Preparation method of two-dimensional MXenes material with inhibited oxidation state
By heat treatment in an inert gas atmosphere, the surface-OH functional groups were removed, and the two-dimensional MXenes material with suppressed oxidation state was prepared, which solved the problem that two-dimensional MXenes was easily oxidized, improved the gas sensing performance and reduced the cost, and was suitable for industrial-scale applications.
Patent Information
- Application Number
- CN202510588983.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-08
- Publication Date
- 2025-08-08
AI Technical Summary
Two-dimensional MXenes materials are easily oxidized, and existing oxidation inhibition methods are costly and are not suitable for industrial-scale applications.
A two-dimensional MXenes material with inhibited oxidation in an inert gas atmosphere is prepared by removing surface-OH functional groups, and nitrogen doping is performed during the process.
The prepared two-dimensional MXenes material has no significant changes in the morphology and chemical bonds, which improves gas sensing performance, is low in cost and is suitable for industrial-scale applications, and has commercial prospects.
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Figure CN120440896A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the field of gas sensing, and in particular relates to a method for preparing a two-dimensional MXenes material with suppressed oxidation state that can be used for gas sensing. Background Art
[0002] MXenes are a newly developed class of graphene-like two-dimensional materials that have attracted widespread attention due to their excellent electrical conductivity, mechanical properties, tunable surface functionality, and large specific surface area. Unlike traditional two-dimensional materials, they are composed of transition metal carbides or nitrides and have a general chemical formula of Mn+1XnTx, where M represents a transition metal element (Ti, V, Mo, Nb), X represents carbon or nitrogen, and T represents a surface terminal functional group (such as -O, -F, -OH, and -Cl). By adjusting the content and type of these functional groups, the physicochemical properties of MXenes can be easily tuned. MXenes have been used in lithium-ion batteries, electrocatalysis, and gas sensing.
[0003] The emission of harmful gases such as NOx, SOx, and VOCs from automobile exhaust, as well as the leakage of flammable and explosive gases such as H2S from chemical and coal mining enterprises, can pollute the environment and harm human health. Gas sensors are devices used to detect the presence and concentration of specific gases, converting information such as gas concentration and composition into output signals. They are widely used in environmental monitoring, industrial safety, and medical diagnostics. High-quality, low-cost, and low-power gas sensors are powerful tools for detecting toxic, hazardous, and flammable gases. Two-dimensional MXenes, due to their unique physicochemical properties, have shown great potential in gas sensing. MXenes are rich in functional groups on their surfaces, which not only enhance their hydrophilicity but also provide abundant active sites for the adsorption and reaction of gas molecules. MXenes have a large surface area, which means they provide more gas adsorption sites, thereby improving gas sensing sensitivity. The large and tunable interlayer spacing of MXenes allows gas molecules to more easily enter and interact with the material, further enhancing gas sensing performance.
[0004] In the research paper "Methods for Inhibiting Oxidation of MXene Nanomaterials and Their Application in Anticorrosion Coatings," Duan Jizhou et al. proposed forming a protective layer on the surface of MXene nanosheets to inhibit oxidation. This method effectively maintains the intact two-dimensional sheet structure of MXene nanosheets and inhibits oxidation. However, this method requires the introduction of covalent silanes, which is costly and hazardous, making it unsuitable for treating commonly used MXene materials. Summary of the Invention
[0005] In order to solve the problem that two-dimensional MXenes materials are easily oxidized, the present invention provides a low-cost, high-performance preparation method of two-dimensional MXenes materials with suppressed oxidation state that is suitable for industrial-scale applications.
[0006] The present invention provides a method for preparing a two-dimensional MXenes material with suppressed oxidation state, the preparation method being as follows:
[0007] (1) taking a fluoride metal salt and an HCl solution, and stirring until the fluoride metal salt is completely dissolved to obtain a solvent;
[0008] (2) adding Ti3AlC2 powder to the solvent described in step (1), heating and stirring, centrifuging, ultrasonicating, and freeze-drying the stirred solution to obtain an intermediate product s-MXenes material;
[0009] (3) Taking the s-MXenes material in step (2), heat-treating it in an inert gas atmosphere to obtain a two-dimensional MXenes material with suppressed oxidation state.
