Method for rapidly synthesizing double-ligand-coated CsPbX3 nanoparticles through ion exchange
The cysteine and titanium dioxide coating treatment was performed on perovskite nanocrystals by ion exchange method, which solved the problem of insufficient stability of perovskite nanocrystals in polar solvents, and achieved long-term stable existence and good fluorescence performance in aqueous solution.
Patent Information
- Application Number
- CN202411841953.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-13
- Publication Date
- 2025-05-06
AI Technical Summary
The stability of perovskite nanocrystals in polar solvents is poor, which affects their application and luminescence effect in aqueous solutions.
CsPbX3 nanoparticles co-coated with cysteine and titanium dioxide were rapidly synthesized through the principle of ion exchange, and the CsPbBr3 parent was synthesized by the heat injection method, and further coated through the ion exchange liquid.
The stability of CsPbX3 nanoparticles is significantly improved, and it can be stable in polar solvents for more than 96 hours, while maintaining good fluorescence performance.
Smart Images
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Abstract
Description
Technical Field
[0001] The invention relates to a method for rapidly synthesizing CsPbX3 nanoparticles coated with double ligands through ion exchange, belonging to the field of analytical technology methods. Background Art
[0002] CsPbX3 (X=C1, Br, I) perovskite nanocrystals have great development potential in solar cells, light-emitting diodes, and other optoelectronic devices. Because of its excellent fluorescence tunability, monochromatic photoluminescence, and high photoluminescence quantum yield. Although perovskite nanocrystals have attracted widespread attention in the scientific community, the research and application of perovskite nanocrystals are still seriously hindered due to their poor stability and easy decomposition when exposed to water.
[0003] In order to improve its stability, scientists have proposed several strategies to improve the aqueous stability of perovskite nanocrystals. On the one hand, quantum dots are isolated from water by coating them with inert or hydrophobic materials, such as silica and polystyrene. For example, embedding CsPbX3 NCs into polystyrene microspheres can improve its aqueous stability for cell imaging. In addition, the intrinsic stability of perovskites can be improved by doping with heteroatoms, halide-rich synthesis, surface functionalization, or changing ligands. However, the stability of these perovskite nanocrystals in polar solvents still needs to be improved, and some of them also affect the luminescence effect. Summary of the invention
[0004] In view of the shortcomings of the prior art, the present invention provides a method for rapidly synthesizing dual-ligand coated CsPbX3 nanoparticles by ion exchange.
[0005] The present invention first synthesizes the CsPbBr3 matrix by hot injection, and then rapidly synthesizes CsPbX3 (X=C1, Br, I) nanoparticles co-coated with cysteine and titanium dioxide based on the ion exchange principle. The nanoparticles can be rapidly synthesized within a few seconds, and the maximum emission wavelengths are 475nm, 512nm, and 656nm, respectively. The perovskite nanoparticles show obvious blue light, green light, and red light under the irradiation of ultraviolet light. Compared with the CsPbBr3 matrix, the stability of the CsPbBr3 coated with dual ligands in polar solutions is greatly improved, and it can stably exist in aqueous solutions for more than 96 hours.
[0006] The present invention is achieved through the following technical solutions:
[0007] A method for rapidly synthesizing dual-ligand coated CsPbX3 nanoparticles by ion exchange comprises the following steps:
[0008] 1) Using cesium carbonate as cesium source, lead bromide as lead source and bromine source, oleic acid and oleylamine as stabilizers, and octadecene as reaction solvent, the CsPbBr3 matrix was synthesized by hot injection method;
[0009] 2) The synthesized and purified CsPbBr3 matrix is mixed with an ion exchange solution, and dual-ligand-coated CsPbX3 nanoparticles are rapidly synthesized based on ion exchange.
