Zinc cadmium sulfide nanocrystal prepared by taking polyelectrolyte complex as nanoreactor and preparation method of zinc cadmium sulfide nanocrystal
The preparation of zinc cadmium sulfide nanocrystals through a polyelectrolyte complex nanoreactor solves the problems of nanocrystal morphology and size control, improves the reaction efficiency of catalysis and drug delivery, and expands its application in catalytic photodegradation and photohydrogen production.
Patent Information
- Application Number
- CN202510736323.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-04
- Publication Date
- 2025-09-16
AI Technical Summary
Existing technologies make it difficult to effectively control the morphology and size of nanocrystals, resulting in low reaction rate and efficiency, and limited applications in fields such as catalytic reactions and drug delivery.
A polyelectrolyte complex is used as a nanoreactor to form a macromolecular complex through electrostatic attraction. ZnCdS nanocrystals are prepared by solvent thermal treatment to control the growth process of the nanocrystals.
A nanoreactor size of 20-50 nanometers and uniformly distributed zinc cadmium sulfide nanocrystals of 2-5 nanometers have been achieved, enhancing the application potential in fields such as catalytic photodegradation and photohydrogen production.
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Figure CN120646897A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the fields of polyelectrolytes, reverse colloid dispersion systems, nanoreactors and nanocrystals, and in particular to cadmium zinc sulfide nanocrystals prepared by using a polyelectrolyte complex as a nanoreactor and a preparation method thereof. Background Art
[0002] A nanoreactor is a material or substance with a nanostructure. Its internal space serves as a reaction field for preparing nanoparticles and controlling the growth of internal crystal nuclei, thereby solving the problem of controllable morphology and size. Nanoreactors typically range in size from 10 to 500 nanometers and typically have a high specific surface area and active sites, thereby increasing reaction rate and efficiency. Nanoreactors can control the synthesis process through reaction conditions and reactant concentrations, and they hold great promise in catalytic reactions, drug delivery, intermediate synthesis, and energy applications.
[0003] A system formed by highly dispersed one or more substances in another (called the dispersion medium) is called a dispersed system. The dispersed substance is called the dispersed phase, while the continuous medium is the dispersion medium. Dispersed systems can form nanoreactors. Generally speaking, a dispersed phase particle size of 1-9 nanometers is a solution, and the particles in the solution are actually in the form of molecules, ions, or hydrated molecules and hydrated ions. Colloids (aqueous solutions of some organic substances, such as starch solutions, are actually colloids) have dispersed phase particles ranging in size from 10 to 100 nanometers. Polyelectrolytes are polymer materials that dissociate in a medium to produce positively or negatively charged molecules. Based on the ionized groups, polyelectrolytes can be divided into: 1. Polyacids: upon ionization, they become anionic polymers, such as polyacrylic acid, polymethacrylic acid, polystyrene sulfonic acid, polyvinyl sulfonic acid, and polyvinyl phosphate; 2. Polyelectrolytes: upon ionization, they become cationic polymers, such as polyethyleneimine, polyvinylamine, and polyvinylpyridine. Other examples include inorganic polyphosphates, polysilicates, and natural nucleic acids or proteins. The latter two are called polymeric ampholytes because they contain both acidic and basic ionizable groups within a single molecule. Summary of the Invention
[0004] The present invention aims to prepare zinc cadmium sulfide nanocrystals using a polyelectrolyte complex as a nanoreactor. Two positively and negatively charged polyelectrolytes can interact through electrostatic attraction to form a macromolecular complex, i.e., a polyelectrolyte complex. The polyelectrolyte complex can aggregate in an aqueous colloid, and this aggregate can serve as a nanocrystal reactor for synthesizing zinc cadmium sulfide nanocrystals. This method is novel and original.
