La-based sound-sensitive nano material as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of nano materials, and discloses a La-based sound-sensitive nano material as well as a preparation method and application thereof. The preparation method of the La-based sound-sensitive nano material comprises the following steps: S1, mixing a lanthanum source, a copper source and a solvent to obtain a mixed solution; s2, adding a pH regulator into the mixed solution, and stirring to obtain sol; s3, the sol is subjected to sintering treatment, and La-based nanocrystalline is obtained; and S4, carrying out ball milling and ultrasonic stripping on the La-based nanocrystal, so as to obtain the La-based sound-sensitive nanomaterial. The preparation method of the La-based sound-sensitive nano material breaks through the limitation of a crystal structure, realizes accurate regulation and control on the purity, nano morphology and active crystal face exposure rate of the La2CuO4 crystal, and endows the La-based sound-sensitive nano material with a specific symmetric Abma space group structure with an efficient sound-sensitive characteristic; therefore, the compound can be used as a sonosensitizer for catalytic degradation of organic pollutants or sonodynamic therapy of tumors.

Description

Technical Field

[0001] This invention relates to the field of nanomaterials technology, specifically to a La-based acoustic nanomaterial, its preparation method, and its applications. Background Technology

[0002] With the increasing demand for efficient and safe functional materials in environmental governance and precision medicine, acoustic sensory agents, as a novel type of functional material that responds to external stimuli (such as ultrasound and light), demonstrate significant application potential in environmental pollution control (such as catalytic degradation of organic pollutants) and biomedical fields (such as sonodynamic therapy for tumors) by efficiently generating reactive oxygen species (ROS). Especially against the backdrop of current trends towards lead-free environmental protection, the need for device miniaturization, and the development of high-efficiency energy conversion technologies, the development of high-performance acoustic sensory agent materials that combine environmental safety, high energy conversion efficiency, and multimodal response capabilities has become a research hotspot.

[0003] Traditional acoustic sensitizer materials (such as organoporphyrins and metal oxide nanoparticles) can generate reactive oxygen species (ROS) in response to external stimuli, but they still face the following key challenges: (1) Limited environmental safety: Acoustic sensitizers containing lead or toxic metals pose potential toxicity risks in biological applications and do not meet the requirements of global lead-free environmental regulations; (2) Insufficient energy conversion efficiency: Most materials have low ROS yields under ultrasound / photoexcitation due to high crystal structure symmetry and weak phonon-electron coupling, making it difficult to meet the needs of actual pollution degradation or tumor treatment; (3) Functional limitation: Existing acoustic sensitizers lack multimodal response capabilities and are difficult to adapt to dynamic stimulation conditions in complex environments or biological systems.

[0004] Lanthanum cuprate (La2CuO4), as a typical perovskite-like layered p-type semiconductor, possesses unique crystal structure advantages and combines the high catalytic activity, long carrier diffusion distance, and charge separation efficiency characteristic of perovskite materials with those of layered materials. In addition, its narrow bandgap significantly improves the utilization efficiency of external energy sources such as sunlight and ultrasound, providing an ideal electronic structure basis for catalysis and acoustic sensing applications. However, existing La2CuO4 preparation processes (such as hydrothermal method, high-temperature solid-state method, combustion method, etc.) have the following significant defects: (1) Poor controllability of synthesis: the reaction process is kinetic and CuO impurity phase is easily generated; (2) Difficulty in morphology control: the product particle size is generally in the micrometer range, the specific surface area is low, and the active sites are not sufficiently exposed; (3) Bottleneck in nano-scale preparation: it is difficult to achieve uniform particle size and stable dispersion in the nanometer range, which seriously restricts its application; (4) Traditional processes often use toxic organic complexing agents (such as citric acid and ethylene glycol), which pose environmental risks and post-processing problems.

[0005] Therefore, there is an urgent need to develop a low-temperature, controllable, and environmentally friendly green synthesis process for La-based sound sensitizers, breaking through the technical barriers of material nano-sizing and exposure of highly active sites, in order to promote their efficient application in environmental catalysis and biomedicine. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of the prior art and provide a La-based acoustic nanomaterial, its preparation method, and its application.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows: In a first aspect, the present invention provides a method for preparing La-based acoustic-sensitive nanomaterials, comprising the following steps: S1. Mix the lanthanum source, copper source and solvent to obtain a mixture; S2. Add a pH adjuster to the mixture and stir to obtain a sol; S3. The sol is sintered to obtain La-based nanocrystals; S4. The La-based nanocrystals are ball-milled and ultrasonically exfoliated to obtain La-based acoustic nanomaterials with the chemical formula La2CuO4; the ultrasonic exfoliating agent used in the ultrasonic exfoliation includes amide compounds and N-methylpyrrolidone.

