membranes also have good wear resistance and corrosion resistance, which means that they can maintain stable performance during long-term use. However, commercial ceramic membranes are usually composed of porous materials such as alumina, titanium dioxide, and silicon carbide particles. The pore spacing is usually large, which means that liquid molecules in the membrane are easy to evaporate, which is not conducive to the preparation of monodisperse emulsions (Non-Patent Literature 1, 2).

[0003] Non-patent literature 1: Ceramics for Membrane Engineering (Van Bodeleyn, 2012)

[0004] Non-patent literature 2: Membrane Engineering: Fundamentals and Applications (Hefford, 2003). Summary of the Invention

[0005] The purpose of this invention is to provide a TiO2@MXene ceramic membrane, its preparation method, and its application in emulsification or demulsification. By utilizing the precise pore structure and excellent antifouling properties of the ceramic membrane, it is possible to prepare monodisperse emulsions with controllable particle size, and also to achieve high efficiency and stability of the membrane material under long-term oil-water separation operation.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] A TiO2@MXene ceramic film includes a support layer and a selective separation layer, wherein the selective separation layer is made of Ti3C2T x Composed of MXene nanosheets, and in Ti3C2T xThe surface of MXene nanosheets is distributed with TiO2 particles, where T is OH, F or O.

[0008] Preferably, the ceramic support is in the form of a sheet, a single tube, or a hollow fiber, and the ceramic material is Al2O3 or ZrO2, with an average pore size of 100–1000 nm.

[0009] The above-mentioned method for preparing TiO2@MXene ceramic films includes the following steps:

[0010] Preparation of Ti3C2T by wet chemical etching x MXene nanosheets are then used to obtain TiO2@MXene ceramic films via high-temperature in-situ oxidation or self-assembly.

[0011] Preferably, the wet chemical etching method is used to prepare Ti3C2T x The specific method for obtaining MXene nanosheets is as follows: LiF is reacted in an HCl solution, then Ti3AlC2 is added to the system, heated in a water bath, and then Ti3C2T is obtained by ultrasonic or oscillatory exfoliation. x MXene nanosheets; among which, Ti3AlC2 is the precursor for synthesizing MXene nanosheets, and HF generated in situ using LiF and HCl is used to etch Ti3AlC2;

[0012] The mass ratio of LiF to Ti3AlC2 is 1:(0.8-1.2); the HCl concentration is 3-8 mol / L.

[0013] Preferably, the specific method for preparing the ceramic membrane by the high-temperature in-situ oxidation method is as follows: Ti3C2T is subjected to vacuum or pressure-assisted filtration. x MXene nanosheets were loaded onto the surface of a ceramic support, dried, and then calcined to obtain a TiO2@MXene ceramic film with a 0D-2D structure.

[0014] Preferably, the Ti3C2T x The loading of MXene nanosheets is 50-500 mg / m³. 2 The drying temperature is 30-60℃, and the drying time is 3-12h; the calcination temperature is 300-600℃, the heating rate is 0.5-5℃ / min, and the holding time is 0-5h.

[0015] Preferably, the specific method for preparing the ceramic film by the self-assembly method is as follows: Ti3C2T xMXene nanosheets were dispersed in TiO2 and water to prepare a mixed solution; HEC and PVA were then added to prepare TiO2-MXene sol; TiO2-MXene sol was coated on the surface of a ceramic support, dried and calcined to obtain a self-assembled 0D-2D structured TiO2@MXene ceramic film.

[0016] The Ti3C2T x The amount of MXene added is 0.5-1.5 wt.% of the amount of TiO2 added; the amount of HEC added is 3-5 wt.% of the amount of TiO2 added; and the amount of PVA added is 0.5-2 wt.% of the amount of TiO2 added.

[0017] Preferably, TiO2-MXene sol is coated on the surface of the ceramic support using an dip-coating method or a spin coating method; the drying temperature is 30-70℃, the drying time is 6-12h; the high-temperature calcination temperature is 400-500℃, the heating rate is 0.5-2℃ / min, and the cooling rate is 1-3℃ / min.

[0018] The above-mentioned TiO2@MXene ceramic membrane is used in the preparation of W / O emulsions.

