An in-plane porous Ti3C2T x flake and its construction method
Patent Information
- Application Number
- CN202510412362.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-03
- Publication Date
- 2025-08-01
- Estimated Expiration
- 2045-04-03
AI Technical Summary
首先是片层堆叠，Ti3C2Tx纳米片因范德华力和氢键作用易发生紧密堆叠，导致活性位点暴露不足，有效比表面积降低，限制了离子吸附和电荷存储能力
[0018] In the present invention, Cu x is introduced into the Ti3C2T 2+ colloidal solution. Through the synergistic action of Cu 2+ and dissolved oxygen in the aqueous solution, Ti in the Ti3C2T x flakes 2+ or Ti in the 3+ is catalytically oxidized to TiO2. Then the generated TiO2 is dissolved using an etchant, leaving uniform pores in the in-plane of the Ti3C2T x flakes. By controlling the reaction time of Cu 2+ and the Ti3C2T x colloidal solution, the size and density of the pores in the in-plane of the Ti3C2T x flakes are controlled. The method of the present invention is simple and the conditions are mild. It can not only form vertical and horizontal intertwined ion transport channels, but also has strong scalability and economy. The method of the present invention does not require complex templates or costly chemical reactions, is suitable for large-scale production, and has high potential for industrial application.
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Figure CN119911907B_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of carbide two-dimensional materials, and specifically relates to an in-plane porous Ti3C2T x flake and a construction method thereof. Background Art
[0002] Ti3C2T x Two-dimensional layered materials have high conductivity, abundant surface functional groups, and adjustable interlayer spacing, which make them show great potential in the field of electrochemical energy storage. However, there are the following key problems in the preparation process of Ti3C2T x flakes. First is the sheet stacking. Ti3C2T x nanosheets are prone to tight stacking due to van der Waals forces and hydrogen bonding, resulting in insufficient exposure of active sites, reduced effective specific surface area, and limited ion adsorption and charge storage capabilities. Second is the limited vertical ion transport. Traditional Ti3C2T x flakes lack an effective pore structure in the vertical direction, and ions need to diffuse along a tortuous path, resulting in a sharp decay of the charge at high current densities.
[0003] Traditional modification methods inhibit stacking by introducing spacers such as carbon nanotubes and graphene, but this method only optimizes the ion transport in the horizontal direction, and there is still a problem of tortuous path in the vertical direction. While traditional chemical etching can expand the interlayer spacing, it is difficult to form uniform in-plane pores on Ti3C2T x flakes, and the strong acid environment is likely to damage the x structural stability of Ti3C2T, resulting in a decline in the mechanical properties of the material and a shortening of the cycle life. In addition, although attempts have been made in the prior art to introduce pores through the template method or redox reaction, these methods are complex in process and high in cost, limiting their large-scale application. Summary of the Invention
[0004] To solve the above technical problems, the present invention provides an in-plane porous Ti3C2T x flake and a construction method thereof. Through a Cu 2+ -induced in-situ etching strategy, uniform in-plane pores are constructed on the Ti3C2T x flake, and the preparation process is simple and environmentally friendly, suitable for large-scale production applications.
[0005] The present invention is specifically realized through the following technical solutions.
[0006] The present invention provides a construction method of an in-plane porous Ti3C2T x flake, including the following steps:
[0007] Mix a Ti3C2T x colloidal solution and an aqueous copper salt solution at room temperature, stir and react, and through Cu2+ Cooperate with dissolved oxygen in the aqueous solution to oxidize Ti in the Ti3C2T x flakes 2+ or Ti 3+ to TiO2.
[0008] After the reaction is completed, an etchant is added to the reaction solution and stirred to react. The etchant is used to etch and remove the generated TiO2 to form in-plane pores. After the etching treatment, after centrifugation and washing, the obtained solid can be dispersed in water.
[0009] Preferably, the copper salt aqueous solution is CuSO4 aqueous solution, CuCl2 aqueous solution or Cu(NO3)2 aqueous solution.
