Simple chemical preparation method of MXene-precious metal composite nanomaterial

Abstract

The invention belongs to the technical field of preparation of low-dimensional nano composite materials, and discloses a simple and rapid preparation method of an MXene-noble metal composite nano material. The method is based on the principle of mild chemical reduction, meanwhile, the reduction capacity of lone pair electrons of MXene is utilized, and mild preparation of the MXene-precious metal composite nanomaterial can be achieved. Controllable preparation of different MXene-noble metal composite nanomaterials can be realized by flexibly adjusting the components of the noble metal precursor. Meanwhile, the used chemicals are few in variety and environment-friendly, and the principle of green chemical synthesis is combined.

Description

Technical Field

[0001] The present invention belongs to the technical field of preparation of low-dimensional nanocomposite materials, and relates to a simple and rapid preparation method of a MXene-noble metal composite nanomaterial. Background Art

[0002] MXene materials are a new type of two-dimensional materials with unique structures and properties. In recent years, they have shown great application potential in many fields. n+1 X n T x , where M is an early noble metal, X is carbon and / or nitrogen, n=1-4, T x Represents the surface termination group (such as O, OH, F, etc.). This structure leads to its chemical structural diversity, making MXene have rich composition and performance tunability. For example, its conductivity can be adjusted from metal to semiconductor or even superconductor, and continuous performance adjustment can be achieved by changing the surface termination group.

[0003] MXene materials have been widely studied and applied in the fields of electrode materials, implantable electrodes, chemical catalysis, photothermal therapy, electromagnetic interference shielding, gas and pressure sensing, water purification and desalination, conductive and enhanced ceramics, metal and polymer composites, lasers and LEDs, circuit interconnects and photodetectors. However, MXene materials may oxidize rapidly under certain environments, which limits their controllable preparation and application. At the same time, the surface chemistry of MXene materials has an important influence on their properties, but controlling the surface chemistry to achieve the needs of specific applications remains a challenge.

[0004] Therefore, this patent takes Ti3C2 nanosheets as an example and proposes a chemical method to modify the MXene surface, and further prepares low-dimensional MXene-noble metal composite nanomaterials with different MXene components, proving the universality of this method. Summary of the invention

[0005] In view of the problem that MXene materials will oxidize rapidly under certain conditions, which is not conducive to controllable preparation, the present invention provides a simple and efficient method for modifying the surface of MXene based on the principle of mild chemical reduction and utilizing the reduction ability of the lone pair electrons of MXene, including: Step 1, adding a noble metal precursor solution to a sodium citrate solution and stirring to obtain a mixed solution of a noble metal precursor and a surfactant precursor; Step 2, dispersing MXene (Ti3C2 nanosheets) into an ultrapure aqueous solution saturated with nitrogen, and ultrasonically treating the solution to obtain a MXene solution; Step 3, adding the precursor mixed solution prepared in step 1 dropwise to the MXene solution prepared in step 2 to obtain a mixed reaction solution; Step 4, subjecting the mixed reaction solution obtained in step 3 to ultrasonic treatment to allow the reaction to occur completely, thereby obtaining a product solution; Step 5, the product solution obtained in step 4 is subjected to centrifugal concentration treatment, and the final product MXene-precious metal composite nanomaterial is obtained by washing with ultrapure water and removing the supernatant.

[0006] Furthermore, the noble metal in step 1 is any one of gold, palladium and platinum, and the precursor solution is usually a chlorate solution of the noble metal; The concentration of the noble metal precursor solution in step 1 is 20-50 mM, the concentration of the sodium citrate solution is 30-80 mM, and the volume ratio of the noble metal precursor solution to the sodium citrate solution is 2-4; Furthermore, the ultrasonic time in step 2 is 5-10 minutes, the ultrasonic parameter is 100-200 w, and the concentration of the MXene solution is 1-2 mg / mL; The liquid droplet acceleration rate in step 3 is 5-10 µL / s; Furthermore, the ultrasonic time in step 4 is 5-10 minutes, the ultrasonic parameter is 100-200 W, and the reaction conditions are normal temperature and pressure; The centrifugal force during the centrifugal concentration treatment in step 5 is 6000-8000 g, and the centrifugation time is 5-10 minutes.