[0008] The present invention provides a method for preparing La-based acoustic-sensitive nanomaterials. Through a synergistic process of sol-gel method, ball milling, and solvent-assisted ultrasonic exfoliation, this method breaks crystal symmetry and achieves precise control over the purity, nanostructure, and active crystal facet exposure rate of La₂CuO₄ crystals, endowing the centrosymmetric Abma space group structure with highly efficient acoustic-sensitive properties. Specifically, the sol-gel method and sintering process in this invention can control lattice recombination kinetics, suppressing impurity phase formation while maintaining the nanoscale primary particle size, reducing oxygen vacancy defects, and improving crystal purity. Secondly, the specific exfoliating agent in the preparation method of the La-based acoustic-sensitive nanomaterials of this invention precisely controls the interlayer spacing and surface energy of La-based nanocrystals through the synergistic effect of molecular size matching and ultrasonic cavitation energy, directionally dissociating the layered structure and significantly improving the proportion of active crystal faces and specific surface area of ​​the La-based acoustic-sensitive nanomaterials. This enhances their ROS generation capacity and enables them to produce a stronger cavitation effect under low-frequency ultrasound, thus allowing them to penetrate deep tissues as acoustic-sensitive agents in sonodynamic therapy, enriching and releasing ROS in the tumor region, solving the problem of insufficient efficacy in deep tissues due to light attenuation in traditional photodynamic therapy (PDT). Furthermore, the preparation method of the La-based acoustic-sensitive nanomaterials of this invention is simple, environmentally friendly, requires no toxic complexing agents throughout the process, and the exfoliating agent is recyclable, meeting green chemistry standards. It achieves high-performance acoustic-sensitive agent preparation while also considering environmental protection and efficient resource utilization, possessing extremely high application value and development prospects.

[0009] In a preferred embodiment of the method for preparing the La-based acoustic nanomaterials of the present invention, in step S1, the lanthanum source is lanthanum nitrate hexahydrate; and the copper source is copper nitrate trihydrate.

[0010] In a preferred embodiment of the method for preparing the La-based acoustic nanomaterials of the present invention, in step S1, the molar ratio of the lanthanum source to the copper source is 2:1.

[0011] In a preferred embodiment of the method for preparing the La-based acoustic nanomaterials of the present invention, the solvent in step S1 is water.

[0012] In a preferred embodiment of the method for preparing the La-based acoustic nanomaterials of the present invention, in step S2, the pH adjuster includes at least one of sodium hydroxide, potassium hydroxide, sodium carbonate, and potassium carbonate.

[0013] In a preferred embodiment of the method for preparing the La-based acoustic nanomaterials of the present invention, in step S2, the molar ratio of the pH adjuster to the copper source is (12-20):1.

[0014] Preferably, in step S2, the molar ratio of the pH adjuster to the copper source is 15:1.

[0015] In a preferred embodiment of the preparation method of the La-based acoustic nanomaterials of the present invention, the stirring time in step S2 is 0.5h-2h.

[0016] In a preferred embodiment of the preparation method of the La-based acoustic nanomaterials of the present invention, in step S3, the sintering temperature is 600℃-750℃ and the time is 2h-4h.

[0017] In a preferred embodiment of the method for preparing La-based acoustic nanomaterials according to the present invention, in step S4, the ball milling speed is 100 rpm-200 rpm and the time is 0.5 h-1 h.

[0018] In a preferred embodiment of the preparation method of the La-based acoustic nanomaterials of the present invention, in step S4, the power of the ultrasonic ablation is 500 W / cm. 2 -600W / cm 2 The time is 0.5h-2h.

[0019] In a preferred embodiment of the method for preparing the La-based acoustic nanomaterials of the present invention, in step S4, the ultrasonic stripping agent comprises an amide compound and N-methylpyrrolidone in a volume ratio of (3-6):1.

[0020] Preferably, the ultrasonic stripping agent comprises an amide compound and N-methylpyrrolidone in a volume ratio of 5:1.