[0010] Preferably, the concentration of the Ti3C2T x colloidal solution is 1.5 mg / mL, the concentration of the copper salt aqueous solution is 0.1 mol / L to 0.3 mol / L, and the volume ratio of the Ti3C2T x colloidal solution to the copper salt aqueous solution is 2:1.
[0011] Preferably, after mixing the Ti3C2T x colloidal solution and the copper salt aqueous solution at room temperature, the stirring reaction time is 2 hours to 4 hours. To ensure the uniformity and sufficiency of the reaction, appropriately reducing the reaction time and extending the reaction time can control the size and density of the in-plane pores.
[0012] Preferably, the etchant is HF aqueous solution with a concentration of 10 wt% to 30 wt%, and the volume ratio of the HF aqueous solution to the copper salt aqueous solution is 1:2.5. During the reaction process, the concentration of the HF solution is controlled at 10 wt% to 30 wt% to ensure that the overall structure of the Ti3C2T x is not damaged.
[0013] Preferably, after adding the etchant, stir and react for 20 minutes to 40 minutes.
[0014] The present invention also provides an in-plane porous Ti3C2T x flake constructed by the above construction method, including horizontal channels and vertical channels. There are horizontal channels between adjacent Ti3C2T x sheets, and pores are distributed in the in-plane of each layer of Ti3C2T x The vertical channels are formed by the pores between the sheets.
[0015] As Figure 1 shown, the mechanism of pore formation in the in-plane of Ti3C2T x can be understood as that the redox potential of Cu 2+ is higher than that of Ti 2+ or Ti 3+Corrected and acting synergistically with dissolved oxygen in the aqueous solution, Ti3C2T in the x Ti in the 2+ or Ti in the 3+ Ti3C2T flakes is catalytically oxidized to TiO2. Then the generated TiO2 is etched, leaving uniform pores in the in-plane of the Ti3C2T x flakes.
[0016] The present invention also provides a self-supporting electrode. The colloidal solution of the in-plane porous Ti3C2T x flakes is vacuum filtered onto a cellulose membrane and vacuum dried at 30 °C to 60 °C to obtain a self-supporting electrode. This self-supporting electrode can be directly used as an electrode for a sodium ion capacitor without adding a conductive agent or a binder.
[0017] Compared with the prior art, the present invention has the following beneficial effects:
[0018] In the present invention, Cu x is introduced into the Ti3C2T 2+ colloidal solution. Through the synergistic action of Cu 2+ and dissolved oxygen in the aqueous solution, Ti in the Ti3C2T x flakes 2+ or Ti in the 3+ is catalytically oxidized to TiO2. Then the generated TiO2 is dissolved using an etchant, leaving uniform pores in the in-plane of the Ti3C2T x flakes. By controlling the reaction time of Cu 2+ and the Ti3C2T x colloidal solution, the size and density of the pores in the in-plane of the Ti3C2T x flakes are controlled. The method of the present invention is simple and the conditions are mild. It can not only form vertical and horizontal intertwined ion transport channels, but also has strong scalability and economy. The method of the present invention does not require complex templates or costly chemical reactions, is suitable for large-scale production, and has high potential for industrial application. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] Figure 1 is a schematic diagram of the principle for constructing in-plane porous Ti3C2T x flakes in the present invention.
[0020] Figure 2 is a transmission electron microscope photograph of the Ti3C2T x flakes in Comparative Example 1.
[0021] Figure 3 In (a), it is a transmission electron microscope photograph of the in-plane porous Ti3C2T x flakes prepared in Example 2, and (b) is the corresponding pore size distribution diagram.
[0022] Figure 4 Among them, (a) is the transmission electron microscopy image of the in-plane porous Ti3C2T x thin flakes prepared in Example 1, and (b) is the corresponding pore size distribution diagram.
[0023] Figure 5 Among them, (a) is the transmission electron microscopy image of the in-plane porous Ti3C2T x thin flakes prepared in Example 3, and (b) is the corresponding pore size distribution diagram.
[0024] Figure 6 Among them, (a) is the galvanostatic charge-discharge curve of the self-supporting electrode prepared from the sample in Comparative Example 1 at different current densities, and (b) is the galvanostatic charge-discharge curve of the self-supporting electrode prepared from the in-plane porous Ti3C2T x thin flakes in Example 1 at different current densities.