[0019] The above-mentioned TiO2@MXene ceramic membrane is used in O / W emulsion demulsification.

[0020] The beneficial effects of this invention are as follows:

[0021] 1. This invention provides a method for preparing TiO2@MXene ceramic membranes with an 0D-2D sandwich structure. This method endows the membrane material with a precise pore structure and excellent oil resistance, enabling it to both prepare monodisperse W / O emulsions and effectively separate O / W emulsions. Additionally, Ti3C2T is prepared via wet chemical etching. x MXene nanosheets were used to prepare TiO2@MXene ceramic films via a high-temperature calcination process. This preparation process is simple, controllable, and utilizes Ti3C2T... x MXene materials possess excellent lateral dimensions. Utilizing their regularly stacked two-dimensional layered structure, they self-assemble on the surface of ceramic membranes. This not only increases the distance between adjacent nanochannels, preventing droplet aggregation during membrane emulsification and enabling the preparation of monodisperse W / O emulsions with controllable particle size, but also leverages its capping effect to efficiently seal large pore defects in the ceramic support, forming TiO2@MXene ceramic membranes with high emulsification flux. The precise pore structure effectively prevents emulsion aggregation.

[0022] 2. The TiO2@MXene ceramic membrane prepared by this invention provides a unique 0D-2D sandwich structure, which expands the transport path of the dispersed phase and reduces the transport resistance of the separated phase between layers. This is of great significance for the use of hydrophilic membranes in membrane emulsification to prepare monodisperse W / O emulsions with controllable particle size.

[0023] 3. Ti3C2T x MXene materials possess abundant variable-valence Ti atoms on their surface. Utilizing their in-situ oxidation properties, ultra-smooth TiO2@MXene hydrophilic nanostructured films with an 0D-2D structure can be formed. The abundant generation of TiO2 particles significantly enhances the surface smoothness and hydrophilicity of the membrane, making this material suitable for demulsification and oil-water separation of O / W emulsions. On one hand, the hydrophilicity of the membrane surface allows for the formation of a continuous and stable hydration layer during oil-water separation, exhibiting oleophobic properties. On the other hand, the ultra-smooth, self-cleaning nanostructure reduces the risk of oil droplet adhesion and deposition in the membrane surface channels, achieving long-term, efficient separation of nano / sub-nano scale emulsions. Consequently, the TiO2@MXene ceramic membrane exhibits excellent anti-oil fouling performance and a low flux decay rate during oil-water separation, which is crucial for achieving highly stable oil-water separation processes.

[0024] 4. The TiO2@MXene ceramic membrane prepared by this invention has excellent chemical resistance and can be reused by simply rinsing the membrane surface. Attached Figure Description

[0025] Figure 1 The images show (a) SEM (scanning electron microscope); (b) AFM (analysis frequency spectroscopy) and (c) macroscopic images of TiO2@MXene ceramic films prepared by the high-temperature in-situ oxidation method at different calcination temperatures in Example 1.

[0026] Figure 2 The images are SEM (scanning electron microscope) images of TiO2@MXene ceramic films with different MXene nanosheet doping levels prepared by the self-assembly method in Example 1.

[0027] Figure 3 The following are the static water contact angles and underwater oil contact angles of the TiO2@MXene ceramic films at different calcination temperatures in Example 2.

[0028] Figure 4 This is a graph showing the adhesion force of diesel fuel to TiO2@MXene ceramic films at different calcination temperatures in Example 2;

[0029] Figure 5 These are the appearance and particle size distribution diagrams of diesel W / O emulsions prepared by the ME process from MT300, MT450, and MT600 membrane materials in Example 2.

[0030] Figure 6 The images show data on pore size and flux variation of membrane materials with different MXene nanosheet doping ratios in Example 2 (a, b); and microscopic images and particle size distribution of heavy oil W / O emulsions prepared with 0-1.5wt% MT membrane materials (ce).

[0031] Figure 7 These are microscopic particle size diagrams of the self-made O / W emulsion in Example 3; macroscopic diagrams of diesel fuel, emulsion, and solutions separated by membrane under various conditions;

[0032] Figure 8 This is a graph showing the membrane flux decay rate of TiO2@MXene ceramic membranes and self-assembled TiO2@MXene ceramic membranes at different calcination temperatures in Example 3 for oil-water separation testing.

