Special-shaped copper peroxide nanoparticles and preparation method thereof

Abstract

The application discloses special-shaped copper peroxide nanoparticles and a preparation method thereof, and belongs to the technical field of metal peroxide preparation. The preparation method comprises the following steps: dissolving polyvinylpyrrolidone and a water-soluble copper salt in anhydrous ethanol to obtain a copper salt solution; providing a sodium hydroxide aqueous solution with a molar concentration of 0.3 M-1.0 M; uniformly mixing the copper salt solution and the sodium hydroxide aqueous solution to obtain a mixed solution; under stirring, adding a hydrogen peroxide solution with a mass concentration of 30% into the mixed solution at a constant speed of 2-5 mL / min, and continuing to react after the adding is completed, so that special-shaped copper peroxide nanoparticles are obtained. Through optimization of the concentration of sodium hydroxide and the adding mode of hydrogen peroxide, the special-shaped copper peroxide nanoparticles with continuous net-shaped, discrete small net-shaped or star-shaped and the like can be prepared at room temperature.

Description

Technical Field

[0001] This application belongs to the field of metal peroxide preparation technology, specifically relating to a special morphology of copper peroxide nanoparticles and its preparation method. Background Technology

[0002] Copper peroxide is a transition metal peroxide composed of copper ions and peroxide groups. Its unique chemical composition endows the material with excellent oxidative activity and tunable interfacial chemical properties, showing broad application prospects in biomedical fields such as catalytic degradation, antibacterial disinfection, controlled release of reactive oxygen species, and tumor microenvironment regulation. Studies have shown that the above-mentioned functions of copper peroxide depend not only on its bulk chemical properties but also on the morphology of its nanostructure. Copper peroxide nanoparticles with different morphologies exhibit significant differences in specific surface area, exposed ratio of surface active sites, and interfacial reaction kinetics, directly determining their efficiency and behavioral characteristics when in contact with reaction substrates or biological systems. Therefore, developing morphology-controllable methods for preparing copper peroxide nanoparticles, and achieving precise control over particle geometry, size distribution, and surface structure, is crucial for revealing structure-activity relationships and promoting their practical applications.

[0003] Currently, liquid-phase chemical synthesis is the mainstream approach for preparing copper peroxide nanoparticles. The core technology typically involves utilizing a copper salt precursor to undergo an oxidation-precipitation reaction with hydrogen peroxide under alkaline conditions, and then controlling the nucleation and growth process of the product by introducing polymeric stabilizers or surface ligands. For example, Chinese patent application CN113213432A discloses a method for obtaining nano-copper peroxide by using polyvinylpyrrolidone as a structure-directing agent, mixing a copper salt solution with sodium hydroxide for precipitation, and then reacting it with hydrogen peroxide. The core idea is to adjust the morphology of the product by controlling the redox reaction process (e.g., the concentration of hydrogen peroxide, the amount of nano-copper hydroxide, and the amount of hydrogen peroxide). Li-Sen Lin et al. (Lin LS, Huang T, Song J, et al. Synthesis of copper peroxide nanodots for H2O2 self-supplying chemodynamic therapy[J]. Journal of the American Chemical Society, 2019, 141(25): 9937-9945.) reported a pathway for preparing copper peroxide nanodots using polyvinylpyrrolidone, copper chloride, sodium hydroxide and hydrogen peroxide as raw materials, and obtained copper peroxide nanoparticles with ultra-small size characteristics.

[0004] However, existing methods still have significant technological limitations in the stable and controllable preparation of special nanostructures. Specifically, current methods cannot effectively and reproducibly achieve the precise construction of copper peroxide nanoparticles with complex morphologies such as continuous network structures, discrete network structures, and star-shaped structures. In the above-mentioned preparation process, the final morphology of copper peroxide is often highly sensitive to the local nucleation rate, oxidant consumption rate, and the self-assembly tendency of primary particles, resulting in a narrow process window. When there are slight fluctuations in operating conditions at the reactor scale, the coupling effect of these factors can easily lead to the product morphology deviating from the target structure, manifested as poor morphology repeatability, loss of long-range ordered structure, or uncontrolled aggregation between particles. This makes it difficult to meet the requirements of structure-activity relationship studies and function-oriented applications with stringent requirements for morphological consistency. Summary of the Invention

[0005] In view of this, the primary objective of this application is to provide a method for preparing copper peroxide nanoparticles with special morphologies. By optimizing the concentration of sodium hydroxide and the method of adding hydrogen peroxide, the method enables the preparation of copper peroxide nanoparticles with special morphologies such as continuous network, discrete small network, or star-shaped structures at room temperature.