[0025] Figure 7 Among them, (a) is the cyclic voltammogram of the self-supporting electrode prepared from the sample in Comparative Example 1 at different scan rates, and (b) is the cyclic voltammogram of the self-supporting electrode prepared from the in-plane porous Ti3C2T x thin flakes in Example 1 at different scan rates.
[0026] Figure 8 are the charge values of the self-supporting electrodes prepared from the samples in Example 1 and Comparative Example 1 at different current densities. Specific Embodiments
[0027] In order to enable those skilled in the art to better understand and implement the technical solutions of the present invention, the present invention will be further described below in conjunction with specific embodiments and drawings, but the specific embodiments cited shall not be construed as limiting the present invention. Unless otherwise specified, the experimental methods and detection methods described in the following embodiments are all conventional methods; unless otherwise specified, the reagents and materials can be purchased on the market.
[0028] Example 1
[0029] A method for constructing in-plane porous Ti3C2T x thin flakes, the steps are as follows:
[0030] (1) Mix 50 mL of a Ti3C2T x colloidal solution with a concentration of 1.5 mg / mL and 25 mL of a copper sulfate aqueous solution with a concentration of 0.2 mol / L at room temperature. After mixing, use a magnetic stirrer to stir and react for 3 hours.
[0031] (2) After the reaction, add 10 mL of an HF aqueous solution with a concentration of 20 wt% to the solution in step (1) and stir for 30 minutes.
[0032] (3) Centrifuge the mixed solution after the reaction in step (2). Discard the supernatant after centrifugation and keep the bottom solid. Wash the bottom solid with deionized water multiple times until the pH value of the washing solution is neutral. Finally, redisperse the solid obtained by centrifugation into water, and the resulting solution is a colloidal solution containing in-plane porous Ti3C2T x flakes.
[0033] Example 2
[0034] A method for constructing in-plane porous Ti3C2T x flakes, the steps are as follows:
[0035] (1) Mix 50 mL of a Ti3C2T x colloidal solution with a concentration of 1.5 mg / mL and 25 mL of an aqueous copper sulfate solution with a concentration of 0.2 mol / L at room temperature. After mixing, stir the reaction for 2 hours using a magnetic stirrer.
[0036] (2) After the reaction, add 10 mL of an HF aqueous solution with a concentration of 20 wt% to the solution in step (1) and stir for 30 minutes.
[0037] (3) Centrifuge the mixed solution after the reaction in step (2). Discard the supernatant after centrifugation and keep the bottom solid. Wash the bottom solid with deionized water multiple times until the pH value of the washing solution is neutral. Finally, redisperse the solid obtained by centrifugation into water, and the resulting solution is a colloidal solution containing in-plane porous Ti3C2T x flakes.
[0038] Example 3
[0039] A method for constructing in-plane porous Ti3C2T x flakes, the steps are as follows:
[0040] (1) Mix 50 mL of a Ti3C2T x colloidal solution with a concentration of 1.5 mg / mL and 25 mL of an aqueous copper sulfate solution with a concentration of 0.2 mol / L at room temperature. After mixing, stir the reaction for 4 hours using a magnetic stirrer.
[0041] (2) After the reaction, add 10 mL of an HF aqueous solution with a concentration of 20 wt% to the solution in step (1) and stir for 30 minutes.
[0042] (3) Centrifuge the mixed solution after the reaction in step (2). Discard the supernatant after centrifugation and keep the bottom solid. Wash the bottom solid with deionized water multiple times until the pH value of the washing solution is neutral. Finally, redisperse the solid obtained by centrifugation into water, and the resulting solution is a colloidal solution containing in-plane porous Ti3C2T x flakes.
[0043] Comparative Example 1
[0044] Untreated Ti3C2T in step (1) of Example 1 x Colloidal solution.
[0045] Effect verification:
[0046] Figure 2 For the Ti3C2T in Comparative Example 1 x Transmission electron micrograph of the thin slice.