[0010] Furthermore, the fluoride metal salt in step (1) includes LiF, NaF, MgF2, AlF3, KF or CaF2.
[0011] Furthermore, the molar ratio of the fluoride metal salt to the HCl solution in step (1) is 1:2-20.
[0012] Furthermore, in step (2), the molar ratio of Ti3AlC2 powder to the fluoride metal salt in the solvent is 1:5 to 30.
[0013] Furthermore, the heating and stirring in step (2) is carried out in a water bath, the water bath heating temperature is 20 to 60° C., and the stirring time is 8 to 48 hours.
[0014] Furthermore, in the ultrasound in step (2), the ultrasound atmosphere is Ar.
[0015] Furthermore, the inert gas in step (3) is He, O2, N2 or Ar.
[0016] Furthermore, the heat treatment temperature in step (3) is 500° C. and the time is 6 to 24 hours.
[0017] The present invention has the following beneficial effects:
[0018] The present invention adopts the strategy of annealing MXenes nanosheets in nitrogen to achieve the nitrogen doping strategy of MXenes nanosheets and the inhibition of oxidation during the subsequent in-situ growth of Co3O4 nanoparticles in one step. Specifically, the oxidation of MXenes mainly comes from the active surface -OH and the transition of edge oxidation to the interior of the material. The present invention achieves the purpose of inhibiting the oxidation of MXenes in subsequent processes by removing the surface -OH functional groups. The oxidation of MXenes during the composite process with materials is a key scientific issue. Compared with other strategies, the present invention has lower cost and simpler operation. At the same time, MXenes can be nitrogen-doped during the process to facilitate subsequent Co-N composite. Compared with the strategy of inhibiting the oxidation of MXenes by annealing in a hydrogen atmosphere, the present invention can achieve the purpose of preventing oxidation and nitrogen doping in one step, facilitate other subsequent treatments of MXene materials, and has good economic value and practicality.
[0019] The two-dimensional MXenes prepared by this method exhibit no significant changes in morphology or chemical bonding, and have been applied in the field of gas sensing to enhance the sensing performance of the sensing material. This method is low-cost, industrially applicable, and offers outstanding performance, with strong commercial potential. BRIEF DESCRIPTION OF THE DRAWINGS
[0020] Figure 1 It is a schematic diagram of the process flow of the present invention;
[0021] Figure 2 is a SEM image of the s-MXenes material obtained in Example 1;
[0022] Figure 3 This is an SEM image of the two-dimensional MXenes material with suppressed oxidation state prepared in Example 1;
[0023] Figure 4 This is an XPS comparison chart of the two-dimensional MXenes material with suppressed oxidation state prepared in Example 1 and the ordinary MXenes material;
[0024] Figure 5 This is a performance diagram of the heterojunction formed between the two-dimensional MXenes material with suppressed oxidation state prepared in Example 1 and Co3O4. DETAILED DESCRIPTION
[0025] In order to make the objectives, technical solutions and advantages of the embodiments of the present invention more clearly understood, the spirit of the contents disclosed in the present invention will be described in detail below. After understanding the embodiments of the contents of the present invention, any technician in the relevant technical field can change and modify the contents of the present invention based on the techniques taught by the contents of the present invention without departing from the spirit and scope of the contents of the present invention.
[0026] The exemplary embodiments of the present invention and the description thereof are used to explain the present invention but are not intended to limit the present invention.