[0006] To achieve the above objectives, this application adopts the following technical solution: One aspect of this application discloses a method for preparing copper peroxide nanoparticles with a special morphology, comprising the following steps: Polyvinylpyrrolidone and water-soluble copper salt were dissolved in anhydrous ethanol to obtain a copper salt solution. Provide an aqueous solution of sodium hydroxide with a molar concentration of 0.3 M to 1.0 M; The copper salt solution and the sodium hydroxide aqueous solution are mixed evenly to obtain a mixture; Under stirring conditions, a 30% hydrogen peroxide solution was added dropwise to the mixture at a constant rate of 2 to 5 mL / min. After the addition was completed, the stirring speed was maintained to continue the reaction, thereby obtaining copper peroxide nanoparticles with special morphology.

[0007] Another aspect of this application discloses a special morphology of copper peroxide nanoparticles, which are prepared using the preparation method described in this application.

[0008] This application has at least the following beneficial effects: This application achieves the controllable preparation of copper peroxide nanoparticles with special morphologies such as continuous network, discrete small network, or star-shaped. Specifically, the controllable preparation of the above-mentioned special morphologies is achieved through the synergistic control of NaOH concentration and slow H2O2 addition process. Furthermore, by controlling the H2O2 dropping rate, it is helpful to control the local oxidation rate and nucleation / growth process, thereby improving the consistency of product morphology and establishing the morphology regulation law.

[0009] Furthermore, the entire reaction process is carried out at room temperature and normal pressure, making it simple and easy to implement. The specially morphological copper peroxide nanoparticles obtained are of great significance as a basic material for studying their surface activity, reaction behavior and potential for biomedical applications. Attached Figure Description

[0010] Figure 1 The results are TEM characterizations of the continuous network copper peroxide prepared in Example 1.

[0011] Figure 2 The results are TEM characterizations of the continuous network copper peroxide prepared in Example 2.

[0012] Figure 3 The results are TEM characterizations of the discrete micro-network copper peroxide prepared in Example 3.

[0013] Figure 4 The TEM characterization results are for the star-shaped copper peroxide prepared in Example 4.

[0014] Figure 5 The results are TEM characterizations of the star-shaped copper peroxide prepared in Example 5.

[0015] Figure 6 The TEM characterization results are for the ultra-small dot-shaped copper peroxide prepared in Comparative Example 1. Detailed Implementation

[0016] The embodiments of this application will be clearly and completely described below. The technical solutions in the embodiments described below are exemplary and only possible technical implementations of this application, not all possible implementations. Those skilled in the art can combine the embodiments of this application to obtain other embodiments without creative effort, and these embodiments are also within the protection scope of this application.

[0017] The first aspect of this application discloses a method for preparing copper peroxide nanoparticles with special morphologies. This method, through precise control of the concentration of sodium hydroxide and the addition method of hydrogen peroxide, directly prepares copper peroxide nanoparticles with special morphologies such as continuous networks, discrete micro-networks, or star-shaped structures in an ethanol-water mixture. This method is simple, reproducible, requires no templates or high temperature and pressure, and is easy to scale up.

[0018] The main steps of the preparation method described in this application are as follows: Preparation of copper salt solution In this step, polyvinylpyrrolidone and water-soluble copper salt are dissolved in anhydrous ethanol to obtain a copper salt solution.

[0019] In this application, water-soluble copper salts are used as the copper source, and specific examples include, but are not limited to, copper chloride, copper sulfate, copper nitrate, and their hydrates. In some specific embodiments, copper chloride dihydrate (CuCl2·2H2O) is used, which has high solubility in anhydrous ethanol and can provide a uniform reaction environment. Alternatively, copper nitrate trihydrate or copper sulfate pentahydrate can be used, as long as they can be fully dissolved in anhydrous ethanol.