[0047] Figure 3 In the figure, (a) is the in-plane porous Ti3C2T prepared in Example 2. x (b) is the corresponding pore size distribution diagram of the thin film. It can be seen that Ti3C2T x Porous structures have appeared on the surface, but the pore density and size are significantly lower than those of samples prepared after 3 and 4 hours of reaction. x The diameters of the 200 pores distributed on the thin film are mainly in the range of 10nm to 40nm, with the majority being pores in the range of 15nm to 30nm.
[0048] Figure 4 In the figure, (a) is the in-plane porous Ti3C2T prepared in Example 1. x Transmission electron microscope photo of the thin slice, (b) is the corresponding pore size distribution diagram. The pore size ranges from 10nm to 80nm. Compared with the Ti3C2T x The pore size of the thin slice is further expanded, and the number of pores is also significantly increased. The pore size distribution diagram shows that the diameter of the pores is mainly 10nm~40nm. x and Cu 2+ Reaction time can increase pore density and pore size.
[0049] Figure 5 (a) is the in-plane porous Ti3C2T prepared in Example 3. x (b) is the corresponding pore size distribution diagram of the thin film. It can be seen that Ti3C2T x The pores on the surface are significantly enlarged and the pore density is also significantly increased. In addition, many pore structures are enlarged and connected to each other to form a larger pore structure. x The diameters of the 200 pores distributed on the thin film are mainly in the range of 30nm to 170nm, with the majority being pores in the range of 30nm to 60nm.
[0050] Example 4
[0051] An in-plane porous Ti3C2Tx Method for constructing a thin sheet, steps:
[0052] (1) Mix 50 mL of a Ti3C2T x colloidal solution with a concentration of 1.5 mg / mL and 25 mL of an aqueous CuCl2 solution with a concentration of 0.1 mol / L at room temperature. After mixing, use a magnetic stirrer to stir the reaction for 3 hours.
[0053] (2) After the reaction, add 10 mL of an aqueous HF solution with a concentration of 30 wt% to the solution in step (1), and stir for 20 minutes.
[0054] (3) Centrifuge the mixture after the reaction in step (2). After centrifugation, discard the supernatant and retain the bottom solid. Wash the bottom solid with deionized water multiple times until the pH value of the washing solution is neutral. Finally, redisperse the solid obtained by centrifugation in water to obtain a solution that is a colloidal solution containing in-plane porous Ti3C2T x thin sheets.
[0055] Example 5
[0056] A method for constructing an in-plane porous Ti3C2T x thin sheet, steps:
[0057] (1) Mix 50 mL of a Ti3C2T x colloidal solution with a concentration of 1.5 mg / mL and 25 mL of an aqueous Cu(NO3)2 solution with a concentration of 0.3 mol / L. After mixing, use a magnetic stirrer to stir the reaction solution for 3 hours.
[0058] (2) After the reaction, add 10 mL of an aqueous HF solution with a concentration of 10 wt% to the solution in step (1), and stir for 40 minutes.
[0059] (3) Centrifuge the mixture after the reaction in step (2). After centrifugation, discard the supernatant and retain the bottom solid. Wash the bottom solid with deionized water multiple times until the pH value of the washing solution is neutral. Finally, redisperse the solid obtained by centrifugation in water to obtain a solution that is a colloidal solution containing in-plane porous Ti3C2T x thin sheets.
[0060] The in-plane porous Ti3C2T prepared in Example 4 and Example 5 x The pore size of the thin sheets is in the range of 10 nm to 80 nm. Similar to Example 1.
[0061] Taking the sample prepared in Example 1 as an example, the following performance tests are carried out. The in-plane porous Ti3C2T obtained in Example 1 xThe colloidal solution of the flakes was vacuum filtered onto a cellulose membrane and then vacuum dried at 50 °C for 8 hours to obtain a self-supporting electrode. Using the same preparation method, the sample in Comparative Example 1 was prepared into a self-supporting electrode. The above self-supporting electrode was used as the self-supporting electrode of the sodium-ion capacitor without adding a conductive agent or a binder. It was assembled into a sodium-ion capacitor: First, the self-supporting electrode, the activated carbon electrode, and the cellulose separator were respectively cut into 1 cm 2 circular discs, which were used as the working electrode, the counter electrode, and the separator, respectively. Ag / AgCl was used as the reference electrode, and at the same time, 1 mol / L aqueous Na2SO4 solution was used as the electrolyte to assemble a sodium-ion capacitor.