[0021] In a preferred embodiment of the method for preparing the La-based acoustic nanomaterials of the present invention, in step S4, the amide compound is formamide and / or N,N-dimethylformamide.

[0022] In a preferred embodiment of the preparation method of the La-based acoustic nanomaterial of the present invention, in step S4, the mass ratio of the ultrasonic stripping agent to the La-based nanocrystals is (300-500):1.

[0023] Secondly, the present invention provides La-based acoustic nanomaterials prepared by the preparation method described above.

[0024] As a preferred embodiment of the La-based acoustic nanomaterial of the present invention, the La-based acoustic nanomaterial has a sheet-like structure; the diameter of the La-based acoustic nanomaterial is 150nm-200nm.

[0025] Thirdly, the present invention provides the application of the aforementioned La-based acoustic-sensitive nanomaterials in the catalytic degradation of organic pollutants.

[0026] Fourthly, the present invention provides the application of the aforementioned La-based acoustic nanomaterials in the preparation of drugs for acoustic dynamic therapy.

[0027] Compared with existing technologies, the beneficial effects of this invention are as follows: First, the preparation method of the La-based acoustic-sensitive nanomaterials of this invention, through the synergistic process of sol-gel method, ball milling, and solvent-assisted ultrasonic exfoliation, breaks the crystal symmetry, achieving precise control over the purity, nanomorphology, and active crystal face exposure rate of La2CuO4 crystals, thus endowing the centrosymmetric Abma space group structure with highly efficient acoustic-sensitive properties. Second, the preparation method of the La-based acoustic-sensitive nanomaterials of this invention can effectively control the nanocrystal size, significantly increasing its specific surface area, allowing the acoustic sensor to generate more reactive oxygen species (ROS) under ultrasonic excitation, especially singlet oxygen (ROS). 1 (O2), thereby efficiently catalyzing the degradation or killing of tumor cells. Simultaneously, the La-based acoustic nanomaterials prepared by the method of this invention exhibit excellent chemical and thermal stability, maintaining structural integrity during the catalytic degradation of organic pollutants or sonodynamic therapy (SDT), avoiding the loss of active substances due to degradation. Furthermore, the preparation method of the La-based acoustic nanomaterials of this invention is simple, environmentally friendly, requires no toxic complexing agents throughout the process, and the ultrasonic stripping agent is recyclable, meeting green chemistry standards. It achieves the preparation of high-performance acoustic agents while simultaneously considering environmental protection and efficient resource utilization, possessing extremely high application value and development prospects. Attached Figure Description

[0028] Figure 1 The image shows the XRD pattern of the La-based acoustic nanomaterial prepared in Example 1 of this invention. Figure 2 This is a TEM image of the La-based acoustic nanomaterial prepared in Example 1 of this invention; Figure 3 The image shows the XRD pattern of the La-based acoustic nanomaterial prepared in Comparative Example 1 of this invention. Figure 4 This is a TEM image of the La-based acoustic nanomaterial prepared in Comparative Example 1 of this invention; Figure 5 The image shows the XRD pattern of the La-based acoustic nanomaterial prepared in Comparative Example 2 of this invention. Figure 6 This is a TEM image of the La-based acoustic nanomaterial prepared in Comparative Example 2 of this invention; Figure 7 This is an absorbance curve of the La-based acoustic nanomaterials prepared in Example 1 of the present invention degrading DPBF; Figure 8 The absorbance curve of the La-based acoustic nanomaterials prepared in Comparative Example 1 of this invention degrading DPBF is shown. Figure 9 The image shows the absorbance curve of the La-based acoustic nanomaterials prepared in Comparative Example 2 of this invention when degrading DPBF. Detailed Implementation

[0029] To better illustrate the objectives, technical solutions, and advantages of this invention, the invention will be further described below with reference to specific embodiments. Those skilled in the art should understand that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0030] The following description, in conjunction with specific embodiments, illustrates the practical effects of the present invention.

[0031] Unless otherwise specified, the experimental methods used in the examples are conventional methods; the materials, reagents, equipment, etc. used are all commercially available unless otherwise specified.