[0033] Figure 9 This is a graph showing the TOC removal rate of TiO2@MXene ceramic membranes and self-assembled TiO2@MXene ceramic membranes at different calcination temperatures in Example 3, used for oil-water separation testing. Detailed Implementation

[0034] To facilitate understanding of the present invention, the invention is further illustrated below with reference to the accompanying drawings and specific embodiments, but the invention is not limited thereto. All technologies implemented based on the above description of the present invention are covered within the scope of protection intended by the present invention. Unless otherwise stated, the raw materials and reagents used in the examples are commercially available products. Reagents, instruments, or operating procedures not described herein are all matters that can be conventionally determined by those skilled in the art.

[0035] This invention relates to TiO2@MXene ceramic films, their preparation methods, and their applications in emulsification and demulsification. TiO2@MXene ceramic films with both emulsification and demulsification functions are prepared using either high-temperature in-situ oxidation of MXene or a self-assembly method. In emulsification, the use of 2D MXene nanosheets to increase the spacing between adjacent pores avoids the widening of droplet size during film emulsification caused by small pore spacing, enabling the preparation of monodisperse emulsions with controllable particle size. The pore spacing can be adjusted by controlling the nanosheet diameter. Furthermore, 2D MXene serves as a two-dimensional platform for depositing 0D TiO2, and its capping effect allows for self-assembly to form complete, defect-free 0D-2D TiO2@MXene hydrophilic ceramic films with high emulsification flux. In terms of demulsification, TiO2 and MXene are interconnected to form an ultra-smooth TiO2@MXene ceramic membrane. Utilizing its hydrophilicity, underwater oleophobicity, low surface roughness, and oil adhesion, it promotes the rapid formation of a continuous and stable hydration layer on the membrane surface. This effectively prevents oil droplets from adhering and coalescing on the membrane surface, enhancing its antifouling capability and achieving highly efficient demulsification and separation of nano / sub-nano emulsions. This TiO2@MXene ceramic membrane possesses both excellent emulsification and demulsification capabilities. Precise control of the micro / nano structure and surface smoothness of the TiO2@MXene ceramic membrane helps solve the problems of difficult droplet size control in traditional emulsification technologies, low flux in existing membrane emulsification technologies, and membrane fouling during the demulsification process.

[0036] Example 1

[0037] Preparation of TiO2@MXene ceramic films with 0D-2D structure

[0038] (1) Preparation of Ti3C2T x MXene nanosheets

[0039] 6 mol / L hydrochloric acid was placed in a polytetrafluoroethylene (PTFE) reactor liner for later use. Then, 1 g of lithium fluoride was added to the reactor liner to generate hydrofluoric acid, which was used to etch the MAX phase (Ti3AlC2). 1 g of the MAX phase (Ti3AlC2) was then placed in the generated hydrofluoric acid solution, heated in a water bath for etching, and then subjected to ultrasonic treatment to remove the etchant, yielding Ti3C2T. x MXene nanosheets.

[0040] (2) High-temperature in-situ oxidation method

[0041] 0.3 mg of Ti3C2T x MXene nanosheets were loaded onto a ceramic membrane support (100 nm pore size, 7 cm length, 0.8 cm diameter) using vacuum or pressure-assisted filtration and then air-dried at room temperature. The resulting Ti3C2T xThe MXene film was placed in a muffle furnace and calcined at high temperature in air atmosphere at a heating rate of 5℃ / min without holding. The calcination temperatures were 300℃, 450℃, and 600℃. During this process, Ti3C2T x The -Ti groups on the MXene surface combine with oxygen atoms to form hydrophilic TiO2 particles, resulting in TiO2@MXene ceramic films with 0D-2D structures of different oxidation degrees.