[0010] According to the preferred embodiment of the present invention, in step (1), the CsPbBr3 matrix is synthesized by hot injection method as follows:
[0011] (1) Cs2CO3, oleic acid and octadecene are mixed and heated under nitrogen protection until CsCO3 is completely dissolved to obtain a precursor solution;
[0012] (2) Octadecene, PbBr2, oleylamine and oleic acid are mixed and heated to 110-130°C under nitrogen protection. After PbBr2 is completely dissolved, the temperature is raised to 140-160°C to obtain a mixed solution. The precursor solution is added to the mixed solution. After reacting for 5 seconds, the reaction mixture is quickly cooled in an ice water bath. The obtained crude product is purified with n-hexane. After discarding the supernatant, the precipitate is dispersed in n-hexane to obtain a CsPbBr3 precursor.
[0013] According to the present invention, preferably, in step (1), the volume ratio of the molar amount of Cs2CO3 to oleic acid is (1.5-2.5):1.2, in units of mmol / mL.
[0014] According to the present invention, preferably, in step (1), the molar ratio of octadecene to oleic acid is 1:(8-12).
[0015] According to the present invention, preferably, in step (1), the heating temperature is 140-160° C. and the heating time is 50-70 min.
[0016] According to the present invention, preferably, in step (2), the molar ratio of octadecene, PbBr2, oleylamine and oleic acid is 1:100:10:10.
[0017] According to the present invention, preferably, in step (2), the volume ratio of the mixed solution to the precursor solution is 1:(12-16).
[0018] According to the present invention, preferably, in step (2), the concentration of the CsPbBr3 precursor is 0.5-5.0 mg / mL.
[0019] According to the present invention, preferably, in step 2), the ion exchange liquid is a hydrobromic acid-cysteine-tetrabutyl titanate aqueous solution, a hydrochloric acid-cysteine-tetrabutyl titanate aqueous solution or a hydroiodic acid-cysteine-tetrabutyl titanate aqueous solution.
[0020] According to the present invention, preferably, in step 2), when the ion exchange liquid is a hydrobromic acid-cysteine-tetrabutyl titanate aqueous solution, CsPbBr3 co-coated with cysteine and titanium dioxide is obtained, and the concentration of hydrobromic acid in the hydrobromic acid-cysteine-tetrabutyl titanate aqueous solution is 0.1-0.5mM, the concentration of L-cysteine is 0.4-0.6mM, and the concentration of tetrabutyl titanate is 0.05-0.08M.
[0021] According to the present invention, preferably, in step 2), when the ion exchange liquid is a hydrochloric acid-cysteine-tetrabutyl titanate aqueous solution, CsPbCl3 co-coated with cysteine and titanium dioxide is obtained, and the concentration of hydrochloric acid in the hydrochloric acid-cysteine-tetrabutyl titanate aqueous solution is 0.1-0.5mM, the concentration of L-cysteine is 0.4-0.6mM, and the concentration of tetrabutyl titanate is 0.05-0.08M.
[0022] According to the present invention, preferably, in step 2), when the ion exchange liquid is a hydroiodic acid-cysteine-tetrabutyl titanate aqueous solution, CsPbI3 co-coated with cysteine and titanium dioxide is obtained, and the concentration of hydroiodic acid in the hydroiodic acid-cysteine-tetrabutyl titanate aqueous solution is 0.1-0.5mM, the concentration of L-cysteine is 0.4-0.6mM, and the concentration of tetrabutyl titanate is 0.05-0.08M.
[0023] According to the present invention, preferably, the hydrobromic acid-cysteine-tetrabutyl titanate aqueous solution is a mixture of hydrobromic acid, cysteine, tetrabutyl titanate and water, the hydrochloric acid-cysteine-tetrabutyl titanate aqueous solution is a mixture of hydrochloric acid, cysteine, tetrabutyl titanate and water, and the hydroiodic acid-cysteine-tetrabutyl titanate aqueous solution is a mixture of hydroiodic acid, cysteine, tetrabutyl titanate and water.
[0024] According to the present invention, preferably, in step 2), the mixing volume ratio of CsPbBr3 matrix and ion exchange liquid is (15-25):1.