[0032] Example 1: This embodiment prepares a La-based acoustic-sensitive nanomaterial with the chemical formula La₂CuO₄. The preparation method includes the following steps: (1) Weigh La(NO3)3·6H2O and Cu(NO3)2·3H2O accurately according to a molar ratio of 2:1, and disperse them in ultrapure water to form a homogeneous mixture; (2) Add NaOH to the mixture in step (1) and stir rapidly for 1 hour to form a sol, and wash thoroughly with ultrapure water (washing: centrifuge to collect the precipitate, 3000 rpm, 4 min); the molar ratio of La(NO3)3·6H2O, Cu(NO3)2·3H2O and NaOH is 2:1:15; (3) Place the sol washed in step (2) in an air atmosphere and sinter at 650°C for 3 hours to obtain La-based nanocrystals. Wash the La-based nanocrystals with ultrapure water (washing: centrifuge to collect the precipitate, 8000 rpm, 5 min). (4) The washed La-based nanocrystals were ball-milled at a speed of 200 rpm, a ball-to-material ratio of 1:1, and a time of 1 h. (5) The ball-milled product was ultrasonically exfoliated using a composite ultrasonic stripping agent consisting of formamide and N-methylpyrrolidone in a volume ratio of 5:1. The ultrasonic frequency was 50 kHz and the power was 600 W / cm. 2 The time was 1 hour; La-based acoustic nanomaterials were obtained.

[0033] The final product, La-based acoustic nanomaterials, was analyzed by XRD and TEM.

[0034] like Figure 1 As shown, the XRD pattern of the La-based acoustic nanomaterial in this embodiment is a perfect match with the standard card PDF#97-000-1076, confirming that the phase is pure La2CuO4 and the space group is Abma.

[0035] like Figure 2 As shown, the La-based acoustic nanomaterial in this embodiment has a sheet-like structure and an average hydrated particle size of approximately 190 nm.

[0036] Comparative Example 1: In this comparative example, a La-based acoustic-sensitive nanomaterial with the chemical formula La₂CuO₄ was prepared. The preparation method includes the following steps: (1) Weigh La(NO3)3·6H2O and Cu(NO3)2·3H2O accurately according to a molar ratio of 2:1, and disperse them in ultrapure water to form a homogeneous mixture; (2) Add NaOH to the mixture in step (1) and stir rapidly for 1 hour to form a sol, and wash thoroughly (washing: centrifuge to collect the precipitate, 3000 rpm, 4 min); the molar ratio of La(NO3)3·6H2O, Cu(NO3)2·3H2O and NaOH is 2:1:15; (3) Place the sol washed in step (2) in an air atmosphere and sinter at 650°C for 3 hours to obtain La-based nanocrystals. Wash the La-based nanocrystals (washing: centrifuge to collect the precipitate, 8000 rpm, 5 min) to obtain La-based acoustic nanomaterials.

[0037] The final product, La-based acoustic nanomaterials, was analyzed by XRD and TEM.

[0038] like Figure 3 As shown, the XRD pattern of the La-based acoustic nanomaterial in this comparative example matches the standard card in PDF#97-000-1076, indicating that it has a La2CuO4 phase with space group Abma.

[0039] like Figure 4 As shown, the La-based acoustic nanomaterial particles in this comparative example are relatively large, with a diameter of approximately 30-40 μm.

[0040] Comparative Example 2: In this comparative example, a La-based acoustic-sensitive nanomaterial with the chemical formula La₂CuO₄ was prepared. The preparation method includes the following steps: (1) Weigh La(NO3)3·6H2O and Cu(NO3)2·3H2O accurately according to a molar ratio of 2:1, and disperse them in ultrapure water to form a homogeneous mixture; (2) Add NaOH to the mixture in step (1) and stir rapidly for 1 hour to form a sol, and wash thoroughly (washing: centrifuge to collect the precipitate, 3000 rpm, 4 min); the molar ratio of La(NO3)3·6H2O, Cu(NO3)2·3H2O and NaOH is 2:1:15; (3) Place the sol washed in step (2) in an air atmosphere and sinter at 650°C for 3 hours to obtain La-based nanocrystals, and wash the La-based nanocrystals (washing: centrifuge to collect the precipitate, 8000 rpm, 5 min); (4) The washed La-based nanocrystals were ball-milled at a speed of 200 rpm, a ball-to-material ratio of 1:1, and a time of 1 h to obtain La-based acoustic nanomaterials.

[0041] The final product, La-based acoustic nanomaterials, was analyzed by XRD and TEM.

[0042] like Figure 5 As shown, the XRD pattern of the La-based acoustic nanomaterial in this comparative example matches the standard card in PDF#97-000-1076, indicating that it has a La2CuO4 phase with space group Abma.

