A method for preparing nano-sb2o3

Abstract

The application relates to the field of inorganic materials, in particular to a method for preparing nano-sb2o3, wherein an O / W emulsion is added into a W / O emulsion, the O / W / O multiple emulsion is obtained after stirring and homogenizing, an organic Sb precursor is added into the O / W / O multiple emulsion, the solid is collected after stirring and reaction, the collected solid is added into deionized water to prepare a suspension, a protease is added, the enzyme is inactivated after enzymolysis, water washing and drying are carried out, and the nano-sb2o3 provided by the application has a hollow spherical structure, has a wide application prospect in high-performance energy storage devices such as secondary batteries, and has important economic value.

Description

Technical Field

[0001] This invention relates to the field of inorganic materials, specifically a method for preparing nano-antimony trioxide. Background Technology

[0002] Antimony trioxide (antimony trioxide) is an important inorganic functional material with wide applications in industry. Traditionally, it has been used primarily as a catalyst in polyester synthesis, a flame retardant synergist for polymers such as polyvinyl chloride (PVC), a glass clarifying agent, and a pigment. With the development of nanotechnology, nanoscale antimony trioxide exhibits superior performance: its large specific surface area and high surface activity significantly improve flame retardant efficiency; in catalysis, nano-antimony trioxide can serve as a catalyst or catalyst support, enhancing reaction activity and selectivity; in optoelectronics, nano-antimony trioxide possesses unique optical and electrical properties, making it suitable for preparing secondary battery anode materials, transparent conductive films, and gas sensors.

[0003] In existing technologies, the preparation methods for nano-antimony trioxide mainly include gas-phase methods, liquid-phase methods, and solid-phase methods. Gas-phase methods, such as physical vapor deposition and chemical vapor deposition, can yield high-purity products, but the equipment is expensive, energy-intensive, and has low yield, making them unsuitable for large-scale production. Solid-phase methods, such as mechanical ball milling, have simple processes, but the product has a wide particle size distribution, is prone to introducing impurities, and its morphology is difficult to control. Liquid-phase methods have become a research hotspot due to their simple operation, mild conditions, and ease of control, and mainly include precipitation methods, sol-gel methods, hydrothermal / solvothermal methods, and microemulsion methods.

[0004] However, the aforementioned liquid-phase methods have significant limitations in preparing hollow spherical structures. For example, traditional precipitation methods struggle to control particle morphology, typically yielding solid particles or irregular aggregates; while hydrothermal methods can achieve morphology control, they require high temperature and pressure conditions and have long reaction cycles; microemulsion methods use large amounts of organic surfactants, leading to environmental pollution, high costs, and difficulties in subsequent removal. In particular, existing technologies for preparing hollow nanomaterials often employ hard template methods (such as polystyrene microspheres and silica spheres) or soft template methods (such as micelles and vesicles). Hard template methods typically require complex synthesis steps for the template agent, and the removal process may damage the structural integrity of the target product. Soft template methods, such as micelles or vesicles, are prone to deformation or rupture, resulting in irregular product morphologies and easy breakage.

[0005] In recent years, Pickering emulsion technology has provided a new approach for the morphology control of nanomaterials. Pickering emulsions utilize solid particles as emulsifiers to form a stable adsorption layer at the oil-water interface, offering advantages such as strong interfacial stability, low toxicity byproducts, and ease of separation. In particular, using biocompatible natural polymers (such as proteins and polysaccharides) as Pickering stabilizers is not only environmentally friendly but also allows for the gentle removal of templates through enzymatic hydrolysis, providing an ideal platform for the preparation of hollow nanomaterials. However, existing technologies have not reported a method for preparing hollow antimony trioxide nanoparticles using natural polymer-stabilized Pickering dual emulsions. Based on the above technological background, this invention proposes a novel, green, controllable, and scalable preparation method. Summary of the Invention

[0006] Objective of the invention: To address the above-mentioned technical problems, this invention proposes a method for preparing nano-antimony trioxide.