[0025] A preferred embodiment of the present invention is a method for rapidly synthesizing dual-ligand coated CsPbX3 nanoparticles by ion exchange, comprising the following steps:
[0026] (1) Add 1.5 mmol Cs2CO3, 1.2 mL oleic acid and 20 mL octadecene to a 100 mL three-necked flask, respectively, and heat to 150°C under nitrogen protection until CsCO3 is completely dissolved to obtain a precursor solution;
[0027] (2) Add 10 mL of octadecene, 0.138 g of PbBr2, 1 mL of oleylamine and 1 mL of oleic acid to a 25 mL three-necked flask, heat to 120°C under nitrogen protection, and raise the temperature to 150°C after PbBr2 is completely dissolved. Finally, add 0.4 mL of the cesium precursor solution prepared in step (1) to the above solution, react for 5 seconds, and quickly cool the reaction mixture in an ice water bath to obtain a crude product of perovskite quantum dots;
[0028] (3) The crude product of perovskite quantum dots was purified three times with n-hexane, and the supernatant was discarded and the precipitate was dispersed in n-hexane to obtain a CsPbBr3 matrix with a concentration of 3 mg / mL, which was stored in a dark place for later use;
[0029] (4) The synthesized and purified CsPbBr3 precursor is mixed with a hydrobromic acid-cysteine-tetrabutyl titanate aqueous solution, a hydrochloric acid-cysteine-tetrabutyl titanate aqueous solution or a hydroiodic acid-cysteine-tetrabutyl titanate aqueous solution, respectively, and CsPbBr3, CsPbCl3 or CsPbI3 nanoparticles co-coated with cysteine and titanium dioxide are rapidly synthesized based on the ion exchange principle.
[0030] The above-mentioned cysteine and titanium dioxide co-coated CsPbBr3, CsPbCl3 or CsPbI3 nanoparticles are dried and adjusted to a concentration of 1 mg / mL and stored for later use.
[0031] The dual ligands can be used to rapidly synthesize dual ligand-coated CsPbBr3, CsPbCl3 and CsPbI3 nanoparticles in a stable manner, and the synthesis process is rapid and only takes a few seconds. At the same time, the stability in polar solvents is greatly improved, and the nanoparticles can be stored in aqueous solution for more than 96 hours.
[0032] CsPbX3 nanoparticles co-coated with cysteine and titanium dioxide were prepared by the above method.
[0033] Preferably according to the present invention, the morphology of CsPbX3 nanoparticles co-coated with cysteine and titanium dioxide is a cubic structure.
[0034] Preferably according to the present invention, the CsPbX3 (X=C1, Br, I) nanoparticles co-coated with cysteine and titanium dioxide are respectively CsPbBr3, CsPbCl3 and CsPbI3 nanoparticles co-coated with cysteine and titanium dioxide. The CsPbBr3 co-coated with cysteine and titanium dioxide is yellow in color under sunlight, has a strong absorption peak at 512nm in the ultraviolet-visible spectrum, has a maximum fluorescence emission wavelength of 512nm, and has a distinct green color under ultraviolet light; the CsPbCl3 co-coated with cysteine and titanium dioxide is light yellow in color under sunlight, has a strong absorption peak at 475nm in the ultraviolet-visible spectrum, has a maximum fluorescence emission wavelength of 475nm, and has a distinct blue color under ultraviolet light; the CsPbI3 co-coated with cysteine and titanium dioxide is red in color under sunlight, has a strong absorption peak at 656nm in the ultraviolet-visible spectrum, has a maximum fluorescence emission wavelength of 656nm, and has a red color under ultraviolet light. The stability in polar solvents is greatly enhanced and it can be stored in aqueous solution for more than 96 hours.
[0035] The technical features and advantages of the present invention are as follows:
[0036] 1. The present invention obtains dual-ligand coated CsPbBr3, CsPbCl3 and CsPbI3 nanoparticles by hot injection and ion exchange, and the synthesis method is rapid and only takes a few seconds.
