Polymer cuprous oxide composite crystal particles and a method for preparing the same

Abstract

The application relates to the technical field of nanocomposites, in particular to a kind of macromolecule@cuprous oxide composite crystal particles and a preparation method thereof.The specific technical scheme is as follows: a kind of macromolecule@cuprous oxide composite crystal particles, the composite crystal particles take macromolecule nanoparticle as guest particle, cuprous oxide as host crystal, make the guest particle disperse in the host crystal and form macromolecule@cuprous oxide composite crystal particles, solve the problem of oxygen vacancy defect distribution regulation in cuprous oxide crystal.

Description

Technical Field

[0001] The present invention relates to the technical field of nanocomposite materials, and in particular to polymer@cuprous oxide composite crystal particles and a preparation method thereof. Background Art

[0002] Cuprous oxide (Cu2O) is a semiconductor material that is abundant, inexpensive, and non-toxic. It has an inverse fluorite crystal structure with a direct band gap of 2 to 2.2 eV, allowing it to absorb sunlight across a broad spectral range. Its narrow band gap and appropriate conduction and valence band energies make it an ideal material for photocatalytic water decomposition to produce hydrogen and for photocatalytic degradation of organic pollutants. However, the low catalytic efficiency of unmodified Cu2O limits its widespread application.

[0003] By utilizing the interaction between the surface functional groups of polymer nanoparticles and crystals, the polymer nanoparticles are embedded in the cuprous oxide crystals, thereby constructing polymer@crystal composite crystal particles. Oxygen vacancies (V O ), which endows materials with new physical and chemical properties or enhanced catalytic performance. In recent years, research on oxygen vacancies has emerged in an endless stream. Oxygen vacancies generated in semiconductor crystals such as titanium dioxide (TiO2), zinc oxide (ZnO), bismuth oxychloride (BiOCl) and tungsten trioxide (WO3) have been extensively studied. In general, methods for constructing oxygen vacancies include heat treatment, chemical reduction, ultraviolet irradiation and ion doping. However, these methods usually require high energy input or complex procedures, and spatially controlling internal defects remains a major challenge. There are currently no reports on the controllable embedding of guest nanoparticles in cuprous oxide crystals to construct oxygen vacancies. Summary of the Invention

[0004] To address the shortcomings of the existing technology, the present invention provides polymer@cuprous oxide composite crystal particles and their preparation method. Amphiphilic block copolymer nanoparticles with uniform particle size distribution and excellent colloidal stability are synthesized via polymerization-induced self-assembly (PISA) mediated by reversible addition-fragmentation chain transfer (RAFT) polymerization. The polymer@cuprous oxide composite crystal particles are then synthesized in situ. By varying the amount of block copolymer nanoparticles added, their embedding depth within the cuprous oxide crystals can be controlled, thereby achieving precise regulation of the spatial distribution of oxygen vacancies, thus resolving the difficult problem of regulating the distribution of oxygen vacancy defects in cuprous oxide crystals.

[0005] To achieve the above objectives, the present invention is implemented through the following technical solutions:

[0006] The invention discloses polymer@cuprous oxide composite crystal particles. The composite crystal particles use polymer nanoparticles as guest particles and cuprous oxide as host crystals, and the guest particles are dispersed in the host crystals to form polymer@cuprous oxide composite crystal particles.

[0007] Preferably, the guest nanoparticles are block copolymer nanoparticles or polymer surface-modified nanoparticles with a particle size of 5 to 200 nm, and the size of the polymer@cuprous oxide composite crystal particles is 0.2 to 100.0 μm.

[0008] Accordingly, a method for preparing polymer@cuprous oxide composite crystal particles comprises dispersing polymer nanoparticles in a cuprous oxide precursor solution, mixing the mixture uniformly, and heating the mixture to form polymer@cuprous oxide composite crystal particles; the polymer nanoparticles are block copolymer nanoparticles or polymer surface-modified nanoparticles; and the cuprous oxide precursor solution is a mixed solution of copper sulfate, potassium hydroxide, aqueous ammonia, and D-(+)-glucose.