[0007] The technical solution adopted is as follows: A method for preparing nano-antimony trioxide: Add chitosan oligosaccharide to the egg white protein solution, stir well, adjust the pH to 5-6, continue stirring to obtain the first aqueous phase, mix the first aqueous phase with the first oil phase, homogenize to obtain O / W emulsion; Carboxymethyl cellulose was added to the egg white protein solution and stirred until homogeneous. The pH was then adjusted to 5-6 and stirred until a second aqueous phase was obtained. The second aqueous phase was mixed with the second oil phase and homogenized to obtain a W / O emulsion. Add the O / W emulsion to the W / O emulsion, stir and homogenize to obtain an O / W / O multiple emulsion. Add the organic antimony precursor to the O / W / O multiple emulsion, stir and react, collect the solid, add the collected solid to deionized water to make a suspension, add protease, enzymatically hydrolyze and inactivate, wash with water and dry.

[0008] Furthermore, the concentration of the egg white protein solution is 20-40 mg / ml.

[0009] At this concentration, a dense monolayer can be formed, while avoiding excessive protein from forming micelles for competitive adsorption in the aqueous phase. When the concentration is below 20 mg / ml, the stability of the emulsion decreases sharply, while above 40 mg / ml it is uneconomical and increases the burden of enzymatic hydrolysis. Moreover, as the concentration of egg white protein solution increases, the viscosity of the aqueous phase increases accordingly. High viscosity leads to uneven distribution of shear stress and wider droplet size distribution. From a molecular level, excessively high concentrations cause unadsorbed protein molecules to form entangled networks in the aqueous phase, hindering oil droplet movement and thus reducing the emulsification effect.

[0010] Furthermore, the organic antimony precursor is antimony glycolate.

[0011] Furthermore, the first oil phase and the second oil phase are different, and are respectively selected from vegetable oil, mineral oil, or liquid aliphatic hydrocarbons. Preferably, the first oil phase is paraffin oil, and the second oil phase is castor oil.

[0012] Furthermore, the method for preparing the egg white protein solution is as follows: Fresh eggs are separated to obtain egg whites. The egg whites are stirred under acidic conditions, centrifuged at low temperature, diluted with deionized water, and then hydrated at low temperature to obtain an egg white protein solution.

[0013] Furthermore, the pH of the acidic conditions is 5-6.

[0014] Under these conditions, the net charge of protein molecules is close to neutral but slightly positive, and the electrostatic repulsion between molecules is weakened, which is conducive to the proper unfolding of protein molecules during stirring, thereby enhancing their interfacial adsorption capacity. When the pH is adjusted to <5, egg white protein exhibits obvious flocculation, while when the pH is adjusted to >6, the molecules do not unfold sufficiently, and the subsequent emulsification ability decreases.

[0015] Furthermore, the mass ratio of egg white protein to chitosan oligosaccharide in the first aqueous phase is 1-10:1-10.

[0016] Furthermore, the mass ratio of egg white protein to carboxymethyl cellulose in the second aqueous phase is 1-10:1-10.

[0017] In O / W emulsions, when protein is in excess, chitosan oligosaccharide molecules cannot completely cover the protein surface, resulting in insufficient emulsion stability. When chitosan oligosaccharide is in excess, the excess chitosan oligosaccharide forms an independent phase in the solution, consuming surfactants and causing excessively high surface charge on the composite particles, which in turn reduces the wettability of the oil phase.

[0018] In w / o emulsions, the hydrophobic amino acids in natural proteins are usually encased within the protein structure, resulting in an imbalance between the hydrophilicity and hydrophobicity of the protein surface. The addition of carboxymethyl cellulose promotes the unfolding of the tertiary structure of egg white proteins, allowing the internal hydrophobic groups to migrate to the protein surface, thereby enhancing its surface hydrophobicity. When carboxymethyl cellulose is used in small amounts, it only acts as a thickener and is insufficient to promote the unfolding of the tertiary structure of egg white proteins. When carboxymethyl cellulose is used in excess, the bulk viscosity of the solution increases dramatically, leading to decreased processability.

[0019] Furthermore, the volume ratio of O / W emulsion to W / O emulsion is 1:4-8.

[0020] Furthermore, after adding the O / W emulsion to the W / O emulsion, sonication is applied while stirring and homogenizing.