[0043] like Figure 6As shown, the La-based acoustic nanomaterials in this comparative example have a particulate structure with a diameter of approximately 150-200 μm.

[0044] Test example: To evaluate the ability of the La-based acoustic nanomaterials prepared in the examples and comparative examples to catalyze the generation of reactive oxygen species (ROS) under ultrasonic stimulation, this test example indirectly characterized the acoustic activity by the degradation efficiency of 1,3-diphenylisobenzofuran (DPBF).

[0045] Test method: (1) The La-based acoustic nanomaterials were dissolved in an aqueous solution containing DPBF indicator to obtain a La-based acoustic nanomaterial dispersion with a concentration of 100 μg / mL.

[0046] (2) Take 3 mL of La-based acoustic nanomaterial dispersion and measure its absorbance curve in the wavelength range of 300 nm to 600 nm. Record the absorbance value at 410 nm (A1).

[0047] (3) Take another 3 mL of La-based acoustic nanomaterial dispersion and sonicate for 3 minutes (1 MHz, 1.0 W / cm). 2 After 50% duty cycle, the absorbance curve of the sample was measured in the wavelength range of 300nm-600nm, and the absorbance value at 410nm (A2) was recorded.

[0048] (4) Compare the curves of steps (2) and (3) and calculate the change in absorbance at 410 nm (A1-A2). The larger the change, the more active oxygen is generated by the La-based acoustic nanomaterial under the same conditions, and the stronger the catalytic activity.

[0049] like Figure 7 , 8 As shown in Figures 9 and 1, the absorbance change of the La-based acoustic nanomaterial in Example 1 at 410 nm was 0.489, while that of the La-based acoustic nanomaterial in Comparative Example 1 was 0.218; and that of the La-based acoustic nanomaterial in Comparative Example 2 was 0.345. This demonstrates that the La-based acoustic nanomaterial of the present invention exhibits the best ROS generation capacity under ultrasonic stimulation, significantly superior to the comparative examples. This verifies that the present invention significantly improves the exposed ratio of active crystal faces of the La-based acoustic nanomaterial and enhances its ROS generation efficiency through optimized preparation process, providing a high-performance candidate material for sonodynamic therapy.

[0050] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A method for preparing La-based acoustic nanomaterials, characterized in that, Includes the following steps: S1. Mix the lanthanum source, copper source and solvent to obtain a mixture; S2. Add a pH adjuster to the mixture and stir to obtain a sol; S3. The sol is sintered to obtain La-based nanocrystals; S4. The La-based nanocrystals are ball-milled and ultrasonically exfoliated to obtain La-based acoustic nanomaterials with the chemical formula La2CuO4; the ultrasonic exfoliating agent used in the ultrasonic exfoliation includes amide compounds and N-methylpyrrolidone.

2. The method for preparing the La-based acoustic nanomaterial as described in claim 1, characterized in that, In step S2, the pH adjuster includes at least one of sodium hydroxide, potassium hydroxide, sodium carbonate, and potassium carbonate.

3. The method for preparing the La-based acoustic nanomaterial as described in claim 1, characterized in that, In step S2, the molar ratio of the pH adjuster to the copper source is (12-20):

1.

4. The method for preparing the La-based acoustic nanomaterial as described in claim 1, characterized in that, In step S3, the sintering temperature is 600℃-750℃ and the time is 2h-4h.

5. The method for preparing the La-based acoustic nanomaterial as described in claim 1, characterized in that, In step S4, the power of the ultrasonic ablation is 500 W / cm. 2 -600W / cm 2 The time is 0.5h-2h.

6. The method for preparing the La-based acoustic nanomaterial as described in claim 1, characterized in that, In step S4, the amide compound is formamide and / or N,N-dimethylformamide; the volume ratio of the amide compound to the N-methylpyrrolidone is (3-6):

1.

7. La-based acoustic nanomaterials prepared by the preparation method according to any one of claims 1-6.

8. The La-based acoustic nanomaterial as described in claim 7, characterized in that, The La-based acoustic nanomaterial has a sheet-like structure; the diameter of the La-based acoustic nanomaterial is 150nm-200nm.

9. The application of the La-based acoustic nanomaterials according to claim 7 or 8 in the catalytic degradation of organic pollutants.

10. The use of the La-based acoustic nanomaterial of claim 7 or 8 in the preparation of a medicament for acoustic dynamic therapy.

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