[0062] Figure 6 In (a), it is the galvanostatic charge-discharge curve of the self-supporting electrode prepared from the sample in Comparative Example 1 at different current densities. In (b), it is the galvanostatic charge-discharge curve of the self-supporting electrode prepared from the in-plane porous Ti3C2T x flakes in Example 1 at different current densities. Figure 7 In (a), it is the cyclic voltammogram of the self-supporting electrode prepared from the sample in Comparative Example 1 at different scan rates. In (b), it is the cyclic voltammogram of the self-supporting electrode prepared from the in-plane porous Ti3C2T x flakes in Example 1 at different scan rates. The discharge time of the self-supporting electrode corresponding to Example 1 is longer at the same current density, far higher than that of Comparative Example 1. The self-supporting electrode corresponding to Example 1 has more excellent sodium-ion storage capacity. Through calculation, the self-supporting electrode corresponding to Example 1 exhibits a high volumetric specific capacity of 563.5 C cm -2 at 2 mA cm -3 , far higher than 306 C cm -3 of the self-supporting electrode corresponding to Comparative Example 1, showing a higher charge value.
[0063] Figure 8 are the charge values of the self-supporting electrodes prepared from the samples in Example 1 and Comparative Example 1 at different current densities. It is worth noting that when the current density increases to 30 mA cm -2 , the charge of the self-supporting electrode corresponding to Example 1 is still 461.3 C cm -3 , almost 10 times that of Comparative Example 1, showing excellent rate performance. It shows that in-plane pores are constructed on the surface of Ti3C2T x , creating more direct channels in the vertical direction, reducing the tortuosity of the vertical ion path, and realizing fast ion diffusion.
[0064] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and its equivalent technologies, these changes and variations are also intended to be included therein.
Claims
1. A method for constructing an in-plane porous Ti3C2T x flake, characterized in that It includes the following steps: Mix the Ti3C2T x colloidal solution with an aqueous copper salt solution at room temperature, stir and react. Through Cu 2+ and the dissolved oxygen in the aqueous solution acting synergistically, oxidize the Ti x in the Ti3C2T 2+ flakes or Ti 3+ to TiO2; After the reaction is completed, an etchant is added to the reaction solution and stirred. The etchant is used to etch and remove the generated TiO2 to form in-plane pores. After centrifugation and washing, the obtained solid is dispersed in water; Ti3C2T x The concentration of the colloidal solution is 1.5 mg / mL, and the concentration of the copper salt aqueous solution is 0.1 mol / L to 0.3 mol / L. Ti3C2T x The volume ratio of the colloidal solution to the copper salt aqueous solution is 2:1; The etchant is an HF aqueous solution with a concentration of 10 wt% - 30 wt%, and the volume ratio of the HF aqueous solution to the copper salt aqueous solution is 1:2.5; Mix the Ti3C2T x colloidal solution with an aqueous copper salt solution at room temperature, and stir the reaction for 2 to 4 hours.
2. The method for constructing the in-plane porous Ti3C2T x flake, characterized in that The copper salt aqueous solution is a CuSO4 aqueous solution, a CuCl2 aqueous solution or a Cu(NO3)2 aqueous solution.
3. The method for constructing an in-plane porous Ti3C2T x flake, characterized in that The stirring reaction time after adding the etchant is 20 minutes - 40 minutes.
4. The in-plane porous Ti3C2T x flake fabricated by the construction method according to claim 1.
5. The in-plane porous Ti3C2T x flake according to claim 4, characterized in that It includes a horizontal channel and a vertical channel, and there is a horizontal channel between adjacent Ti3C2T x sheets, and pores are distributed in the in-plane of each Ti3C2T x sheet, and the vertical channel is formed by the pores between the sheets.
Citation Information
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