[0021] When ultrasound propagates in a liquid, it generates periodic compression-rareness cycles. When the sound pressure amplitude exceeds the cavitation threshold, tiny gas nuclei in the liquid rapidly expand and collapse, generating microjets and shock waves. These high-energy micro-region events can instantaneously form nanoscale channels at the oil-water interface of W / O droplets, allowing O / W droplets to "squeeze" into the interior. The acoustic radiation force of ultrasound can also drive droplets to move towards the sound pressure node, promoting droplet aggregation and fusion. The preferred ultrasound power is 300-500W. When ultrasound is not applied, it becomes more difficult for O / W droplets to enter W / O droplets, resulting in poor uniformity of the formed nano-antimony trioxide morphology.

[0022] Furthermore, the protease is any one or a combination of two or more of papain, flavor protease, neutral protease, and alkaline protease.

[0023] Furthermore, the nano-antimony trioxide has a hollow spherical structure.

[0024] The beneficial effects of this invention are: 1. The core of this invention lies in the creative use of an O / W / O type double Pickering emulsion stabilized by a specific protein complex as a microreactor, which confines the hydrolysis reaction of the organic antimony precursor to a specific region of the emulsion, thereby guiding the formation of hollow structure particles. The preparation method is green and environmentally friendly, and suitable for industrial and large-scale production.

[0025] 2. This invention innovatively embeds an O / W emulsion into a W / O emulsion and combines it with ultrasonic treatment. By utilizing the acoustic cavitation effect to generate microjets and transient negative pressure, nanoscale channels are opened on the surface of W / O water droplets. O / W droplets enter the interior of the water droplets with the help of capillary force and acoustic radiation force, promoting the formation of O / W / O multiple emulsions. This not only shortens the formation time of O / W / O multiple emulsions, but also avoids the damage to the droplet structure caused by the high shear of mechanical stirring, ensuring that the final product has a narrow particle size distribution.

[0026] 3. In O / W / O multi-phase emulsions, the intermediate aqueous phase is not a continuous phase, but rather independent nanodroplets encapsulated by inner and outer oil phases. Egg white protein-chitosan oligosaccharide composite particles and egg white protein-carboxymethyl cellulose composite particles act as interfacial barriers, forcing the deposition reaction to occur only in the intermediate aqueous phase. This provides the geometric basis for the hollow structure and prevents the unlimited growth of crystal nuclei. The inner oil phase acts as a sacrificial template, remaining inert and not participating in the reaction during the deposition process. The presence of the inner oil phase prevents antimony trioxide from growing inward, ensuring the formation of a complete shell rather than solid particles.

[0027] 4. Under mild conditions, proteases specifically cleave protein peptide bonds without eroding the inorganic shell. Degradation products diffuse into the bulk solution through the shell's mesopores, avoiding mechanical stress on the shell. Compared to high-temperature calcination, which leads to grain coarsening and structural collapse, enzymatic hydrolysis maintains structural integrity and has minimal impact on the electrochemical performance of antimony trioxide.

[0028] 5. Hollow antimony trioxide can significantly shorten the Li... + The hollow structure improves the diffusion path, enhances ion transport efficiency, and thus improves rate performance. Furthermore, it exposes more active sites, increasing the efficiency of Li₂. + The adsorption and reaction sites of the hollow structure can improve the specific capacity. The core challenge of lithium battery anode materials is the volume expansion caused by lithium ion insertion / extraction during charging and discharging. This expansion can lead to particle pulverization, electrode structure damage, and ultimately reduce cycle life. The internal voids of the hollow structure can effectively accommodate this volume change, prevent particle collapse, and improve cycle stability.

[0029] 6. The nano-antimony trioxide provided by this invention has broad application prospects in high-performance energy storage devices such as secondary batteries and has significant economic value. Attached Figure Description

[0030] Figure 1 This is a TEM image of the antimony trioxide nanoparticles prepared in Example 1 of the present invention. Detailed Implementation

[0031] Unless otherwise specified in the examples, the conditions were performed under standard conditions or as recommended by the manufacturer. Reagents or instruments whose manufacturers are not specified are all commercially available products. Techniques not mentioned in this invention refer to existing technologies. Unless otherwise specified, the following examples and comparative examples are parallel experiments, using the same processing steps and parameters.