[0027] Example 1
[0028] LiF and HCl solutions were mixed at a molar ratio of 1:5 and stirred until the LiF was completely dissolved to obtain a solvent. Ti3AlC2 particles were prepared at a molar ratio of 5:1 to LiF. In a fume hood, the Ti3AlC2 particles were slowly added to the solvent. The mixture was heated in a 35°C water bath for 6 hours. The stirred solution was centrifuged, ultrasonicated under a nitrogen atmosphere for 1 hour, and freeze-dried to obtain the intermediate s-MXenes material. The s-MXenes were placed in a tube furnace under a nitrogen atmosphere and heated at 500°C for 6 hours. The mixture was then cooled naturally to room temperature to obtain a two-dimensional MXene material with suppressed oxidation.
[0029] Figure 3 This is the SEM image of the two-dimensional MXenes material with suppressed oxidation state prepared in this example. Figure 3 It can be seen that after annealing in N2 atmosphere, no TiO2 nanoparticles appear on the surface of N-MX. The XPS comparison of the two-dimensional MXenes material with suppressed oxidation state prepared in this example and the ordinary MXenes material is shown in Figure 2. Figure 4 As shown in the figure, the XPS data comparison of Ti 2p shows that after annealing in N2 atmosphere, the Ti 2p peak of N-MX has no obvious Ti 4+ area changes; at the same time, after annealing in air, the Ti 2p peak still maintains the Ti 2+ and Ti 3+ , which proves the inhibition of MXene oxidation in this example.
[0030] Example 2
[0031] Mix NaF and HCl solutions in a 1:2 molar ratio and stir until the NaF is completely dissolved to obtain a solvent. Prepare Ti3AlC2 particles at a 5:1 molar ratio of Ti3AlC2 to NaF. In a fume hood, slowly add the Ti3AlC2 particles to the solvent. Heat in a 35°C water bath for 6 hours. Centrifuge the stirred solution, ultrasonicate it under a nitrogen atmosphere for 1 hour, and freeze-dry it to obtain the intermediate s-MXenes material. The s-MXenes are placed in a tube furnace under nitrogen atmosphere and maintained at 500°C for 6 hours. Then, naturally cool to room temperature to obtain a two-dimensional MXene material with suppressed oxidation.
[0032] Example 3
[0033] LiF and HCl solutions were mixed at a molar ratio of 1:5 and stirred until the LiF was completely dissolved to obtain a solvent. Ti3AlC2 particles were prepared at a molar ratio of 5:1 to LiF. In a fume hood, the Ti3AlC2 particles were slowly added to the solvent. The mixture was heated in a 35°C water bath for 6 hours. The stirred solution was centrifuged, ultrasonicated under a nitrogen atmosphere for 1 hour, and freeze-dried to obtain the intermediate s-MXenes material. The s-MXenes were placed in a tube furnace under a nitrogen atmosphere and maintained at 500°C for 12 hours. The mixture was then cooled naturally to room temperature to obtain a two-dimensional MXene material with suppressed oxidation.
[0034] Example 4
[0035] LiF and HCl solutions were mixed at a molar ratio of 1:5 and stirred until the LiF was completely dissolved to obtain a solvent. Ti3AlC2 particles were prepared at a molar ratio of 5:1 to LiF. In a fume hood, the Ti3AlC2 particles were slowly added to the solvent. The mixture was heated in a 35°C water bath for 6 hours. The stirred solution was centrifuged, ultrasonicated under a nitrogen atmosphere for 1 hour, and freeze-dried to obtain the intermediate s-MXenes material. The s-MXenes were placed in a tube furnace under a nitrogen atmosphere and maintained at 500°C for 24 hours. The mixture was then cooled naturally to room temperature to obtain a two-dimensional MXene material with suppressed oxidation.