[0020] In the copper salt solution, based on the volume of anhydrous ethanol, the concentration of polyvinylpyrrolidone (PVP) is preferably 0.05 g / mL to 0.2 g / mL, more preferably 0.1 g / mL. The concentration of the water-soluble copper salt is preferably 0.005 mol / L to 0.05 mol / L, more preferably 0.01 mol / L. A suitable PVP concentration can prevent the uncontrolled aggregation of nanoparticles, while an appropriate copper salt concentration ensures a moderate nucleation density, which is beneficial for the complete development of special morphologies. Those skilled in the art can choose appropriate concentrations as needed, and therefore there are no particular limitations.

[0021] Preparation of sodium hydroxide aqueous solution In this step, sodium hydroxide provides an alkaline environment to promote the conversion of copper ions into copper hydroxide or hydroxyl complexes, becoming intermediate precursors for the subsequent hydrogen peroxide oxidation reaction. In this application, the concentration of the sodium hydroxide aqueous solution is crucial, as it works in conjunction with the subsequent addition of H₂O₂ to achieve the preparation of copper peroxide with specific morphologies. Specifically, the molar concentration of the sodium hydroxide aqueous solution is 0.3 M to 1.0 M, for example, any concentration or a range between 0.3 M, 0.4 M, 0.5 M, 0.7 M, or 1.0 M. Different sodium hydroxide concentrations yield copper peroxide with different morphologies. Mix copper salt solution and sodium hydroxide aqueous solution In this step, the copper salt solution and the sodium hydroxide aqueous solution are mixed thoroughly to obtain a mixture. Mixing can be achieved by adding the sodium hydroxide aqueous solution to the copper salt solution with stirring, adding it in the reverse direction, or simultaneously pouring both into the reactor and mixing. The mixing process is typically carried out at room temperature with stirring to rapidly bring the system to a homogeneous state. In a preferred embodiment, the volume ratio of the copper salt solution to the sodium hydroxide aqueous solution is 1:0.1. For example, 5 mL of copper salt solution is taken and 0.1 mL of sodium hydroxide aqueous solution is added. This ratio helps maintain the ethanol-water mixed solvent ratio, ensuring the dissolution state of PVP and that subsequent reactions proceed under quasi-homogeneous conditions.

[0022] Add hydrogen peroxide After obtaining the mixture, a 30% (w / min) hydrogen peroxide solution is added dropwise to the mixture at a constant rate of 2–5 mL / min under continuous stirring. Hydrogen peroxide acts as an oxidant, oxidizing the intermediate copper species to copper peroxide. A 30% (w / min) concentration is used because it is a commercially available and readily available concentration; furthermore, this concentration provides moderate reactivity and avoids excessive dilution of the reaction system due to high water content. The dropping rate of the hydrogen peroxide solution is one of the key parameters controlling the product morphology; specifically, it can be any rate from 2 mL / min, 3 mL / min, 4 mL / min, and 5 mL / min, or a range between any two rates. The dropping rate of hydrogen peroxide should not be too fast or too slow. If the dropping rate is too fast (e.g., exceeding 5 mL / min), the local oxidation rate in the system will be too rapid, the supersaturation will rise sharply, and the product will tend to aggregate randomly, which is not conducive to controlling the ordered morphology such as continuous network, discrete network, or star-shaped structures. If the dropping rate is too low (e.g., below 2 mL / min), the reaction time will be too long, which will easily introduce side reactions and reduce the uniformity of the product. In some preferred examples, the dropping rate of hydrogen peroxide solution is 3 mL / min.

[0023] In this application, the preparation of copper peroxide nanoparticles with special morphologies is achieved by synergistically controlling the concentration of sodium hydroxide and the addition method of hydrogen peroxide (i.e., slow dropwise addition). Specifically, the concentration of NaOH determines the structural template characteristics of the intermediate by affecting the hydrolysis state, primary particle size, and aggregation behavior of the copper precursor; while the slow dropwise addition of H2O2 provides a kinetic window for the transformation of the intermediate into the final product by controlling the local oxidation rate and supersaturation in the system. If the concentration of NaOH is changed alone without using the slow dropwise addition method, the local reaction rate is too fast, the differences in the precursor state are masked, and the controllable differentiation of morphology cannot be achieved; conversely, if only slow dropwise addition is used but the concentration of sodium hydroxide is not appropriate, the morphological evolution sequence from continuous network → discrete network → star-shaped cannot be obtained. Therefore, it can be seen that the concentration of sodium hydroxide and the addition method of hydrogen peroxide are synergistically controlled, and both are indispensable, constituting the key technical means for the formation of copper peroxide with special morphology in this application.