[0032] Example 1: A method for preparing nano-antimony trioxide: Fresh eggs were manually separated to obtain egg whites, which were continuously stirred at pH 5.0 for 30 min. Subsequently, the egg whites were centrifuged at 10,000 rpm for 15 min at 4 °C to remove insoluble components, and diluted with deionized water to 30 mg / ml. The mixture was then incubated overnight at 4 °C to ensure complete hydration and obtain an egg white protein solution.

[0033] Take 50 ml of egg white protein solution, then add 500 mg of chitosan oligosaccharide and stir continuously on a magnetic stirrer for 30 min until completely dissolved. Next, adjust the pH of the resulting mixture to 6.0 and continue stirring for 60 min to obtain the aqueous phase. Mix 30 ml of the aqueous phase with 10 ml of paraffin oil and homogenize at 10000 rpm for 3 min to obtain an O / W emulsion.

[0034] Take 50 ml of egg white protein solution, then add 500 mg of carboxymethyl cellulose, and stir continuously on a magnetic stirrer for 30 min until the carboxymethyl cellulose is completely dissolved. Then adjust the pH of the mixture to 6.0 and continue stirring for 60 min to obtain the aqueous phase. Mix 10 ml of the aqueous phase with 150 ml of castor oil, and homogenize directly at 10000 rpm for 3 min to obtain a W / O emulsion. The above O / W emulsion was added to the above W / O emulsion, and stirred at 400 rpm for 10 min under 400 W ultrasonic power to obtain an O / W / O multiple emulsion. 5 g of antimony glycolate was dissolved in 10 ml of ethanol and added dropwise to the O / W / O multiple emulsion. The mixture was then stirred at 80 rpm at room temperature for 24 h. After the reaction, the solid was collected by centrifugation. A 2% suspension was prepared by adding deionized water to the collected solid and incubating it in a 50°C water bath for 10 min. Neutral protease was added at a dosage of 5000 U / g, and the mixture was enzymatically digested for 2 h. The solid was then inactivated in a 95°C water bath for 10 min. After cooling, the solid was washed three times with 50°C deionized water and dried. TEM images are shown below. Figure 1 It can be seen that the particle size is uniform, the wall thickness is moderate, and there is no damage.

[0035] Example 2: It is basically the same as Example 1, except that the concentration of the egg white protein solution is 20 mg / ml.

[0036] A method for preparing nano-antimony trioxide: Fresh eggs were manually separated to obtain egg whites, which were continuously stirred at pH 5.0 for 30 min. Subsequently, the egg whites were centrifuged at 10,000 rpm for 15 min at 4°C to remove insoluble components, and diluted with deionized water to 20 mg / ml. The mixture was then incubated overnight at 4°C to ensure complete hydration and obtain an egg white protein solution.

[0037] Take 50 ml of egg white protein solution, then add 500 mg of chitosan oligosaccharide and stir continuously on a magnetic stirrer for 30 min until completely dissolved. Next, adjust the pH of the resulting mixture to 6.0 and continue stirring for 60 min to obtain the aqueous phase. Mix 30 ml of the aqueous phase with 10 ml of paraffin oil and homogenize at 10000 rpm for 3 min to obtain an O / W emulsion.

[0038] Take 50 ml of egg white protein solution, then add 500 mg of carboxymethyl cellulose, and stir continuously on a magnetic stirrer for 30 min until the carboxymethyl cellulose is completely dissolved. Then adjust the pH of the mixture to 6.0 and continue stirring for 60 min to obtain the aqueous phase. Mix 10 ml of the aqueous phase with 150 ml of castor oil, and homogenize directly at 10000 rpm for 3 min to obtain a W / O emulsion. The above O / W emulsion was added to the above W / O emulsion, and stirred at 400 rpm for 10 min under 400 W ultrasonic power to obtain an O / W / O multiple emulsion. 5 g of antimony glycolide was dissolved in 10 ml of ethanol and added dropwise to the O / W / O multiple emulsion. The mixture was then stirred at 80 rpm at room temperature for 24 h. After the reaction was completed, the solid was collected by centrifugation. The collected solid was added to deionized water to prepare a 2% suspension solution, which was incubated in a 50 °C water bath for 10 min. Neutral protease was added at a dosage of 5000 U / g, and the mixture was enzymatically hydrolyzed for 2 h. The mixture was then inactivated in a 95 °C water bath for 10 min. After cooling, the mixture was washed three times with 50 °C deionized water and then dried.