[0042] refer to Figure 1 By controlling the calcination temperature, the oxidation level of the TiO2@MXene ceramic film surface was controlled. It was found that with increasing calcination temperature, the oxidation level of the TiO2@MXene ceramic film surface gradually increased, the number of surface oxide particles increased, and the smoothness gradually improved. Specifically, at 300℃, the film surface was macroscopically dark black. SEM analysis showed that the oxidation level of the TiO2@MXene ceramic film was low, with the surface dominated by two-dimensional nanosheet wrinkled structures. When the temperature was increased to 450℃, the macroscopic film surface changed from dark black to off-white. SEM analysis showed that the oxidation level of the TiO2@MXene ceramic film significantly increased, and a large number of white hydrophilic TiO2 particles appeared on the film surface. When the temperature was increased to 600℃, the macroscopic film surface changed from off-white to a smooth bright white. SEM analysis showed that the oxidation level of the TiO2@MXene ceramic film further increased, and the oxide particles were relatively small and uniformly distributed, resulting in a smooth film surface.

[0043] The surface roughness variations of TiO2@MXene ceramic films with three different oxidation degrees were characterized using AFM. The results showed that the surface roughness of the TiO2@MXene ceramic films initially increased and then decreased. Specifically, the arithmetic mean roughness (R0) of the films... a The wavelength increased from 21.910 nm to 59.806 nm and then decreased to 26.253 nm, with the root mean square deviation (R) of the profile increasing. q The wavelength of the film also decreased accordingly from 28.367 nm to 70.643 nm to 33.712 nm. At 300 °C, the film surface is mainly composed of a wrinkled structure formed by the stacking of nanosheets, so the surface roughness is relatively low. At 450 °C, due to the significant increase in oxidation, a large number of TiO2 particles protrude on the film surface, thus significantly improving the surface roughness. At 600 °C, the oxidation degree is further increased. At this time, the oxidation degree of the MXene film is relatively high, the two-dimensional structure of the original nanosheets basically disappears, and a large number of tiny particles are uniformly distributed on the surface, resulting in a decrease in the surface roughness of the film.

[0044] (3) Self-assembly method

[0045] 0.6 g of TiO2 powder (5 nm) was added to 30 mL of deionized water and ultrasonically dispersed until homogeneous. Then, a certain amount of Ti3C2T was added. x The addition of MXene nanosheets to Ti3C2T x The MXene and TiO2 mixture was ultrasonically dispersed in an ice bath for 15 min. Next, 20 mL of a 3 wt.% hydroxyethyl cellulose (HEC) solution was added, and the mixture was stirred for 10 min. Then, 10 mL of a 0.5 wt.% polyvinyl alcohol (PVA) solution was added, and the mixture was stirred for another 10 min to obtain the MXene-TiO2 sol. HEC and PVA were used as thickeners and drying control agents, respectively, with MXene / TiO2 (mass ratio) of 0 wt.%, 0.5 wt.%, and 1.5 wt.%.

[0046] TiO2-MXene sol was coated on the surface of the ceramic support using either dip-coating or spin coating methods; the drying temperature was 45℃ and the drying time was 6h; the high-temperature calcination temperature was 400℃, the heating rate was 0.5℃ / min, and the cooling rate was 1℃ / min.

[0047] refer to Figure 2 Based on Ti3C2T x The "capping effect" and excellent mechanical flexibility of MXene membrane materials enable the self-assembly of 2D MXene nanosheets and 0D TiO2 nanoparticles to design and construct a 0D-2D MXene-TiO2 mesoporous composite membrane with a porous ceramic membrane material as the support. During the self-assembly process, MXene provides a two-dimensional platform for depositing TiO2 nanoparticles, forming a "brick structure" with TiO2, thereby efficiently sealing the macroporous defects of the ceramic support for the preparation of W / O emulsions. Specifically, SEM characterization of the support and composite membrane revealed significant macroporous defects in the support. The membrane without MXene nanosheets (0% MT) showed obvious infiltration on its surface, and no complete boundary layer was observed between the membrane and the support. With increasing MXene nanosheet doping, a complete membrane layer with a thickness of ~3 μm was prepared, indicating that the "capping effect" of MXene effectively compensates for the macroporous defects of the support and prevents nanoparticle infiltration.