[0005] The method for preparing zinc cadmium sulfide nanocrystals using a polyelectrolyte complex as a nanoreactor is carried out according to the following steps:
[0006] (1) Preparation of anionic polyelectrolyte reverse miniemulsion colloids and loading of target metal ions
[0007] At room temperature, a quantitative concentration of anionic polyelectrolyte aqueous solution and a quantitative amount of appropriate solvent are weighed and mixed, and then quickly transferred to an ultrasonic crusher, and crushed at room temperature for a certain time according to the set method to form a polyelectrolyte reverse miniemulsion colloid; after the colloid is formed, a soluble salt solution containing the target metal ion is added at a fixed speed while maintaining ultrasonic crushing. After the end, ultrasonication is continued for a fixed time to complete the loading of the target metal ion in the polyelectrolyte reverse miniemulsion colloid.
[0008] Among them, the anionic polyelectrolyte is such as sodium polystyrene sulfonate, sodium alginate or polyacrylic acid; the solvent is a mixed solvent formed by cyclohexane and methanol in a certain ratio; the soluble salt containing the target metal ion is zinc nitrate / zinc sulfate / zinc chloride and cadmium nitrate / cadmium sulfate / cadmium chloride, etc.
[0009] The mass concentration of the anionic polyelectrolyte aqueous solution is 1%, and the mass ratio of the anionic polyelectrolyte aqueous solution, cyclohexane, methanol and 0.1% soluble metal salt (cadmium salt and zinc salt aqueous solutions with equal mass and equal mass concentration) aqueous solution is 10:90:10:1.0-2.0.
[0010] After the anionic polyelectrolyte aqueous solution and the solvent are mixed, ultrasonically crushed at room temperature for 10 minutes at a power of 200 W using an ultrasonic crusher; the target ion soluble salt solution is added, and the metal salt aqueous solution is added at a fixed rate of one tenth of the mass of the soluble salt solution per minute. After the addition is completed, ultrasonication is continued for 10 minutes.
[0011] (2) Preparation of cationic polyelectrolyte reverse miniemulsion colloids and sulfide loading
[0012] At room temperature, a cationic polyelectrolyte aqueous solution of a quantitative concentration and a quantitative appropriate solvent are weighed and mixed, and then quickly transferred to an ultrasonic pulverizer, and pulverized at room temperature for a certain time according to a set method to form a polyelectrolyte reverse miniemulsion colloid; after the colloid is formed, a soluble sulfide aqueous solution is added at a fixed rate while maintaining ultrasonic pulverization, and after the end, ultrasonication is continued for a fixed time to complete the loading of sulfide in the polyelectrolyte reverse miniemulsion colloid.
[0013] Among them, the cationic polyelectrolyte is such as polyethyleneimine, chitosan or polydiallyldimethylammonium chloride; the solvent is a mixed solvent formed by cyclohexane and methanol in a certain ratio; the soluble sulfide aqueous solution is a sodium sulfide / potassium sulfide aqueous solution, etc.
[0014] The mass concentration of the cationic polyelectrolyte aqueous solution is 1%, and the mass ratio of the cationic polyelectrolyte aqueous solution, cyclohexane, methanol and 0.1% soluble sulfide aqueous solution is 10:90:10:1.0-2.0.
[0015] The cationic polyelectrolyte aqueous solution and the solvent are mixed and ultrasonically crushed at room temperature for 10 minutes at a power of 200 W using an ultrasonic crusher; the soluble sulfide aqueous solution is added at a fixed rate of one tenth of the mass of the soluble sulfide aqueous solution per minute, and ultrasonication is continued for 10 minutes after the addition is completed.
[0016] (3) Preparation of reverse miniemulsion colloids containing polyelectrolyte complexes
[0017] The anionic polyelectrolyte reverse miniemulsion colloid containing the target metal ion prepared in the quantitative step (1) and the cationic polyelectrolyte reverse miniemulsion colloid containing the sulfide prepared in the quantitative step (2) are mixed evenly at room temperature, and then enter the high-pressure homogenizer for high-pressure nano-sizing to complete the preparation of the reverse colloid containing the polyelectrolyte complex.