[0037] 2. The present invention is safe to operate. The stability of the prepared titanium dioxide and L-cysteine dual ligand stabilized perovskite nanocrystals in polar solvents is greatly improved and can be stored in aqueous solution for more than 96 hours.
[0038] 3. The raw materials required for the present invention are easy to obtain and can be ion exchanged within a few seconds. Due to the coating effect of cysteine and titanium dioxide, the generated CsPbBr3, CsPbCl3 and CsPbI3 nanoparticles have good water solubility, good stability in polar solutions, can be stored in aqueous solutions for more than 96 hours, and have characteristic fluorescence wavelengths. BRIEF DESCRIPTION OF THE DRAWINGS
[0039] Figure 1 Fluorescence image and ultraviolet spectrum of CsPbX3 nanoparticles coated with titanium dioxide and L-cysteine dual ligands.
[0040] Figure 2 This is a high-resolution transmission morphology image of CsPbCl3 nanoparticles coated with titanium dioxide and L-cysteine dual ligands.
[0041] Figure 3 This is a high-resolution transmission morphology image of CsPbBr3 nanoparticles coated with titanium dioxide and L-cysteine dual ligands.
[0042] Figure 4 This is a high-resolution transmission morphology image of CsPbI3 nanoparticles coated with titanium dioxide and L-cysteine dual ligands.
[0043] Figure 5 This is the energy dispersive X-ray spectrum of the CsPbBr3 nanoparticles coated with titanium dioxide and L-cysteine dual ligands prepared in Example 1.
[0044] Figure 6 This is the X-ray diffraction analysis spectrum of the CsPbBr3 nanoparticles coated with titanium dioxide and L-cysteine dual ligands prepared in Example 1.
[0045] Figure 7 This is the energy dispersive X-ray mapping spectrum of the CsPbBr3 nanoparticles coated with titanium dioxide and L-cysteine dual ligands prepared in Example 1.
[0046] Figure 8 This is a polar solvent stability experiment of the CsPbBr3 nanoparticles coated with titanium dioxide and L-cysteine dual ligands prepared in Example 1. The left reagent bottle in the picture is the CsPbBr3 matrix, and the right reagent bottle is the CsPbBr3 nanoparticles coated with titanium dioxide and L-cysteine dual ligands. DETAILED DESCRIPTION
[0047] The present invention is further illustrated by the following examples, but is not limited thereto.
[0048] The fluorescence spectrum of the CsPbBr3 nanoparticles coated with titanium dioxide and L-cysteine dual ligands described in the examples was acquired by using a F-4700 fluorescence spectrophotometer.
[0049] The UV-visible absorption spectra were acquired by an Agilent Cary 60 UV-visible spectrophotometer.
[0050] Example 1
[0051] The preparation method of CsPbBr3 nanoparticles coated with titanium dioxide and L-cysteine dual ligands comprises the following steps:
[0052] (1) Add 1.5 mmol Cs2CO3, 1.2 mL oleic acid and 20 mL octadecene to a 100 mL three-necked flask, respectively, and heat to 150°C under nitrogen protection until CsCO3 is completely dissolved to obtain a precursor solution;
[0053] (2) Add 10 mL of octadecene, 0.138 g of PbBr2, 1 mL of oleylamine and 1 mL of oleic acid to a 25 mL three-necked flask, heat to 120°C under nitrogen protection, and raise the temperature to 150°C after PbBr2 is completely dissolved. Finally, add 0.4 mL of the cesium precursor solution prepared in step (1) to the above solution, react for 5 seconds, and quickly cool the reaction mixture in an ice water bath to obtain a crude product of perovskite quantum dots;
[0054] (3) The crude product of perovskite quantum dots was purified three times with n-hexane, and the supernatant was discarded and the precipitate was dispersed in n-hexane to obtain a CsPbBr3 matrix with a concentration of 3 mg / mL, which was stored in a dark place for later use;
[0055] (4) 20 mL of the synthesized and purified CsPbBr3 precursor was mixed with 1 mL of hydrobromic acid-cysteine-tetrabutyl titanate aqueous solution to rapidly synthesize CsPbBr3 nanoparticles co-coated with cysteine and titanium dioxide based on the ion exchange principle.