[0036] Example 5
[0037] LiF and HCl solutions were mixed at a molar ratio of 1:5 and stirred until the LiF was completely dissolved to obtain a solvent. Ti3AlC2 particles were prepared at a molar ratio of 5:1 to LiF. In a fume hood, the Ti3AlC2 particles were slowly added to the solvent. The mixture was heated in a 35°C water bath for 6 hours. The stirred solution was centrifuged, sonicated under an Ar atmosphere for 1 hour, and freeze-dried to obtain the intermediate s-MXenes material. The s-MXenes were placed in a tube furnace under a N2 atmosphere and maintained at 500°C for 6 hours. The mixture was then cooled naturally to room temperature to obtain a two-dimensional MXene material with suppressed oxidation.
[0038] Example 6
[0039] LiF and HCl solutions were mixed at a molar ratio of 1:5 and stirred until the LiF was completely dissolved to obtain a solvent. Ti3AlC2 particles were prepared at a molar ratio of 5:1 to LiF. In a fume hood, the Ti3AlC2 particles were slowly added to the solvent. The mixture was heated in a 35°C water bath for 6 hours. The stirred solution was centrifuged, sonicated under an Ar atmosphere for 1 hour, and freeze-dried to obtain the intermediate s-MXenes material. The s-MXenes were placed in a tube furnace under a N2 atmosphere and maintained at 500°C for 24 hours. The mixture was then cooled naturally to room temperature to obtain a two-dimensional MXene material with suppressed oxidation.
[0040] Example 7
[0041] LiF and HCl solutions were mixed at a molar ratio of 1:5 and stirred until the LiF was completely dissolved to obtain a solvent. Ti3AlC2 particles were prepared at a molar ratio of 5:1 to LiF. In a fume hood, the Ti3AlC2 particles were slowly added to the solvent. The mixture was heated in a 35°C water bath for 12 hours. The stirred solution was centrifuged, sonicated under an Ar atmosphere for 1 hour, and freeze-dried to obtain the intermediate s-MXenes material. The s-MXenes were placed in a tube furnace under a N2 atmosphere and maintained at 500°C for 6 hours. The mixture was then cooled naturally to room temperature to obtain a two-dimensional MXene material with suppressed oxidation.
[0042] Example 8
[0043] LiF and HCl solutions were mixed at a molar ratio of 1:5 and stirred until the LiF was completely dissolved to obtain a solvent. Ti3AlC2 particles were prepared at a molar ratio of 5:1 to LiF. In a fume hood, the Ti3AlC2 particles were slowly added to the solvent. The mixture was heated in a 35°C water bath for 24 hours. The stirred solution was centrifuged, ultrasonicated under an Ar atmosphere for 1 hour, and freeze-dried to obtain the intermediate s-MXenes material. The s-MXenes were placed in a tube furnace under a N2 atmosphere and maintained at 500°C for 6 hours. The mixture was then cooled naturally to room temperature to obtain a two-dimensional MXene material with suppressed oxidation.
[0044] Example 9
[0045] LiF and HCl solutions were mixed at a molar ratio of 1:5 and stirred until the LiF was completely dissolved to obtain a solvent. Ti3AlC2 particles were prepared at a molar ratio of 5:1 to LiF. In a fume hood, the Ti3AlC2 particles were slowly added to the solvent. The mixture was heated in a 55°C water bath for 24 hours. The stirred solution was centrifuged, ultrasonicated under an Ar atmosphere for 1 hour, and freeze-dried to obtain the intermediate s-MXenes material. The s-MXenes were placed in a tube furnace under a N2 atmosphere and maintained at 500°C for 6 hours. The mixture was then cooled naturally to room temperature to obtain a two-dimensional MXene material with suppressed oxidation.
[0046] Example 10
[0047] LiF and HCl solutions were mixed at a molar ratio of 1:15 and stirred until the LiF was completely dissolved to obtain a solvent. Ti3AlC2 particles were prepared at a molar ratio of 5:1 to LiF. In a fume hood, the Ti3AlC2 particles were slowly added to the solvent. The mixture was heated in a 35°C water bath for 6 hours. The stirred solution was centrifuged, sonicated under an Ar atmosphere for 1 hour, and freeze-dried to obtain the intermediate s-MXenes material. The s-MXenes were placed in a tube furnace under a N2 atmosphere and maintained at 500°C for 6 hours. The mixture was then cooled naturally to room temperature to obtain a two-dimensional MXene material with suppressed oxidation.
