MXene-derived perovskite oxide hollow crystal / MXene composite material and preparation method thereof
By hydrothermally treating MXene under weak oxidizing and weak alkaline conditions, h-ABO3/MXene composite materials were prepared, which solved the problem of the single structure of MXene-derived materials in the prior art. This enabled the controllable preparation of hollow nanostructures of multi-component metal oxides, thereby improving the functionality and application potential of the materials.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- NORTHEASTERN UNIV CHINA
- Filing Date
- 2026-01-15
- Publication Date
- 2026-04-14
AI Technical Summary
Existing technologies struggle to prepare MXene-derived composite materials with complex chemical compositions and fine nanostructures, and cannot flexibly control the structure and elemental composition of metal oxides in the products, thus limiting the application of MXene-based materials in the field of multifunctional nanomaterials.
By performing a one-step hydrothermal treatment on MXene under weak oxidation and weak alkaline conditions, and utilizing the Oswald ripening-Korkendall effect, in-situ growth of MXene and perovskite oxide hollow crystals was achieved, forming an h-ABO3/MXene composite material.
The controllable preparation of hollow nanostructures of MXene-derived multi-metal oxides was achieved, which enhanced the bonding force of the composite interface, endowed MXene with new functions such as ferroelectric properties, and improved its performance in electrochemical energy storage, catalysis and microwave absorption.
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Figure CN121849955A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of MXene composite material technology, specifically relating to an MXene-derived perovskite oxide hollow crystal / MXene composite material and its preparation method. Background Technology
[0002] MXene's large specific surface area and high reactivity make it a unique precursor material for the preparation of novel nanomaterials. Current research indicates that using Ti-based MXene (Ti3C2 or Ti2C) as a precursor, TiO2 nanoparticles and MXene composites can be prepared under liquid-phase oxidation conditions (such as oxidation conditions containing 10% H2O2 by volume or hydrothermal conditions at 120℃) (Nanoscale, 2016, 8, 7580-7587, Inorg. Chem. 2019, 58, 9, 5414-5418). Over-oxidation can completely convert MXene into pure TiO2 nanoparticles. Under strongly alkaline and anaerobic conditions (such as 6M KOH), Ti3C2MXene can be converted into alkali metal ion-intercalated MXene nanoribbons (Nano Energy 2017, 40, 1-8). Under strongly alkaline and strongly oxidizing conditions (such as 1M NaOH containing 2.2% H2O2 by volume), Ti3C2MXene can be completely converted into alkali metal titanate nanoribbons under hydrothermal conditions at 140℃ (ACS Nano 2017, ...). (11, 4792-4800). Although existing technologies have made preliminary explorations into MXene-derived materials, MXene is converted into single metal oxides or alkali metal titanates, with product morphologies mainly consisting of nanoparticles or nanoribbons / wires, exhibiting relatively simple structures. Furthermore, there is insufficient preservation of the MXene's own structure and control over the uniformity of composite materials, and a lack of controllable preparation methods for multi-component, multi-morphological metal oxide / MXene composite materials. Existing techniques struggle to prepare MXene-derived composite materials with complex chemical compositions and fine nanostructures, and cannot flexibly control the structure and elemental composition of the metal oxides in the products, thus limiting the application of MXene-based materials in the field of multifunctional nanomaterials.
[0003] In summary, highly reactive MXenes are extremely sensitive to reaction conditions. Under different pH values and oxidation levels, MXene derivatives exhibit significant differences in chemical composition and nanostructure, fundamentally due to variations in the MXene transformation reaction mechanism under different conditions. Therefore, precise control of reaction conditions holds promise for achieving novel reaction pathways and mechanisms, thereby overcoming the limitations of existing MXene derivatives with simple chemical compositions and structures. This could enable the preparation of MXene derivatives with complex chemical compositions and fine nanostructures (such as hollow perovskite oxide crystals), enhancing or expanding the applications of MXene-derived materials in energy storage, catalysis, and microwave absorption. Summary of the Invention
[0004] To address the shortcomings of existing technologies, the purpose of this invention is to provide a simple, structurally controllable, and high-performance MXene-derived perovskite oxide hollow crystal / MXene composite material and its preparation method.