[0007] The present invention proposes a simple chemical preparation method for MXene-precious metal composite nanomaterials. The method uses the reduction ability of MXene's own lone pair electrons to achieve simple and gentle preparation without a strong reducing agent and at normal temperature and pressure. By flexibly adjusting the components of the precious metal precursor, different MXene-precious metal composite nanomaterials can be prepared in a controlled manner. At the same time, the types of chemicals used are few and environmentally friendly, and the principle of composite green chemical synthesis is followed. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 is a flow chart of a method for preparing a MXene-noble metal composite nanomaterial provided in an embodiment of the present invention; Figure 2 This is a low-magnification scanning electron microscope image of the MXene-Au composite nanomaterial prepared by the present invention; Figure 3 It is a high-magnification scanning electron microscope image of the MXene-Au composite nanomaterial prepared in an embodiment of the present invention. DETAILED DESCRIPTION

[0009] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0010] In order to enable those skilled in the art to fully understand how to implement the present invention in detail, this section is an explanatory embodiment that expands and describes the technical solution of the claims.

[0011] like Figure 1 As shown, the preparation method of the MXene-noble metal composite nanomaterial provided in the embodiment of the present invention includes: S101, adding a certain amount of noble metal precursor solution to the sodium citrate solution and stirring to obtain a mixed solution of the noble metal precursor and the surfactant precursor; S102, dispersing MXene (Ti3C2 nanosheets) into an ultrapure aqueous solution saturated with nitrogen, and ultrasonically treating the solution to obtain a MXene solution; S103, adding the precursor mixed solution prepared in S101 dropwise to the MXene solution prepared in S102 to obtain a mixed reaction solution; ultrasonically treating the mixed reaction solution obtained in S103 to allow the reaction to occur completely to obtain a product solution, and centrifugally concentrating the product solution. Example

[0012] A method for preparing a MXene-Au composite nanomaterial comprises the following steps: 1) Add chloroauric acid precursor solution (25 mM, 100 µL) to sodium citrate solution (40 mM, 50 µL) and stir to obtain a mixed solution of gold precursor and surfactant precursor; 2) MXene (Ti3C2 nanosheets) was dispersed in a nitrogen-saturated ultrapure aqueous solution and ultrasonicated (100 w, 5 min) to obtain a MXene solution (100 µL, 1 mg / mL); 3) Add the precursor mixed solution prepared in step 1 dropwise (5 µL / s) to the MXene solution prepared in step 2 to obtain a mixed reaction solution; 4) subjecting the mixed reaction solution obtained in step 3 to ultrasonic treatment (100 W, 5 minutes) to complete the reaction and obtain a product solution; 5) The product solution obtained in step 4 is centrifuged and concentrated (6000 g, 5 minutes), and the supernatant is removed after washing with ultrapure water to obtain the final product MXene-Au composite nanomaterial. Example

[0013] A method for preparing a MXene-Pd composite nanomaterial comprises the following steps: 1) Adding a chloropalladic acid precursor solution (35 mM, 200 µL) to a sodium citrate solution (60 mM, 100 µL) and stirring to obtain a mixed solution of a palladium precursor and a surfactant precursor; 2) MXene (Ti3C2 nanosheets) was dispersed in a nitrogen-saturated ultrapure aqueous solution and ultrasonicated (200 w, 7 min) to obtain a MXene solution (200 µL, 2 mg / mL); 3) Add the precursor mixed solution prepared in step 1 dropwise (10 µL / s) to the MXene solution prepared in step 2 to obtain a mixed reaction solution; 4) subjecting the mixed reaction solution obtained in step 3 to ultrasonic treatment (200 W, 7 minutes) to complete the reaction and obtain a product solution; 5) The product solution obtained in step 4 is centrifuged and concentrated (8000 g, 8 minutes), and the final product, MXene-Pd composite nanomaterial, is obtained by washing with ultrapure water and removing the supernatant. Example