[0018] The mass ratio of the metal ion-containing anionic polyelectrolyte reverse miniemulsion colloid in step (1) to the sulfide-containing cationic polyelectrolyte reverse miniemulsion colloid in step (2) is 100: 100. The high pressure homogenizer uses a high pressure of 10-20 MPa and a temperature controlled at 40°C.
[0019] (4) Preparation of zinc cadmium sulfide nanocrystals using polyelectrolyte complex as nanoreactor
[0020] The reverse miniemulsion colloid containing the polyelectrolyte complex prepared in the quantitative step (3) is loaded into a high-pressure reactor; it is transferred to an oven at a set temperature and kept warm for a predetermined time. After solvent thermal treatment, the reaction liquid is taken out to obtain zinc cadmium sulfide nanocrystals prepared using the polyelectrolyte complex as a nanoreactor.
[0021] Wherein, the volume ratio of the polyelectrolyte complex-containing reverse miniemulsion colloid prepared in step (3) to the high-pressure reactor is 50:100; the insulation temperature is set to 120-150° C., and the predetermined insulation time is 36-48 hours.
[0022] The present invention prepares zinc cadmium sulfide nanocrystals using a polyelectrolyte complex nanoreactor. The nanocrystals prepared by this method have potential applications in catalytic photodegradation and photocatalytic hydrogen production. The present invention has the following advantages:
[0023] 1. The prepared polyelectrolyte complex can obtain a nanoreactor with a size of 20-50 nanometers;
[0024] 2. After solvent thermal treatment, zinc cadmium sulfide nanocrystals with a polyelectrolyte complex as a carrier can be obtained. The nanocrystal size is 2-5 nanometers and is evenly distributed in the polyelectrolyte complex. BRIEF DESCRIPTION OF THE DRAWINGS
[0025] Figure 1 This is an electron microscope photograph of zinc cadmium sulfide nanocrystals prepared using the polyelectrolyte complex as a nanoreactor in Example 1. DETAILED DESCRIPTION
[0026] The present invention will be further described in detail below in conjunction with the embodiments.
[0027] Example 1
[0028] (1) Preparation of anionic polyelectrolyte reverse miniemulsion colloids and loading of target metal ions
[0029] At room temperature, 10 g of a 1% mass concentration aqueous solution of anionic sodium polystyrene sulfonate, 90 g of cyclohexane, and 10 g of methanol were weighed and mixed, and the mixture was quickly transferred to an ultrasonic grinder. After ultrasonic grinding at 200 W power at room temperature for 10 minutes, 0.5 g of a 0.1% mass concentration cadmium nitrate and 0.5 g of a 0.1% mass concentration zinc nitrate metal salt mixed aqueous solution was added dropwise at a fixed speed of 0.1 g / min. After the addition was completed, ultrasonication was continued for 10 minutes to complete the loading of the target metal ions into the polyelectrolyte reverse miniemulsion colloid.
[0030] (2) Preparation of cationic polyelectrolyte reverse miniemulsion colloids and sulfide loading
[0031] At room temperature, 10 g of a 1% mass concentration aqueous solution of polyethyleneimine was weighed, mixed with 90 g of cyclohexane and 10 g of methanol, and quickly transferred to an ultrasonic grinder. After ultrasonic grinding at room temperature at a power of 200 W for 10 minutes, 1.0 g of a 0.1% mass concentration aqueous solution of sodium sulfide was added dropwise at a fixed speed of 0.1 g / min. After the addition was completed, ultrasonication was continued for 10 minutes to complete the loading of sulfide in the polyelectrolyte reverse miniemulsion colloid.
[0032] (3) Preparation of reverse miniemulsion colloids containing polyelectrolyte complexes
[0033] 100 g of the anionic polyelectrolyte reverse miniemulsion colloid containing the target metal ion prepared in step (1) and 100 g of the sulfide-containing cationic polyelectrolyte reverse miniemulsion colloid prepared in step (2) were mixed uniformly at room temperature and then placed in a high-pressure homogenizer for high-pressure nanocomposite processing. The high-pressure homogenizer used a high pressure of 10 MPa and a temperature controlled at 40° C. to complete the preparation of the reverse colloid containing the polyelectrolyte complex. The prepared polyelectrolyte complex had an average size of 50 nanometers.