[0005] The MXene-derived perovskite oxide hollow crystal / MXene composite material of this invention has a chemical composition that can be represented as h-ABO3 / MXene, where h-ABO3 represents MXene-derived perovskite oxide hollow crystals, A is a divalent alkaline earth metal element in the reaction solution, B is a transition metal element in the MXene precursor, and O is oxygen. h-ABO3 has a hollow nanocrystalline structure, which is uniformly distributed on MXene. The formation principle of h-ABO3 / MXene is as follows: under weak oxidizing conditions, MXene first generates oxide BO particles, and then under weakly alkaline conditions (alkaline earth metal hydroxide solution), BO reacts with alkaline earth metal hydroxide. Under the synergistic effect of Oswald ripening and Kirkendal effect, h-ABO3 hollow nanocrystals are generated.
[0006] Furthermore, the preparation method of h-ABO3 / MXene according to the present invention includes: using MXene with an accordion-like multilayer structure or a few-layer nanosheet structure as a precursor, performing a one-step hydrothermal treatment on the MXene material under weak oxidation and weak alkaline conditions (as an A source in h-ABO3 and providing an alkaline reaction environment), the reacted MXene provides a B source for h-ABO3, and the unreacted MXene serves as a carrier for h-ABO3, finally obtaining the h-ABO3 / MXene composite material.
[0007] This invention effectively regulates the structure and chemical composition of h-ABO3 in h-ABO3 / MXene by selecting different MXene structures and types, weak oxidation, and weak alkaline solutions.
[0008] The h-ABO3 is a hollow crystal of perovskite oxide composed of strontium titanate, barium titanate, calcium titanate, strontium niobate, barium niobate, calcium niobate, strontium tantalate, barium strontium titanate, barium strontium niobate, strontium titanate, barium titanate, or other transition metal elements and one or more alkaline earth metals.
[0009] The MXene has an accordion-like multilayer structure or a few-layer nanosheet structure, and is Ti3C2MXene, Ti2C MXene, Ti2N MXene, Nb4C3MXene, Nb2C MXene, Mo2C MXene, Ta4C3MXene, TiNbC MXene, Mo2TiC2MXene, Ti2TaC2MXene, or other MXenes with an accordion-like multilayer structure or a few-layer nanosheet structure.
[0010] A method for preparing an MXene-derived perovskite oxide hollow crystal / MXene (h-ABO3 / MXene) composite material mainly includes the following steps: (1) Disperse the MXene material in a mixed solution containing an oxidant and an alkaline solution; (2) After reacting the mixture of MXene from step (1) with oxidant and alkali solution under hydrothermal conditions for 0.5 h to 48 h, the resulting dispersion is separated, washed and dried to obtain h-ABO3 / MXene composite material.
[0011] In the above preparation method, the MXene has an accordion-like multilayer structure or a few-layer nanosheet structure, and is Ti3C2MXene, Ti2C MXene, Ti2N MXene, Nb4C3MXene, Nb2C MXene, Mo2C MXene, Ta4C3MXene, TiNbC MXene, Mo2TiC2MXene, Ti2TaC2MXene, or other MXenes with an accordion-like multilayer structure or a few-layer nanosheet structure.
[0012] In the above preparation method, the oxidant is one or more of inorganic peroxides, organic peroxides, halogen elements, and high-valence metal salts; wherein, inorganic peroxides include hydrogen peroxide, ammonium persulfate, sodium persulfate, and sodium peroxide; organic peroxides include peracetic acid, tert-butyl hydroperoxide, and m-chloroperoxybenzoic acid; halogen elements include liquid bromine and chlorine; and high-valence metal salts include potassium permanganate, potassium dichromate, and cerium ammonium nitrate.