[0024] Furthermore, stirring is carried out continuously throughout the process, preferably at a stirring speed of 500 rpm to 1000 rpm. After the dropwise addition is completed, the stirring speed is maintained for a period of time to ensure that the oxidation reaction is complete and that the morphology of the nanoparticles is fully developed and stabilized. The temperature during the continued reaction is controlled within the room temperature range of 20°C to 25°C, without the need for additional heating or cooling, making the operation simple. The duration of the continued reaction can be freely controlled according to the degree of reaction; in some specific examples, the reaction time is preferably 25 to 35 minutes, for example, 30 minutes.

[0025] Post-processing After the reaction, the suspension contains the target product, copper peroxide nanoparticles. To obtain a pure product, post-processing steps well-known in the art are typically required. In some specific examples, post-processing includes centrifugal washing, a well-known practice. As a specific example, the centrifugation speed is set at 10,000 rpm to 15,000 rpm, and the centrifugation temperature is controlled at 15°C to 20°C. Preferably, each centrifugation lasts 10 to 15 minutes, and the washing is repeated 2 to 3 times. Anhydrous ethanol is used as the washing reagent, which effectively dissolves residual PVP and ionic impurities while avoiding changes in particle surface properties or excessive aggregation that may be caused by water washing. The collected product is then directly dispersed in anhydrous ethanol and stored at 4°C.

[0026] The preparation method described in this application yields copper peroxide nanoparticles with unique morphologies. The morphology of these nanoparticles can be controlled within the aforementioned range by adjusting the preparation parameters, specifically exhibiting continuous network, discrete micro-network, or star-shaped structures. Continuous networks consist of slender copper peroxide nanorods or nanoribbons interwoven and overlapping to form a continuous porous network structure at the micrometer scale. Discrete micro-networks are relatively small independent network segments or micro-networks composed of a small number of nanounits. Star-shaped structures refer to particles exhibiting a starfish-like or needle-like morphology with multiple pointed branches radiating outwards from the center. These unique morphologies endow the copper peroxide nanoparticles with a high specific surface area and abundant active sites.

[0027] The present application will be further illustrated below with reference to specific embodiments. It should be noted that the specific embodiments below are for illustrative purposes only and do not limit the scope of the present application in any way.

[0028] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the specification of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application.

[0029] In addition, unless otherwise specified, methods without detailed conditions or steps are conventional methods, and the reagents and materials used are commercially available.

[0030] Example 1: Preparation of continuous network copper peroxide (1) Mix 0.5 g PVP and 0.0085 g (5×10 -5 1 mol) CuCl2·2H2O was dissolved in 5 mL of anhydrous ethanol and stirred until completely dissolved to obtain solution A.

[0031] (2) Weigh 1.2 g NaOH and dissolve it in 100 mL of deionized water to prepare a 0.3 M NaOH aqueous solution, thus obtaining solution B.

[0032] (3) Take 5 mL of solution A and 0.5 mL of solution B, stir and mix them evenly at room temperature to obtain solution C.

[0033] (4) Take 100 μL of concentrated H2O2 with a mass fraction of 30% into a syringe, fix it on the syringe pump, and add it dropwise to the above mixture C at a rate of 3 mL / h while stirring. After the addition is complete, continue the reaction at room temperature for 30 minutes.

[0034] (5) After the reaction is complete, centrifuge the reaction solution at 13,000 rpm for 10 minutes at 15°C and discard the supernatant. Wash the precipitate twice with anhydrous ethanol (add 2 mL of ethanol each time and centrifuge under the same conditions).

[0035] (6) The final product was dispersed in 1 mL of anhydrous ethanol and stored in a refrigerator at 4°C.

[0036] TEM characterization showed that the product was a continuous, random network structure formed by interconnected ultra-small nanodots. Figure 1 ).

[0037] Example 2: Preparation of continuous network copper peroxide This embodiment uses the same implementation method as Example 1, except that the concentration of the NaOH aqueous solution in step (2) is 0.4 M. Other process steps and parameter conditions are the same as in Example 1.

[0038] TEM characterization showed that the product's network structure was more compact, but still a continuous network. Figure 2 ).