[0034] (4) Preparation of zinc cadmium sulfide nanocrystals using polyelectrolyte complex as nanoreactor
[0035] 50 ml of the reverse miniemulsion containing the polyelectrolyte complex prepared in step (3) was placed in a 100 ml autoclave and transferred to an oven set at a holding temperature of 150° C. for a predetermined holding time of 36 hours. After solvent thermal treatment, the reaction solution was removed to obtain zinc cadmium sulfide nanocrystals prepared using the polyelectrolyte complex as a nanoreactor. The nanocrystals had an average size of 5 nm and were uniformly distributed within the polyelectrolyte complex.
[0036] Example 2
[0037] (1) Preparation of anionic polyelectrolyte reverse miniemulsion colloids and loading of target metal ions
[0038] At room temperature, 10 g of a 1% mass concentration aqueous solution of anionic sodium alginate was weighed, mixed with 90 g of cyclohexane and 10 g of methanol, and quickly transferred to an ultrasonic grinder. After ultrasonic grinding at 200 W power at room temperature for 10 minutes, 1.0 g of a 0.1% mass concentration of cadmium sulfate and 1.0 g of a 0.1% mass concentration of zinc sulfate metal salt mixed aqueous solution was added dropwise at a fixed speed of 0.2 g / min. After the addition was completed, ultrasonication was continued for 10 minutes to complete the loading of the target metal ions into the polyelectrolyte reverse miniemulsion colloid.
[0039] (2) Preparation of cationic polyelectrolyte reverse miniemulsion colloids and sulfide loading
[0040] At room temperature, 10 g of a 1% mass concentration chitosan aqueous solution was weighed, mixed with 90 g of cyclohexane and 10 g of methanol, and quickly transferred to an ultrasonic grinder. After ultrasonic grinding at room temperature at a power of 200 W for 10 minutes, 2.0 g of a 0.1% mass concentration potassium sulfide aqueous solution was added dropwise at a fixed speed of 0.2 g / min. After the addition was completed, ultrasonication was continued for 10 minutes to complete the loading of sulfide in the polyelectrolyte reverse miniemulsion colloid.
[0041] (3) Preparation of reverse miniemulsion colloids containing polyelectrolyte complexes
[0042] 100 g of the anionic polyelectrolyte reverse miniemulsion colloid containing the target metal ion prepared in step (1) and 100 g of the sulfide-containing cationic polyelectrolyte reverse miniemulsion colloid prepared in step (2) were mixed uniformly at room temperature and then placed in a high-pressure homogenizer for high-pressure nanofiberization. The high-pressure homogenizer used a high pressure of 20 MPa and a temperature controlled at 40° C. to complete the preparation of the reverse colloid containing the polyelectrolyte complex. The prepared polyelectrolyte complex can produce a nanoreactor with an average size of 20 nanometers.
[0043] (4) Preparation of zinc cadmium sulfide nanocrystals using polyelectrolyte complex as nanoreactor
[0044] 50 ml of the reverse miniemulsion containing the polyelectrolyte complex prepared in step (3) was placed in a 100 ml autoclave and transferred to an oven set at a holding temperature of 120° C. for a predetermined holding time of 48 hours. After solvent thermal treatment, the reaction solution was removed to obtain zinc cadmium sulfide nanocrystals prepared using the polyelectrolyte complex as a nanoreactor. The nanocrystals had an average size of 2 nm and were uniformly distributed within the polyelectrolyte complex.