[0013] In the above preparation method, the weak alkaline solution simultaneously provides alkaline earth metal elements and an alkaline reaction environment, and is selected from one or more mixed aqueous solutions of alkaline earth metal hydroxides; wherein, alkaline earth metal hydroxides include magnesium hydroxide, calcium hydroxide, strontium hydroxide, or barium hydroxide.
[0014] In the above preparation method, the mass ratio of MXene to alkaline earth metal hydroxide in the alkaline solution is 1:(5~50), and the molar concentration of the alkaline solution is 0.05 mol / L~0.5 mol / L.
[0015] In the above preparation method, the mass ratio of MXene to oxidant is 1:(0.02~0.9).
[0016] In the above preparation method, the hydrothermal reaction time is 0.5 h to 48 h, and the hydrothermal reaction temperature is 80℃ to 200℃.
[0017] The key technical point of this invention is: This invention provides an MXene-derived perovskite oxide hollow crystal / MXene (h-ABO3 / MXene) composite material, wherein A is an alkaline earth metal in the alkaline earth metal hydroxide reaction solution, B is a transition metal element in the MXene precursor, and O is oxygen. h-ABO3 has a hollow nanocrystalline structure, uniformly distributed on MXene. The formation principle of h-ABO3 / MXene is as follows: under weakly oxidizing conditions, MXene first generates BO oxide particles, and then under weakly alkaline conditions (alkaline earth metal hydroxide solution), BO reacts with the alkaline earth metal hydroxide, achieving the formation of h-ABO3 hollow nanocrystals under the synergistic effect of Oswald ripening and Kirkendal.
[0018] The beneficial effects of this invention are: This invention addresses the challenges of MXene's tendency to stack and its limited ability to generate single-structure composites, as well as the lack of controllable preparation methods for multi-component and multi-morphological metal oxide / MXene composites. It proposes a one-step hydrothermal method under weakly alkaline and weakly oxidizing conditions to prepare h-ABO3 / MXene composites. By controlling the types of MXene, weakly alkaline earth metal hydroxides, and oxidants, hollow nanocrystals of different perovskite oxides can be grown in situ on the MXene surface, achieving controllable preparation of MXene-derived multi-component metal oxides and hollow nanostructures. This method is simple and operates under mild conditions. The resulting h-ABO3 / MXene composite combines the high conductivity of MXene with the functional properties of perovskite oxides and the advantages of a hollow nanostructure. It effectively suppresses MXene stacking, enhances the interfacial bonding, and endows MXene with new functions (such as ferroelectric properties), demonstrating superior performance potential in electrochemical energy storage, catalysis, and microwave absorption. Attached Figure Description
[0019] Figure 1Scanning electron microscope (SEM) images and XRD diffraction patterns of the accordion-shaped multilayer Ti3C2MXene and the hollow strontium titanate / accordion-shaped multilayer Ti3C2MXene composite material in Example 1; wherein a is the SEM image of the accordion-shaped Ti3C2MXene, b is the SEM image of the hollow strontium titanate / accordion-shaped multilayer Ti3C2MXene composite material, and c is the XRD diffraction pattern of the hollow strontium titanate / accordion-shaped multilayer Ti3C2MXene composite material.
[0020] Figure 2 Scanning electron microscope (SEM) images of few-layer Ti3C2MXene and hollow strontium titanate / few-layer Ti3C2MXene composite materials in Example 2; where a is an SEM image of few-layer Ti3C2MXene and b is an SEM image of hollow strontium titanate / few-layer Ti3C2MXene composite material.
[0021] Figure 3 Transmission electron microscope (TEM) image and corresponding EDS pattern of the hollow strontium titanate / few-layer Ti3C2MXene composite material in Example 2; where a is the TEM image and b is the corresponding EDS elemental mapping.