[0039] Example 3: It is basically the same as Example 1, except that the concentration of the egg white protein solution is 40 mg / ml.

[0040] A method for preparing nano-antimony trioxide: Fresh eggs were manually separated to obtain egg whites, which were continuously stirred at pH 5.0 for 30 min. Subsequently, the egg whites were centrifuged at 10,000 rpm for 15 min at 4°C to remove insoluble components, and diluted with deionized water to 40 mg / ml. The mixture was then incubated overnight at 4°C to ensure complete hydration and obtain an egg white protein solution.

[0041] Take 50 ml of egg white protein solution, then add 500 mg of chitosan oligosaccharide and stir continuously on a magnetic stirrer for 30 min until completely dissolved. Next, adjust the pH of the resulting mixture to 6.0 and continue stirring for 60 min to obtain the aqueous phase. Mix 30 ml of the aqueous phase with 10 ml of paraffin oil and homogenize at 10000 rpm for 3 min to obtain an O / W emulsion.

[0042] Take 50 ml of egg white protein solution, then add 500 mg of carboxymethyl cellulose, and stir continuously on a magnetic stirrer for 30 min until the carboxymethyl cellulose is completely dissolved. Then adjust the pH of the mixture to 6.0 and continue stirring for 60 min to obtain the aqueous phase. Mix 10 ml of the aqueous phase with 150 ml of castor oil, and homogenize directly at 10000 rpm for 3 min to obtain a W / O emulsion. The above O / W emulsion was added to the above W / O emulsion, and stirred at 400 rpm for 10 min under 400 W ultrasonic power to obtain an O / W / O multiple emulsion. 5 g of antimony glycolide was dissolved in 10 ml of ethanol and added dropwise to the O / W / O multiple emulsion. The mixture was then stirred at 80 rpm at room temperature for 24 h. After the reaction was completed, the solid was collected by centrifugation. The collected solid was added to deionized water to prepare a 2% suspension solution, which was incubated in a 50 °C water bath for 10 min. Neutral protease was added at a dosage of 5000 U / g, and the mixture was enzymatically hydrolyzed for 2 h. The mixture was then inactivated in a 95 °C water bath for 10 min. After cooling, the mixture was washed three times with 50 °C deionized water and then dried.

[0043] Example 4: It is basically the same as Example 1, except that the ultrasonic power is 300W.

[0044] A method for preparing nano-antimony trioxide: Fresh eggs were manually separated to obtain egg whites, which were continuously stirred at pH 5.0 for 30 min. Subsequently, the egg whites were centrifuged at 10,000 rpm for 15 min at 4 °C to remove insoluble components, and diluted with deionized water to 30 mg / ml. The mixture was then incubated overnight at 4 °C to ensure complete hydration and obtain an egg white protein solution.

[0045] Take 50 ml of egg white protein solution, then add 500 mg of chitosan oligosaccharide and stir continuously on a magnetic stirrer for 30 min until completely dissolved. Next, adjust the pH of the resulting mixture to 6.0 and continue stirring for 60 min to obtain the aqueous phase. Mix 30 ml of the aqueous phase with 10 ml of paraffin oil and homogenize at 10000 rpm for 3 min to obtain an O / W emulsion.

[0046] Take 50 ml of egg white protein solution, then add 500 mg of carboxymethyl cellulose, and stir continuously on a magnetic stirrer for 30 min until the carboxymethyl cellulose is completely dissolved. Then adjust the pH of the mixture to 6.0 and continue stirring for 60 min to obtain the aqueous phase. Mix 10 ml of the aqueous phase with 150 ml of castor oil, and homogenize directly at 10000 rpm for 3 min to obtain a W / O emulsion. The above O / W emulsion was added to the above W / O emulsion, and stirred at 400 rpm for 10 min under 300 W ultrasonic power to obtain an O / W / O multiple emulsion. 5 g of antimony glycol was dissolved in 10 ml of ethanol and added dropwise to the O / W / O multiple emulsion. The mixture was then stirred at 80 rpm at room temperature for 24 h. After the reaction was completed, the solid was collected by centrifugation. The collected solid was added to deionized water to prepare a 2% suspension solution, which was incubated in a 50 °C water bath for 10 min. Neutral protease was added at a dosage of 5000 U / g, and the mixture was enzymatically hydrolyzed for 2 h. The mixture was then inactivated in a 95 °C water bath for 10 min. After cooling, the mixture was washed three times with 50 °C deionized water and then dried.