[0048] Example 2

[0049] Preparation of diesel and heavy oil W / O emulsions using TiO2@MXene ceramic membranes

[0050] (1) Preparation of diesel W / O emulsion

[0051] refer to Figure 3The changes in the water contact angle and underwater oil contact angle of TiO2@MXene ceramic films with three different oxidation degrees were characterized. It was found that with the increase of hydrophilic TiO2 particles, the static water contact angle of the TiO2@MXene ceramic film decreased rapidly, while the underwater oil contact angle gradually increased. Specifically, when the calcination temperature was increased from 300℃ to 600℃, the hydrophilic contact angle decreased from 67.5° to 7.5°, exhibiting superhydrophilicity; while the increased hydrophilicity led to a more continuous and stable hydration layer on the film surface, resulting in an increase in the underwater oil contact angle from 96.7° to 133.3°.

[0052] refer to Figure 4 The adhesion force of TiO2@MXene ceramic films to diesel fuel was characterized, showing an overall decreasing trend. Specifically, as the calcination temperature increased from 300℃ to 600℃, the adhesion force decreased from 0.253 mN to 0.197 mN. (Reference) Figure 5 A composite emulsifier, consisting of a 1:1 mixture of Span 20 and Span 80 at a mass fraction of 2 wt.%, was selected. Water was used as the dispersed phase, and diesel fuel as the continuous phase. MT300, MT450, and MT600 membranes were used for the membrane emulsification experiments. It can be seen that the W / O emulsions prepared by the three membranes all exhibited an opaque, milky-white appearance. The particle size and distribution of the W / O emulsions were quantitatively analyzed using a particle size analyzer. (Reference) Figure 5 (d, e) It was found that the emulsions prepared by MT300 and MT450 both exhibited a bimodal distribution. This is because only a small portion of the MXene surface in the membrane material is oxidized into TiO2 particles. When water molecules enter the oil phase from the membrane pores under external pressure, they preferentially flow out through the gaps in the oxidized TiO2 particles, causing aggregation between W / O emulsion droplets and resulting in larger particle sizes in some emulsions. In contrast, the surface of the MT600 membrane material is almost completely oxidized. The resulting TiO2@MXene (0D-2D) sandwich structure can, on the one hand, modify the large pore defects on the alumina surface to limit the preparation of monodisperse W / O emulsions with narrow particle size distribution, and on the other hand, broaden the transport path of the dispersed phase with its unique 0D-2D nanochannels, preventing emulsion aggregation. Specifically, the average particle size of the emulsion is 157.2 nm, and the PDI (polydispersity index) of the emulsion is 0.159.

[0053] (2) Preparation of heavy oil W / O emulsion

[0054] Span85 and Tween80 were used as emulsifiers, and the ratio of emulsifier to heavy oil was (Span85+Tween80):(Span85+Tween80+heavy oil) = 0.01:100; the ratio of heavy oil to deionized water was 10:1; the operating pressure was 2 MPa, and emulsification was carried out using a membrane emulsification device.

[0055] refer to Figure 6 First, the performance of the self-assembled 0D-2D MXene-TiO2 ceramic membrane was analyzed. It was observed that the TiO2 membrane with a larger support and more defects had a larger average pore size and a higher pure water flux. With increasing MT sol doping, the average pore size of the membrane decreased, and the permeation performance of the composite membrane declined. This indicates that the capping effect of MXene promotes a more complete MXene-TiO2 membrane layer, thus resulting in relatively higher permeation resistance.

[0056] Optical microscopy analysis of the emulsion particle size distribution revealed that as the doping concentration of Mxene nanosheets increased, the emulsion particle size gradually decreased and became more uniform. Specifically, the emulsion particle size decreased from 2.76 μm to 1.95 μm, while the particle size span also decreased from 1.4 to 1.29.

[0057] Example 3

[0058] TiO2@MXene ceramic membranes are used for demulsification and oil-water separation of O / W emulsions.

[0059] refer to Figure 7 Using Span80 and Span20 as emulsifiers, the ratio of emulsifier to diesel oil was (Span80+Span20):(Span80+Span20+diesel oil) = 1:100; the ratio of diesel oil to deionized water was 1:100. A 10,000 ppm O / W emulsion was prepared using a high-speed shear mill. Oil-water separation tests were conducted on the emulsion using three membranes with different oxidation levels. The oil-water separation was characterized by TOC (total organic carbon). The results showed that the membranes achieved separation efficiencies of over 99% for the emulsion, with MT300 achieving a TOC removal rate of 99.18%, MT450 99.20%, and MT600 99.11%.