[0022] Figure 4 Scanning electron microscope (SEM) images of few-layer Nb2C MXene and hollow strontium niobate / few-layer Nb2C MXene composites in Example 3; where a is an SEM image of few-layer Nb2C MXene and b is an SEM image of hollow strontium niobate / few-layer Nb2C MXene composite.
[0023] Figure 5 Electron micrographs of the hollow barium strontium titanate / few-layer Ti3C2MXene composite material in Example 4; where a is a scanning electron microscope image, b is a sample morphology image obtained by EDS elemental analysis, c is the elemental distribution of Sr obtained by EDS test, d is the elemental distribution of Ba obtained by EDS test, and e is the elemental distribution of Ti obtained by EDS test. Detailed Implementation
[0024] Example 1 Preparation of hollow strontium titanate / accordion-shaped multilayer Ti3C2MXene nanocomposites: Accordion-shaped multilayer Ti3C2MXene can be prepared by selectively etching the Al layer in Ti3AlC2MAX using the classic HF acid or halogen salt molten salt method (Adv. Mater., 2011, 23, 4248-4253, Nat. Mater. 2020, 19, 1476-1122).
[0025] 0.1 g of accordion-shaped multilayer Ti3C2MXene was added to 30 mL of 0.5 mol / L Sr(OH)2 solution containing 0.17 mL H2O2 (30%), mixed thoroughly, and placed in a 50 mL hydrothermal reactor. The mixture was treated at 140 °C for 12 h. After centrifugation, the precipitate was removed by acid washing with 0.1 M HCl, followed by washing with deionized water until neutral. The precipitate was then freeze-dried under vacuum to obtain a hollow strontium titanate / accordion-shaped multilayer Ti3C2MXene composite material. Scanning electron micrographs of the accordion-shaped multilayer Ti3C2MXene and the hollow strontium titanate / accordion-shaped multilayer Ti3C2MXene composite materials are shown below. Figure 1 As shown in a, 1b. From Figure 1 a and Figure 1 As shown in b, under the weakly alkaline environment provided by the alkaline earth metal hydroxide Sr(OH)2, the accordion-like multilayer Ti3C2MXene morphology is completely preserved through weak oxidation treatment (low H2O2 content), and a large number of hollow particles are formed in situ on the nanosheets. Figure 1 The XRD diffraction pattern of c shows that the hollow particles generated by the reaction are strontium titanate, and some MXene is retained (the 6° position corresponds to the 002 crystal plane of Ti3C2MXene).
[0026] Example 2 Preparation of hollow strontium titanate nanocubes / few-layer Ti3C2MXene composite materials: Few-layer Ti3C2MXene can be prepared by the LiF+HCl method (Nature, 2014, 516, 78-81).
[0027] 0.1 g of few-layer Ti3C2MXene nanosheets were added to 30 mL of 0.15 mol / L Sr(OH)2 solution containing 85 μL H2O2 (30%), mixed evenly, and placed in a 50 mL hydrothermal reactor. The mixture was treated at 140 °C for 12 h. The dispersion was centrifuged to obtain a precipitate, which was then washed with 0.1 M HCl to remove impurities and washed with deionized water until neutral. After vacuum freeze-drying, hollow strontium titanate nanocubes / few-layer Ti3C2MXene composite material was obtained.
[0028] Scanning electron microscope (SEM) images of few-layer Ti3C2MXene and hollow strontium titanate cubic / few-layer Ti3C2MXene composites are shown below. Figure 2 As shown in a, 2b. From Figure 2 a and Figure 2As shown in b, under the weakly alkaline and weakly oxidizing conditions of alkaline earth metal hydroxide Sr(OH)2 (with low H2O2 content), hollow strontium titanate nanocubes were generated in situ on Ti3C2MXene nanosheets. Figure 3 As shown in a, 3b. From Figure 3 As shown in a and 3b, a structure combining hollow strontium titanate nanocubic shells with Ti3C2MXene was successfully prepared.