[0009] Preferably, the preparation process of the polymer@cuprous oxide composite crystal particles is as follows: adding a potassium hydroxide solution to a copper sulfate solution at 300-500 rpm, adding a polymer nanoparticle dispersion after 1-10 minutes, and then adding ammonia water and D-(+)-glucose solution in sequence, and continuing to stir; then reacting in an oil bath without stirring; after the reaction is completed, centrifuging and washing in water to obtain the polymer@cuprous oxide composite crystal particles.

[0010] Preferably, the volume ratio of the copper sulfate solution, potassium hydroxide solution, polymer nanoparticle dispersion, ammonia water, and D-(+)-glucose solution is 1200:60-600:1-60:1-20:60-600.

[0011] Preferably, the concentration of the copper sulfate solution is 0.01 to 0.5 mol / L, the concentration of the potassium hydroxide solution is 0.5 to 5 mol / L, the concentration of the polymer nanoparticles is 5 to 20%, w / w, the concentration of the ammonia water is 5% to 28%, w / w, and the concentration of the D-(+)-glucose solution is 0.1 to 5 mol / L.

[0012] Preferably, the preparation process of the polymer nanoparticles is as follows: adding a macromolecular chain transfer agent and an initiator to a solvent to dissolve them, and then adding monomers; introducing an inert gas to remove oxygen, heating and stirring, and polymerizing to form block copolymer nanoparticles;

[0013] The macromolecular chain transfer agent is single-end disulfide-modified polymethacrylate, the initiator is an azo initiator, and the monomer is methacrylate.

[0014] Preferably, the molar ratio of the macromolecular chain transfer agent, initiator and monomer is 1:5:50-500, the solvent is water, and the ratio of the total mass of the macromolecular chain transfer agent, initiator and monomer to the mass of the solvent is 1:4-19.

[0015] Preferably, inert gas is introduced into an ice-water bath for deoxygenation for 15 to 25 minutes, and then the reaction is carried out in an oil bath at 50 to 70° C. for 12 to 36 hours with a stirring speed of 500 to 650 rpm.

[0016] The present invention has the following beneficial effects:

[0017] 1. This invention provides a simple method for embedding guest nanoparticles into cuprous oxide crystals, yielding polymer@cuprous oxide composite crystal particles. Oxygen vacancies are generated at the interface between the guest nanoparticles and the cuprous oxide crystals. By varying the nanoparticle concentration, the embedding depth and, therefore, the spatial distribution of oxygen vacancies within the cuprous oxide crystals can be controlled. This method addresses the difficult problem of regulating the distribution of oxygen vacancy defects in cuprous oxide crystals.

[0018] 2. The present invention synthesizes amphiphilic block copolymer nanoparticles with uniform particle size distribution and good colloidal stability through polymerization-induced self-assembly mediated by reversible addition-fragmentation chain transfer polymerization. The surface stabilizing chains of the block copolymer nanoparticles contain hydroxyl (-OH) functional groups that can react with Cu + A strong interaction occurs, and as the crystal grows, the guest nanoparticles are embedded in the cuprous oxide crystals to obtain polymer@cuprous oxide composite crystal particles. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 The block copolymer nanoparticles poly(glycerol methacrylate) prepared in Example 1 51 -poly(benzyl methacrylate) 100 Transmission electron micrograph of

[0020] Figure 2 A low-magnification scanning electron microscope photograph of the pure cuprous oxide crystal particles prepared in Example 2, and a scanning electron microscope photograph of the cross-section of a single pure cuprous oxide crystal obtained after argon ion beam milling;

[0021] Figure 3 A low-magnification scanning electron microscope photograph of the polymer@cuprous oxide crystal particles prepared in Example 3, and a scanning electron microscope photograph of the cross-section of a single polymer@cuprous oxide composite crystal obtained after argon ion milling;

[0022] Figure 4A low-magnification scanning electron microscope photograph of the polymer@cuprous oxide crystal particles prepared in Example 4, and a scanning electron microscope photograph of a cross section of a single polymer@cuprous oxide composite crystal after argon ion cutting;

[0023] Figure 5 An electron paramagnetic resonance spectrum of the pure cuprous oxide crystal particles and the polymer@cuprous oxide crystal particles prepared in Examples 2-4. DETAILED DESCRIPTION

[0024] The technical solutions in the embodiments of the present application will be apparently and completely described in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all the other embodiments obtained by those of ordinary skill in the art without any creative effort belong to the scope of protection of the present application.