[0048] Example 11
[0049] LiF and HCl solutions were mixed at a molar ratio of 1:15 and stirred until the LiF was completely dissolved to obtain a solvent. Ti3AlC2 particles were prepared at a molar ratio of 5:1 to LiF. In a fume hood, the Ti3AlC2 particles were slowly added to the solvent. The mixture was heated in a 35°C water bath for 6 hours. The stirred solution was centrifuged, sonicated under an Ar atmosphere for 1 hour, and freeze-dried to obtain the intermediate s-MXenes material. The s-MXenes were placed in a tube furnace under a N2 atmosphere and maintained at 500°C for 24 hours. The mixture was then cooled naturally to room temperature to obtain a two-dimensional MXene material with suppressed oxidation.
[0050] Example 12
[0051] LiF and HCl solutions were mixed at a molar ratio of 1:15 and stirred until the LiF was completely dissolved to obtain a solvent. Ti3AlC2 particles were prepared at a molar ratio of 5:1 to LiF. In a fume hood, the Ti3AlC2 particles were slowly added to the solvent. The mixture was heated in a 35°C water bath for 24 hours. The stirred solution was centrifuged, sonicated under an Ar atmosphere for 1 hour, and freeze-dried to obtain the intermediate s-MXenes material. The s-MXenes were placed in a tube furnace under a N2 atmosphere and maintained at 500°C for 6 hours. The mixture was then cooled naturally to room temperature to obtain a two-dimensional MXene material with suppressed oxidation.
[0052] Example 13
[0053] LiF and HCl solutions were mixed at a molar ratio of 1:30 and stirred until the LiF was completely dissolved to obtain a solvent. Ti3AlC2 particles were prepared at a molar ratio of 5:1 to LiF. In a fume hood, the Ti3AlC2 particles were slowly added to the solvent. The mixture was heated in a 35°C water bath for 6 hours. The stirred solution was centrifuged, sonicated under an Ar atmosphere for 1 hour, and freeze-dried to obtain the intermediate s-MXenes material. The s-MXenes were placed in a tube furnace under a N2 atmosphere and maintained at 500°C for 6 hours. The mixture was then cooled naturally to room temperature to obtain a two-dimensional MXene material with suppressed oxidation.
[0054] Example 14
[0055] LiF and HCl solutions were mixed at a molar ratio of 1:30 and stirred until the LiF was completely dissolved to obtain a solvent. Ti3AlC2 particles were prepared at a molar ratio of 5:1 to LiF. In a fume hood, the Ti3AlC2 particles were slowly added to the solvent. The mixture was heated in a 35°C water bath for 6 hours. The stirred solution was centrifuged, sonicated under an Ar atmosphere for 1 hour, and freeze-dried to obtain the intermediate s-MXenes material. The s-MXenes were placed in a tube furnace under a N2 atmosphere and maintained at 500°C for 24 hours. The mixture was then cooled naturally to room temperature to obtain a two-dimensional MXene material with suppressed oxidation.
[0056] Example 15
[0057] LiF and HCl solutions were mixed at a molar ratio of 1:30 and stirred until the LiF was completely dissolved to obtain a solvent. Ti3AlC2 particles were prepared at a molar ratio of 5:1 to LiF. In a fume hood, the Ti3AlC2 particles were slowly added to the solvent. The mixture was heated in a 35°C water bath for 6 hours. The stirred solution was centrifuged, ultrasonicated under a nitrogen atmosphere for 1 hour, and freeze-dried to obtain the intermediate s-MXenes material. The s-MXenes were placed in a tube furnace under a nitrogen atmosphere and heated at 500°C for 6 hours. The mixture was then cooled naturally to room temperature to obtain a two-dimensional MXene material with suppressed oxidation.