[0029] Example 3 Preparation of hollow strontium niobate nanocubes / few-layer Nb2C MXene composite materials: Few-layer Nb2C MXene can be prepared by HF etching and intercalation stripping (Angew. Chem. 2023, 135, e202303539).
[0030] 0.1 g of few-layer Nb₂C MXene nanosheets were added to 30 mL of 0.15 mol / L Sr(OH)₂ solution containing 85 μL H₂O₂ (30%), mixed thoroughly, and placed in a 50 mL hydrothermal reactor. The mixture was treated at 140 °C for 12 h. The dispersion was centrifuged to obtain a precipitate, which was then washed with 0.1 M HCl to remove impurities, followed by washing with deionized water until neutral. After vacuum freeze-drying, hollow strontium niobate nanocubes / few-layer Nb₂C MXene composite material was obtained. Figure 4 ).
[0031] Example 4 Preparation of hollow barium strontium titanate nanocubes / few-layer Ti3C2MXene composite materials: 0.1 g of few-layer Ti3C2MXene nanosheets were added to a mixture of 30 mL of 0.075 mol / L Sr(OH)2 and 0.075 mol / L Ba(OH)2 containing 85 μL H2O2 (30%). The mixture was thoroughly mixed and placed in a 50 mL hydrothermal reactor. The mixture was treated at 140 °C for 12 h. The dispersion was centrifuged to obtain a precipitate. The precipitate was then removed by acid washing with 0.1 M HCl, followed by washing with deionized water until neutral. After vacuum freeze-drying, hollow barium strontium titanate cubes / Ti3C2MXene composite material was obtained.
[0032] Depend on Figure 5 Electron micrographs and corresponding EDS elemental distribution diagrams show that hollow barium strontium titanate was formed in situ on Ti3C2MXene nanosheets by treatment with a mixture of Sr(OH)2 and Ba(OH)2 and H2O2 solution.
[0033] Example 5 Preparation of hollow strontium vanadate nanospheres / V2C MXene composite materials: Few-layer V2C MXene can be prepared by the LiF+HCl method (Nature, 2014, 516, 78-81).
[0034] 0.1 g of few-layer V2C MXene was added to 30 mL of 0.3 mol / L Sr(OH)2 solution containing 0.15 mL of bromine water, mixed thoroughly, placed in a 50 mL hydrothermal reactor, and treated at 80 °C for 12 h. The dispersion was centrifuged to obtain a precipitate, which was then washed with 0.1 MHCl to remove impurities, washed with deionized water until neutral, and then freeze-dried under vacuum to successfully prepare hollow strontium vanadate nanospheres / V2C MXene composite material.
[0035] Example 6 Preparation of hollow strontium titanate niobate / TiNbC MXene composite material: Accordion-shaped multilayer TiNbC MXene can be prepared by selectively etching the Al layer in TiNbAlC MAX using the LiF+HCl method (Adv. Energy Mater. 2022, 12, 2201189).
[0036] 0.1 g of accordion-shaped multilayer TiNbC MXene was added to 30 mL of 0.5 mol / L Sr(OH)2 solution containing 0.3 mL of peracetic acid. The mixture was thoroughly mixed and placed in a 50 mL hydrothermal reactor. The mixture was treated at 200 °C for 12 h. The dispersion was centrifuged to obtain a precipitate. The precipitate was then removed by acid washing with 0.1 M HCl and washed with deionized water until neutral. After vacuum freeze-drying, hollow strontium titanate niobate / TiNbC MXene composite material was successfully prepared.
Claims
1. A hollow crystal / MXene composite material of MXene-derived perovskite oxide, characterized in that, The chemical composition of the composite material is represented as h-ABO3 / MXene, where h-ABO3 represents hollow crystals of MXene-derived perovskite oxide, where A is a divalent alkaline earth metal element, B is a transition metal element in the MXene precursor, and O is oxygen. h-ABO3 has a hollow nanocrystalline structure and is uniformly distributed on MXene.