[0014] A method for preparing a MXene-Pt composite nanomaterial comprises the following steps: 1) Adding chloroplatinic acid precursor solution (50 mM, 300 µL) to sodium citrate solution (80 mM, 150 µL) and stirring to obtain a mixed solution of platinum precursor and surfactant precursor; 2) MXene (Ti3C2 nanosheets) was dispersed in a nitrogen-saturated ultrapure aqueous solution and ultrasonicated (150 w, 10 min) to obtain a MXene solution (300 µL, 1 mg / mL); 3) Add the precursor mixed solution prepared in step 1 dropwise (10 µL / s) to the MXene solution prepared in step 2 to obtain a mixed reaction solution; 4) subjecting the mixed reaction solution obtained in step 3 to ultrasonic treatment (150 W, 10 minutes) to complete the reaction and obtain a product solution; 5) The product solution obtained in step 4 is centrifuged and concentrated (7000 g, 7 minutes), and the final product, MXene-Pt composite nanomaterial, is obtained by washing with ultrapure water and removing the supernatant.

[0015] Figure 2 and 3The low-magnification and high-magnification scanning electron microscope characterization images of the MXene-Au composite nanomaterial prepared in Example 1 of the present invention respectively show that the gold nanoparticles have a multi-branched morphology, an average size of about 500 nm, and are uniformly loaded on the MXene flat substrate, indicating the effectiveness of the preparation method.

[0016] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any modifications, equivalent substitutions and improvements made by any technician familiar with the technical field within the technical scope disclosed by the present invention and within the spirit and principle of the present invention should be covered by the protection scope of the present invention.

Claims

1. A simple and rapid preparation method of MXene-noble metal composite nanomaterials, comprising: Step 1, adding a noble metal precursor solution to a sodium citrate solution and stirring to obtain a mixed solution of a noble metal precursor and a surfactant precursor; Step 2, dispersing MXene (Ti3C2 nanosheets) into an ultrapure aqueous solution saturated with nitrogen, and ultrasonically treating the solution to obtain a MXene solution; Step 3, adding the precursor mixed solution prepared in step 1 dropwise to the MXene solution prepared in step 2 to obtain a mixed reaction solution; Step 4, subjecting the mixed reaction solution obtained in step 3 to ultrasonic treatment to allow the reaction to occur completely, thereby obtaining a product solution; Step 5, the product solution obtained in step 4 is subjected to centrifugal concentration treatment, and the final product MXene-precious metal composite nanomaterial is obtained by washing with ultrapure water and removing the supernatant.

2. The method for preparing a MXene-noble metal composite nanomaterial according to claim 1, characterized in that: The noble metal in step 1 is any one of gold, palladium and platinum, and the precursor solution is usually a chlorate solution of the noble metal; In the step 1, the concentration of the noble metal precursor solution is 20-50 mM, the concentration of the sodium citrate solution is 30-80 mM, and the volume ratio of the noble metal precursor solution to the sodium citrate solution is 2-4.

3. The method for preparing a MXene-noble metal composite nanomaterial according to claim 1, characterized in that: The MXene composition in step 2 is usually n+1 X n T x , where M is an early noble metal, X is carbon and / or nitrogen, n=1-4, T x represents the surface termination group (such as O, OH, F, etc.); the ultrasonic time in the step 2 is 5-10 minutes, the ultrasonic parameter is 100-200 w, and the MXene solution concentration is 1-2 mg / mL; The liquid droplet acceleration rate in step 3 is 5-10 µL / s.

4. The method for preparing a MXene-noble metal composite nanomaterial according to claim 1, characterized in that: The ultrasonic time in step 4 is 5-10 minutes, the ultrasonic parameter is 100-200 W, and the reaction conditions are normal temperature and pressure; The centrifugal force during the centrifugal concentration treatment in step 5 is 6000-8000 g, and the centrifugation time is 5-10 minutes.

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