[0045] Example 3
[0046] (1) Preparation of anionic polyelectrolyte reverse miniemulsion colloids and loading of target metal ions
[0047] At room temperature, 10 g of a 1% mass concentration anionic polyacrylic acid aqueous solution was weighed, mixed with 90 g of cyclohexane and 10 g of methanol, and quickly transferred to an ultrasonic grinder. After ultrasonic grinding at 200 W power at room temperature for 10 minutes, 0.75 g of a 0.1% mass concentration cadmium chloride and 0.75 g of a 0.1% mass concentration zinc chloride metal salt mixed aqueous solution was added dropwise at a fixed speed of 0.15 g / min. After the addition was completed, ultrasonication was continued for 10 minutes to complete the loading of the target metal ions into the polyelectrolyte reverse miniemulsion colloid.
[0048] (2) Preparation of cationic polyelectrolyte reverse miniemulsion colloids and sulfide loading
[0049] At room temperature, 10 g of a 1% mass concentration aqueous solution of polydiallyldimethylammonium chloride was weighed, mixed with 90 g of cyclohexane and 10 g of methanol, and quickly transferred to an ultrasonic grinder. After ultrasonic grinding at room temperature at a power of 200 W for 10 minutes, 1.5 g of a 0.1% mass concentration aqueous solution of potassium sulfide was added dropwise at a fixed speed of 0.15 g / min. After the addition was completed, ultrasonication was continued for 10 minutes to complete the loading of sulfide into the polyelectrolyte reverse miniemulsion colloid.
[0050] (3) Preparation of reverse miniemulsion colloids containing polyelectrolyte complexes
[0051] At room temperature, 100 g of the anionic polyelectrolyte reverse miniemulsion colloid containing the target metal ion prepared in step (1) and 100 g of the sulfide cationic polyelectrolyte reverse miniemulsion colloid prepared in step (2) were mixed uniformly and then placed in a high-pressure homogenizer for high-pressure nanofiberization. The high-pressure homogenizer used a high pressure of 15 MPa and a temperature controlled at 40°C to complete the preparation of the reverse colloid containing the polyelectrolyte complex. The prepared polyelectrolyte complex can produce a nanoreactor with an average size of 30 nanometers.
[0052] (4) Preparation of zinc cadmium sulfide nanocrystals using polyelectrolyte complex as nanoreactor
[0053] 50 ml of the reverse miniemulsion containing the polyelectrolyte complex prepared in step (3) was placed in a 100 ml autoclave and transferred to an oven set at a holding temperature of 130° C. for a predetermined holding time of 40 hours. After solvent thermal treatment, the reaction solution was removed to obtain zinc cadmium sulfide nanocrystals prepared using the polyelectrolyte complex as a nanoreactor. The nanocrystals had an average size of 3 nm and were uniformly distributed within the polyelectrolyte complex.
[0054] The above description of the embodiments is intended to facilitate understanding and application of the present invention by those skilled in the art. It will be apparent that those skilled in the art can readily make various modifications to these embodiments and apply the general principles described herein to other embodiments without requiring inventive effort. Therefore, the present invention is not limited to the embodiments described herein, and modifications made by those skilled in the art based on the present disclosure are intended to fall within the scope of protection of the present invention.
Claims
1. A method for preparing zinc cadmium sulfide nanocrystals using a polyelectrolyte complex as a nanoreactor, characterized in that: The method is carried out according to the following steps: (1) ultrasonically grinding an anionic polyelectrolyte aqueous solution and a solvent to form a polyelectrolyte reverse miniemulsion colloid, then adding a soluble salt solution containing the target metal ion, and continuing ultrasonic grinding to obtain an anionic polyelectrolyte reverse miniemulsion colloid containing the target metal ion; (2) ultrasonically grinding the cationic polyelectrolyte aqueous solution and the solvent to form a polyelectrolyte reverse miniemulsion colloid; then adding a soluble sulfide solution and maintaining the ultrasonic grinding to obtain a sulfide-containing cationic polyelectrolyte reverse miniemulsion colloid; (3) An anionic polyelectrolyte reverse miniemulsion colloid containing the target metal ion and a cationic polyelectrolyte reverse miniemulsion colloid containing the sulfide are mixed and subjected to high-pressure nanocrystallization to obtain a reverse miniemulsion colloid containing a polyelectrolyte complex; the mixture is then placed in a high-pressure reactor, transferred to an oven for heat preservation, and heat-treated to obtain zinc cadmium sulfide nanocrystals.