2. The MXene-derived perovskite oxide hollow crystal / MXene composite material according to claim 1, characterized in that, The h-ABO3 is a hollow crystal of perovskite oxide composed of strontium titanate, barium titanate, calcium titanate, strontium niobate, barium niobate, calcium niobate, strontium tantalate, barium strontium titanate, barium strontium niobate, strontium titanate, barium titanate, or other transition metal elements and one or more alkaline earth metals.
3. The MXene-derived perovskite oxide hollow crystal / MXene composite material according to claim 1, characterized in that, The MXene has an accordion-like multilayer structure or a few-layer nanosheet structure, and is Ti3C2 MXene, Ti2C MXene, Ti2NMXene, Nb4C3 MXene, Nb2C MXene, Mo2C MXene, Ta4C3 MXene, TiNbC MXene, Mo2TiC2 MXene, Ti2TaC2 MXene, or other MXenes with an accordion-like multilayer structure or a few-layer nanosheet structure.
4. A method for preparing the MXene-derived perovskite oxide hollow crystal / MXene composite material according to any one of claims 1-3, characterized in that, Includes the following steps: Using MXene as a precursor, the MXene material was subjected to a one-step hydrothermal treatment under weak oxidizing and weak alkaline conditions. The reacted MXene provided the B source for h-ABO3, and the unreacted MXene served as the carrier for h-ABO3, resulting in an h-ABO3 / MXene composite material. The alkaline solution used served as the A source in h-ABO3 and provided an alkaline reaction environment.
5. The method for preparing the MXene-derived perovskite oxide hollow crystal / MXene composite material according to claim 4, characterized in that, The following steps are performed: (1) Disperse the MXene material in a mixed solution containing an oxidant and an alkaline solution; (2) React the MXene from step (1) with the mixed solution of the oxidant and alkaline solution under hydrothermal conditions for 0.5 h to 48 h, and then separate, wash and dry the resulting dispersion to obtain the h-ABO3 / MXene composite material.
6. The method for preparing the MXene-derived perovskite oxide hollow crystal / MXene composite material according to claim 5, characterized in that, The oxidant is one or more of inorganic peroxides, organic peroxides, halogens, and high-valence metal salts; wherein, inorganic peroxides include hydrogen peroxide, ammonium persulfate, sodium persulfate, and sodium peroxide; organic peroxides include peracetic acid, tert-butyl hydroperoxide, and m-chloroperoxybenzoic acid; halogens include liquid bromine and chlorine; and high-valence metal salts include potassium permanganate, potassium dichromate, and cerium ammonium nitrate.
7. The method for preparing the MXene-derived perovskite oxide hollow crystal / MXene composite material according to claim 5, characterized in that, The alkaline solution is selected from one or more mixed aqueous solutions of alkaline earth metal hydroxides; wherein, alkaline earth metal hydroxides include magnesium hydroxide, calcium hydroxide, strontium hydroxide, or barium hydroxide.
8. The method for preparing the MXene-derived perovskite oxide hollow crystal / MXene composite material according to claim 5, characterized in that, The mass ratio of MXene to alkaline earth metal hydroxide in the alkaline solution is 1:(5~50), and the molar concentration of the alkaline solution is 0.05 mol / L~0.5 mol / L.
9. The method for preparing the MXene-derived perovskite oxide hollow crystal / MXene composite material according to claim 5, characterized in that, The mass ratio of MXene to oxidant is 1:(0.02~0.9).
10. The method for preparing the MXene-derived perovskite oxide hollow crystal / MXene composite material according to claim 5, characterized in that, The hydrothermal reaction time is 0.5 h to 48 h, and the hydrothermal reaction temperature is 80℃ to 200℃.