[0060] refer to Figure 8-9 To monitor the antifouling properties of three membranes with different oxidation levels and a self-assembled membrane during oil-water separation, a 1-hour oil-water separation test was conducted using four membranes, and their flux decay rates were measured. It was found that as the degree of membrane oxidation increased, the antifouling ability of the membrane surface improved, and the flux decay rate decreased significantly. The self-assembled membrane, due to the MXene nanosheets compensating for the macroporous defects of the support and the loading of superhydrophilic TiO2 particles, formed a stable hydration layer, thus effectively resisting fouling. Specifically, the flux decay rate of MT300 was 63.65% in 1 hour, MT450 was 29.61%, MT600 was 6.63%, and 1.5% MT was 7.5%. This indicates that the ultra-smooth, anti-fouling membrane, due to the underwater oleophobic properties resulting from its high oxidation level, increases its antifouling ability during oil-water separation and significantly improves the membrane's stability in this process.

[0061] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. Use of a TiO2@MXene ceramic membrane in the preparation of a W / O emulsion and in the demulsification of an O / W emulsion, characterized by, The TiO2@MXene ceramic membrane comprises a support layer and a selective separation layer, the selective separation layer is composed of Ti3C2T x MXene nanosheets, and Ti3C2T x MXene nanosheets, and Ti3C2T The preparation method includes the following steps: Fabrication of Ti3C2T by wet chemical etching method x MXene nanosheets, and then TiO2@MXene ceramic membranes are obtained by high-temperature in-situ oxidation method or self-assembly method. The specific method for preparing ceramic films by high-temperature in-situ oxidation is as follows: Ti3C2T x MXene nanosheets are loaded on the surface of a ceramic support, dried and calcined to obtain a TiO2@MXene ceramic film with 0D-2D structure; wherein, Ti3C2T x The loading of MXene nanosheets is 50-500 mg / m 2 The calcination temperature is 300-600℃; The specific method for preparing ceramic membranes by self-assembly is as follows: Ti3C2T x MXene nanosheets were dispersed in TiO2 and water to prepare a mixed solution; HEC and PVA were then added to prepare TiO2-MXene sol; TiO2-MXene sol was coated on the surface of a ceramic support, dried and calcined to obtain a self-assembled 0D-2D structured TiO2@MXene ceramic film. Ti3C2T x The amount of MXene added is 0.5-1.5 wt.% of the amount of TiO2 added; the calcination temperature is 400-500℃.

2. Use according to claim 1, characterized in that, The ceramic support is in the form of sheets, single tubes, or hollow fibers. The ceramic material is Al2O3 or ZrO2, and the average pore size of the support is 100~1000nm.

3. Use according to claim 1, characterized in that, Preparation of Ti3C2T by wet chemical etching x The specific method for obtaining MXene nanosheets is as follows: LiF is reacted in an HCl solution, then Ti3AlC2 is added to the system, heated in a water bath, and then Ti3C2T is obtained by ultrasonic or oscillatory exfoliation. x MXene nanosheets; Among them, Ti3AlC2 is the precursor for synthesizing MXene nanosheets, and HF generated in situ using LiF and HCl is used to etch Ti3AlC2. The mass ratio of LiF to Ti3AlC2 is 1:(0.8-1.2); the HCl concentration is 3-8 mol / L.

4. Use according to claim 1, characterized in that, In the high-temperature in-situ oxidation method, the drying temperature is 30-60℃ and the drying time is 3-12h; the calcination heating rate is 0.5-5℃ / min and the holding time is 0-5h.

5. The use according to claim 1, characterized in that, In the self-assembly method, the amount of HEC added is 3-5 wt.% of the amount of TiO2 added, and the amount of PVA added is 0.5-2 wt.% of the amount of TiO2 added.

6. Use according to claim 5, characterized in that, TiO2-MXene sol was coated on the surface of the ceramic support using either dip-coating or spin coating methods; the drying temperature was 30-70℃, and the drying time was 6-12h; the calcination heating rate was 0.5-2℃ / min, and the cooling rate was 1-3℃ / min.

Images