[0025] If not specifically indicated, the technical means used in the examples is the conventional means well known to those of ordinary skill in the art.

[0026] 1. The present application discloses a polymer@cuprous oxide composite crystal particle, which is composed of block copolymer nanoparticles as guest particles, cuprous oxide as host crystal, i.e. the guest particles are dispersed in the host crystal. The particle size of the block copolymer nanoparticles is 5-200 nm, and the size of the polymer@cuprous oxide composite crystal particle is 0.2-100.0 μm. As another embodiment, nanoparticles modified by polymer, such as gold nanoparticles, silica nanoparticles, and metal organic framework nanoparticles, can also be used as the guest particles.

[0027] 2. The present application discloses a preparation method of polymer@cuprous oxide composite crystal particles. Amphiphilic block copolymer nanoparticles with uniform particle size distribution and good colloidal stability are synthesized by polymerization-induced self-assembly through reversible addition-fragmentation chain transfer polymerization. Then, the block copolymer nanoparticles are used as additives to in-situ synthesize polymer@cuprous oxide composite crystal particles by hydrothermal reaction.

[0028] Specifically, the block copolymer nanoparticles are dispersed in a precursor solution, mixed uniformly, heated, and polymer@cuprous oxide composite crystal particles are formed. The precursor solution is a mixed solution of copper sulfate, potassium hydroxide, ammonia, and D-(+)-glucose.

[0029] The preparation process for the polymer@cuprous oxide composite crystal particles is as follows: At a rotational speed of 300-500 rpm, potassium hydroxide solution is added to a copper sulfate solution. After 1-10 minutes, a dispersion of block copolymer nanoparticles is added, followed by aqueous ammonia and D-(+)-glucose solution, and stirring is continued for 1-20 minutes. The reaction is then carried out in an oil bath at 40-60°C for 3-12 hours without stirring. After the reaction is complete, the particles are washed three times by centrifugation in water to obtain the polymer@cuprous oxide composite crystal particles.

[0030] The volume ratio of the copper sulfate solution, potassium hydroxide solution, block copolymer nanoparticle dispersion, ammonia water, and D-(+)-glucose solution is 1200:60-600:1-60:1-20:60-600. The concentration of the copper sulfate solution is 0.01-0.5 mol / L, the concentration of the potassium hydroxide solution is 0.5-5 mol / L, the concentration of the block copolymer nanoparticles is 5-20% (w / w), the concentration of the ammonia water is 5%-28% (w / w), and the concentration of the D-(+)-glucose solution is 0.1-5 mol / L.

[0031] Furthermore, the block copolymer nanoparticles are synthesized by a polymerization-induced self-assembly method mediated by reversible addition-fragmentation chain transfer polymerization. The preparation process comprises: dissolving a macromolecular chain transfer agent and an initiator in a solvent, then adding monomers. After introducing an inert gas to remove oxygen, the mixture is heated and stirred to polymerize to form the block copolymer nanoparticles.

[0032] The macromolecular chain transfer agent is single-end disulfide-modified poly(methacrylate), the initiator is an azo initiator, such as 4,4'-azobis(4-cyanovaleric acid), and the monomer is methacrylate, such as benzyl methacrylate.

[0033] Furthermore, the molar ratio of the macromolecular chain transfer agent, the initiator, and the monomer is 1:5:50-500, the solvent is water, and the ratio of the total mass of the macromolecular chain transfer agent, the initiator, and the monomer to the mass of the solvent is 1:4-19. Inert gas (such as nitrogen) is introduced into an ice-water bath for deoxygenation for 15-25 minutes, and then the reaction is carried out in an oil bath at 50-70° C. for 12-36 hours with a stirring speed of 500-650 rpm.

[0034] The present invention will be further described below with reference to specific embodiments.