[0039] Example 3: Preparation of discrete micro-network copper peroxide This embodiment uses the same implementation method as Example 1, except that the concentration of the NaOH aqueous solution in step (2) is 0.5 M. Other process steps and parameter conditions are the same as in Example 1.

[0040] TEM characterization showed that the product appeared as multiple separate, independent small network aggregates with a size of 50-100 nm. Figure 3 ).

[0041] Example 4: Preparation of star-shaped copper peroxide This embodiment uses the same implementation method as Example 1, except that the concentration of the NaOH aqueous solution in step (2) is 0.7 M. Other process steps and parameter conditions are the same as in Example 1.

[0042] TEM characterization showed that the product exhibited a star-shaped structure with multiple radial protrusions, with a size of approximately 100-200 nm. Figure 4 ).

[0043] Example 5: Preparation of star-shaped copper peroxide This embodiment uses the same implementation method as Example 1, except that the concentration of the NaOH aqueous solution in step (2) is 1.0 M. Other process steps and parameter conditions are the same as in Example 1.

[0044] TEM characterization showed that the star-shaped structure of the product was clearer and the branches were more obvious. Figure 5 ).

[0045] Comparative Example 1: Preparation of Copper Peroxide This comparative example uses the same implementation method as Example 1, except that the concentration of the NaOH aqueous solution in step (2) is 0.2 M. Other process steps and parameter conditions are the same as in Example 1.

[0046] TEM characterization showed that the product appeared as ultrasmall nanodots with a diameter of approximately 5-8 nm. Figure 6 ).

[0047] As can be seen from the above embodiments, this application has achieved the preparation of ketone peroxide nanoparticles with special morphology by precisely controlling the concentration of sodium hydroxide and the dropping method of hydrogen peroxide. This is of great significance for studying the basic materials for their surface activity, reaction behavior and potential for biomedical applications.

[0048] It should be noted that this application is not limited to the above-described embodiments. The above embodiments are merely examples, and any embodiments with the same structure and effect as the technical concept within the scope of this application are included in the technical scope of this application. Furthermore, various modifications that can be conceived by those skilled in the art to the embodiments, and other ways of constructing by combining some of the constituent elements of the embodiments, without departing from the spirit of this application, are also included in the scope of this application.

Claims

1. A method for preparing copper peroxide nanoparticles with special morphology, characterized in that, Includes the following steps: Polyvinylpyrrolidone and water-soluble copper salt were dissolved in anhydrous ethanol to obtain a copper salt solution. Provide an aqueous solution of sodium hydroxide with a molar concentration of 0.3 M to 1.0 M; The copper salt solution and the sodium hydroxide aqueous solution are mixed evenly to obtain a mixture; Under stirring conditions, a 30% hydrogen peroxide solution was added dropwise to the mixture at a constant rate of 2 to 5 mL / min. After the addition was completed, the stirring speed was maintained to continue the reaction, thereby obtaining copper peroxide nanoparticles with special morphology.

2. The preparation method according to claim 1, characterized in that, The water-soluble copper salt is copper chloride dihydrate.

3. The preparation method according to claim 1, characterized in that, In the copper salt solution, the concentration of polyvinylpyrrolidone is 0.1 g / mL, measured by the volume of anhydrous ethanol, and the concentration of the water-soluble copper salt is 0.01 mol / L.

4. The preparation method according to claim 1, characterized in that, The molar concentration of the sodium hydroxide aqueous solution is 0.3 M ~ 1.0 M; the volume ratio of the copper salt solution to the sodium hydroxide aqueous solution is 1:0.

1.

5. The preparation method according to claim 1, characterized in that, The stirring speed is 500-1000 rpm, and the temperature for continued reaction is 20-25℃.

6. The preparation method according to claim 1, characterized in that, Following the stirring reaction, the process also includes post-treatment steps such as centrifugation and washing.

7. The preparation method according to claim 6, characterized in that, The centrifugation speed is 10000~15000 rpm, the temperature is 15~20℃, and the time is 10~15 minutes; the washing reagent is anhydrous ethanol.

8. A special morphology of copper peroxide nanoparticles, characterized in that, It is prepared by the preparation method according to any one of claims 1-7.

9. The copper peroxide nanoparticles with special morphology as described in claim 8, characterized in that, The copper peroxide nanoparticles are one of the following: continuous network, discrete small network, or star-shaped.

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