2. The method for preparing zinc cadmium sulfide nanocrystals using a polyelectrolyte complex as a nanoreactor according to claim 1, characterized in that: In step (1), the mass concentration of the anionic polyelectrolyte aqueous solution is 1%, and the anionic polyelectrolyte is: sodium polystyrene sulfonate, sodium alginate or polyacrylic acid; the solvent is a mixed solvent of cyclohexane and methanol; and the soluble salts containing the target metal ions are zinc nitrate / zinc sulfate / zinc chloride and cadmium nitrate / cadmium sulfate / cadmium chloride.
3. The method for preparing zinc cadmium sulfide nanocrystals using a polyelectrolyte complex as a nanoreactor according to claim 2, characterized in that: The mass ratio of the anionic polyelectrolyte aqueous solution, cyclohexane, methanol and 0.1% soluble metal salt aqueous solution is 10:90:10:1.0-2.0, and the cadmium salt aqueous solution and the zinc salt aqueous solution have the same mass and the same mass concentration.
4. The method for preparing zinc cadmium sulfide nanocrystals using a polyelectrolyte complex as a nanoreactor according to claim 1, characterized in that: In step (1), ultrasonic pulverization is performed by ultrasonic pulverizing at room temperature for 10 minutes at a power of 200 W using an ultrasonic pulverizer; the target ion soluble salt solution is added at a fixed speed of one tenth of the mass of the soluble salt solution per minute, and ultrasonication is continued for 10 minutes after the addition is completed.
5. The method for preparing zinc cadmium sulfide nanocrystals using a polyelectrolyte complex as a nanoreactor according to claim 1, characterized in that: In step (2), the mass concentration of the cationic polyelectrolyte aqueous solution is 1%, the cationic polyelectrolyte is: polyethyleneimine, chitosan or polydiallyldimethylammonium chloride; the solvent is a mixed solvent of cyclohexane and methanol; and the soluble sulfide is sodium sulfide / potassium sulfide.
6. The method for preparing zinc cadmium sulfide nanocrystals using a polyelectrolyte complex as a nanoreactor according to claim 5, characterized in that: The mass ratio of the cationic polyelectrolyte aqueous solution, cyclohexane, methanol and 0.1% soluble sulfide aqueous solution is 10:90:10:1.0-2.
0.
7. The method for preparing zinc cadmium sulfide nanocrystals using a polyelectrolyte complex as a nanoreactor according to claim 1, characterized in that: In step (2), ultrasonic pulverization is performed by ultrasonic pulverizing at room temperature for 10 minutes at a power of 200 W using an ultrasonic pulverizer; the soluble sulfide aqueous solution is added at a fixed speed of one tenth of the mass of the soluble sulfide aqueous solution per minute, and ultrasonication is continued for 10 minutes after the dropwise addition is completed.
8. The method for preparing zinc cadmium sulfide nanocrystals using a polyelectrolyte complex as a nanoreactor according to claim 1, characterized in that: In step (3), the mass ratio of the metal ion-containing anionic polyelectrolyte reverse miniemulsion colloid to the sulfide-containing cationic polyelectrolyte reverse miniemulsion colloid is 100:100, the high pressure homogenizer uses a high pressure of 10-20 MPa, and the temperature is controlled at 40°C.
9. The method for preparing zinc cadmium sulfide nanocrystals using a polyelectrolyte complex as a nanoreactor according to claim 1, characterized in that: In step (3), the volume ratio of the polyelectrolyte complex-containing reverse miniemulsion colloid to the high-pressure reactor is 50:100; the heat treatment temperature is 120-150° C., and the time is 36-48 hours.
10. Zinc cadmium sulfide nanocrystals prepared according to the method according to any one of claims 1 to 9.