[0035] Example 1

[0036] The preparation process of block copolymer nanoparticles is as follows:

[0037] 167.8 mg of poly(glycerol methacrylate) 51A macromolecular chain transfer agent, 1.1 mg of 4,4'-azobis(4-cyanovaleric acid), and 4.7 g of deionized water were added to a 10 mL round-bottom flask with a magnetic stirrer. After the solid in the flask was completely dissolved, 352.4 mg of benzyl methacrylate was added. The flask was sealed with a rubber stopper and nitrogen was passed into the flask in an ice-water bath for 20 minutes to deoxygenate. The flask was then placed in a 70°C oil bath for 24 hours with a stirring speed of 650 rpm. After the reaction was completed, the flask was immersed in an ice-water bath and exposed to air to quench the reaction, finally obtaining block copolymer nanoparticles of poly(glycerol methacrylate). 51 -poly(benzyl methacrylate) 100 , its transmission electron microscope image is as follows Figure 1 As shown, the average diameter is about 30 nm.

[0038] Example 2

[0039] The preparation process of pure cuprous oxide crystal particles is as follows:

[0040] Set the speed to 400 rpm, add 24 mL of 0.0125 mol / L copper sulfate solution to a 75 mL round-bottom flask with a magnetic stirrer, followed by 3 mL of 0.8 mol / L potassium hydroxide solution. After 2 minutes, add 0.06 mL of 12.5%, w / w ammonia water and 3 mL of 0.158 mol / L D-(+)-glucose solution in sequence, and continue stirring for 5 minutes. React for 3 hours in a 40°C oil bath without stirring. After the reaction is completed, centrifuge and wash three times in water to obtain pure cuprous oxide crystal particles. Its low-magnification scanning electron microscope photo and the scanning electron microscope photo of the cross-section of a single pure cuprous oxide crystal obtained after argon ion beam cutting are shown in Figure 2. Figure 2 As shown, the crystal particle size is 2 to 10 μm.

[0041] Example 3

[0042] The preparation process of polymer@cuprous oxide composite crystal particles is as follows:

[0043] A 75 mL round bottom flask with magnetic stirring was set at 400 rpm. 24 mL of 0.0125 mol / L copper sulfate solution was added, followed by 3 mL of 0.8 mol / L potassium hydroxide solution. After 2 minutes, 0.3 mL of 10%, w / w block copolymer nanoparticle dispersion (the concentration of the nanoparticles in the whole system was 0.1%, w / w) was added, followed by 0.06 mL of 12.5%, w / w ammonia water and 3 mL of 0.158 mol / L D-(+)-glucose solution. The stirring was continued for 5 minutes. The reaction was carried out at 40°C oil bath for 3 hours without stirring. After the reaction, the polymer@cuprous oxide composite crystal particles were obtained by centrifugal washing in water for three times. The low-magnification scanning electron microscope (SEM) photograph of the polymer@cuprous oxide composite crystal particles and the scanning electron microscope photograph of the section of a single polymer@cuprous oxide composite crystal after argon ion cutting are shown in Figure 3 The size of the composite crystal particles was 1-4 μm.

[0044] Example 4

[0045] The preparation process of the polymer@cuprous oxide composite crystal particles was as follows:

[0046] A 75 mL round bottom flask with magnetic stirring was set at 400 rpm. 24 mL of 0.0125 mol / L copper sulfate solution was added, followed by 3 mL of 0.8 mol / L potassium hydroxide solution. After 2 minutes, 0.61 mL of 10%, w / w block copolymer nanoparticle dispersion (the concentration of the nanoparticles in the whole system was 0.2%, w / w) was added, followed by 0.06 mL of 12.5%, w / w ammonia water and 3 mL of 0.158 mol / L D-(+)-glucose solution. The stirring was continued for 5 minutes. The reaction was carried out at 40°C oil bath for 3 hours without stirring. After the reaction, the polymer@cuprous oxide composite crystal particles were obtained by centrifugal washing in water for three times. The low-magnification scanning electron microscope (SEM) photograph of the polymer@cuprous oxide composite crystal particles and the scanning electron microscope photograph of the section of a single polymer@cuprous oxide composite crystal after argon ion cutting are shown in Figure 4 The size of the composite crystal particles was 1-3 μm.

[0047] Example 5

[0048] The test process of the electron paramagnetic resonance spectrum was as follows:

[0049] 35 mg of the pure cuprous oxide crystal particles prepared in Example 2, the polymer@cuprous oxide crystal particles prepared in Example 3 and Example 4 were respectively placed in a standard quartz tube with an outer diameter of 5 mm, and the microwave power was set at 10 mW. The results are shown in Figure 5As shown, the polymer@cuprous oxide composite crystal particles have obvious oxygen vacancy signals, and the analysis spectrum found that the oxygen vacancy concentration increases with the increase of block copolymer nanoparticle concentration.