[0056] Embodiment 2:
[0057] The preparation method of CsPbCl3 nanoparticles coated with titanium dioxide and L-cysteine dual ligands is carried out according to Example 1, except that:
[0058] Step (4), 20 mL of the synthesized purified CsPbBr3 matrix and 1 mL of hydrochloric acid-cysteine-tetrabutyl titanate aqueous solution are mixed to rapidly synthesize CsPbCl3 nanoparticles co-coated with cysteine and titanium dioxide based on the ion exchange principle.
[0059] Embodiment 3:
[0060] The preparation method of CsPbI3 nanoparticles coated with titanium dioxide and L-cysteine dual ligands is carried out according to Example 1, except that:
[0061] Step (4), 20 mL of the synthesized purified CsPbBr3 matrix and 1 mL of hydroiodic acid-cysteine-tetrabutyl titanate aqueous solution are mixed to rapidly synthesize CsPbI3 nanoparticles co-coated with cysteine and titanium dioxide based on the ion exchange principle.
[0062] Experimental example:
[0063] 1. The fluorescence image and ultraviolet spectrum of the CsPbX3 nanoparticles coated with titanium dioxide and L-cysteine dual ligands prepared in Examples 1-3 are shown in Figure 1It can be seen that the color of CsPbBr3 co-coated with cysteine and titanium dioxide is yellow under sunlight, and the ultraviolet-visible spectrum has a strong absorption peak at 512nm, the maximum fluorescence emission wavelength is 512nm, and the color under ultraviolet light is obviously green; the color of CsPbCl3 co-coated with cysteine and titanium dioxide is light yellow under sunlight, and the ultraviolet-visible spectrum has a strong absorption peak at 475nm, the maximum fluorescence emission wavelength is 475nm, and the color under ultraviolet light is obviously blue; the color of CsPbI3 co-coated with cysteine and titanium dioxide is red under sunlight, and the ultraviolet-visible spectrum has a strong absorption peak at 656nm, the maximum fluorescence emission wavelength is 656nm, and the color under ultraviolet light is red.
[0064] 2. The high-resolution transmission morphology of the CsPbBr3 nanoparticles coated with titanium dioxide and L-cysteine dual ligands prepared in Example 1 is shown in Figure 3 ,
[0065] The high-resolution transmission morphology of the CsPbCl3 nanoparticles coated with titanium dioxide and L-cysteine dual ligands prepared in Example 2 is shown in FIG. Figure 2 ,
[0066] The high-resolution transmission morphology of the CsPbI3 nanoparticles coated with titanium dioxide and L-cysteine dual ligands prepared in Example 3 is shown in Figure 4 ,
[0067] pass Figure 2-4 It can be seen that the morphology of CsPbX3 nanoparticles coated with titanium dioxide and L-cysteine dual ligands is a clear cubic structure.
[0068] 3. The energy dispersive X-ray spectrum, X-ray diffraction and energy dispersive X-ray mapping spectrum of the CsPbBr3 nanoparticles coated with titanium dioxide and L-cysteine dual ligands prepared in Example 1 are shown in Table 1. Figure 5-Figure 7 , indicating that the present invention successfully prepared CsPbBr3 nanoparticles coated with titanium dioxide and L-cysteine dual ligands.
[0069] 4. The titanium dioxide and L-cysteine dual ligand coated CsPbBr3 nanoparticles prepared in Example 1 were added to water, acetonitrile, dimethylformamide, methanol, acetone, and phosphate buffer respectively, and left for different time periods after dissolution. The CsPbBr3 matrix was used as a control. The stability in different solvents was shown in FIG. Figure 8 , it can be seen that the stability of CsPbBr3 nanoparticles coated with titanium dioxide and L-cysteine dual ligands in polar solvents is greatly enhanced.