[0047] Example 5: It is basically the same as Example 1, except that the ultrasonic power is 500W.

[0048] A method for preparing nano-antimony trioxide: Fresh eggs were manually separated to obtain egg whites, which were continuously stirred at pH 5.0 for 30 min. Subsequently, the egg whites were centrifuged at 10,000 rpm for 15 min at 4 °C to remove insoluble components, and diluted with deionized water to 30 mg / ml. The mixture was then incubated overnight at 4 °C to ensure complete hydration and obtain an egg white protein solution.

[0049] Take 50 ml of egg white protein solution, then add 500 mg of chitosan oligosaccharide and stir continuously on a magnetic stirrer for 30 min until completely dissolved. Next, adjust the pH of the resulting mixture to 6.0 and continue stirring for 60 min to obtain the aqueous phase. Mix 30 ml of the aqueous phase with 10 ml of paraffin oil and homogenize at 10000 rpm for 3 min to obtain an O / W emulsion.

[0050] Take 50 ml of egg white protein solution, then add 500 mg of carboxymethyl cellulose, and stir continuously on a magnetic stirrer for 30 min until the carboxymethyl cellulose is completely dissolved. Then adjust the pH of the mixture to 6.0 and continue stirring for 60 min to obtain the aqueous phase. Mix 10 ml of the aqueous phase with 150 ml of castor oil, and homogenize directly at 10000 rpm for 3 min to obtain a W / O emulsion. The above O / W emulsion was added to the above W / O emulsion, and stirred at 400 rpm for 10 min under 500 W ultrasonic power to obtain an O / W / O multiple emulsion. 5 g of antimony glycol was dissolved in 10 ml of ethanol and added dropwise to the O / W / O multiple emulsion. Then, the mixture was stirred at 80 rpm at room temperature for 24 h. After the reaction was completed, the solid was collected by centrifugation. The collected solid was added to deionized water to prepare a 2% suspension solution, and incubated in a 50 °C water bath for 10 min. Neutral protease was added at a dosage of 5000 U / g, and the mixture was enzymatically hydrolyzed for 2 h. The mixture was then inactivated in a 95 °C water bath for 10 min, removed and cooled, and washed three times with 50 °C deionized water before drying.

[0051] Example 6: It is basically the same as Example 1, except that ultrasound is not applied.

[0052] A method for preparing nano-antimony trioxide: Fresh eggs were manually separated to obtain egg whites, which were continuously stirred at pH 5.0 for 30 min. Subsequently, the egg whites were centrifuged at 10,000 rpm for 15 min at 4 °C to remove insoluble components, and diluted with deionized water to 30 mg / ml. The mixture was then incubated overnight at 4 °C to ensure complete hydration and obtain an egg white protein solution.

[0053] Take 50 ml of egg white protein solution, then add 500 mg of chitosan oligosaccharide and stir continuously on a magnetic stirrer for 30 min until completely dissolved. Next, adjust the pH of the resulting mixture to 6.0 and continue stirring for 60 min to obtain the aqueous phase. Mix 30 ml of the aqueous phase with 10 ml of paraffin oil and homogenize at 10000 rpm for 3 min to obtain an O / W emulsion.

[0054] Take 50 ml of egg white protein solution, then add 500 mg of carboxymethyl cellulose, and stir continuously on a magnetic stirrer for 30 min until the carboxymethyl cellulose is completely dissolved. Then adjust the pH of the mixture to 6.0 and continue stirring for 60 min to obtain the aqueous phase. Mix 10 ml of the aqueous phase with 150 ml of castor oil, and homogenize directly at 10000 rpm for 3 min to obtain a W / O emulsion. The above O / W emulsion was added to the above W / O emulsion, and stirred at 400 rpm for 10 min to obtain an O / W / O multiple emulsion. 5 g of antimony glycolate was dissolved in 10 ml of ethanol and added dropwise to the O / W / O multiple emulsion. The mixture was then stirred at 80 rpm at room temperature for 24 h. After the reaction was completed, the solid was collected by centrifugation. The collected solid was added to deionized water to prepare a 2% suspension solution, which was incubated in a 50°C water bath for 10 min. Neutral protease was added at a dosage of 5000 U / g, and the mixture was enzymatically hydrolyzed for 2 h. The mixture was then inactivated in a 95°C water bath for 10 min. After cooling, the mixture was washed three times with 50°C deionized water and then dried.