[0050] The embodiments described above are merely descriptions of preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Without departing from the spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by persons skilled in the art should fall within the scope of protection defined by the claims of the present invention.

Claims

1. A polymer@cuprous oxide composite crystal particle, characterized by: The composite crystal particles use polymer nanoparticles as guest particles and cuprous oxide as host crystals, so that the guest particles are dispersed in the host crystals to form polymer@cuprous oxide composite crystal particles; The preparation process is as follows: polymer nanoparticles are dispersed in a cuprous oxide precursor solution, mixed evenly, and heated to form polymer@cuprous oxide composite crystal particles; the polymer nanoparticles are block copolymer nanoparticles; the cuprous oxide precursor solution is a mixed solution of copper sulfate, potassium hydroxide, aqueous ammonia, and D-(+)-glucose; The preparation process of the polymer nanoparticles is as follows: adding a macromolecular chain transfer agent and an initiator to a solvent to dissolve them, and then adding monomers; introducing an inert gas to remove oxygen, heating and stirring, and polymerizing to form block copolymer nanoparticles; The macromolecular chain transfer agent is single-end disulfide-modified polymethacrylate, the initiator is an azo initiator, and the monomer is methacrylate.

2. The polymer@cuprous oxide composite crystal particles according to claim 1, characterized in that: The guest particles are block copolymer nanoparticles with a particle size of 5 to 200 nm, and the size of the polymer@cuprous oxide composite crystal particles is 0.2 to 100.0 μm.

3. A method for preparing polymer@cuprous oxide composite crystal particles according to claim 1 or 2, characterized in that: The polymer nanoparticles are dispersed in a cuprous oxide precursor solution, mixed evenly, and heated to form polymer@cuprous oxide composite crystal particles; the polymer nanoparticles are block copolymer nanoparticles; and the cuprous oxide precursor solution is a mixed solution of copper sulfate, potassium hydroxide, ammonia water, and D-(+)-glucose.

4. The preparation method according to claim 3, wherein: The preparation process of the polymer@cuprous oxide composite crystal particles comprises: adding a potassium hydroxide solution to a copper sulfate solution at 300-500 rpm, adding a polymer nanoparticle dispersion after 1-10 minutes, and then adding ammonia water and a D-(+)-glucose solution in sequence, and continuing to stir; then reacting in an oil bath without stirring; and after the reaction is completed, centrifuging and washing in water to obtain the polymer@cuprous oxide composite crystal particles.

5. The preparation method according to claim 4, characterized in that: The volume ratio of the copper sulfate solution, potassium hydroxide solution, polymer nanoparticle dispersion, ammonia water and D-(+)-glucose solution is 1200:60-600:1-60:1-20:60-600.

6. The preparation method according to claim 4 or 5, characterized in that: The concentration of the copper sulfate solution is 0.01-0.5 mol / L, the concentration of the potassium hydroxide solution is 0.5-5 mol / L, the concentration of the polymer nanoparticles is 5-20% (w / w), the concentration of the ammonia water is 5%-28% (w / w), and the concentration of the D-(+)-glucose solution is 0.1-5 mol / L.

7. The preparation method according to claim 3 or 4, characterized in that: The preparation process of the polymer nanoparticles is as follows: adding a macromolecular chain transfer agent and an initiator to a solvent to dissolve them, and then adding monomers; introducing an inert gas to remove oxygen, heating and stirring, and polymerizing to form block copolymer nanoparticles; The macromolecular chain transfer agent is single-end disulfide-modified polymethacrylate, the initiator is an azo initiator, and the monomer is methacrylate.

8. The preparation method according to claim 7, characterized in that: The molar ratio of the macromolecular chain transfer agent, the initiator and the monomer is 1:5:50-500, the solvent is water, and the ratio of the total mass of the macromolecular chain transfer agent and the monomer to the mass of the solvent is 1:4-19.

9. The preparation method according to claim 7, characterized in that: Inert gas is introduced into an ice-water bath to deoxygenate for 15 to 25 minutes, and then the mixture is reacted in an oil bath at 50 to 70°C for 12 to 36 hours with a stirring speed of 500 to 650 rpm.

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