[0058] Example 16
[0059] LiF and HCl solutions were mixed at a molar ratio of 1:30 and stirred until the LiF was completely dissolved to obtain a solvent. Ti3AlC2 particles were prepared at a molar ratio of 5:1 to LiF. In a fume hood, the Ti3AlC2 particles were slowly added to the solvent. The mixture was heated in a 55°C water bath for 6 hours. The stirred solution was centrifuged, sonicated under an Ar atmosphere for 1 hour, and freeze-dried to obtain the intermediate s-MXenes material. The s-MXenes were placed in a tube furnace under a N2 atmosphere and maintained at 500°C for 6 hours. The mixture was then cooled naturally to room temperature to obtain a two-dimensional MXene material with suppressed oxidation.
[0060] Example 17
[0061] LiF and HCl solutions were mixed at a molar ratio of 1:30 and stirred until the LiF was completely dissolved to obtain a solvent. Ti3AlC2 particles were prepared at a molar ratio of 5:1 to LiF. In a fume hood, the Ti3AlC2 particles were slowly added to the solvent. The mixture was heated in a 55°C water bath for 12 hours. The stirred solution was centrifuged, sonicated under an Ar atmosphere for 1 hour, and freeze-dried to obtain the intermediate s-MXenes material. The s-MXenes were placed in a tube furnace under a N2 atmosphere and maintained at 500°C for 6 hours. The mixture was then cooled naturally to room temperature to obtain a two-dimensional MXene material with suppressed oxidation.
[0062] The above embodiments are merely examples of the present invention. While the preferred embodiments and accompanying drawings are provided for illustrative purposes, the present invention is not limited to the above embodiments. Various substitutions, changes, and modifications are possible by anyone skilled in the art without departing from the spirit and scope of the present invention and the appended claims. Therefore, the present invention should not be limited to the preferred embodiments and accompanying drawings.
Claims
1. A method for preparing a two-dimensional MXenes material with suppressed oxidation state, characterized in that The preparation method is as follows: (1) taking a fluoride metal salt and an HCl solution, and stirring until the fluoride metal salt is completely dissolved to obtain a solvent; (2) adding Ti3AlC2 powder to the solvent described in step (1), heating and stirring, centrifuging, ultrasonicating, and freeze-drying the stirred solution to obtain an intermediate product s-MXenes material; (3) Taking the s-MXenes material in step (2), heat-treating it in an inert gas atmosphere to obtain a two-dimensional MXenes material with suppressed oxidation state.
2. The method for preparing a two-dimensional MXenes material with suppressed oxidation state according to claim 1, characterized in that The fluoride metal salt described in step (1) includes LiF, NaF, MgF2, AlF3, KF or CaF2.
3. The method for preparing a two-dimensional MXenes material with suppressed oxidation state according to claim 1 or 2, characterized in that The molar ratio of the fluoride metal salt to the HCl solution in step (1) is 1:2-20.
4. The method for preparing a two-dimensional MXenes material with suppressed oxidation state according to claim 1, characterized in that In step (2), the molar ratio of Ti3AlC2 powder to the fluoride metal salt in the solvent is 1:5 to 30.
5. The method for preparing a two-dimensional MXenes material with suppressed oxidation state according to claim 1, characterized in that The heating and stirring in step (2) is carried out in a water bath with a heating temperature of 20 to 60° C. and a stirring time of 8 to 48 hours.
6. The method for preparing a two-dimensional MXenes material with suppressed oxidation state according to claim 1, characterized in that In the step (2), the ultrasonic atmosphere is Ar.
7. The method for preparing a two-dimensional MXenes material with suppressed oxidation state according to claim 1, characterized in that The inert gas in step (3) is He, O2, N2 or Ar.
8. The method for preparing a two-dimensional MXenes material with suppressed oxidation state according to claim 1, characterized in that The heat treatment temperature in step (3) is 500° C. and the time is 6 to 24 hours.