[0055] Performance testing The nano-antimony trioxide prepared in Examples 1-6 above, and commercially available antimony trioxide (AsiaMei Nano, AM-Sb2O3-001-1), were mixed with acetylene black and polyvinylidene fluoride at a mass ratio of 8:1:1. A slurry was prepared using N-methylpyrrolidone as a solvent, coated onto copper foil, dried, and cut into electrode sheets. Using a lithium metal sheet as the counter electrode and Celgard 2400 as the separator, 1 mol of lithium hexafluorophosphate was dissolved in 1 L of a mixed organic solvent of diethyl carbonate (DEC) / ethylene carbonate (EC) / dimethyl carbonate (DMC) as the electrolyte (V(DEC):V(EC):V(DMC)=1:1:1). CR2032 coin cells were assembled in a glove box, designated as test groups 1-7. The electrochemical performance of the assembled lithium-ion batteries was tested, and the results are shown in Table 1 below. Table 1: As shown in Table 1 above, the nano-antimony trioxide prepared by this invention has excellent electrochemical performance and better cycle stability than commercially available nano-antimony trioxide.

[0056] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing nano-antimony trioxide, characterized in that, Specifically as follows: Add chitosan oligosaccharide to the egg white protein solution, stir well, adjust the pH to 5-6, continue stirring to obtain the first aqueous phase, mix the first aqueous phase with the first oil phase, homogenize to obtain O / W emulsion; Carboxymethyl cellulose was added to the egg white protein solution and stirred until homogeneous. The pH was then adjusted to 5-6 and stirred until a second aqueous phase was obtained. The second aqueous phase was mixed with the second oil phase and homogenized to obtain a W / O emulsion. Add the O / W emulsion to the W / O emulsion, stir and homogenize to obtain an O / W / O multiple emulsion. Add the organic antimony precursor to the O / W / O multiple emulsion, stir and react, collect the solid, add the collected solid to deionized water to make a suspension, add protease, enzymatically hydrolyze and inactivate, wash with water and dry.

2. The method for preparing nano-antimony trioxide as described in claim 1, characterized in that, The concentration of the egg white protein solution is 20-40 mg / ml.

3. The method for preparing nano-antimony trioxide as described in claim 1, characterized in that, The method for preparing the egg white protein solution is as follows: Fresh eggs are separated to obtain egg whites. The egg whites are stirred under acidic conditions, centrifuged at low temperature, diluted with deionized water, and then hydrated at low temperature to obtain an egg white protein solution.

4. The method for preparing nano-antimony trioxide as described in claim 3, characterized in that, The pH of the acidic conditions is 5-6.

5. The method for preparing nano-antimony trioxide as described in claim 1, characterized in that, The mass ratio of egg white protein to chitosan oligosaccharide in the first aqueous phase is 1-10:1-10.

6. The method for preparing nano-antimony trioxide as described in claim 1, characterized in that, The mass ratio of egg white protein to carboxymethyl cellulose in the second aqueous phase is 1-10:1-10.

7. The method for preparing nano-antimony trioxide as described in claim 1, characterized in that, The volume ratio of O / W emulsion to W / O emulsion is 1:4-8.

8. The method for preparing nano-antimony trioxide as described in claim 1, characterized in that, When O / W emulsion is added to W / O emulsion, it is stirred and homogenized while being sonicated.

9. The method for preparing nano-antimony trioxide as described in claim 1, characterized in that, The protease is any one or a combination of two or more of papain, flavor protease, neutral protease, and alkaline protease.

10. The method for preparing nano-antimony trioxide as described in claim 1, characterized in that, The nano-antimony trioxide has a hollow spherical structure.

Images