Claims
1. A method for rapidly synthesizing dual-ligand coated CsPbX3 nanoparticles by ion exchange, comprising the following steps: 1) Using cesium carbonate as cesium source, lead bromide as lead source and bromine source, oleic acid and oleylamine as stabilizers, and octadecene as reaction solvent, the CsPbBr3 matrix was synthesized by hot injection method; 2) The synthesized and purified CsPbBr3 matrix is mixed with an ion exchange solution, and dual-ligand-coated CsPbX3 nanoparticles are rapidly synthesized based on ion exchange.
2. The method according to claim 1, characterized in that In step (1), the CsPbBr3 matrix is synthesized by hot injection as follows: (1) Cs2CO3, oleic acid and octadecene are mixed and heated under nitrogen protection until CsCO3 is completely dissolved to obtain a precursor solution; (2) Octadecene, PbBr2, oleylamine and oleic acid are mixed and heated to 120°C under nitrogen protection. After PbBr2 is completely dissolved, the temperature is raised to 150°C to obtain a mixed solution. The precursor solution is added to the mixed solution. After reacting for 5 seconds, the reaction mixture is quickly cooled in an ice water bath. The obtained crude product is purified with n-hexane. After discarding the supernatant, the precipitate is dispersed in n-hexane to obtain a CsPbBr3 precursor.
3. The method according to claim 2, characterized in that In step (1), the volume ratio of the molar amount of Cs2CO3 to oleic acid is (1.5-2.5):1.2, unit: mmol / mL, the molar ratio of octadecene to oleic acid is 1:(8-12), the heating temperature is 140-160°C, and the heating time is 60 min.
4. The method according to claim 2, characterized in that: In step (2), the molar ratio of octadecene, PbBr2, oleylamine and oleic acid is 1:100:10:10, the volume ratio of the mixed solution to the precursor solution is 1:(12-16), and the concentration of the CsPbBr3 precursor is 0.5-5.0 mg / mL.
5. The method according to claim 1, characterized in that In step 2), the ion exchange liquid is a hydrobromic acid-cysteine-tetrabutyl titanate aqueous solution, a hydrochloric acid-cysteine-tetrabutyl titanate aqueous solution or a hydroiodic acid-cysteine-tetrabutyl titanate aqueous solution.
6. The method according to claim 5, characterized in that When the ion exchange liquid is a hydrobromic acid-cysteine-tetrabutyl titanate aqueous solution, CsPbBr3 co-coated with cysteine and titanium dioxide is obtained, and the concentration of hydrobromic acid in the hydrobromic acid-cysteine-tetrabutyl titanate aqueous solution is 0.1-0.5 mM, the concentration of L-cysteine is 0.4-0.6 mM, and the concentration of tetrabutyl titanate is 0.05-0.08 M; In step 2), when the ion exchange liquid is a hydrochloric acid-cysteine-tetrabutyl titanate aqueous solution, CsPbCl3 co-coated with cysteine and titanium dioxide is obtained, and the concentration of hydrochloric acid in the hydrochloric acid-cysteine-tetrabutyl titanate aqueous solution is 0.1-0.5mM, the concentration of L-cysteine is 0.4-0.6mM, and the concentration of tetrabutyl titanate is 0.05-0.08M; In step 2), when the ion exchange liquid is a hydroiodic acid-cysteine-tetrabutyl titanate aqueous solution, CsPbI3 co-coated with cysteine and titanium dioxide is obtained, and the concentration of hydroiodic acid in the hydroiodic acid-cysteine-tetrabutyl titanate aqueous solution is 0.1-0.5mM, the concentration of L-cysteine is 0.4-0.6mM, and the concentration of tetrabutyl titanate is 0.05-0.08M.
7. The method according to claim 1, characterized in that In step 2), the mixing volume ratio of CsPbBr3 matrix and ion exchange liquid is (15-25):
1.
8. CsPbX3 nanoparticles co-coated with cysteine and titanium dioxide, prepared by the method described in claims 1-7.
9. The CsPbX3 nanoparticles co-coated with cysteine and titanium dioxide according to claim 8 have a cubic structure.